xref: /titanic_51/usr/src/uts/sun4v/io/vdc.c (revision c5aee8047f101b999b8f96ced79e802071372a52)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*
28  * LDoms virtual disk client (vdc) device driver
29  *
30  * This driver runs on a guest logical domain and communicates with the virtual
31  * disk server (vds) driver running on the service domain which is exporting
32  * virtualized "disks" to the guest logical domain.
33  *
34  * The driver can be divided into four sections:
35  *
36  * 1) generic device driver housekeeping
37  *	_init, _fini, attach, detach, ops structures, etc.
38  *
39  * 2) communication channel setup
40  *	Setup the communications link over the LDC channel that vdc uses to
41  *	talk to the vDisk server. Initialise the descriptor ring which
42  *	allows the LDC clients to transfer data via memory mappings.
43  *
44  * 3) Support exported to upper layers (filesystems, etc)
45  *	The upper layers call into vdc via strategy(9E) and DKIO(7I)
46  *	ioctl calls. vdc will copy the data to be written to the descriptor
47  *	ring or maps the buffer to store the data read by the vDisk
48  *	server into the descriptor ring. It then sends a message to the
49  *	vDisk server requesting it to complete the operation.
50  *
51  * 4) Handling responses from vDisk server.
52  *	The vDisk server will ACK some or all of the messages vdc sends to it
53  *	(this is configured during the handshake). Upon receipt of an ACK
54  *	vdc will check the descriptor ring and signal to the upper layer
55  *	code waiting on the IO.
56  */
57 
58 #include <sys/atomic.h>
59 #include <sys/conf.h>
60 #include <sys/disp.h>
61 #include <sys/ddi.h>
62 #include <sys/dkio.h>
63 #include <sys/efi_partition.h>
64 #include <sys/fcntl.h>
65 #include <sys/file.h>
66 #include <sys/kstat.h>
67 #include <sys/mach_descrip.h>
68 #include <sys/modctl.h>
69 #include <sys/mdeg.h>
70 #include <sys/note.h>
71 #include <sys/open.h>
72 #include <sys/random.h>
73 #include <sys/sdt.h>
74 #include <sys/stat.h>
75 #include <sys/sunddi.h>
76 #include <sys/types.h>
77 #include <sys/promif.h>
78 #include <sys/var.h>
79 #include <sys/vtoc.h>
80 #include <sys/archsystm.h>
81 #include <sys/sysmacros.h>
82 
83 #include <sys/cdio.h>
84 #include <sys/dktp/fdisk.h>
85 #include <sys/dktp/dadkio.h>
86 #include <sys/fs/dv_node.h>
87 #include <sys/mhd.h>
88 #include <sys/scsi/generic/sense.h>
89 #include <sys/scsi/impl/uscsi.h>
90 #include <sys/scsi/impl/services.h>
91 #include <sys/scsi/targets/sddef.h>
92 
93 #include <sys/ldoms.h>
94 #include <sys/ldc.h>
95 #include <sys/vio_common.h>
96 #include <sys/vio_mailbox.h>
97 #include <sys/vio_util.h>
98 #include <sys/vdsk_common.h>
99 #include <sys/vdsk_mailbox.h>
100 #include <sys/vdc.h>
101 
102 #define	VD_OLDVTOC_LIMIT	0x7fffffff
103 
104 /*
105  * function prototypes
106  */
107 
108 /* standard driver functions */
109 static int	vdc_open(dev_t *dev, int flag, int otyp, cred_t *cred);
110 static int	vdc_close(dev_t dev, int flag, int otyp, cred_t *cred);
111 static int	vdc_strategy(struct buf *buf);
112 static int	vdc_print(dev_t dev, char *str);
113 static int	vdc_dump(dev_t dev, caddr_t addr, daddr_t blkno, int nblk);
114 static int	vdc_read(dev_t dev, struct uio *uio, cred_t *cred);
115 static int	vdc_write(dev_t dev, struct uio *uio, cred_t *cred);
116 static int	vdc_ioctl(dev_t dev, int cmd, intptr_t arg, int mode,
117 			cred_t *credp, int *rvalp);
118 static int	vdc_aread(dev_t dev, struct aio_req *aio, cred_t *cred);
119 static int	vdc_awrite(dev_t dev, struct aio_req *aio, cred_t *cred);
120 
121 static int	vdc_getinfo(dev_info_t *dip, ddi_info_cmd_t cmd,
122 			void *arg, void **resultp);
123 static int	vdc_attach(dev_info_t *dip, ddi_attach_cmd_t cmd);
124 static int	vdc_detach(dev_info_t *dip, ddi_detach_cmd_t cmd);
125 static int	vdc_prop_op(dev_t dev, dev_info_t *dip, ddi_prop_op_t prop_op,
126 		    int mod_flags, char *name, caddr_t valuep, int *lengthp);
127 
128 /* setup */
129 static void	vdc_min(struct buf *bufp);
130 static int	vdc_send(vdc_t *vdc, caddr_t pkt, size_t *msglen);
131 static int	vdc_do_ldc_init(vdc_t *vdc, vdc_server_t *srvr);
132 static int	vdc_start_ldc_connection(vdc_t *vdc);
133 static int	vdc_create_device_nodes(vdc_t *vdc);
134 static int	vdc_create_device_nodes_efi(vdc_t *vdc);
135 static int	vdc_create_device_nodes_vtoc(vdc_t *vdc);
136 static void	vdc_create_io_kstats(vdc_t *vdc);
137 static void	vdc_create_err_kstats(vdc_t *vdc);
138 static void	vdc_set_err_kstats(vdc_t *vdc);
139 static int	vdc_get_md_node(dev_info_t *dip, md_t **mdpp,
140 		    mde_cookie_t *vd_nodep);
141 static int	vdc_init_ports(vdc_t *vdc, md_t *mdp, mde_cookie_t vd_nodep);
142 static void	vdc_fini_ports(vdc_t *vdc);
143 static void	vdc_switch_server(vdc_t *vdcp);
144 static int	vdc_do_ldc_up(vdc_t *vdc);
145 static void	vdc_terminate_ldc(vdc_t *vdc, vdc_server_t *srvr);
146 static int	vdc_init_descriptor_ring(vdc_t *vdc);
147 static void	vdc_destroy_descriptor_ring(vdc_t *vdc);
148 static int	vdc_setup_devid(vdc_t *vdc);
149 static void	vdc_store_label_efi(vdc_t *, efi_gpt_t *, efi_gpe_t *);
150 static void	vdc_store_label_vtoc(vdc_t *, struct dk_geom *,
151 		    struct extvtoc *);
152 static void	vdc_store_label_unk(vdc_t *vdc);
153 static boolean_t vdc_is_opened(vdc_t *vdc);
154 static void	vdc_update_size(vdc_t *vdc, size_t, size_t, size_t);
155 static int	vdc_update_vio_bsize(vdc_t *vdc, uint32_t);
156 
157 /* handshake with vds */
158 static int		vdc_init_ver_negotiation(vdc_t *vdc, vio_ver_t ver);
159 static int		vdc_ver_negotiation(vdc_t *vdcp);
160 static int		vdc_init_attr_negotiation(vdc_t *vdc);
161 static int		vdc_attr_negotiation(vdc_t *vdcp);
162 static int		vdc_init_dring_negotiate(vdc_t *vdc);
163 static int		vdc_dring_negotiation(vdc_t *vdcp);
164 static int		vdc_send_rdx(vdc_t *vdcp);
165 static int		vdc_rdx_exchange(vdc_t *vdcp);
166 static boolean_t	vdc_is_supported_version(vio_ver_msg_t *ver_msg);
167 
168 /* processing incoming messages from vDisk server */
169 static void	vdc_process_msg_thread(vdc_t *vdc);
170 static int	vdc_recv(vdc_t *vdc, vio_msg_t *msgp, size_t *nbytesp);
171 
172 static uint_t	vdc_handle_cb(uint64_t event, caddr_t arg);
173 static int	vdc_process_data_msg(vdc_t *vdc, vio_msg_t *msg);
174 static int	vdc_handle_ver_msg(vdc_t *vdc, vio_ver_msg_t *ver_msg);
175 static int	vdc_handle_attr_msg(vdc_t *vdc, vd_attr_msg_t *attr_msg);
176 static int	vdc_handle_dring_reg_msg(vdc_t *vdc, vio_dring_reg_msg_t *msg);
177 static int 	vdc_send_request(vdc_t *vdcp, int operation,
178 		    caddr_t addr, size_t nbytes, int slice, diskaddr_t offset,
179 		    buf_t *bufp, vio_desc_direction_t dir, int flags);
180 static int	vdc_map_to_shared_dring(vdc_t *vdcp, int idx);
181 static int 	vdc_populate_descriptor(vdc_t *vdcp, int operation,
182 		    caddr_t addr, size_t nbytes, int slice, diskaddr_t offset,
183 		    buf_t *bufp, vio_desc_direction_t dir, int flags);
184 static int 	vdc_do_sync_op(vdc_t *vdcp, int operation, caddr_t addr,
185 		    size_t nbytes, int slice, diskaddr_t offset,
186 		    vio_desc_direction_t dir, boolean_t);
187 static int	vdc_do_op(vdc_t *vdc, int op, caddr_t addr, size_t nbytes,
188 		    int slice, diskaddr_t offset, struct buf *bufp,
189 		    vio_desc_direction_t dir, int flags);
190 
191 static int	vdc_wait_for_response(vdc_t *vdcp, vio_msg_t *msgp);
192 static int	vdc_drain_response(vdc_t *vdcp, struct buf *buf);
193 static int	vdc_depopulate_descriptor(vdc_t *vdc, uint_t idx);
194 static int	vdc_populate_mem_hdl(vdc_t *vdcp, vdc_local_desc_t *ldep);
195 static int	vdc_verify_seq_num(vdc_t *vdc, vio_dring_msg_t *dring_msg);
196 
197 /* dkio */
198 static int	vd_process_ioctl(dev_t dev, int cmd, caddr_t arg, int mode,
199 		    int *rvalp);
200 static int	vd_process_efi_ioctl(void *vdisk, int cmd, uintptr_t arg);
201 static void	vdc_create_fake_geometry(vdc_t *vdc);
202 static int	vdc_validate_geometry(vdc_t *vdc);
203 static void	vdc_validate(vdc_t *vdc);
204 static void	vdc_validate_task(void *arg);
205 static int	vdc_null_copy_func(vdc_t *vdc, void *from, void *to,
206 		    int mode, int dir);
207 static int	vdc_get_wce_convert(vdc_t *vdc, void *from, void *to,
208 		    int mode, int dir);
209 static int	vdc_set_wce_convert(vdc_t *vdc, void *from, void *to,
210 		    int mode, int dir);
211 static int	vdc_get_vtoc_convert(vdc_t *vdc, void *from, void *to,
212 		    int mode, int dir);
213 static int	vdc_set_vtoc_convert(vdc_t *vdc, void *from, void *to,
214 		    int mode, int dir);
215 static int	vdc_get_extvtoc_convert(vdc_t *vdc, void *from, void *to,
216 		    int mode, int dir);
217 static int	vdc_set_extvtoc_convert(vdc_t *vdc, void *from, void *to,
218 		    int mode, int dir);
219 static int	vdc_get_geom_convert(vdc_t *vdc, void *from, void *to,
220 		    int mode, int dir);
221 static int	vdc_set_geom_convert(vdc_t *vdc, void *from, void *to,
222 		    int mode, int dir);
223 static int	vdc_get_efi_convert(vdc_t *vdc, void *from, void *to,
224 		    int mode, int dir);
225 static int	vdc_set_efi_convert(vdc_t *vdc, void *from, void *to,
226 		    int mode, int dir);
227 
228 static void 	vdc_ownership_update(vdc_t *vdc, int ownership_flags);
229 static int	vdc_access_set(vdc_t *vdc, uint64_t flags);
230 static vdc_io_t	*vdc_eio_queue(vdc_t *vdc, int index);
231 static void	vdc_eio_unqueue(vdc_t *vdc, clock_t deadline,
232 		    boolean_t complete_io);
233 static int	vdc_eio_check(vdc_t *vdc, int flags);
234 static void	vdc_eio_thread(void *arg);
235 
236 /*
237  * Module variables
238  */
239 
240 /*
241  * Tunable variables to control how long vdc waits before timing out on
242  * various operations
243  */
244 static int	vdc_hshake_retries = 3;
245 
246 static int	vdc_timeout = 0; /* units: seconds */
247 static int 	vdc_ldcup_timeout = 1; /* units: seconds */
248 
249 static uint64_t vdc_hz_min_ldc_delay;
250 static uint64_t vdc_min_timeout_ldc = 1 * MILLISEC;
251 static uint64_t vdc_hz_max_ldc_delay;
252 static uint64_t vdc_max_timeout_ldc = 100 * MILLISEC;
253 
254 static uint64_t vdc_ldc_read_init_delay = 1 * MILLISEC;
255 static uint64_t vdc_ldc_read_max_delay = 100 * MILLISEC;
256 
257 /* values for dumping - need to run in a tighter loop */
258 static uint64_t	vdc_usec_timeout_dump = 100 * MILLISEC;	/* 0.1s units: ns */
259 static int	vdc_dump_retries = 100;
260 
261 static uint16_t	vdc_scsi_timeout = 60;	/* 60s units: seconds  */
262 
263 static uint64_t vdc_ownership_delay = 6 * MICROSEC; /* 6s units: usec */
264 
265 /* Count of the number of vdc instances attached */
266 static volatile uint32_t	vdc_instance_count = 0;
267 
268 /* Tunable to log all SCSI errors */
269 static boolean_t vdc_scsi_log_error = B_FALSE;
270 
271 /* Soft state pointer */
272 static void	*vdc_state;
273 
274 /*
275  * Controlling the verbosity of the error/debug messages
276  *
277  * vdc_msglevel - controls level of messages
278  * vdc_matchinst - 64-bit variable where each bit corresponds
279  *                 to the vdc instance the vdc_msglevel applies.
280  */
281 int		vdc_msglevel = 0x0;
282 uint64_t	vdc_matchinst = 0ull;
283 
284 /*
285  * Supported vDisk protocol version pairs.
286  *
287  * The first array entry is the latest and preferred version.
288  */
289 static const vio_ver_t	vdc_version[] = {{1, 1}};
290 
291 static struct cb_ops vdc_cb_ops = {
292 	vdc_open,	/* cb_open */
293 	vdc_close,	/* cb_close */
294 	vdc_strategy,	/* cb_strategy */
295 	vdc_print,	/* cb_print */
296 	vdc_dump,	/* cb_dump */
297 	vdc_read,	/* cb_read */
298 	vdc_write,	/* cb_write */
299 	vdc_ioctl,	/* cb_ioctl */
300 	nodev,		/* cb_devmap */
301 	nodev,		/* cb_mmap */
302 	nodev,		/* cb_segmap */
303 	nochpoll,	/* cb_chpoll */
304 	vdc_prop_op,	/* cb_prop_op */
305 	NULL,		/* cb_str */
306 	D_MP | D_64BIT,	/* cb_flag */
307 	CB_REV,		/* cb_rev */
308 	vdc_aread,	/* cb_aread */
309 	vdc_awrite	/* cb_awrite */
310 };
311 
312 static struct dev_ops vdc_ops = {
313 	DEVO_REV,	/* devo_rev */
314 	0,		/* devo_refcnt */
315 	vdc_getinfo,	/* devo_getinfo */
316 	nulldev,	/* devo_identify */
317 	nulldev,	/* devo_probe */
318 	vdc_attach,	/* devo_attach */
319 	vdc_detach,	/* devo_detach */
320 	nodev,		/* devo_reset */
321 	&vdc_cb_ops,	/* devo_cb_ops */
322 	NULL,		/* devo_bus_ops */
323 	nulldev,	/* devo_power */
324 	ddi_quiesce_not_needed,	/* devo_quiesce */
325 };
326 
327 static struct modldrv modldrv = {
328 	&mod_driverops,
329 	"virtual disk client",
330 	&vdc_ops,
331 };
332 
333 static struct modlinkage modlinkage = {
334 	MODREV_1,
335 	&modldrv,
336 	NULL
337 };
338 
339 /* -------------------------------------------------------------------------- */
340 
341 /*
342  * Device Driver housekeeping and setup
343  */
344 
345 int
346 _init(void)
347 {
348 	int	status;
349 
350 	if ((status = ddi_soft_state_init(&vdc_state, sizeof (vdc_t), 1)) != 0)
351 		return (status);
352 	if ((status = mod_install(&modlinkage)) != 0)
353 		ddi_soft_state_fini(&vdc_state);
354 	return (status);
355 }
356 
357 int
358 _info(struct modinfo *modinfop)
359 {
360 	return (mod_info(&modlinkage, modinfop));
361 }
362 
363 int
364 _fini(void)
365 {
366 	int	status;
367 
368 	if ((status = mod_remove(&modlinkage)) != 0)
369 		return (status);
370 	ddi_soft_state_fini(&vdc_state);
371 	return (0);
372 }
373 
374 static int
375 vdc_getinfo(dev_info_t *dip, ddi_info_cmd_t cmd,  void *arg, void **resultp)
376 {
377 	_NOTE(ARGUNUSED(dip))
378 
379 	int	instance = VDCUNIT((dev_t)arg);
380 	vdc_t	*vdc = NULL;
381 
382 	switch (cmd) {
383 	case DDI_INFO_DEVT2DEVINFO:
384 		if ((vdc = ddi_get_soft_state(vdc_state, instance)) == NULL) {
385 			*resultp = NULL;
386 			return (DDI_FAILURE);
387 		}
388 		*resultp = vdc->dip;
389 		return (DDI_SUCCESS);
390 	case DDI_INFO_DEVT2INSTANCE:
391 		*resultp = (void *)(uintptr_t)instance;
392 		return (DDI_SUCCESS);
393 	default:
394 		*resultp = NULL;
395 		return (DDI_FAILURE);
396 	}
397 }
398 
399 static int
400 vdc_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
401 {
402 	kt_did_t eio_tid, ownership_tid;
403 	int	instance;
404 	int	rv;
405 	vdc_server_t *srvr;
406 	vdc_t	*vdc = NULL;
407 
408 	switch (cmd) {
409 	case DDI_DETACH:
410 		/* the real work happens below */
411 		break;
412 	case DDI_SUSPEND:
413 		/* nothing to do for this non-device */
414 		return (DDI_SUCCESS);
415 	default:
416 		return (DDI_FAILURE);
417 	}
418 
419 	ASSERT(cmd == DDI_DETACH);
420 	instance = ddi_get_instance(dip);
421 	DMSGX(1, "[%d] Entered\n", instance);
422 
423 	if ((vdc = ddi_get_soft_state(vdc_state, instance)) == NULL) {
424 		cmn_err(CE_NOTE, "[%d] Couldn't get state structure", instance);
425 		return (DDI_FAILURE);
426 	}
427 
428 	if (vdc_is_opened(vdc)) {
429 		DMSG(vdc, 0, "[%d] Cannot detach: device is open", instance);
430 		return (DDI_FAILURE);
431 	}
432 
433 	if (vdc->dkio_flush_pending) {
434 		DMSG(vdc, 0,
435 		    "[%d] Cannot detach: %d outstanding DKIO flushes\n",
436 		    instance, vdc->dkio_flush_pending);
437 		return (DDI_FAILURE);
438 	}
439 
440 	if (vdc->validate_pending) {
441 		DMSG(vdc, 0,
442 		    "[%d] Cannot detach: %d outstanding validate request\n",
443 		    instance, vdc->validate_pending);
444 		return (DDI_FAILURE);
445 	}
446 
447 	DMSG(vdc, 0, "[%d] proceeding...\n", instance);
448 
449 	/* If we took ownership, release ownership */
450 	mutex_enter(&vdc->ownership_lock);
451 	if (vdc->ownership & VDC_OWNERSHIP_GRANTED) {
452 		rv = vdc_access_set(vdc, VD_ACCESS_SET_CLEAR);
453 		if (rv == 0) {
454 			vdc_ownership_update(vdc, VDC_OWNERSHIP_NONE);
455 		}
456 	}
457 	mutex_exit(&vdc->ownership_lock);
458 
459 	/* mark instance as detaching */
460 	vdc->lifecycle	= VDC_LC_DETACHING;
461 
462 	/*
463 	 * Try and disable callbacks to prevent another handshake. We have to
464 	 * disable callbacks for all servers.
465 	 */
466 	for (srvr = vdc->server_list; srvr != NULL; srvr = srvr->next) {
467 		rv = ldc_set_cb_mode(srvr->ldc_handle, LDC_CB_DISABLE);
468 		DMSG(vdc, 0, "callback disabled (ldc=%lu, rv=%d)\n",
469 		    srvr->ldc_id, rv);
470 	}
471 
472 	if (vdc->initialized & VDC_THREAD) {
473 		mutex_enter(&vdc->read_lock);
474 		if ((vdc->read_state == VDC_READ_WAITING) ||
475 		    (vdc->read_state == VDC_READ_RESET)) {
476 			vdc->read_state = VDC_READ_RESET;
477 			cv_signal(&vdc->read_cv);
478 		}
479 
480 		mutex_exit(&vdc->read_lock);
481 
482 		/* wake up any thread waiting for connection to come online */
483 		mutex_enter(&vdc->lock);
484 		if (vdc->state == VDC_STATE_INIT_WAITING) {
485 			DMSG(vdc, 0,
486 			    "[%d] write reset - move to resetting state...\n",
487 			    instance);
488 			vdc->state = VDC_STATE_RESETTING;
489 			cv_signal(&vdc->initwait_cv);
490 		} else if (vdc->state == VDC_STATE_FAILED) {
491 			vdc->io_pending = B_TRUE;
492 			cv_signal(&vdc->io_pending_cv);
493 		}
494 		mutex_exit(&vdc->lock);
495 
496 		/* now wait until state transitions to VDC_STATE_DETACH */
497 		thread_join(vdc->msg_proc_thr->t_did);
498 		ASSERT(vdc->state == VDC_STATE_DETACH);
499 		DMSG(vdc, 0, "[%d] Reset thread exit and join ..\n",
500 		    vdc->instance);
501 	}
502 
503 	mutex_enter(&vdc->lock);
504 
505 	if (vdc->initialized & VDC_DRING)
506 		vdc_destroy_descriptor_ring(vdc);
507 
508 	vdc_fini_ports(vdc);
509 
510 	if (vdc->eio_thread) {
511 		eio_tid = vdc->eio_thread->t_did;
512 		vdc->failfast_interval = 0;
513 		ASSERT(vdc->num_servers == 0);
514 		cv_signal(&vdc->eio_cv);
515 	} else {
516 		eio_tid = 0;
517 	}
518 
519 	if (vdc->ownership & VDC_OWNERSHIP_WANTED) {
520 		ownership_tid = vdc->ownership_thread->t_did;
521 		vdc->ownership = VDC_OWNERSHIP_NONE;
522 		cv_signal(&vdc->ownership_cv);
523 	} else {
524 		ownership_tid = 0;
525 	}
526 
527 	mutex_exit(&vdc->lock);
528 
529 	if (eio_tid != 0)
530 		thread_join(eio_tid);
531 
532 	if (ownership_tid != 0)
533 		thread_join(ownership_tid);
534 
535 	if (vdc->initialized & VDC_MINOR)
536 		ddi_remove_minor_node(dip, NULL);
537 
538 	if (vdc->io_stats) {
539 		kstat_delete(vdc->io_stats);
540 		vdc->io_stats = NULL;
541 	}
542 
543 	if (vdc->err_stats) {
544 		kstat_delete(vdc->err_stats);
545 		vdc->err_stats = NULL;
546 	}
547 
548 	if (vdc->initialized & VDC_LOCKS) {
549 		mutex_destroy(&vdc->lock);
550 		mutex_destroy(&vdc->read_lock);
551 		mutex_destroy(&vdc->ownership_lock);
552 		cv_destroy(&vdc->initwait_cv);
553 		cv_destroy(&vdc->dring_free_cv);
554 		cv_destroy(&vdc->membind_cv);
555 		cv_destroy(&vdc->sync_blocked_cv);
556 		cv_destroy(&vdc->read_cv);
557 		cv_destroy(&vdc->running_cv);
558 		cv_destroy(&vdc->io_pending_cv);
559 		cv_destroy(&vdc->ownership_cv);
560 		cv_destroy(&vdc->eio_cv);
561 	}
562 
563 	if (vdc->minfo)
564 		kmem_free(vdc->minfo, sizeof (struct dk_minfo));
565 
566 	if (vdc->cinfo)
567 		kmem_free(vdc->cinfo, sizeof (struct dk_cinfo));
568 
569 	if (vdc->vtoc)
570 		kmem_free(vdc->vtoc, sizeof (struct extvtoc));
571 
572 	if (vdc->geom)
573 		kmem_free(vdc->geom, sizeof (struct dk_geom));
574 
575 	if (vdc->devid) {
576 		ddi_devid_unregister(dip);
577 		ddi_devid_free(vdc->devid);
578 	}
579 
580 	if (vdc->initialized & VDC_SOFT_STATE)
581 		ddi_soft_state_free(vdc_state, instance);
582 
583 	DMSG(vdc, 0, "[%d] End %p\n", instance, (void *)vdc);
584 
585 	return (DDI_SUCCESS);
586 }
587 
588 
589 static int
590 vdc_do_attach(dev_info_t *dip)
591 {
592 	int		instance;
593 	vdc_t		*vdc = NULL;
594 	int		status;
595 	md_t		*mdp;
596 	mde_cookie_t	vd_node;
597 
598 	ASSERT(dip != NULL);
599 
600 	instance = ddi_get_instance(dip);
601 	if (ddi_soft_state_zalloc(vdc_state, instance) != DDI_SUCCESS) {
602 		cmn_err(CE_NOTE, "[%d] Couldn't alloc state structure",
603 		    instance);
604 		return (DDI_FAILURE);
605 	}
606 
607 	if ((vdc = ddi_get_soft_state(vdc_state, instance)) == NULL) {
608 		cmn_err(CE_NOTE, "[%d] Couldn't get state structure", instance);
609 		return (DDI_FAILURE);
610 	}
611 
612 	/*
613 	 * We assign the value to initialized in this case to zero out the
614 	 * variable and then set bits in it to indicate what has been done
615 	 */
616 	vdc->initialized = VDC_SOFT_STATE;
617 
618 	vdc_hz_min_ldc_delay = drv_usectohz(vdc_min_timeout_ldc);
619 	vdc_hz_max_ldc_delay = drv_usectohz(vdc_max_timeout_ldc);
620 
621 	vdc->dip	= dip;
622 	vdc->instance	= instance;
623 	vdc->vdisk_type	= VD_DISK_TYPE_UNK;
624 	vdc->vdisk_label = VD_DISK_LABEL_UNK;
625 	vdc->state	= VDC_STATE_INIT;
626 	vdc->lifecycle	= VDC_LC_ATTACHING;
627 	vdc->session_id = 0;
628 	vdc->vdisk_bsize = DEV_BSIZE;
629 	vdc->vio_bmask = 0;
630 	vdc->vio_bshift = 0;
631 	vdc->max_xfer_sz = maxphys / vdc->vdisk_bsize;
632 
633 	/*
634 	 * We assume, for now, that the vDisk server will export 'read'
635 	 * operations to us at a minimum (this is needed because of checks
636 	 * in vdc for supported operations early in the handshake process).
637 	 * The vDisk server will return ENOTSUP if this is not the case.
638 	 * The value will be overwritten during the attribute exchange with
639 	 * the bitmask of operations exported by server.
640 	 */
641 	vdc->operations = VD_OP_MASK_READ;
642 
643 	vdc->vtoc = NULL;
644 	vdc->geom = NULL;
645 	vdc->cinfo = NULL;
646 	vdc->minfo = NULL;
647 
648 	mutex_init(&vdc->lock, NULL, MUTEX_DRIVER, NULL);
649 	cv_init(&vdc->initwait_cv, NULL, CV_DRIVER, NULL);
650 	cv_init(&vdc->dring_free_cv, NULL, CV_DRIVER, NULL);
651 	cv_init(&vdc->membind_cv, NULL, CV_DRIVER, NULL);
652 	cv_init(&vdc->running_cv, NULL, CV_DRIVER, NULL);
653 	cv_init(&vdc->io_pending_cv, NULL, CV_DRIVER, NULL);
654 
655 	vdc->io_pending = B_FALSE;
656 	vdc->threads_pending = 0;
657 	vdc->sync_op_blocked = B_FALSE;
658 	cv_init(&vdc->sync_blocked_cv, NULL, CV_DRIVER, NULL);
659 
660 	mutex_init(&vdc->ownership_lock, NULL, MUTEX_DRIVER, NULL);
661 	cv_init(&vdc->ownership_cv, NULL, CV_DRIVER, NULL);
662 	cv_init(&vdc->eio_cv, NULL, CV_DRIVER, NULL);
663 
664 	/* init blocking msg read functionality */
665 	mutex_init(&vdc->read_lock, NULL, MUTEX_DRIVER, NULL);
666 	cv_init(&vdc->read_cv, NULL, CV_DRIVER, NULL);
667 	vdc->read_state = VDC_READ_IDLE;
668 
669 	vdc->initialized |= VDC_LOCKS;
670 
671 	/* get device and port MD node for this disk instance */
672 	if (vdc_get_md_node(dip, &mdp, &vd_node) != 0) {
673 		cmn_err(CE_NOTE, "[%d] Could not get machine description node",
674 		    instance);
675 		return (DDI_FAILURE);
676 	}
677 
678 	if (vdc_init_ports(vdc, mdp, vd_node) != 0) {
679 		cmn_err(CE_NOTE, "[%d] Error initialising ports", instance);
680 		return (DDI_FAILURE);
681 	}
682 
683 	(void) md_fini_handle(mdp);
684 
685 	/* Create the kstats for saving the I/O statistics used by iostat(1M) */
686 	vdc_create_io_kstats(vdc);
687 	vdc_create_err_kstats(vdc);
688 
689 	/* Initialize remaining structures before starting the msg thread */
690 	vdc->vdisk_label = VD_DISK_LABEL_UNK;
691 	vdc->vtoc = kmem_zalloc(sizeof (struct extvtoc), KM_SLEEP);
692 	vdc->geom = kmem_zalloc(sizeof (struct dk_geom), KM_SLEEP);
693 	vdc->minfo = kmem_zalloc(sizeof (struct dk_minfo), KM_SLEEP);
694 
695 	/* initialize the thread responsible for managing state with server */
696 	vdc->msg_proc_thr = thread_create(NULL, 0, vdc_process_msg_thread,
697 	    vdc, 0, &p0, TS_RUN, minclsyspri);
698 	if (vdc->msg_proc_thr == NULL) {
699 		cmn_err(CE_NOTE, "[%d] Failed to create msg processing thread",
700 		    instance);
701 		return (DDI_FAILURE);
702 	}
703 
704 	/*
705 	 * If there are multiple servers then start the eio thread.
706 	 */
707 	if (vdc->num_servers > 1) {
708 		vdc->eio_thread = thread_create(NULL, 0, vdc_eio_thread, vdc, 0,
709 		    &p0, TS_RUN, v.v_maxsyspri - 2);
710 		if (vdc->eio_thread == NULL) {
711 			cmn_err(CE_NOTE, "[%d] Failed to create error "
712 			    "I/O thread", instance);
713 			return (DDI_FAILURE);
714 		}
715 	}
716 
717 	vdc->initialized |= VDC_THREAD;
718 
719 	atomic_inc_32(&vdc_instance_count);
720 
721 	/*
722 	 * Check the disk label. This will send requests and do the handshake.
723 	 * We don't really care about the disk label now. What we really need is
724 	 * the handshake do be done so that we know the type of the disk (slice
725 	 * or full disk) and the appropriate device nodes can be created.
726 	 */
727 
728 	mutex_enter(&vdc->lock);
729 	(void) vdc_validate_geometry(vdc);
730 	mutex_exit(&vdc->lock);
731 
732 	/*
733 	 * Now that we have the device info we can create the device nodes
734 	 */
735 	status = vdc_create_device_nodes(vdc);
736 	if (status) {
737 		DMSG(vdc, 0, "[%d] Failed to create device nodes",
738 		    instance);
739 		goto return_status;
740 	}
741 
742 	/*
743 	 * Fill in the fields of the error statistics kstat that were not
744 	 * available when creating the kstat
745 	 */
746 	vdc_set_err_kstats(vdc);
747 
748 	ddi_report_dev(dip);
749 	vdc->lifecycle	= VDC_LC_ONLINE;
750 	DMSG(vdc, 0, "[%d] Attach tasks successful\n", instance);
751 
752 return_status:
753 	DMSG(vdc, 0, "[%d] Attach completed\n", instance);
754 	return (status);
755 }
756 
757 static int
758 vdc_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
759 {
760 	int	status;
761 
762 	switch (cmd) {
763 	case DDI_ATTACH:
764 		if ((status = vdc_do_attach(dip)) != 0)
765 			(void) vdc_detach(dip, DDI_DETACH);
766 		return (status);
767 	case DDI_RESUME:
768 		/* nothing to do for this non-device */
769 		return (DDI_SUCCESS);
770 	default:
771 		return (DDI_FAILURE);
772 	}
773 }
774 
775 static int
776 vdc_do_ldc_init(vdc_t *vdc, vdc_server_t *srvr)
777 {
778 	int			status = 0;
779 	ldc_status_t		ldc_state;
780 	ldc_attr_t		ldc_attr;
781 
782 	ASSERT(vdc != NULL);
783 	ASSERT(srvr != NULL);
784 
785 	ldc_attr.devclass = LDC_DEV_BLK;
786 	ldc_attr.instance = vdc->instance;
787 	ldc_attr.mode = LDC_MODE_UNRELIABLE;	/* unreliable transport */
788 	ldc_attr.mtu = VD_LDC_MTU;
789 
790 	if ((srvr->state & VDC_LDC_INIT) == 0) {
791 		status = ldc_init(srvr->ldc_id, &ldc_attr,
792 		    &srvr->ldc_handle);
793 		if (status != 0) {
794 			DMSG(vdc, 0, "[%d] ldc_init(chan %ld) returned %d",
795 			    vdc->instance, srvr->ldc_id, status);
796 			return (status);
797 		}
798 		srvr->state |= VDC_LDC_INIT;
799 	}
800 	status = ldc_status(srvr->ldc_handle, &ldc_state);
801 	if (status != 0) {
802 		DMSG(vdc, 0, "[%d] Cannot discover LDC status [err=%d]",
803 		    vdc->instance, status);
804 		goto init_exit;
805 	}
806 	srvr->ldc_state = ldc_state;
807 
808 	if ((srvr->state & VDC_LDC_CB) == 0) {
809 		status = ldc_reg_callback(srvr->ldc_handle, vdc_handle_cb,
810 		    (caddr_t)srvr);
811 		if (status != 0) {
812 			DMSG(vdc, 0, "[%d] LDC callback reg. failed (%d)",
813 			    vdc->instance, status);
814 			goto init_exit;
815 		}
816 		srvr->state |= VDC_LDC_CB;
817 	}
818 
819 	/*
820 	 * At this stage we have initialised LDC, we will now try and open
821 	 * the connection.
822 	 */
823 	if (srvr->ldc_state == LDC_INIT) {
824 		status = ldc_open(srvr->ldc_handle);
825 		if (status != 0) {
826 			DMSG(vdc, 0, "[%d] ldc_open(chan %ld) returned %d",
827 			    vdc->instance, srvr->ldc_id, status);
828 			goto init_exit;
829 		}
830 		srvr->state |= VDC_LDC_OPEN;
831 	}
832 
833 init_exit:
834 	if (status) {
835 		vdc_terminate_ldc(vdc, srvr);
836 	}
837 
838 	return (status);
839 }
840 
841 static int
842 vdc_start_ldc_connection(vdc_t *vdc)
843 {
844 	int		status = 0;
845 
846 	ASSERT(vdc != NULL);
847 
848 	ASSERT(MUTEX_HELD(&vdc->lock));
849 
850 	status = vdc_do_ldc_up(vdc);
851 
852 	DMSG(vdc, 0, "[%d] Finished bringing up LDC\n", vdc->instance);
853 
854 	return (status);
855 }
856 
857 static int
858 vdc_stop_ldc_connection(vdc_t *vdcp)
859 {
860 	int	status;
861 
862 	ASSERT(vdcp != NULL);
863 
864 	ASSERT(MUTEX_HELD(&vdcp->lock));
865 
866 	DMSG(vdcp, 0, ": Resetting connection to vDisk server : state %d\n",
867 	    vdcp->state);
868 
869 	status = ldc_down(vdcp->curr_server->ldc_handle);
870 	DMSG(vdcp, 0, "ldc_down() = %d\n", status);
871 
872 	vdcp->initialized &= ~VDC_HANDSHAKE;
873 	DMSG(vdcp, 0, "initialized=%x\n", vdcp->initialized);
874 
875 	return (status);
876 }
877 
878 static void
879 vdc_create_io_kstats(vdc_t *vdc)
880 {
881 	if (vdc->io_stats != NULL) {
882 		DMSG(vdc, 0, "[%d] I/O kstat already exists\n", vdc->instance);
883 		return;
884 	}
885 
886 	vdc->io_stats = kstat_create(VDC_DRIVER_NAME, vdc->instance, NULL,
887 	    "disk", KSTAT_TYPE_IO, 1, KSTAT_FLAG_PERSISTENT);
888 	if (vdc->io_stats != NULL) {
889 		vdc->io_stats->ks_lock = &vdc->lock;
890 		kstat_install(vdc->io_stats);
891 	} else {
892 		cmn_err(CE_NOTE, "[%d] Failed to create kstat: I/O statistics"
893 		    " will not be gathered", vdc->instance);
894 	}
895 }
896 
897 static void
898 vdc_create_err_kstats(vdc_t *vdc)
899 {
900 	vd_err_stats_t	*stp;
901 	char	kstatmodule_err[KSTAT_STRLEN];
902 	char	kstatname[KSTAT_STRLEN];
903 	int	ndata = (sizeof (vd_err_stats_t) / sizeof (kstat_named_t));
904 	int	instance = vdc->instance;
905 
906 	if (vdc->err_stats != NULL) {
907 		DMSG(vdc, 0, "[%d] ERR kstat already exists\n", vdc->instance);
908 		return;
909 	}
910 
911 	(void) snprintf(kstatmodule_err, sizeof (kstatmodule_err),
912 	    "%serr", VDC_DRIVER_NAME);
913 	(void) snprintf(kstatname, sizeof (kstatname),
914 	    "%s%d,err", VDC_DRIVER_NAME, instance);
915 
916 	vdc->err_stats = kstat_create(kstatmodule_err, instance, kstatname,
917 	    "device_error", KSTAT_TYPE_NAMED, ndata, KSTAT_FLAG_PERSISTENT);
918 
919 	if (vdc->err_stats == NULL) {
920 		cmn_err(CE_NOTE, "[%d] Failed to create kstat: Error statistics"
921 		    " will not be gathered", instance);
922 		return;
923 	}
924 
925 	stp = (vd_err_stats_t *)vdc->err_stats->ks_data;
926 	kstat_named_init(&stp->vd_softerrs,	"Soft Errors",
927 	    KSTAT_DATA_UINT32);
928 	kstat_named_init(&stp->vd_transerrs,	"Transport Errors",
929 	    KSTAT_DATA_UINT32);
930 	kstat_named_init(&stp->vd_protoerrs,	"Protocol Errors",
931 	    KSTAT_DATA_UINT32);
932 	kstat_named_init(&stp->vd_vid,		"Vendor",
933 	    KSTAT_DATA_CHAR);
934 	kstat_named_init(&stp->vd_pid,		"Product",
935 	    KSTAT_DATA_CHAR);
936 	kstat_named_init(&stp->vd_capacity,	"Size",
937 	    KSTAT_DATA_ULONGLONG);
938 
939 	vdc->err_stats->ks_update  = nulldev;
940 
941 	kstat_install(vdc->err_stats);
942 }
943 
944 static void
945 vdc_set_err_kstats(vdc_t *vdc)
946 {
947 	vd_err_stats_t  *stp;
948 
949 	if (vdc->err_stats == NULL)
950 		return;
951 
952 	mutex_enter(&vdc->lock);
953 
954 	stp = (vd_err_stats_t *)vdc->err_stats->ks_data;
955 	ASSERT(stp != NULL);
956 
957 	stp->vd_capacity.value.ui64 = vdc->vdisk_size * vdc->vdisk_bsize;
958 	(void) strcpy(stp->vd_vid.value.c, "SUN");
959 	(void) strcpy(stp->vd_pid.value.c, "VDSK");
960 
961 	mutex_exit(&vdc->lock);
962 }
963 
964 static int
965 vdc_create_device_nodes_efi(vdc_t *vdc)
966 {
967 	ddi_remove_minor_node(vdc->dip, "h");
968 	ddi_remove_minor_node(vdc->dip, "h,raw");
969 
970 	if (ddi_create_minor_node(vdc->dip, "wd", S_IFBLK,
971 	    VD_MAKE_DEV(vdc->instance, VD_EFI_WD_SLICE),
972 	    DDI_NT_BLOCK, 0) != DDI_SUCCESS) {
973 		cmn_err(CE_NOTE, "[%d] Couldn't add block node 'wd'",
974 		    vdc->instance);
975 		return (EIO);
976 	}
977 
978 	/* if any device node is created we set this flag */
979 	vdc->initialized |= VDC_MINOR;
980 
981 	if (ddi_create_minor_node(vdc->dip, "wd,raw", S_IFCHR,
982 	    VD_MAKE_DEV(vdc->instance, VD_EFI_WD_SLICE),
983 	    DDI_NT_BLOCK, 0) != DDI_SUCCESS) {
984 		cmn_err(CE_NOTE, "[%d] Couldn't add block node 'wd,raw'",
985 		    vdc->instance);
986 		return (EIO);
987 	}
988 
989 	return (0);
990 }
991 
992 static int
993 vdc_create_device_nodes_vtoc(vdc_t *vdc)
994 {
995 	ddi_remove_minor_node(vdc->dip, "wd");
996 	ddi_remove_minor_node(vdc->dip, "wd,raw");
997 
998 	if (ddi_create_minor_node(vdc->dip, "h", S_IFBLK,
999 	    VD_MAKE_DEV(vdc->instance, VD_EFI_WD_SLICE),
1000 	    DDI_NT_BLOCK, 0) != DDI_SUCCESS) {
1001 		cmn_err(CE_NOTE, "[%d] Couldn't add block node 'h'",
1002 		    vdc->instance);
1003 		return (EIO);
1004 	}
1005 
1006 	/* if any device node is created we set this flag */
1007 	vdc->initialized |= VDC_MINOR;
1008 
1009 	if (ddi_create_minor_node(vdc->dip, "h,raw", S_IFCHR,
1010 	    VD_MAKE_DEV(vdc->instance, VD_EFI_WD_SLICE),
1011 	    DDI_NT_BLOCK, 0) != DDI_SUCCESS) {
1012 		cmn_err(CE_NOTE, "[%d] Couldn't add block node 'h,raw'",
1013 		    vdc->instance);
1014 		return (EIO);
1015 	}
1016 
1017 	return (0);
1018 }
1019 
1020 /*
1021  * Function:
1022  *	vdc_create_device_nodes
1023  *
1024  * Description:
1025  *	This function creates the block and character device nodes under
1026  *	/devices. It is called as part of the attach(9E) of the instance
1027  *	during the handshake with vds after vds has sent the attributes
1028  *	to vdc.
1029  *
1030  *	If the device is of type VD_DISK_TYPE_SLICE then the minor node
1031  *	of 2 is used in keeping with the Solaris convention that slice 2
1032  *	refers to a whole disk. Slices start at 'a'
1033  *
1034  * Parameters:
1035  *	vdc 		- soft state pointer
1036  *
1037  * Return Values
1038  *	0		- Success
1039  *	EIO		- Failed to create node
1040  */
1041 static int
1042 vdc_create_device_nodes(vdc_t *vdc)
1043 {
1044 	char		name[sizeof ("s,raw")];
1045 	dev_info_t	*dip = NULL;
1046 	int		instance, status;
1047 	int		num_slices = 1;
1048 	int		i;
1049 
1050 	ASSERT(vdc != NULL);
1051 
1052 	instance = vdc->instance;
1053 	dip = vdc->dip;
1054 
1055 	switch (vdc->vdisk_type) {
1056 	case VD_DISK_TYPE_DISK:
1057 	case VD_DISK_TYPE_UNK:
1058 		num_slices = V_NUMPAR;
1059 		break;
1060 	case VD_DISK_TYPE_SLICE:
1061 		num_slices = 1;
1062 		break;
1063 	default:
1064 		ASSERT(0);
1065 	}
1066 
1067 	/*
1068 	 * Minor nodes are different for EFI disks: EFI disks do not have
1069 	 * a minor node 'g' for the minor number corresponding to slice
1070 	 * VD_EFI_WD_SLICE (slice 7) instead they have a minor node 'wd'
1071 	 * representing the whole disk.
1072 	 */
1073 	for (i = 0; i < num_slices; i++) {
1074 
1075 		if (i == VD_EFI_WD_SLICE) {
1076 			if (vdc->vdisk_label == VD_DISK_LABEL_EFI)
1077 				status = vdc_create_device_nodes_efi(vdc);
1078 			else
1079 				status = vdc_create_device_nodes_vtoc(vdc);
1080 			if (status != 0)
1081 				return (status);
1082 			continue;
1083 		}
1084 
1085 		(void) snprintf(name, sizeof (name), "%c", 'a' + i);
1086 		if (ddi_create_minor_node(dip, name, S_IFBLK,
1087 		    VD_MAKE_DEV(instance, i), DDI_NT_BLOCK, 0) != DDI_SUCCESS) {
1088 			cmn_err(CE_NOTE, "[%d] Couldn't add block node '%s'",
1089 			    instance, name);
1090 			return (EIO);
1091 		}
1092 
1093 		/* if any device node is created we set this flag */
1094 		vdc->initialized |= VDC_MINOR;
1095 
1096 		(void) snprintf(name, sizeof (name), "%c%s", 'a' + i, ",raw");
1097 
1098 		if (ddi_create_minor_node(dip, name, S_IFCHR,
1099 		    VD_MAKE_DEV(instance, i), DDI_NT_BLOCK, 0) != DDI_SUCCESS) {
1100 			cmn_err(CE_NOTE, "[%d] Couldn't add raw node '%s'",
1101 			    instance, name);
1102 			return (EIO);
1103 		}
1104 	}
1105 
1106 	return (0);
1107 }
1108 
1109 /*
1110  * Driver prop_op(9e) entry point function. Return the number of blocks for
1111  * the partition in question or forward the request to the property facilities.
1112  */
1113 static int
1114 vdc_prop_op(dev_t dev, dev_info_t *dip, ddi_prop_op_t prop_op, int mod_flags,
1115     char *name, caddr_t valuep, int *lengthp)
1116 {
1117 	int instance = ddi_get_instance(dip);
1118 	vdc_t *vdc;
1119 	uint64_t nblocks;
1120 	uint_t blksize;
1121 
1122 	vdc = ddi_get_soft_state(vdc_state, instance);
1123 
1124 	if (dev == DDI_DEV_T_ANY || vdc == NULL) {
1125 		return (ddi_prop_op(dev, dip, prop_op, mod_flags,
1126 		    name, valuep, lengthp));
1127 	}
1128 
1129 	mutex_enter(&vdc->lock);
1130 	(void) vdc_validate_geometry(vdc);
1131 	if (vdc->vdisk_label == VD_DISK_LABEL_UNK) {
1132 		mutex_exit(&vdc->lock);
1133 		return (ddi_prop_op(dev, dip, prop_op, mod_flags,
1134 		    name, valuep, lengthp));
1135 	}
1136 	nblocks = vdc->slice[VDCPART(dev)].nblocks;
1137 	blksize = vdc->vdisk_bsize;
1138 	mutex_exit(&vdc->lock);
1139 
1140 	return (ddi_prop_op_nblocks_blksize(dev, dip, prop_op, mod_flags,
1141 	    name, valuep, lengthp, nblocks, blksize));
1142 }
1143 
1144 /*
1145  * Function:
1146  *	vdc_is_opened
1147  *
1148  * Description:
1149  *	This function checks if any slice of a given virtual disk is
1150  *	currently opened.
1151  *
1152  * Parameters:
1153  *	vdc 		- soft state pointer
1154  *
1155  * Return Values
1156  *	B_TRUE		- at least one slice is opened.
1157  *	B_FALSE		- no slice is opened.
1158  */
1159 static boolean_t
1160 vdc_is_opened(vdc_t *vdc)
1161 {
1162 	int i;
1163 
1164 	/* check if there's any layered open */
1165 	for (i = 0; i < V_NUMPAR; i++) {
1166 		if (vdc->open_lyr[i] > 0)
1167 			return (B_TRUE);
1168 	}
1169 
1170 	/* check if there is any other kind of open */
1171 	for (i = 0; i < OTYPCNT; i++) {
1172 		if (vdc->open[i] != 0)
1173 			return (B_TRUE);
1174 	}
1175 
1176 	return (B_FALSE);
1177 }
1178 
1179 static int
1180 vdc_mark_opened(vdc_t *vdc, int slice, int flag, int otyp)
1181 {
1182 	uint8_t slicemask;
1183 	int i;
1184 
1185 	ASSERT(otyp < OTYPCNT);
1186 	ASSERT(slice < V_NUMPAR);
1187 	ASSERT(MUTEX_HELD(&vdc->lock));
1188 
1189 	slicemask = 1 << slice;
1190 
1191 	/*
1192 	 * If we have a single-slice disk which was unavailable during the
1193 	 * attach then a device was created for each 8 slices. Now that
1194 	 * the type is known, we prevent opening any slice other than 0
1195 	 * even if a device still exists.
1196 	 */
1197 	if (vdc->vdisk_type == VD_DISK_TYPE_SLICE && slice != 0)
1198 		return (EIO);
1199 
1200 	/* check if slice is already exclusively opened */
1201 	if (vdc->open_excl & slicemask)
1202 		return (EBUSY);
1203 
1204 	/* if open exclusive, check if slice is already opened */
1205 	if (flag & FEXCL) {
1206 		if (vdc->open_lyr[slice] > 0)
1207 			return (EBUSY);
1208 		for (i = 0; i < OTYPCNT; i++) {
1209 			if (vdc->open[i] & slicemask)
1210 				return (EBUSY);
1211 		}
1212 		vdc->open_excl |= slicemask;
1213 	}
1214 
1215 	/* mark slice as opened */
1216 	if (otyp == OTYP_LYR) {
1217 		vdc->open_lyr[slice]++;
1218 	} else {
1219 		vdc->open[otyp] |= slicemask;
1220 	}
1221 
1222 	return (0);
1223 }
1224 
1225 static void
1226 vdc_mark_closed(vdc_t *vdc, int slice, int flag, int otyp)
1227 {
1228 	uint8_t slicemask;
1229 
1230 	ASSERT(otyp < OTYPCNT);
1231 	ASSERT(slice < V_NUMPAR);
1232 	ASSERT(MUTEX_HELD(&vdc->lock));
1233 
1234 	slicemask = 1 << slice;
1235 
1236 	if (otyp == OTYP_LYR) {
1237 		ASSERT(vdc->open_lyr[slice] > 0);
1238 		vdc->open_lyr[slice]--;
1239 	} else {
1240 		vdc->open[otyp] &= ~slicemask;
1241 	}
1242 
1243 	if (flag & FEXCL)
1244 		vdc->open_excl &= ~slicemask;
1245 }
1246 
1247 static int
1248 vdc_open(dev_t *dev, int flag, int otyp, cred_t *cred)
1249 {
1250 	_NOTE(ARGUNUSED(cred))
1251 
1252 	int	instance, nodelay;
1253 	int	slice, status = 0;
1254 	vdc_t	*vdc;
1255 
1256 	ASSERT(dev != NULL);
1257 	instance = VDCUNIT(*dev);
1258 
1259 	if (otyp >= OTYPCNT)
1260 		return (EINVAL);
1261 
1262 	if ((vdc = ddi_get_soft_state(vdc_state, instance)) == NULL) {
1263 		cmn_err(CE_NOTE, "[%d] Couldn't get state structure", instance);
1264 		return (ENXIO);
1265 	}
1266 
1267 	DMSG(vdc, 0, "minor = %d flag = %x, otyp = %x\n",
1268 	    getminor(*dev), flag, otyp);
1269 
1270 	slice = VDCPART(*dev);
1271 
1272 	nodelay = flag & (FNDELAY | FNONBLOCK);
1273 
1274 	if ((flag & FWRITE) && (!nodelay) &&
1275 	    !(VD_OP_SUPPORTED(vdc->operations, VD_OP_BWRITE))) {
1276 		return (EROFS);
1277 	}
1278 
1279 	mutex_enter(&vdc->lock);
1280 
1281 	status = vdc_mark_opened(vdc, slice, flag, otyp);
1282 
1283 	if (status != 0) {
1284 		mutex_exit(&vdc->lock);
1285 		return (status);
1286 	}
1287 
1288 	/*
1289 	 * If the disk type is unknown then we have to wait for the
1290 	 * handshake to complete because we don't know if the slice
1291 	 * device we are opening effectively exists.
1292 	 */
1293 	if (vdc->vdisk_type != VD_DISK_TYPE_UNK && nodelay) {
1294 
1295 		/* don't resubmit a validate request if there's already one */
1296 		if (vdc->validate_pending > 0) {
1297 			mutex_exit(&vdc->lock);
1298 			return (0);
1299 		}
1300 
1301 		/* call vdc_validate() asynchronously to avoid blocking */
1302 		if (taskq_dispatch(system_taskq, vdc_validate_task,
1303 		    (void *)vdc, TQ_NOSLEEP) == NULL) {
1304 			vdc_mark_closed(vdc, slice, flag, otyp);
1305 			mutex_exit(&vdc->lock);
1306 			return (ENXIO);
1307 		}
1308 
1309 		vdc->validate_pending++;
1310 		mutex_exit(&vdc->lock);
1311 		return (0);
1312 	}
1313 
1314 	mutex_exit(&vdc->lock);
1315 
1316 	vdc_validate(vdc);
1317 
1318 	mutex_enter(&vdc->lock);
1319 
1320 	if (vdc->vdisk_type == VD_DISK_TYPE_UNK ||
1321 	    (vdc->vdisk_type == VD_DISK_TYPE_SLICE && slice != 0) ||
1322 	    (!nodelay && (vdc->vdisk_label == VD_DISK_LABEL_UNK ||
1323 	    vdc->slice[slice].nblocks == 0))) {
1324 		vdc_mark_closed(vdc, slice, flag, otyp);
1325 		status = EIO;
1326 	}
1327 
1328 	mutex_exit(&vdc->lock);
1329 
1330 	return (status);
1331 }
1332 
1333 static int
1334 vdc_close(dev_t dev, int flag, int otyp, cred_t *cred)
1335 {
1336 	_NOTE(ARGUNUSED(cred))
1337 
1338 	int	instance;
1339 	int	slice;
1340 	int	rv, rval;
1341 	vdc_t	*vdc;
1342 
1343 	instance = VDCUNIT(dev);
1344 
1345 	if (otyp >= OTYPCNT)
1346 		return (EINVAL);
1347 
1348 	if ((vdc = ddi_get_soft_state(vdc_state, instance)) == NULL) {
1349 		cmn_err(CE_NOTE, "[%d] Couldn't get state structure", instance);
1350 		return (ENXIO);
1351 	}
1352 
1353 	DMSG(vdc, 0, "[%d] flag = %x, otyp = %x\n", instance, flag, otyp);
1354 
1355 	slice = VDCPART(dev);
1356 
1357 	/*
1358 	 * Attempt to flush the W$ on a close operation. If this is
1359 	 * not a supported IOCTL command or the backing device is read-only
1360 	 * do not fail the close operation.
1361 	 */
1362 	rv = vd_process_ioctl(dev, DKIOCFLUSHWRITECACHE, NULL, FKIOCTL, &rval);
1363 
1364 	if (rv != 0 && rv != ENOTSUP && rv != ENOTTY && rv != EROFS) {
1365 		DMSG(vdc, 0, "[%d] flush failed with error %d on close\n",
1366 		    instance, rv);
1367 		return (EIO);
1368 	}
1369 
1370 	mutex_enter(&vdc->lock);
1371 	vdc_mark_closed(vdc, slice, flag, otyp);
1372 	mutex_exit(&vdc->lock);
1373 
1374 	return (0);
1375 }
1376 
1377 static int
1378 vdc_ioctl(dev_t dev, int cmd, intptr_t arg, int mode, cred_t *credp, int *rvalp)
1379 {
1380 	_NOTE(ARGUNUSED(credp))
1381 
1382 	return (vd_process_ioctl(dev, cmd, (caddr_t)arg, mode, rvalp));
1383 }
1384 
1385 static int
1386 vdc_print(dev_t dev, char *str)
1387 {
1388 	cmn_err(CE_NOTE, "vdc%d:  %s", VDCUNIT(dev), str);
1389 	return (0);
1390 }
1391 
1392 static int
1393 vdc_dump(dev_t dev, caddr_t addr, daddr_t blkno, int nblk)
1394 {
1395 	int	rv, flags;
1396 	size_t	nbytes = nblk * DEV_BSIZE;
1397 	int	instance = VDCUNIT(dev);
1398 	vdc_t	*vdc = NULL;
1399 	diskaddr_t vio_blkno;
1400 
1401 	if ((vdc = ddi_get_soft_state(vdc_state, instance)) == NULL) {
1402 		cmn_err(CE_NOTE, "[%d] Couldn't get state structure", instance);
1403 		return (ENXIO);
1404 	}
1405 
1406 	DMSG(vdc, 2, "[%d] dump %ld bytes at block 0x%lx : addr=0x%p\n",
1407 	    instance, nbytes, blkno, (void *)addr);
1408 
1409 	/* convert logical block to vio block */
1410 	if ((blkno & vdc->vio_bmask) != 0) {
1411 		DMSG(vdc, 0, "Misaligned block number (%lu)\n", blkno);
1412 		return (EINVAL);
1413 	}
1414 	vio_blkno = blkno >> vdc->vio_bshift;
1415 
1416 	/*
1417 	 * If we are panicking, we need the state to be "running" so that we
1418 	 * can submit I/Os, but we don't want to check for any backend error.
1419 	 */
1420 	flags = (ddi_in_panic())? VDC_OP_STATE_RUNNING : VDC_OP_NORMAL;
1421 
1422 	rv = vdc_do_op(vdc, VD_OP_BWRITE, addr, nbytes, VDCPART(dev),
1423 	    vio_blkno, NULL, VIO_write_dir, flags);
1424 
1425 	if (rv) {
1426 		DMSG(vdc, 0, "Failed to do a disk dump (err=%d)\n", rv);
1427 		return (rv);
1428 	}
1429 
1430 	DMSG(vdc, 0, "[%d] End\n", instance);
1431 
1432 	return (0);
1433 }
1434 
1435 /* -------------------------------------------------------------------------- */
1436 
1437 /*
1438  * Disk access routines
1439  *
1440  */
1441 
1442 /*
1443  * vdc_strategy()
1444  *
1445  * Return Value:
1446  *	0:	As per strategy(9E), the strategy() function must return 0
1447  *		[ bioerror(9f) sets b_flags to the proper error code ]
1448  */
1449 static int
1450 vdc_strategy(struct buf *buf)
1451 {
1452 	diskaddr_t vio_blkno;
1453 	vdc_t	*vdc = NULL;
1454 	int	instance = VDCUNIT(buf->b_edev);
1455 	int	op = (buf->b_flags & B_READ) ? VD_OP_BREAD : VD_OP_BWRITE;
1456 	int	slice;
1457 
1458 	if ((vdc = ddi_get_soft_state(vdc_state, instance)) == NULL) {
1459 		cmn_err(CE_NOTE, "[%d] Couldn't get state structure", instance);
1460 		bioerror(buf, ENXIO);
1461 		biodone(buf);
1462 		return (0);
1463 	}
1464 
1465 	DMSG(vdc, 2, "[%d] %s %ld bytes at block %llx : b_addr=0x%p\n",
1466 	    instance, (buf->b_flags & B_READ) ? "Read" : "Write",
1467 	    buf->b_bcount, buf->b_lblkno, (void *)buf->b_un.b_addr);
1468 
1469 	bp_mapin(buf);
1470 
1471 	if ((long)buf->b_private == VD_SLICE_NONE) {
1472 		/* I/O using an absolute disk offset */
1473 		slice = VD_SLICE_NONE;
1474 	} else {
1475 		slice = VDCPART(buf->b_edev);
1476 	}
1477 
1478 	/*
1479 	 * In the buf structure, b_lblkno represents a logical block number
1480 	 * using a block size of 512 bytes. For the VIO request, this block
1481 	 * number has to be converted to be represented with the block size
1482 	 * used by the VIO protocol.
1483 	 */
1484 	if ((buf->b_lblkno & vdc->vio_bmask) != 0) {
1485 		bioerror(buf, EINVAL);
1486 		biodone(buf);
1487 		return (0);
1488 	}
1489 	vio_blkno = buf->b_lblkno >> vdc->vio_bshift;
1490 
1491 	/* submit the I/O, any error will be reported in the buf structure */
1492 	(void) vdc_do_op(vdc, op, (caddr_t)buf->b_un.b_addr,
1493 	    buf->b_bcount, slice, vio_blkno,
1494 	    buf, (op == VD_OP_BREAD) ? VIO_read_dir : VIO_write_dir,
1495 	    VDC_OP_NORMAL);
1496 
1497 	return (0);
1498 }
1499 
1500 /*
1501  * Function:
1502  *	vdc_min
1503  *
1504  * Description:
1505  *	Routine to limit the size of a data transfer. Used in
1506  *	conjunction with physio(9F).
1507  *
1508  * Arguments:
1509  *	bp - pointer to the indicated buf(9S) struct.
1510  *
1511  */
1512 static void
1513 vdc_min(struct buf *bufp)
1514 {
1515 	vdc_t	*vdc = NULL;
1516 	int	instance = VDCUNIT(bufp->b_edev);
1517 
1518 	vdc = ddi_get_soft_state(vdc_state, instance);
1519 	VERIFY(vdc != NULL);
1520 
1521 	if (bufp->b_bcount > (vdc->max_xfer_sz * vdc->vdisk_bsize)) {
1522 		bufp->b_bcount = vdc->max_xfer_sz * vdc->vdisk_bsize;
1523 	}
1524 }
1525 
1526 static int
1527 vdc_read(dev_t dev, struct uio *uio, cred_t *cred)
1528 {
1529 	_NOTE(ARGUNUSED(cred))
1530 
1531 	DMSGX(1, "[%d] Entered", VDCUNIT(dev));
1532 	return (physio(vdc_strategy, NULL, dev, B_READ, vdc_min, uio));
1533 }
1534 
1535 static int
1536 vdc_write(dev_t dev, struct uio *uio, cred_t *cred)
1537 {
1538 	_NOTE(ARGUNUSED(cred))
1539 
1540 	DMSGX(1, "[%d] Entered", VDCUNIT(dev));
1541 	return (physio(vdc_strategy, NULL, dev, B_WRITE, vdc_min, uio));
1542 }
1543 
1544 static int
1545 vdc_aread(dev_t dev, struct aio_req *aio, cred_t *cred)
1546 {
1547 	_NOTE(ARGUNUSED(cred))
1548 
1549 	DMSGX(1, "[%d] Entered", VDCUNIT(dev));
1550 	return (aphysio(vdc_strategy, anocancel, dev, B_READ, vdc_min, aio));
1551 }
1552 
1553 static int
1554 vdc_awrite(dev_t dev, struct aio_req *aio, cred_t *cred)
1555 {
1556 	_NOTE(ARGUNUSED(cred))
1557 
1558 	DMSGX(1, "[%d] Entered", VDCUNIT(dev));
1559 	return (aphysio(vdc_strategy, anocancel, dev, B_WRITE, vdc_min, aio));
1560 }
1561 
1562 
1563 /* -------------------------------------------------------------------------- */
1564 
1565 /*
1566  * Handshake support
1567  */
1568 
1569 
1570 /*
1571  * Function:
1572  *	vdc_init_ver_negotiation()
1573  *
1574  * Description:
1575  *
1576  * Arguments:
1577  *	vdc	- soft state pointer for this instance of the device driver.
1578  *
1579  * Return Code:
1580  *	0	- Success
1581  */
1582 static int
1583 vdc_init_ver_negotiation(vdc_t *vdc, vio_ver_t ver)
1584 {
1585 	vio_ver_msg_t	pkt;
1586 	size_t		msglen = sizeof (pkt);
1587 	int		status = -1;
1588 
1589 	ASSERT(vdc != NULL);
1590 	ASSERT(mutex_owned(&vdc->lock));
1591 
1592 	DMSG(vdc, 0, "[%d] Entered.\n", vdc->instance);
1593 
1594 	/*
1595 	 * set the Session ID to a unique value
1596 	 * (the lower 32 bits of the clock tick)
1597 	 */
1598 	vdc->session_id = ((uint32_t)gettick() & 0xffffffff);
1599 	DMSG(vdc, 0, "[%d] Set SID to 0x%lx\n", vdc->instance, vdc->session_id);
1600 
1601 	pkt.tag.vio_msgtype = VIO_TYPE_CTRL;
1602 	pkt.tag.vio_subtype = VIO_SUBTYPE_INFO;
1603 	pkt.tag.vio_subtype_env = VIO_VER_INFO;
1604 	pkt.tag.vio_sid = vdc->session_id;
1605 	pkt.dev_class = VDEV_DISK;
1606 	pkt.ver_major = ver.major;
1607 	pkt.ver_minor = ver.minor;
1608 
1609 	status = vdc_send(vdc, (caddr_t)&pkt, &msglen);
1610 	DMSG(vdc, 0, "[%d] Ver info sent (status = %d)\n",
1611 	    vdc->instance, status);
1612 	if ((status != 0) || (msglen != sizeof (vio_ver_msg_t))) {
1613 		DMSG(vdc, 0, "[%d] Failed to send Ver negotiation info: "
1614 		    "id(%lx) rv(%d) size(%ld)", vdc->instance,
1615 		    vdc->curr_server->ldc_handle, status, msglen);
1616 		if (msglen != sizeof (vio_ver_msg_t))
1617 			status = ENOMSG;
1618 	}
1619 
1620 	return (status);
1621 }
1622 
1623 /*
1624  * Function:
1625  *	vdc_ver_negotiation()
1626  *
1627  * Description:
1628  *
1629  * Arguments:
1630  *	vdcp	- soft state pointer for this instance of the device driver.
1631  *
1632  * Return Code:
1633  *	0	- Success
1634  */
1635 static int
1636 vdc_ver_negotiation(vdc_t *vdcp)
1637 {
1638 	vio_msg_t vio_msg;
1639 	int status;
1640 
1641 	if (status = vdc_init_ver_negotiation(vdcp, vdc_version[0]))
1642 		return (status);
1643 
1644 	/* release lock and wait for response */
1645 	mutex_exit(&vdcp->lock);
1646 	status = vdc_wait_for_response(vdcp, &vio_msg);
1647 	mutex_enter(&vdcp->lock);
1648 	if (status) {
1649 		DMSG(vdcp, 0,
1650 		    "[%d] Failed waiting for Ver negotiation response, rv(%d)",
1651 		    vdcp->instance, status);
1652 		return (status);
1653 	}
1654 
1655 	/* check type and sub_type ... */
1656 	if (vio_msg.tag.vio_msgtype != VIO_TYPE_CTRL ||
1657 	    vio_msg.tag.vio_subtype == VIO_SUBTYPE_INFO) {
1658 		DMSG(vdcp, 0, "[%d] Invalid ver negotiation response\n",
1659 		    vdcp->instance);
1660 		return (EPROTO);
1661 	}
1662 
1663 	return (vdc_handle_ver_msg(vdcp, (vio_ver_msg_t *)&vio_msg));
1664 }
1665 
1666 /*
1667  * Function:
1668  *	vdc_init_attr_negotiation()
1669  *
1670  * Description:
1671  *
1672  * Arguments:
1673  *	vdc	- soft state pointer for this instance of the device driver.
1674  *
1675  * Return Code:
1676  *	0	- Success
1677  */
1678 static int
1679 vdc_init_attr_negotiation(vdc_t *vdc)
1680 {
1681 	vd_attr_msg_t	pkt;
1682 	size_t		msglen = sizeof (pkt);
1683 	int		status;
1684 
1685 	ASSERT(vdc != NULL);
1686 	ASSERT(mutex_owned(&vdc->lock));
1687 
1688 	DMSG(vdc, 0, "[%d] entered\n", vdc->instance);
1689 
1690 	/* fill in tag */
1691 	pkt.tag.vio_msgtype = VIO_TYPE_CTRL;
1692 	pkt.tag.vio_subtype = VIO_SUBTYPE_INFO;
1693 	pkt.tag.vio_subtype_env = VIO_ATTR_INFO;
1694 	pkt.tag.vio_sid = vdc->session_id;
1695 	/* fill in payload */
1696 	pkt.max_xfer_sz = vdc->max_xfer_sz;
1697 	pkt.vdisk_block_size = vdc->vdisk_bsize;
1698 	pkt.xfer_mode = VIO_DRING_MODE_V1_0;
1699 	pkt.operations = 0;	/* server will set bits of valid operations */
1700 	pkt.vdisk_type = 0;	/* server will set to valid device type */
1701 	pkt.vdisk_media = 0;	/* server will set to valid media type */
1702 	pkt.vdisk_size = 0;	/* server will set to valid size */
1703 
1704 	status = vdc_send(vdc, (caddr_t)&pkt, &msglen);
1705 	DMSG(vdc, 0, "Attr info sent (status = %d)\n", status);
1706 
1707 	if ((status != 0) || (msglen != sizeof (vd_attr_msg_t))) {
1708 		DMSG(vdc, 0, "[%d] Failed to send Attr negotiation info: "
1709 		    "id(%lx) rv(%d) size(%ld)", vdc->instance,
1710 		    vdc->curr_server->ldc_handle, status, msglen);
1711 		if (msglen != sizeof (vd_attr_msg_t))
1712 			status = ENOMSG;
1713 	}
1714 
1715 	return (status);
1716 }
1717 
1718 /*
1719  * Function:
1720  *	vdc_attr_negotiation()
1721  *
1722  * Description:
1723  *
1724  * Arguments:
1725  *	vdc	- soft state pointer for this instance of the device driver.
1726  *
1727  * Return Code:
1728  *	0	- Success
1729  */
1730 static int
1731 vdc_attr_negotiation(vdc_t *vdcp)
1732 {
1733 	int status;
1734 	vio_msg_t vio_msg;
1735 
1736 	if (status = vdc_init_attr_negotiation(vdcp))
1737 		return (status);
1738 
1739 	/* release lock and wait for response */
1740 	mutex_exit(&vdcp->lock);
1741 	status = vdc_wait_for_response(vdcp, &vio_msg);
1742 	mutex_enter(&vdcp->lock);
1743 	if (status) {
1744 		DMSG(vdcp, 0,
1745 		    "[%d] Failed waiting for Attr negotiation response, rv(%d)",
1746 		    vdcp->instance, status);
1747 		return (status);
1748 	}
1749 
1750 	/* check type and sub_type ... */
1751 	if (vio_msg.tag.vio_msgtype != VIO_TYPE_CTRL ||
1752 	    vio_msg.tag.vio_subtype == VIO_SUBTYPE_INFO) {
1753 		DMSG(vdcp, 0, "[%d] Invalid attr negotiation response\n",
1754 		    vdcp->instance);
1755 		return (EPROTO);
1756 	}
1757 
1758 	return (vdc_handle_attr_msg(vdcp, (vd_attr_msg_t *)&vio_msg));
1759 }
1760 
1761 
1762 /*
1763  * Function:
1764  *	vdc_init_dring_negotiate()
1765  *
1766  * Description:
1767  *
1768  * Arguments:
1769  *	vdc	- soft state pointer for this instance of the device driver.
1770  *
1771  * Return Code:
1772  *	0	- Success
1773  */
1774 static int
1775 vdc_init_dring_negotiate(vdc_t *vdc)
1776 {
1777 	vio_dring_reg_msg_t	pkt;
1778 	size_t			msglen = sizeof (pkt);
1779 	int			status = -1;
1780 	int			retry;
1781 	int			nretries = 10;
1782 
1783 	ASSERT(vdc != NULL);
1784 	ASSERT(mutex_owned(&vdc->lock));
1785 
1786 	for (retry = 0; retry < nretries; retry++) {
1787 		status = vdc_init_descriptor_ring(vdc);
1788 		if (status != EAGAIN)
1789 			break;
1790 		drv_usecwait(vdc_min_timeout_ldc);
1791 	}
1792 
1793 	if (status != 0) {
1794 		DMSG(vdc, 0, "[%d] Failed to init DRing (status = %d)\n",
1795 		    vdc->instance, status);
1796 		return (status);
1797 	}
1798 
1799 	DMSG(vdc, 0, "[%d] Init of descriptor ring completed (status = %d)\n",
1800 	    vdc->instance, status);
1801 
1802 	/* fill in tag */
1803 	pkt.tag.vio_msgtype = VIO_TYPE_CTRL;
1804 	pkt.tag.vio_subtype = VIO_SUBTYPE_INFO;
1805 	pkt.tag.vio_subtype_env = VIO_DRING_REG;
1806 	pkt.tag.vio_sid = vdc->session_id;
1807 	/* fill in payload */
1808 	pkt.dring_ident = 0;
1809 	pkt.num_descriptors = vdc->dring_len;
1810 	pkt.descriptor_size = vdc->dring_entry_size;
1811 	pkt.options = (VIO_TX_DRING | VIO_RX_DRING);
1812 	pkt.ncookies = vdc->dring_cookie_count;
1813 	pkt.cookie[0] = vdc->dring_cookie[0];	/* for now just one cookie */
1814 
1815 	status = vdc_send(vdc, (caddr_t)&pkt, &msglen);
1816 	if (status != 0) {
1817 		DMSG(vdc, 0, "[%d] Failed to register DRing (err = %d)",
1818 		    vdc->instance, status);
1819 	}
1820 
1821 	return (status);
1822 }
1823 
1824 
1825 /*
1826  * Function:
1827  *	vdc_dring_negotiation()
1828  *
1829  * Description:
1830  *
1831  * Arguments:
1832  *	vdc	- soft state pointer for this instance of the device driver.
1833  *
1834  * Return Code:
1835  *	0	- Success
1836  */
1837 static int
1838 vdc_dring_negotiation(vdc_t *vdcp)
1839 {
1840 	int status;
1841 	vio_msg_t vio_msg;
1842 
1843 	if (status = vdc_init_dring_negotiate(vdcp))
1844 		return (status);
1845 
1846 	/* release lock and wait for response */
1847 	mutex_exit(&vdcp->lock);
1848 	status = vdc_wait_for_response(vdcp, &vio_msg);
1849 	mutex_enter(&vdcp->lock);
1850 	if (status) {
1851 		DMSG(vdcp, 0,
1852 		    "[%d] Failed waiting for Dring negotiation response,"
1853 		    " rv(%d)", vdcp->instance, status);
1854 		return (status);
1855 	}
1856 
1857 	/* check type and sub_type ... */
1858 	if (vio_msg.tag.vio_msgtype != VIO_TYPE_CTRL ||
1859 	    vio_msg.tag.vio_subtype == VIO_SUBTYPE_INFO) {
1860 		DMSG(vdcp, 0, "[%d] Invalid Dring negotiation response\n",
1861 		    vdcp->instance);
1862 		return (EPROTO);
1863 	}
1864 
1865 	return (vdc_handle_dring_reg_msg(vdcp,
1866 	    (vio_dring_reg_msg_t *)&vio_msg));
1867 }
1868 
1869 
1870 /*
1871  * Function:
1872  *	vdc_send_rdx()
1873  *
1874  * Description:
1875  *
1876  * Arguments:
1877  *	vdc	- soft state pointer for this instance of the device driver.
1878  *
1879  * Return Code:
1880  *	0	- Success
1881  */
1882 static int
1883 vdc_send_rdx(vdc_t *vdcp)
1884 {
1885 	vio_msg_t	msg;
1886 	size_t		msglen = sizeof (vio_msg_t);
1887 	int		status;
1888 
1889 	/*
1890 	 * Send an RDX message to vds to indicate we are ready
1891 	 * to send data
1892 	 */
1893 	msg.tag.vio_msgtype = VIO_TYPE_CTRL;
1894 	msg.tag.vio_subtype = VIO_SUBTYPE_INFO;
1895 	msg.tag.vio_subtype_env = VIO_RDX;
1896 	msg.tag.vio_sid = vdcp->session_id;
1897 	status = vdc_send(vdcp, (caddr_t)&msg, &msglen);
1898 	if (status != 0) {
1899 		DMSG(vdcp, 0, "[%d] Failed to send RDX message (%d)",
1900 		    vdcp->instance, status);
1901 	}
1902 
1903 	return (status);
1904 }
1905 
1906 /*
1907  * Function:
1908  *	vdc_handle_rdx()
1909  *
1910  * Description:
1911  *
1912  * Arguments:
1913  *	vdc	- soft state pointer for this instance of the device driver.
1914  *	msgp	- received msg
1915  *
1916  * Return Code:
1917  *	0	- Success
1918  */
1919 static int
1920 vdc_handle_rdx(vdc_t *vdcp, vio_rdx_msg_t *msgp)
1921 {
1922 	_NOTE(ARGUNUSED(vdcp))
1923 	_NOTE(ARGUNUSED(msgp))
1924 
1925 	ASSERT(msgp->tag.vio_msgtype == VIO_TYPE_CTRL);
1926 	ASSERT(msgp->tag.vio_subtype == VIO_SUBTYPE_ACK);
1927 	ASSERT(msgp->tag.vio_subtype_env == VIO_RDX);
1928 
1929 	DMSG(vdcp, 1, "[%d] Got an RDX msg", vdcp->instance);
1930 
1931 	return (0);
1932 }
1933 
1934 /*
1935  * Function:
1936  *	vdc_rdx_exchange()
1937  *
1938  * Description:
1939  *
1940  * Arguments:
1941  *	vdc	- soft state pointer for this instance of the device driver.
1942  *
1943  * Return Code:
1944  *	0	- Success
1945  */
1946 static int
1947 vdc_rdx_exchange(vdc_t *vdcp)
1948 {
1949 	int status;
1950 	vio_msg_t vio_msg;
1951 
1952 	if (status = vdc_send_rdx(vdcp))
1953 		return (status);
1954 
1955 	/* release lock and wait for response */
1956 	mutex_exit(&vdcp->lock);
1957 	status = vdc_wait_for_response(vdcp, &vio_msg);
1958 	mutex_enter(&vdcp->lock);
1959 	if (status) {
1960 		DMSG(vdcp, 0, "[%d] Failed waiting for RDX response, rv(%d)",
1961 		    vdcp->instance, status);
1962 		return (status);
1963 	}
1964 
1965 	/* check type and sub_type ... */
1966 	if (vio_msg.tag.vio_msgtype != VIO_TYPE_CTRL ||
1967 	    vio_msg.tag.vio_subtype != VIO_SUBTYPE_ACK) {
1968 		DMSG(vdcp, 0, "[%d] Invalid RDX response\n", vdcp->instance);
1969 		return (EPROTO);
1970 	}
1971 
1972 	return (vdc_handle_rdx(vdcp, (vio_rdx_msg_t *)&vio_msg));
1973 }
1974 
1975 
1976 /* -------------------------------------------------------------------------- */
1977 
1978 /*
1979  * LDC helper routines
1980  */
1981 
1982 static int
1983 vdc_recv(vdc_t *vdc, vio_msg_t *msgp, size_t *nbytesp)
1984 {
1985 	int		status;
1986 	uint64_t	delay_time;
1987 	size_t		len;
1988 
1989 	/*
1990 	 * Until we get a blocking ldc read we have to retry until the entire
1991 	 * LDC message has arrived before ldc_read() will return that message.
1992 	 * If ldc_read() succeed but returns a zero length message then that
1993 	 * means that the LDC queue is empty and we have to wait for a
1994 	 * notification from the LDC callback which will set the read_state to
1995 	 * VDC_READ_PENDING. Note we also bail out if the channel is reset or
1996 	 * goes away.
1997 	 */
1998 	delay_time = vdc_ldc_read_init_delay;
1999 
2000 	for (;;) {
2001 
2002 		len = *nbytesp;
2003 		/*
2004 		 * vdc->curr_server is protected by vdc->lock but to avoid
2005 		 * contentions we don't take the lock here. We can do this
2006 		 * safely because vdc_recv() is only called from thread
2007 		 * process_msg_thread() which is also the only thread that
2008 		 * can change vdc->curr_server.
2009 		 */
2010 		status = ldc_read(vdc->curr_server->ldc_handle,
2011 		    (caddr_t)msgp, &len);
2012 
2013 		if (status == EAGAIN) {
2014 			delay_time *= 2;
2015 			if (delay_time >= vdc_ldc_read_max_delay)
2016 				delay_time = vdc_ldc_read_max_delay;
2017 			delay(delay_time);
2018 			continue;
2019 		}
2020 
2021 		if (status != 0) {
2022 			DMSG(vdc, 0, "ldc_read returned %d\n", status);
2023 			break;
2024 		}
2025 
2026 		if (len != 0) {
2027 			*nbytesp = len;
2028 			break;
2029 		}
2030 
2031 		mutex_enter(&vdc->read_lock);
2032 
2033 		while (vdc->read_state != VDC_READ_PENDING) {
2034 
2035 			/* detect if the connection has been reset */
2036 			if (vdc->read_state == VDC_READ_RESET) {
2037 				mutex_exit(&vdc->read_lock);
2038 				return (ECONNRESET);
2039 			}
2040 
2041 			vdc->read_state = VDC_READ_WAITING;
2042 			cv_wait(&vdc->read_cv, &vdc->read_lock);
2043 		}
2044 
2045 		vdc->read_state = VDC_READ_IDLE;
2046 		mutex_exit(&vdc->read_lock);
2047 
2048 		delay_time = vdc_ldc_read_init_delay;
2049 	}
2050 
2051 	return (status);
2052 }
2053 
2054 
2055 
2056 #ifdef DEBUG
2057 void
2058 vdc_decode_tag(vdc_t *vdcp, vio_msg_t *msg)
2059 {
2060 	char *ms, *ss, *ses;
2061 	switch (msg->tag.vio_msgtype) {
2062 #define	Q(_s)	case _s : ms = #_s; break;
2063 	Q(VIO_TYPE_CTRL)
2064 	Q(VIO_TYPE_DATA)
2065 	Q(VIO_TYPE_ERR)
2066 #undef Q
2067 	default: ms = "unknown"; break;
2068 	}
2069 
2070 	switch (msg->tag.vio_subtype) {
2071 #define	Q(_s)	case _s : ss = #_s; break;
2072 	Q(VIO_SUBTYPE_INFO)
2073 	Q(VIO_SUBTYPE_ACK)
2074 	Q(VIO_SUBTYPE_NACK)
2075 #undef Q
2076 	default: ss = "unknown"; break;
2077 	}
2078 
2079 	switch (msg->tag.vio_subtype_env) {
2080 #define	Q(_s)	case _s : ses = #_s; break;
2081 	Q(VIO_VER_INFO)
2082 	Q(VIO_ATTR_INFO)
2083 	Q(VIO_DRING_REG)
2084 	Q(VIO_DRING_UNREG)
2085 	Q(VIO_RDX)
2086 	Q(VIO_PKT_DATA)
2087 	Q(VIO_DESC_DATA)
2088 	Q(VIO_DRING_DATA)
2089 #undef Q
2090 	default: ses = "unknown"; break;
2091 	}
2092 
2093 	DMSG(vdcp, 3, "(%x/%x/%x) message : (%s/%s/%s)\n",
2094 	    msg->tag.vio_msgtype, msg->tag.vio_subtype,
2095 	    msg->tag.vio_subtype_env, ms, ss, ses);
2096 }
2097 #endif
2098 
2099 /*
2100  * Function:
2101  *	vdc_send()
2102  *
2103  * Description:
2104  *	The function encapsulates the call to write a message using LDC.
2105  *	If LDC indicates that the call failed due to the queue being full,
2106  *	we retry the ldc_write(), otherwise we return the error returned by LDC.
2107  *
2108  * Arguments:
2109  *	ldc_handle	- LDC handle for the channel this instance of vdc uses
2110  *	pkt		- address of LDC message to be sent
2111  *	msglen		- the size of the message being sent. When the function
2112  *			  returns, this contains the number of bytes written.
2113  *
2114  * Return Code:
2115  *	0		- Success.
2116  *	EINVAL		- pkt or msglen were NULL
2117  *	ECONNRESET	- The connection was not up.
2118  *	EWOULDBLOCK	- LDC queue is full
2119  *	xxx		- other error codes returned by ldc_write
2120  */
2121 static int
2122 vdc_send(vdc_t *vdc, caddr_t pkt, size_t *msglen)
2123 {
2124 	size_t	size = 0;
2125 	int	status = 0;
2126 	clock_t delay_ticks;
2127 
2128 	ASSERT(vdc != NULL);
2129 	ASSERT(mutex_owned(&vdc->lock));
2130 	ASSERT(msglen != NULL);
2131 	ASSERT(*msglen != 0);
2132 
2133 #ifdef DEBUG
2134 	vdc_decode_tag(vdc, (vio_msg_t *)(uintptr_t)pkt);
2135 #endif
2136 	/*
2137 	 * Wait indefinitely to send if channel
2138 	 * is busy, but bail out if we succeed or
2139 	 * if the channel closes or is reset.
2140 	 */
2141 	delay_ticks = vdc_hz_min_ldc_delay;
2142 	do {
2143 		size = *msglen;
2144 		status = ldc_write(vdc->curr_server->ldc_handle, pkt, &size);
2145 		if (status == EWOULDBLOCK) {
2146 			delay(delay_ticks);
2147 			/* geometric backoff */
2148 			delay_ticks *= 2;
2149 			if (delay_ticks > vdc_hz_max_ldc_delay)
2150 				delay_ticks = vdc_hz_max_ldc_delay;
2151 		}
2152 	} while (status == EWOULDBLOCK);
2153 
2154 	/* if LDC had serious issues --- reset vdc state */
2155 	if (status == EIO || status == ECONNRESET) {
2156 		/* LDC had serious issues --- reset vdc state */
2157 		mutex_enter(&vdc->read_lock);
2158 		if ((vdc->read_state == VDC_READ_WAITING) ||
2159 		    (vdc->read_state == VDC_READ_RESET))
2160 			cv_signal(&vdc->read_cv);
2161 		vdc->read_state = VDC_READ_RESET;
2162 		mutex_exit(&vdc->read_lock);
2163 
2164 		/* wake up any waiters in the reset thread */
2165 		if (vdc->state == VDC_STATE_INIT_WAITING) {
2166 			DMSG(vdc, 0, "[%d] write reset - "
2167 			    "vdc is resetting ..\n", vdc->instance);
2168 			vdc->state = VDC_STATE_RESETTING;
2169 			cv_signal(&vdc->initwait_cv);
2170 		}
2171 
2172 		return (ECONNRESET);
2173 	}
2174 
2175 	/* return the last size written */
2176 	*msglen = size;
2177 
2178 	return (status);
2179 }
2180 
2181 /*
2182  * Function:
2183  *	vdc_get_md_node
2184  *
2185  * Description:
2186  *	Get the MD, the device node for the given disk instance. The
2187  *	caller is responsible for cleaning up the reference to the
2188  *	returned MD (mdpp) by calling md_fini_handle().
2189  *
2190  * Arguments:
2191  *	dip	- dev info pointer for this instance of the device driver.
2192  *	mdpp	- the returned MD.
2193  *	vd_nodep - the returned device node.
2194  *
2195  * Return Code:
2196  *	0	- Success.
2197  *	ENOENT	- Expected node or property did not exist.
2198  *	ENXIO	- Unexpected error communicating with MD framework
2199  */
2200 static int
2201 vdc_get_md_node(dev_info_t *dip, md_t **mdpp, mde_cookie_t *vd_nodep)
2202 {
2203 	int		status = ENOENT;
2204 	char		*node_name = NULL;
2205 	md_t		*mdp = NULL;
2206 	int		num_nodes;
2207 	int		num_vdevs;
2208 	mde_cookie_t	rootnode;
2209 	mde_cookie_t	*listp = NULL;
2210 	boolean_t	found_inst = B_FALSE;
2211 	int		listsz;
2212 	int		idx;
2213 	uint64_t	md_inst;
2214 	int		obp_inst;
2215 	int		instance = ddi_get_instance(dip);
2216 
2217 	/*
2218 	 * Get the OBP instance number for comparison with the MD instance
2219 	 *
2220 	 * The "cfg-handle" property of a vdc node in an MD contains the MD's
2221 	 * notion of "instance", or unique identifier, for that node; OBP
2222 	 * stores the value of the "cfg-handle" MD property as the value of
2223 	 * the "reg" property on the node in the device tree it builds from
2224 	 * the MD and passes to Solaris.  Thus, we look up the devinfo node's
2225 	 * "reg" property value to uniquely identify this device instance.
2226 	 * If the "reg" property cannot be found, the device tree state is
2227 	 * presumably so broken that there is no point in continuing.
2228 	 */
2229 	if (!ddi_prop_exists(DDI_DEV_T_ANY, dip, DDI_PROP_DONTPASS, OBP_REG)) {
2230 		cmn_err(CE_WARN, "'%s' property does not exist", OBP_REG);
2231 		return (ENOENT);
2232 	}
2233 	obp_inst = ddi_prop_get_int(DDI_DEV_T_ANY, dip, DDI_PROP_DONTPASS,
2234 	    OBP_REG, -1);
2235 	DMSGX(1, "[%d] OBP inst=%d\n", instance, obp_inst);
2236 
2237 	/*
2238 	 * We now walk the MD nodes to find the node for this vdisk.
2239 	 */
2240 	if ((mdp = md_get_handle()) == NULL) {
2241 		cmn_err(CE_WARN, "unable to init machine description");
2242 		return (ENXIO);
2243 	}
2244 
2245 	num_nodes = md_node_count(mdp);
2246 	ASSERT(num_nodes > 0);
2247 
2248 	listsz = num_nodes * sizeof (mde_cookie_t);
2249 
2250 	/* allocate memory for nodes */
2251 	listp = kmem_zalloc(listsz, KM_SLEEP);
2252 
2253 	rootnode = md_root_node(mdp);
2254 	ASSERT(rootnode != MDE_INVAL_ELEM_COOKIE);
2255 
2256 	/*
2257 	 * Search for all the virtual devices, we will then check to see which
2258 	 * ones are disk nodes.
2259 	 */
2260 	num_vdevs = md_scan_dag(mdp, rootnode,
2261 	    md_find_name(mdp, VDC_MD_VDEV_NAME),
2262 	    md_find_name(mdp, "fwd"), listp);
2263 
2264 	if (num_vdevs <= 0) {
2265 		cmn_err(CE_NOTE, "No '%s' node found", VDC_MD_VDEV_NAME);
2266 		status = ENOENT;
2267 		goto done;
2268 	}
2269 
2270 	DMSGX(1, "[%d] num_vdevs=%d\n", instance, num_vdevs);
2271 	for (idx = 0; idx < num_vdevs; idx++) {
2272 		status = md_get_prop_str(mdp, listp[idx], "name", &node_name);
2273 		if ((status != 0) || (node_name == NULL)) {
2274 			cmn_err(CE_NOTE, "Unable to get name of node type '%s'"
2275 			    ": err %d", VDC_MD_VDEV_NAME, status);
2276 			continue;
2277 		}
2278 
2279 		DMSGX(1, "[%d] Found node '%s'\n", instance, node_name);
2280 		if (strcmp(VDC_MD_DISK_NAME, node_name) == 0) {
2281 			status = md_get_prop_val(mdp, listp[idx],
2282 			    VDC_MD_CFG_HDL, &md_inst);
2283 			DMSGX(1, "[%d] vdc inst in MD=%lx\n",
2284 			    instance, md_inst);
2285 			if ((status == 0) && (md_inst == obp_inst)) {
2286 				found_inst = B_TRUE;
2287 				break;
2288 			}
2289 		}
2290 	}
2291 
2292 	if (!found_inst) {
2293 		DMSGX(0, "Unable to find correct '%s' node", VDC_MD_DISK_NAME);
2294 		status = ENOENT;
2295 		goto done;
2296 	}
2297 	DMSGX(0, "[%d] MD inst=%lx\n", instance, md_inst);
2298 
2299 	*vd_nodep = listp[idx];
2300 	*mdpp = mdp;
2301 done:
2302 	kmem_free(listp, listsz);
2303 	return (status);
2304 }
2305 
2306 /*
2307  * Function:
2308  *	vdc_init_ports
2309  *
2310  * Description:
2311  *	Initialize all the ports for this vdisk instance.
2312  *
2313  * Arguments:
2314  *	vdc	- soft state pointer for this instance of the device driver.
2315  *	mdp	- md pointer
2316  *	vd_nodep - device md node.
2317  *
2318  * Return Code:
2319  *	0	- Success.
2320  *	ENOENT	- Expected node or property did not exist.
2321  */
2322 static int
2323 vdc_init_ports(vdc_t *vdc, md_t *mdp, mde_cookie_t vd_nodep)
2324 {
2325 	int		status = 0;
2326 	int		idx;
2327 	int		num_nodes;
2328 	int		num_vports;
2329 	int		num_chans;
2330 	int		listsz;
2331 	mde_cookie_t	vd_port;
2332 	mde_cookie_t	*chanp = NULL;
2333 	mde_cookie_t	*portp = NULL;
2334 	vdc_server_t	*srvr;
2335 	vdc_server_t	*prev_srvr = NULL;
2336 
2337 	/*
2338 	 * We now walk the MD nodes to find the port nodes for this vdisk.
2339 	 */
2340 	num_nodes = md_node_count(mdp);
2341 	ASSERT(num_nodes > 0);
2342 
2343 	listsz = num_nodes * sizeof (mde_cookie_t);
2344 
2345 	/* allocate memory for nodes */
2346 	portp = kmem_zalloc(listsz, KM_SLEEP);
2347 	chanp = kmem_zalloc(listsz, KM_SLEEP);
2348 
2349 	num_vports = md_scan_dag(mdp, vd_nodep,
2350 	    md_find_name(mdp, VDC_MD_PORT_NAME),
2351 	    md_find_name(mdp, "fwd"), portp);
2352 	if (num_vports == 0) {
2353 		DMSGX(0, "Found no '%s' node for '%s' port\n",
2354 		    VDC_MD_PORT_NAME, VDC_MD_VDEV_NAME);
2355 		status = ENOENT;
2356 		goto done;
2357 	}
2358 
2359 	DMSGX(1, "Found %d '%s' node(s) for '%s' port\n",
2360 	    num_vports, VDC_MD_PORT_NAME, VDC_MD_VDEV_NAME);
2361 
2362 	vdc->num_servers = 0;
2363 	for (idx = 0; idx < num_vports; idx++) {
2364 
2365 		/* initialize this port */
2366 		vd_port = portp[idx];
2367 		srvr = kmem_zalloc(sizeof (vdc_server_t), KM_SLEEP);
2368 		srvr->vdcp = vdc;
2369 		srvr->svc_state = VDC_SERVICE_OFFLINE;
2370 		srvr->log_state = VDC_SERVICE_NONE;
2371 
2372 		/* get port id */
2373 		if (md_get_prop_val(mdp, vd_port, VDC_MD_ID, &srvr->id) != 0) {
2374 			cmn_err(CE_NOTE, "vDisk port '%s' property not found",
2375 			    VDC_MD_ID);
2376 			kmem_free(srvr, sizeof (vdc_server_t));
2377 			continue;
2378 		}
2379 
2380 		/* set the connection timeout */
2381 		if (md_get_prop_val(mdp, vd_port, VDC_MD_TIMEOUT,
2382 		    &srvr->ctimeout) != 0) {
2383 			srvr->ctimeout = 0;
2384 		}
2385 
2386 		/* get the ldc id */
2387 		num_chans = md_scan_dag(mdp, vd_port,
2388 		    md_find_name(mdp, VDC_MD_CHAN_NAME),
2389 		    md_find_name(mdp, "fwd"), chanp);
2390 
2391 		/* expecting at least one channel */
2392 		if (num_chans <= 0) {
2393 			cmn_err(CE_NOTE, "No '%s' node for '%s' port",
2394 			    VDC_MD_CHAN_NAME, VDC_MD_VDEV_NAME);
2395 			kmem_free(srvr, sizeof (vdc_server_t));
2396 			continue;
2397 		} else if (num_chans != 1) {
2398 			DMSGX(0, "Expected 1 '%s' node for '%s' port, "
2399 			    "found %d\n", VDC_MD_CHAN_NAME, VDC_MD_VDEV_NAME,
2400 			    num_chans);
2401 		}
2402 
2403 		/*
2404 		 * We use the first channel found (index 0), irrespective of how
2405 		 * many are there in total.
2406 		 */
2407 		if (md_get_prop_val(mdp, chanp[0], VDC_MD_ID,
2408 		    &srvr->ldc_id) != 0) {
2409 			cmn_err(CE_NOTE, "Channel '%s' property not found",
2410 			    VDC_MD_ID);
2411 			kmem_free(srvr, sizeof (vdc_server_t));
2412 			continue;
2413 		}
2414 
2415 		/*
2416 		 * now initialise LDC channel which will be used to
2417 		 * communicate with this server
2418 		 */
2419 		if (vdc_do_ldc_init(vdc, srvr) != 0) {
2420 			kmem_free(srvr, sizeof (vdc_server_t));
2421 			continue;
2422 		}
2423 
2424 		/* add server to list */
2425 		if (prev_srvr)
2426 			prev_srvr->next = srvr;
2427 		else
2428 			vdc->server_list = srvr;
2429 
2430 		prev_srvr = srvr;
2431 
2432 		/* inc numbers of servers */
2433 		vdc->num_servers++;
2434 	}
2435 
2436 	/*
2437 	 * Adjust the max number of handshake retries to match
2438 	 * the number of vdisk servers.
2439 	 */
2440 	if (vdc_hshake_retries < vdc->num_servers)
2441 		vdc_hshake_retries = vdc->num_servers;
2442 
2443 	/* pick first server as current server */
2444 	if (vdc->server_list != NULL) {
2445 		vdc->curr_server = vdc->server_list;
2446 		status = 0;
2447 	} else {
2448 		status = ENOENT;
2449 	}
2450 
2451 done:
2452 	kmem_free(chanp, listsz);
2453 	kmem_free(portp, listsz);
2454 	return (status);
2455 }
2456 
2457 
2458 /*
2459  * Function:
2460  *	vdc_do_ldc_up
2461  *
2462  * Description:
2463  *	Bring the channel for the current server up.
2464  *
2465  * Arguments:
2466  *	vdc	- soft state pointer for this instance of the device driver.
2467  *
2468  * Return Code:
2469  *	0		- Success.
2470  *	EINVAL		- Driver is detaching / LDC error
2471  *	ECONNREFUSED	- Other end is not listening
2472  */
2473 static int
2474 vdc_do_ldc_up(vdc_t *vdc)
2475 {
2476 	int		status;
2477 	ldc_status_t	ldc_state;
2478 
2479 	ASSERT(MUTEX_HELD(&vdc->lock));
2480 
2481 	DMSG(vdc, 0, "[%d] Bringing up channel %lx\n",
2482 	    vdc->instance, vdc->curr_server->ldc_id);
2483 
2484 	if (vdc->lifecycle == VDC_LC_DETACHING)
2485 		return (EINVAL);
2486 
2487 	if ((status = ldc_up(vdc->curr_server->ldc_handle)) != 0) {
2488 		switch (status) {
2489 		case ECONNREFUSED:	/* listener not ready at other end */
2490 			DMSG(vdc, 0, "[%d] ldc_up(%lx,...) return %d\n",
2491 			    vdc->instance, vdc->curr_server->ldc_id, status);
2492 			status = 0;
2493 			break;
2494 		default:
2495 			DMSG(vdc, 0, "[%d] Failed to bring up LDC: "
2496 			    "channel=%ld, err=%d", vdc->instance,
2497 			    vdc->curr_server->ldc_id, status);
2498 			break;
2499 		}
2500 	}
2501 
2502 	if (ldc_status(vdc->curr_server->ldc_handle, &ldc_state) == 0) {
2503 		vdc->curr_server->ldc_state = ldc_state;
2504 		if (ldc_state == LDC_UP) {
2505 			DMSG(vdc, 0, "[%d] LDC channel already up\n",
2506 			    vdc->instance);
2507 			vdc->seq_num = 1;
2508 			vdc->seq_num_reply = 0;
2509 		}
2510 	}
2511 
2512 	return (status);
2513 }
2514 
2515 /*
2516  * Function:
2517  *	vdc_terminate_ldc()
2518  *
2519  * Description:
2520  *
2521  * Arguments:
2522  *	vdc	- soft state pointer for this instance of the device driver.
2523  *	srvr	- vdc per-server info structure
2524  *
2525  * Return Code:
2526  *	None
2527  */
2528 static void
2529 vdc_terminate_ldc(vdc_t *vdc, vdc_server_t *srvr)
2530 {
2531 	int	instance = ddi_get_instance(vdc->dip);
2532 
2533 	if (srvr->state & VDC_LDC_OPEN) {
2534 		DMSG(vdc, 0, "[%d] ldc_close()\n", instance);
2535 		(void) ldc_close(srvr->ldc_handle);
2536 	}
2537 	if (srvr->state & VDC_LDC_CB) {
2538 		DMSG(vdc, 0, "[%d] ldc_unreg_callback()\n", instance);
2539 		(void) ldc_unreg_callback(srvr->ldc_handle);
2540 	}
2541 	if (srvr->state & VDC_LDC_INIT) {
2542 		DMSG(vdc, 0, "[%d] ldc_fini()\n", instance);
2543 		(void) ldc_fini(srvr->ldc_handle);
2544 		srvr->ldc_handle = NULL;
2545 	}
2546 
2547 	srvr->state &= ~(VDC_LDC_INIT | VDC_LDC_CB | VDC_LDC_OPEN);
2548 }
2549 
2550 /*
2551  * Function:
2552  *	vdc_fini_ports()
2553  *
2554  * Description:
2555  *	Finalize all ports by closing the channel associated with each
2556  *	port and also freeing the server structure.
2557  *
2558  * Arguments:
2559  *	vdc	- soft state pointer for this instance of the device driver.
2560  *
2561  * Return Code:
2562  *	None
2563  */
2564 static void
2565 vdc_fini_ports(vdc_t *vdc)
2566 {
2567 	int		instance = ddi_get_instance(vdc->dip);
2568 	vdc_server_t	*srvr, *prev_srvr;
2569 
2570 	ASSERT(vdc != NULL);
2571 	ASSERT(mutex_owned(&vdc->lock));
2572 
2573 	DMSG(vdc, 0, "[%d] initialized=%x\n", instance, vdc->initialized);
2574 
2575 	srvr = vdc->server_list;
2576 
2577 	while (srvr) {
2578 
2579 		vdc_terminate_ldc(vdc, srvr);
2580 
2581 		/* next server */
2582 		prev_srvr = srvr;
2583 		srvr = srvr->next;
2584 
2585 		/* free server */
2586 		kmem_free(prev_srvr, sizeof (vdc_server_t));
2587 	}
2588 
2589 	vdc->server_list = NULL;
2590 	vdc->num_servers = 0;
2591 }
2592 
2593 /* -------------------------------------------------------------------------- */
2594 
2595 /*
2596  * Descriptor Ring helper routines
2597  */
2598 
2599 /*
2600  * Function:
2601  *	vdc_init_descriptor_ring()
2602  *
2603  * Description:
2604  *
2605  * Arguments:
2606  *	vdc	- soft state pointer for this instance of the device driver.
2607  *
2608  * Return Code:
2609  *	0	- Success
2610  */
2611 static int
2612 vdc_init_descriptor_ring(vdc_t *vdc)
2613 {
2614 	vd_dring_entry_t	*dep = NULL;	/* DRing Entry pointer */
2615 	int	status = 0;
2616 	int	i;
2617 
2618 	DMSG(vdc, 0, "[%d] initialized=%x\n", vdc->instance, vdc->initialized);
2619 
2620 	ASSERT(vdc != NULL);
2621 	ASSERT(mutex_owned(&vdc->lock));
2622 
2623 	/* ensure we have enough room to store max sized block */
2624 	ASSERT(maxphys <= VD_MAX_BLOCK_SIZE);
2625 
2626 	if ((vdc->initialized & VDC_DRING_INIT) == 0) {
2627 		DMSG(vdc, 0, "[%d] ldc_mem_dring_create\n", vdc->instance);
2628 		/*
2629 		 * Calculate the maximum block size we can transmit using one
2630 		 * Descriptor Ring entry from the attributes returned by the
2631 		 * vDisk server. This is subject to a minimum of 'maxphys'
2632 		 * as we do not have the capability to split requests over
2633 		 * multiple DRing entries.
2634 		 */
2635 		if ((vdc->max_xfer_sz * vdc->vdisk_bsize) < maxphys) {
2636 			DMSG(vdc, 0, "[%d] using minimum DRing size\n",
2637 			    vdc->instance);
2638 			vdc->dring_max_cookies = maxphys / PAGESIZE;
2639 		} else {
2640 			vdc->dring_max_cookies =
2641 			    (vdc->max_xfer_sz * vdc->vdisk_bsize) / PAGESIZE;
2642 		}
2643 		vdc->dring_entry_size = (sizeof (vd_dring_entry_t) +
2644 		    (sizeof (ldc_mem_cookie_t) *
2645 		    (vdc->dring_max_cookies - 1)));
2646 		vdc->dring_len = VD_DRING_LEN;
2647 
2648 		status = ldc_mem_dring_create(vdc->dring_len,
2649 		    vdc->dring_entry_size, &vdc->dring_hdl);
2650 		if ((vdc->dring_hdl == NULL) || (status != 0)) {
2651 			DMSG(vdc, 0, "[%d] Descriptor ring creation failed",
2652 			    vdc->instance);
2653 			return (status);
2654 		}
2655 		vdc->initialized |= VDC_DRING_INIT;
2656 	}
2657 
2658 	if ((vdc->initialized & VDC_DRING_BOUND) == 0) {
2659 		DMSG(vdc, 0, "[%d] ldc_mem_dring_bind\n", vdc->instance);
2660 		vdc->dring_cookie =
2661 		    kmem_zalloc(sizeof (ldc_mem_cookie_t), KM_SLEEP);
2662 
2663 		status = ldc_mem_dring_bind(vdc->curr_server->ldc_handle,
2664 		    vdc->dring_hdl,
2665 		    LDC_SHADOW_MAP|LDC_DIRECT_MAP, LDC_MEM_RW,
2666 		    &vdc->dring_cookie[0],
2667 		    &vdc->dring_cookie_count);
2668 		if (status != 0) {
2669 			DMSG(vdc, 0, "[%d] Failed to bind descriptor ring "
2670 			    "(%lx) to channel (%lx) status=%d\n",
2671 			    vdc->instance, vdc->dring_hdl,
2672 			    vdc->curr_server->ldc_handle, status);
2673 			return (status);
2674 		}
2675 		ASSERT(vdc->dring_cookie_count == 1);
2676 		vdc->initialized |= VDC_DRING_BOUND;
2677 	}
2678 
2679 	status = ldc_mem_dring_info(vdc->dring_hdl, &vdc->dring_mem_info);
2680 	if (status != 0) {
2681 		DMSG(vdc, 0,
2682 		    "[%d] Failed to get info for descriptor ring (%lx)\n",
2683 		    vdc->instance, vdc->dring_hdl);
2684 		return (status);
2685 	}
2686 
2687 	if ((vdc->initialized & VDC_DRING_LOCAL) == 0) {
2688 		DMSG(vdc, 0, "[%d] local dring\n", vdc->instance);
2689 
2690 		/* Allocate the local copy of this dring */
2691 		vdc->local_dring =
2692 		    kmem_zalloc(vdc->dring_len * sizeof (vdc_local_desc_t),
2693 		    KM_SLEEP);
2694 		vdc->initialized |= VDC_DRING_LOCAL;
2695 	}
2696 
2697 	/*
2698 	 * Mark all DRing entries as free and initialize the private
2699 	 * descriptor's memory handles. If any entry is initialized,
2700 	 * we need to free it later so we set the bit in 'initialized'
2701 	 * at the start.
2702 	 */
2703 	vdc->initialized |= VDC_DRING_ENTRY;
2704 	for (i = 0; i < vdc->dring_len; i++) {
2705 		dep = VDC_GET_DRING_ENTRY_PTR(vdc, i);
2706 		dep->hdr.dstate = VIO_DESC_FREE;
2707 
2708 		status = ldc_mem_alloc_handle(vdc->curr_server->ldc_handle,
2709 		    &vdc->local_dring[i].desc_mhdl);
2710 		if (status != 0) {
2711 			DMSG(vdc, 0, "![%d] Failed to alloc mem handle for"
2712 			    " descriptor %d", vdc->instance, i);
2713 			return (status);
2714 		}
2715 		vdc->local_dring[i].is_free = B_TRUE;
2716 		vdc->local_dring[i].dep = dep;
2717 	}
2718 
2719 	/* Initialize the starting index */
2720 	vdc->dring_curr_idx = 0;
2721 
2722 	return (status);
2723 }
2724 
2725 /*
2726  * Function:
2727  *	vdc_destroy_descriptor_ring()
2728  *
2729  * Description:
2730  *
2731  * Arguments:
2732  *	vdc	- soft state pointer for this instance of the device driver.
2733  *
2734  * Return Code:
2735  *	None
2736  */
2737 static void
2738 vdc_destroy_descriptor_ring(vdc_t *vdc)
2739 {
2740 	vdc_local_desc_t	*ldep = NULL;	/* Local Dring Entry Pointer */
2741 	ldc_mem_handle_t	mhdl = NULL;
2742 	ldc_mem_info_t		minfo;
2743 	int			status = -1;
2744 	int			i;	/* loop */
2745 
2746 	ASSERT(vdc != NULL);
2747 	ASSERT(mutex_owned(&vdc->lock));
2748 
2749 	DMSG(vdc, 0, "[%d] Entered\n", vdc->instance);
2750 
2751 	if (vdc->initialized & VDC_DRING_ENTRY) {
2752 		DMSG(vdc, 0,
2753 		    "[%d] Removing Local DRing entries\n", vdc->instance);
2754 		for (i = 0; i < vdc->dring_len; i++) {
2755 			ldep = &vdc->local_dring[i];
2756 			mhdl = ldep->desc_mhdl;
2757 
2758 			if (mhdl == NULL)
2759 				continue;
2760 
2761 			if ((status = ldc_mem_info(mhdl, &minfo)) != 0) {
2762 				DMSG(vdc, 0,
2763 				    "ldc_mem_info returned an error: %d\n",
2764 				    status);
2765 
2766 				/*
2767 				 * This must mean that the mem handle
2768 				 * is not valid. Clear it out so that
2769 				 * no one tries to use it.
2770 				 */
2771 				ldep->desc_mhdl = NULL;
2772 				continue;
2773 			}
2774 
2775 			if (minfo.status == LDC_BOUND) {
2776 				(void) ldc_mem_unbind_handle(mhdl);
2777 			}
2778 
2779 			(void) ldc_mem_free_handle(mhdl);
2780 
2781 			ldep->desc_mhdl = NULL;
2782 		}
2783 		vdc->initialized &= ~VDC_DRING_ENTRY;
2784 	}
2785 
2786 	if (vdc->initialized & VDC_DRING_LOCAL) {
2787 		DMSG(vdc, 0, "[%d] Freeing Local DRing\n", vdc->instance);
2788 		kmem_free(vdc->local_dring,
2789 		    vdc->dring_len * sizeof (vdc_local_desc_t));
2790 		vdc->initialized &= ~VDC_DRING_LOCAL;
2791 	}
2792 
2793 	if (vdc->initialized & VDC_DRING_BOUND) {
2794 		DMSG(vdc, 0, "[%d] Unbinding DRing\n", vdc->instance);
2795 		status = ldc_mem_dring_unbind(vdc->dring_hdl);
2796 		if (status == 0) {
2797 			vdc->initialized &= ~VDC_DRING_BOUND;
2798 		} else {
2799 			DMSG(vdc, 0, "[%d] Error %d unbinding DRing %lx",
2800 			    vdc->instance, status, vdc->dring_hdl);
2801 		}
2802 		kmem_free(vdc->dring_cookie, sizeof (ldc_mem_cookie_t));
2803 	}
2804 
2805 	if (vdc->initialized & VDC_DRING_INIT) {
2806 		DMSG(vdc, 0, "[%d] Destroying DRing\n", vdc->instance);
2807 		status = ldc_mem_dring_destroy(vdc->dring_hdl);
2808 		if (status == 0) {
2809 			vdc->dring_hdl = NULL;
2810 			bzero(&vdc->dring_mem_info, sizeof (ldc_mem_info_t));
2811 			vdc->initialized &= ~VDC_DRING_INIT;
2812 		} else {
2813 			DMSG(vdc, 0, "[%d] Error %d destroying DRing (%lx)",
2814 			    vdc->instance, status, vdc->dring_hdl);
2815 		}
2816 	}
2817 }
2818 
2819 /*
2820  * Function:
2821  *	vdc_map_to_shared_dring()
2822  *
2823  * Description:
2824  *	Copy contents of the local descriptor to the shared
2825  *	memory descriptor.
2826  *
2827  * Arguments:
2828  *	vdcp	- soft state pointer for this instance of the device driver.
2829  *	idx	- descriptor ring index
2830  *
2831  * Return Code:
2832  *	None
2833  */
2834 static int
2835 vdc_map_to_shared_dring(vdc_t *vdcp, int idx)
2836 {
2837 	vdc_local_desc_t	*ldep;
2838 	vd_dring_entry_t	*dep;
2839 	int			rv;
2840 
2841 	ldep = &(vdcp->local_dring[idx]);
2842 
2843 	/* for now leave in the old pop_mem_hdl stuff */
2844 	if (ldep->nbytes > 0) {
2845 		rv = vdc_populate_mem_hdl(vdcp, ldep);
2846 		if (rv) {
2847 			DMSG(vdcp, 0, "[%d] Cannot populate mem handle\n",
2848 			    vdcp->instance);
2849 			return (rv);
2850 		}
2851 	}
2852 
2853 	/*
2854 	 * fill in the data details into the DRing
2855 	 */
2856 	dep = ldep->dep;
2857 	ASSERT(dep != NULL);
2858 
2859 	dep->payload.req_id = VDC_GET_NEXT_REQ_ID(vdcp);
2860 	dep->payload.operation = ldep->operation;
2861 	dep->payload.addr = ldep->offset;
2862 	dep->payload.nbytes = ldep->nbytes;
2863 	dep->payload.status = (uint32_t)-1;	/* vds will set valid value */
2864 	dep->payload.slice = ldep->slice;
2865 	dep->hdr.dstate = VIO_DESC_READY;
2866 	dep->hdr.ack = 1;		/* request an ACK for every message */
2867 
2868 	return (0);
2869 }
2870 
2871 /*
2872  * Function:
2873  *	vdc_send_request
2874  *
2875  * Description:
2876  *	This routine writes the data to be transmitted to vds into the
2877  *	descriptor, notifies vds that the ring has been updated and
2878  *	then waits for the request to be processed.
2879  *
2880  * Arguments:
2881  *	vdcp	  - the soft state pointer
2882  *	operation - operation we want vds to perform (VD_OP_XXX)
2883  *	addr	  - address of data buf to be read/written.
2884  *	nbytes	  - number of bytes to read/write
2885  *	slice	  - the disk slice this request is for
2886  *	offset	  - relative disk offset
2887  *	bufp	  - buf of operation
2888  *	dir	  - direction of operation (READ/WRITE/BOTH)
2889  *
2890  * Return Codes:
2891  *	0
2892  *	ENXIO
2893  */
2894 static int
2895 vdc_send_request(vdc_t *vdcp, int operation, caddr_t addr,
2896     size_t nbytes, int slice, diskaddr_t offset, buf_t *bufp,
2897     vio_desc_direction_t dir, int flags)
2898 {
2899 	int	rv = 0;
2900 
2901 	ASSERT(vdcp != NULL);
2902 	ASSERT(slice == VD_SLICE_NONE || slice < V_NUMPAR);
2903 
2904 	mutex_enter(&vdcp->lock);
2905 
2906 	/*
2907 	 * If this is a block read/write operation we update the I/O statistics
2908 	 * to indicate that the request is being put on the waitq to be
2909 	 * serviced.
2910 	 *
2911 	 * We do it here (a common routine for both synchronous and strategy
2912 	 * calls) for performance reasons - we are already holding vdc->lock
2913 	 * so there is no extra locking overhead. We would have to explicitly
2914 	 * grab the 'lock' mutex to update the stats if we were to do this
2915 	 * higher up the stack in vdc_strategy() et. al.
2916 	 */
2917 	if ((operation == VD_OP_BREAD) || (operation == VD_OP_BWRITE)) {
2918 		DTRACE_IO1(start, buf_t *, bufp);
2919 		VD_KSTAT_WAITQ_ENTER(vdcp);
2920 	}
2921 
2922 	/*
2923 	 * If the request does not expect the state to be VDC_STATE_RUNNING
2924 	 * then we just try to populate the descriptor ring once.
2925 	 */
2926 	if (!(flags & VDC_OP_STATE_RUNNING)) {
2927 		rv = vdc_populate_descriptor(vdcp, operation, addr,
2928 		    nbytes, slice, offset, bufp, dir, flags);
2929 		goto done;
2930 	}
2931 
2932 	do {
2933 		while (vdcp->state != VDC_STATE_RUNNING) {
2934 
2935 			/* return error if detaching */
2936 			if (vdcp->state == VDC_STATE_DETACH) {
2937 				rv = ENXIO;
2938 				goto done;
2939 			}
2940 
2941 			/*
2942 			 * If we are panicking and the disk is not ready then
2943 			 * we can't send any request because we can't complete
2944 			 * the handshake now.
2945 			 */
2946 			if (ddi_in_panic()) {
2947 				rv = EIO;
2948 				goto done;
2949 			}
2950 
2951 			/*
2952 			 * If the state is faulted, notify that a new I/O is
2953 			 * being submitted to force the system to check if any
2954 			 * server has recovered.
2955 			 */
2956 			if (vdcp->state == VDC_STATE_FAILED) {
2957 				vdcp->io_pending = B_TRUE;
2958 				cv_signal(&vdcp->io_pending_cv);
2959 			}
2960 
2961 			cv_wait(&vdcp->running_cv, &vdcp->lock);
2962 
2963 			/* if service is still faulted then fail the request */
2964 			if (vdcp->state == VDC_STATE_FAILED) {
2965 				rv = EIO;
2966 				goto done;
2967 			}
2968 		}
2969 
2970 	} while (vdc_populate_descriptor(vdcp, operation, addr,
2971 	    nbytes, slice, offset, bufp, dir, flags));
2972 
2973 done:
2974 	/*
2975 	 * If this is a block read/write we update the I/O statistics kstat
2976 	 * to indicate that this request has been placed on the queue for
2977 	 * processing (i.e sent to the vDisk server) - iostat(1M) will
2978 	 * report the time waiting for the vDisk server under the %b column
2979 	 * In the case of an error we simply take it off the wait queue.
2980 	 */
2981 	if ((operation == VD_OP_BREAD) || (operation == VD_OP_BWRITE)) {
2982 		if (rv == 0) {
2983 			VD_KSTAT_WAITQ_TO_RUNQ(vdcp);
2984 			DTRACE_PROBE1(send, buf_t *, bufp);
2985 		} else {
2986 			VD_UPDATE_ERR_STATS(vdcp, vd_transerrs);
2987 			VD_KSTAT_WAITQ_EXIT(vdcp);
2988 			DTRACE_IO1(done, buf_t *, bufp);
2989 		}
2990 	}
2991 
2992 	mutex_exit(&vdcp->lock);
2993 
2994 	return (rv);
2995 }
2996 
2997 
2998 /*
2999  * Function:
3000  *	vdc_populate_descriptor
3001  *
3002  * Description:
3003  *	This routine writes the data to be transmitted to vds into the
3004  *	descriptor, notifies vds that the ring has been updated and
3005  *	then waits for the request to be processed.
3006  *
3007  * Arguments:
3008  *	vdcp	  - the soft state pointer
3009  *	operation - operation we want vds to perform (VD_OP_XXX)
3010  *	addr	  - address of data buf to be read/written.
3011  *	nbytes	  - number of bytes to read/write
3012  *	slice	  - the disk slice this request is for
3013  *	offset	  - relative disk offset
3014  *	bufp	  - buf of operation
3015  *	dir	  - direction of operation (READ/WRITE/BOTH)
3016  *
3017  * Return Codes:
3018  *	0
3019  *	EAGAIN
3020  *	ECONNRESET
3021  *	ENXIO
3022  */
3023 static int
3024 vdc_populate_descriptor(vdc_t *vdcp, int operation, caddr_t addr,
3025     size_t nbytes, int slice, diskaddr_t offset,
3026     buf_t *bufp, vio_desc_direction_t dir, int flags)
3027 {
3028 	vdc_local_desc_t	*local_dep = NULL; /* Local Dring Pointer */
3029 	int			idx;		/* Index of DRing entry used */
3030 	int			next_idx;
3031 	vio_dring_msg_t		dmsg;
3032 	size_t			msglen;
3033 	int			rv;
3034 
3035 	ASSERT(MUTEX_HELD(&vdcp->lock));
3036 	vdcp->threads_pending++;
3037 loop:
3038 	DMSG(vdcp, 2, ": dring_curr_idx = %d\n", vdcp->dring_curr_idx);
3039 
3040 	/* Get next available D-Ring entry */
3041 	idx = vdcp->dring_curr_idx;
3042 	local_dep = &(vdcp->local_dring[idx]);
3043 
3044 	if (!local_dep->is_free) {
3045 		DMSG(vdcp, 2, "[%d]: dring full - waiting for space\n",
3046 		    vdcp->instance);
3047 		cv_wait(&vdcp->dring_free_cv, &vdcp->lock);
3048 		if (vdcp->state == VDC_STATE_RUNNING ||
3049 		    vdcp->state == VDC_STATE_HANDLE_PENDING) {
3050 			goto loop;
3051 		}
3052 		vdcp->threads_pending--;
3053 		return (ECONNRESET);
3054 	}
3055 
3056 	next_idx = idx + 1;
3057 	if (next_idx >= vdcp->dring_len)
3058 		next_idx = 0;
3059 	vdcp->dring_curr_idx = next_idx;
3060 
3061 	ASSERT(local_dep->is_free);
3062 
3063 	local_dep->operation = operation;
3064 	local_dep->addr = addr;
3065 	local_dep->nbytes = nbytes;
3066 	local_dep->slice = slice;
3067 	local_dep->offset = offset;
3068 	local_dep->buf = bufp;
3069 	local_dep->dir = dir;
3070 	local_dep->flags = flags;
3071 
3072 	local_dep->is_free = B_FALSE;
3073 
3074 	rv = vdc_map_to_shared_dring(vdcp, idx);
3075 	if (rv) {
3076 		DMSG(vdcp, 0, "[%d]: cannot bind memory - waiting ..\n",
3077 		    vdcp->instance);
3078 		/* free the descriptor */
3079 		local_dep->is_free = B_TRUE;
3080 		vdcp->dring_curr_idx = idx;
3081 		cv_wait(&vdcp->membind_cv, &vdcp->lock);
3082 		if (vdcp->state == VDC_STATE_RUNNING ||
3083 		    vdcp->state == VDC_STATE_HANDLE_PENDING) {
3084 			goto loop;
3085 		}
3086 		vdcp->threads_pending--;
3087 		return (ECONNRESET);
3088 	}
3089 
3090 	/*
3091 	 * Send a msg with the DRing details to vds
3092 	 */
3093 	VIO_INIT_DRING_DATA_TAG(dmsg);
3094 	VDC_INIT_DRING_DATA_MSG_IDS(dmsg, vdcp);
3095 	dmsg.dring_ident = vdcp->dring_ident;
3096 	dmsg.start_idx = idx;
3097 	dmsg.end_idx = idx;
3098 	vdcp->seq_num++;
3099 
3100 	DTRACE_PROBE2(populate, int, vdcp->instance,
3101 	    vdc_local_desc_t *, local_dep);
3102 	DMSG(vdcp, 2, "ident=0x%lx, st=%u, end=%u, seq=%ld\n",
3103 	    vdcp->dring_ident, dmsg.start_idx, dmsg.end_idx, dmsg.seq_num);
3104 
3105 	/*
3106 	 * note we're still holding the lock here to
3107 	 * make sure the message goes out in order !!!...
3108 	 */
3109 	msglen = sizeof (dmsg);
3110 	rv = vdc_send(vdcp, (caddr_t)&dmsg, &msglen);
3111 	switch (rv) {
3112 	case ECONNRESET:
3113 		/*
3114 		 * vdc_send initiates the reset on failure.
3115 		 * Since the transaction has already been put
3116 		 * on the local dring, it will automatically get
3117 		 * retried when the channel is reset. Given that,
3118 		 * it is ok to just return success even though the
3119 		 * send failed.
3120 		 */
3121 		rv = 0;
3122 		break;
3123 
3124 	case 0: /* EOK */
3125 		DMSG(vdcp, 1, "sent via LDC: rv=%d\n", rv);
3126 		break;
3127 
3128 	default:
3129 		goto cleanup_and_exit;
3130 	}
3131 
3132 	vdcp->threads_pending--;
3133 	return (rv);
3134 
3135 cleanup_and_exit:
3136 	DMSG(vdcp, 0, "unexpected error, rv=%d\n", rv);
3137 	return (ENXIO);
3138 }
3139 
3140 /*
3141  * Function:
3142  *	vdc_do_op
3143  *
3144  * Description:
3145  * 	Wrapper around vdc_submit_request(). Each request is associated with a
3146  *	buf structure. If a buf structure is provided (bufp != NULL) then the
3147  *	request will be submitted with that buf, and the caller can wait for
3148  *	completion of the request with biowait(). If a buf structure is not
3149  *	provided (bufp == NULL) then a buf structure is created and the function
3150  *	waits for the completion of the request.
3151  *
3152  *	If the flag VD_OP_STATE_RUNNING is set then vdc_submit_request() will
3153  *	submit the request only when the vdisk is in state VD_STATE_RUNNING.
3154  *	If the vdisk is not in that state then the vdc_submit_request() will
3155  *	wait for that state to be reached. After the request is submitted, the
3156  *	reply will be processed asynchronously by the vdc_process_msg_thread()
3157  *	thread.
3158  *
3159  *	If the flag VD_OP_STATE_RUNNING is not set then vdc_submit_request()
3160  *	submit the request whatever the state of the vdisk is. Then vdc_do_op()
3161  *	will wait for a reply message, process the reply and complete the
3162  *	request.
3163  *
3164  * Arguments:
3165  *	vdc	- the soft state pointer
3166  *	op	- operation we want vds to perform (VD_OP_XXX)
3167  *	addr	- address of data buf to be read/written.
3168  *	nbytes	- number of bytes to read/write
3169  *	slice	- the disk slice this request is for
3170  *	offset	- relative disk offset
3171  *	bufp	- buf structure associated with the request (can be NULL).
3172  *	dir	- direction of operation (READ/WRITE/BOTH)
3173  *	flags	- flags for the request.
3174  *
3175  * Return Codes:
3176  *	0	- the request has been succesfully submitted and completed.
3177  *	!= 0	- the request has failed. In that case, if a buf structure
3178  *		  was provided (bufp != NULL) then the B_ERROR flag is set
3179  *		  and the b_error field of the buf structure is set to EIO.
3180  */
3181 static int
3182 vdc_do_op(vdc_t *vdc, int op, caddr_t addr, size_t nbytes, int slice,
3183     diskaddr_t offset, struct buf *bufp, vio_desc_direction_t dir, int flags)
3184 {
3185 	vio_msg_t vio_msg;
3186 	struct buf buf;
3187 	int rv;
3188 
3189 	if (bufp == NULL) {
3190 		/*
3191 		 * We use buf just as a convenient way to get a notification
3192 		 * that the request is completed, so we initialize buf to the
3193 		 * minimum we need.
3194 		 */
3195 		bioinit(&buf);
3196 		buf.b_bcount = nbytes;
3197 		buf.b_flags = B_BUSY;
3198 		bufp = &buf;
3199 	}
3200 
3201 	rv = vdc_send_request(vdc, op, addr, nbytes, slice, offset, bufp,
3202 	    dir, flags);
3203 
3204 	if (rv != 0)
3205 		goto done;
3206 
3207 	/*
3208 	 * If the request should be done in VDC_STATE_RUNNING state then the
3209 	 * reply will be received and processed by vdc_process_msg_thread()
3210 	 * and we just have to handle the panic case. Otherwise we have to
3211 	 * wait for the reply message and process it.
3212 	 */
3213 	if (flags & VDC_OP_STATE_RUNNING) {
3214 
3215 		if (ddi_in_panic()) {
3216 			rv = vdc_drain_response(vdc, bufp);
3217 			goto done;
3218 		}
3219 
3220 	} else {
3221 		/* wait for the response message */
3222 		rv = vdc_wait_for_response(vdc, &vio_msg);
3223 		if (rv) {
3224 			/*
3225 			 * If this is a block read/write we update the I/O
3226 			 * statistics kstat to take it off the run queue.
3227 			 */
3228 			mutex_enter(&vdc->lock);
3229 			if (op == VD_OP_BREAD || op == VD_OP_BWRITE) {
3230 				VD_UPDATE_ERR_STATS(vdc, vd_transerrs);
3231 				VD_KSTAT_RUNQ_EXIT(vdc);
3232 				DTRACE_IO1(done, buf_t *, bufp);
3233 			}
3234 			mutex_exit(&vdc->lock);
3235 			goto done;
3236 		}
3237 
3238 		rv = vdc_process_data_msg(vdc, &vio_msg);
3239 		if (rv)
3240 			goto done;
3241 	}
3242 
3243 	if (bufp == &buf)
3244 		rv = biowait(bufp);
3245 
3246 done:
3247 	if (bufp == &buf) {
3248 		biofini(bufp);
3249 	} else if (rv != 0) {
3250 		bioerror(bufp, EIO);
3251 		biodone(bufp);
3252 	}
3253 
3254 	return (rv);
3255 }
3256 
3257 /*
3258  * Function:
3259  *	vdc_do_sync_op
3260  *
3261  * Description:
3262  * 	Wrapper around vdc_do_op that serializes requests.
3263  *
3264  * Arguments:
3265  *	vdcp	  - the soft state pointer
3266  *	operation - operation we want vds to perform (VD_OP_XXX)
3267  *	addr	  - address of data buf to be read/written.
3268  *	nbytes	  - number of bytes to read/write
3269  *	slice	  - the disk slice this request is for
3270  *	offset	  - relative disk offset
3271  *	dir	  - direction of operation (READ/WRITE/BOTH)
3272  *	rconflict - check for reservation conflict in case of failure
3273  *
3274  * rconflict should be set to B_TRUE by most callers. Callers invoking the
3275  * VD_OP_SCSICMD operation can set rconflict to B_FALSE if they check the
3276  * result of a successful operation with vdc_scsi_status().
3277  *
3278  * Return Codes:
3279  *	0
3280  *	EAGAIN
3281  *	EFAULT
3282  *	ENXIO
3283  *	EIO
3284  */
3285 static int
3286 vdc_do_sync_op(vdc_t *vdcp, int operation, caddr_t addr, size_t nbytes,
3287     int slice, diskaddr_t offset, vio_desc_direction_t dir, boolean_t rconflict)
3288 {
3289 	int status;
3290 	int flags = VDC_OP_NORMAL;
3291 
3292 	/*
3293 	 * Grab the lock, if blocked wait until the server
3294 	 * response causes us to wake up again.
3295 	 */
3296 	mutex_enter(&vdcp->lock);
3297 	vdcp->sync_op_cnt++;
3298 	while (vdcp->sync_op_blocked && vdcp->state != VDC_STATE_DETACH) {
3299 		if (ddi_in_panic()) {
3300 			/* don't block if we are panicking */
3301 			vdcp->sync_op_cnt--;
3302 			mutex_exit(&vdcp->lock);
3303 			return (EIO);
3304 		} else {
3305 			cv_wait(&vdcp->sync_blocked_cv, &vdcp->lock);
3306 		}
3307 	}
3308 
3309 	if (vdcp->state == VDC_STATE_DETACH) {
3310 		cv_broadcast(&vdcp->sync_blocked_cv);
3311 		vdcp->sync_op_cnt--;
3312 		mutex_exit(&vdcp->lock);
3313 		return (ENXIO);
3314 	}
3315 
3316 	/* now block anyone other thread entering after us */
3317 	vdcp->sync_op_blocked = B_TRUE;
3318 
3319 	mutex_exit(&vdcp->lock);
3320 
3321 	if (!rconflict)
3322 		flags &= ~VDC_OP_ERRCHK_CONFLICT;
3323 
3324 	status = vdc_do_op(vdcp, operation, addr, nbytes, slice, offset,
3325 	    NULL, dir, flags);
3326 
3327 	mutex_enter(&vdcp->lock);
3328 
3329 	DMSG(vdcp, 2, ": operation returned %d\n", status);
3330 
3331 	if (vdcp->state == VDC_STATE_DETACH) {
3332 		status = ENXIO;
3333 	}
3334 
3335 	vdcp->sync_op_blocked = B_FALSE;
3336 	vdcp->sync_op_cnt--;
3337 
3338 	/* signal the next waiting thread */
3339 	cv_signal(&vdcp->sync_blocked_cv);
3340 
3341 	mutex_exit(&vdcp->lock);
3342 
3343 	return (status);
3344 }
3345 
3346 
3347 /*
3348  * Function:
3349  *	vdc_drain_response()
3350  *
3351  * Description:
3352  * 	When a guest is panicking, the completion of requests needs to be
3353  * 	handled differently because interrupts are disabled and vdc
3354  * 	will not get messages. We have to poll for the messages instead.
3355  *
3356  *	Note: since we are panicking we don't implement	the io:::done
3357  *	DTrace probe or update the I/O statistics kstats.
3358  *
3359  * Arguments:
3360  *	vdc	- soft state pointer for this instance of the device driver.
3361  *	buf	- if buf is NULL then we drain all responses, otherwise we
3362  *		  poll until we receive a ACK/NACK for the specific I/O
3363  *		  described by buf.
3364  *
3365  * Return Code:
3366  *	0	- Success. If we were expecting a response to a particular
3367  *		  request then this means that a response has been received.
3368  */
3369 static int
3370 vdc_drain_response(vdc_t *vdc, struct buf *buf)
3371 {
3372 	int 			rv, idx, retries;
3373 	size_t			msglen;
3374 	vdc_local_desc_t 	*ldep = NULL;	/* Local Dring Entry Pointer */
3375 	vio_dring_msg_t		dmsg;
3376 	struct buf		*mbuf;
3377 	boolean_t		ack;
3378 
3379 	mutex_enter(&vdc->lock);
3380 
3381 	retries = 0;
3382 	for (;;) {
3383 		msglen = sizeof (dmsg);
3384 		rv = ldc_read(vdc->curr_server->ldc_handle, (caddr_t)&dmsg,
3385 		    &msglen);
3386 		if (rv) {
3387 			rv = EINVAL;
3388 			break;
3389 		}
3390 
3391 		/*
3392 		 * if there are no packets wait and check again
3393 		 */
3394 		if ((rv == 0) && (msglen == 0)) {
3395 			if (retries++ > vdc_dump_retries) {
3396 				rv = EAGAIN;
3397 				break;
3398 			}
3399 
3400 			drv_usecwait(vdc_usec_timeout_dump);
3401 			continue;
3402 		}
3403 
3404 		/*
3405 		 * Ignore all messages that are not ACKs/NACKs to
3406 		 * DRing requests.
3407 		 */
3408 		if ((dmsg.tag.vio_msgtype != VIO_TYPE_DATA) ||
3409 		    (dmsg.tag.vio_subtype_env != VIO_DRING_DATA)) {
3410 			DMSG(vdc, 0, "discard pkt: type=%d sub=%d env=%d\n",
3411 			    dmsg.tag.vio_msgtype,
3412 			    dmsg.tag.vio_subtype,
3413 			    dmsg.tag.vio_subtype_env);
3414 			continue;
3415 		}
3416 
3417 		/*
3418 		 * Record if the packet was ACK'ed or not. If the packet was not
3419 		 * ACK'ed then we will just mark the request as failed; we don't
3420 		 * want to reset the connection at this point.
3421 		 */
3422 		switch (dmsg.tag.vio_subtype) {
3423 		case VIO_SUBTYPE_ACK:
3424 			ack = B_TRUE;
3425 			break;
3426 		case VIO_SUBTYPE_NACK:
3427 			ack = B_FALSE;
3428 			break;
3429 		default:
3430 			continue;
3431 		}
3432 
3433 		idx = dmsg.start_idx;
3434 		if (idx >= vdc->dring_len) {
3435 			DMSG(vdc, 0, "[%d] Bogus ack data : start %d\n",
3436 			    vdc->instance, idx);
3437 			continue;
3438 		}
3439 		ldep = &vdc->local_dring[idx];
3440 		if (ldep->dep->hdr.dstate != VIO_DESC_DONE) {
3441 			DMSG(vdc, 0, "[%d] Entry @ %d - state !DONE %d\n",
3442 			    vdc->instance, idx, ldep->dep->hdr.dstate);
3443 			continue;
3444 		}
3445 
3446 		mbuf = ldep->buf;
3447 		ASSERT(mbuf != NULL);
3448 		mbuf->b_resid = mbuf->b_bcount - ldep->dep->payload.nbytes;
3449 		bioerror(mbuf, ack ? ldep->dep->payload.status : EIO);
3450 		biodone(mbuf);
3451 
3452 		rv = vdc_depopulate_descriptor(vdc, idx);
3453 		if (buf != NULL && buf == mbuf) {
3454 			rv = 0;
3455 			goto done;
3456 		}
3457 
3458 		/* if this is the last descriptor - break out of loop */
3459 		if ((idx + 1) % vdc->dring_len == vdc->dring_curr_idx) {
3460 			/*
3461 			 * If we were expecting a response for a particular
3462 			 * request then we return with an error otherwise we
3463 			 * have successfully completed the drain.
3464 			 */
3465 			rv = (buf != NULL)? ESRCH: 0;
3466 			break;
3467 		}
3468 	}
3469 
3470 done:
3471 	mutex_exit(&vdc->lock);
3472 	DMSG(vdc, 0, "End idx=%d\n", idx);
3473 
3474 	return (rv);
3475 }
3476 
3477 
3478 /*
3479  * Function:
3480  *	vdc_depopulate_descriptor()
3481  *
3482  * Description:
3483  *
3484  * Arguments:
3485  *	vdc	- soft state pointer for this instance of the device driver.
3486  *	idx	- Index of the Descriptor Ring entry being modified
3487  *
3488  * Return Code:
3489  *	0	- Success
3490  */
3491 static int
3492 vdc_depopulate_descriptor(vdc_t *vdc, uint_t idx)
3493 {
3494 	vd_dring_entry_t *dep = NULL;		/* Dring Entry Pointer */
3495 	vdc_local_desc_t *ldep = NULL;		/* Local Dring Entry Pointer */
3496 	int		status = ENXIO;
3497 	int		rv = 0;
3498 
3499 	ASSERT(vdc != NULL);
3500 	ASSERT(idx < vdc->dring_len);
3501 	ldep = &vdc->local_dring[idx];
3502 	ASSERT(ldep != NULL);
3503 	ASSERT(MUTEX_HELD(&vdc->lock));
3504 
3505 	DTRACE_PROBE2(depopulate, int, vdc->instance, vdc_local_desc_t *, ldep);
3506 	DMSG(vdc, 2, ": idx = %d\n", idx);
3507 
3508 	dep = ldep->dep;
3509 	ASSERT(dep != NULL);
3510 	ASSERT((dep->hdr.dstate == VIO_DESC_DONE) ||
3511 	    (dep->payload.status == ECANCELED));
3512 
3513 	VDC_MARK_DRING_ENTRY_FREE(vdc, idx);
3514 
3515 	ldep->is_free = B_TRUE;
3516 	status = dep->payload.status;
3517 	DMSG(vdc, 2, ": is_free = %d : status = %d\n", ldep->is_free, status);
3518 
3519 	/*
3520 	 * If no buffers were used to transfer information to the server when
3521 	 * populating the descriptor then no memory handles need to be unbound
3522 	 * and we can return now.
3523 	 */
3524 	if (ldep->nbytes == 0) {
3525 		cv_signal(&vdc->dring_free_cv);
3526 		return (status);
3527 	}
3528 
3529 	/*
3530 	 * If the upper layer passed in a misaligned address we copied the
3531 	 * data into an aligned buffer before sending it to LDC - we now
3532 	 * copy it back to the original buffer.
3533 	 */
3534 	if (ldep->align_addr) {
3535 		ASSERT(ldep->addr != NULL);
3536 
3537 		if (dep->payload.nbytes > 0)
3538 			bcopy(ldep->align_addr, ldep->addr,
3539 			    dep->payload.nbytes);
3540 		kmem_free(ldep->align_addr,
3541 		    sizeof (caddr_t) * P2ROUNDUP(ldep->nbytes, 8));
3542 		ldep->align_addr = NULL;
3543 	}
3544 
3545 	rv = ldc_mem_unbind_handle(ldep->desc_mhdl);
3546 	if (rv != 0) {
3547 		DMSG(vdc, 0, "?[%d] unbind mhdl 0x%lx @ idx %d failed (%d)",
3548 		    vdc->instance, ldep->desc_mhdl, idx, rv);
3549 		/*
3550 		 * The error returned by the vDisk server is more informative
3551 		 * and thus has a higher priority but if it isn't set we ensure
3552 		 * that this function returns an error.
3553 		 */
3554 		if (status == 0)
3555 			status = EINVAL;
3556 	}
3557 
3558 	cv_signal(&vdc->membind_cv);
3559 	cv_signal(&vdc->dring_free_cv);
3560 
3561 	return (status);
3562 }
3563 
3564 /*
3565  * Function:
3566  *	vdc_populate_mem_hdl()
3567  *
3568  * Description:
3569  *
3570  * Arguments:
3571  *	vdc	- soft state pointer for this instance of the device driver.
3572  *	idx	- Index of the Descriptor Ring entry being modified
3573  *	addr	- virtual address being mapped in
3574  *	nybtes	- number of bytes in 'addr'
3575  *	operation - the vDisk operation being performed (VD_OP_xxx)
3576  *
3577  * Return Code:
3578  *	0	- Success
3579  */
3580 static int
3581 vdc_populate_mem_hdl(vdc_t *vdcp, vdc_local_desc_t *ldep)
3582 {
3583 	vd_dring_entry_t	*dep = NULL;
3584 	ldc_mem_handle_t	mhdl;
3585 	caddr_t			vaddr;
3586 	size_t			nbytes;
3587 	uint8_t			perm = LDC_MEM_RW;
3588 	uint8_t			maptype;
3589 	int			rv = 0;
3590 	int			i;
3591 
3592 	ASSERT(vdcp != NULL);
3593 
3594 	dep = ldep->dep;
3595 	mhdl = ldep->desc_mhdl;
3596 
3597 	switch (ldep->dir) {
3598 	case VIO_read_dir:
3599 		perm = LDC_MEM_W;
3600 		break;
3601 
3602 	case VIO_write_dir:
3603 		perm = LDC_MEM_R;
3604 		break;
3605 
3606 	case VIO_both_dir:
3607 		perm = LDC_MEM_RW;
3608 		break;
3609 
3610 	default:
3611 		ASSERT(0);	/* catch bad programming in vdc */
3612 	}
3613 
3614 	/*
3615 	 * LDC expects any addresses passed in to be 8-byte aligned. We need
3616 	 * to copy the contents of any misaligned buffers to a newly allocated
3617 	 * buffer and bind it instead (and copy the the contents back to the
3618 	 * original buffer passed in when depopulating the descriptor)
3619 	 */
3620 	vaddr = ldep->addr;
3621 	nbytes = ldep->nbytes;
3622 	if (((uint64_t)vaddr & 0x7) != 0) {
3623 		ASSERT(ldep->align_addr == NULL);
3624 		ldep->align_addr =
3625 		    kmem_alloc(sizeof (caddr_t) *
3626 		    P2ROUNDUP(nbytes, 8), KM_SLEEP);
3627 		DMSG(vdcp, 0, "[%d] Misaligned address %p reallocating "
3628 		    "(buf=%p nb=%ld op=%d)\n",
3629 		    vdcp->instance, (void *)vaddr, (void *)ldep->align_addr,
3630 		    nbytes, ldep->operation);
3631 		if (perm != LDC_MEM_W)
3632 			bcopy(vaddr, ldep->align_addr, nbytes);
3633 		vaddr = ldep->align_addr;
3634 	}
3635 
3636 	maptype = LDC_IO_MAP|LDC_SHADOW_MAP|LDC_DIRECT_MAP;
3637 	rv = ldc_mem_bind_handle(mhdl, vaddr, P2ROUNDUP(nbytes, 8),
3638 	    maptype, perm, &dep->payload.cookie[0], &dep->payload.ncookies);
3639 	DMSG(vdcp, 2, "[%d] bound mem handle; ncookies=%d\n",
3640 	    vdcp->instance, dep->payload.ncookies);
3641 	if (rv != 0) {
3642 		DMSG(vdcp, 0, "[%d] Failed to bind LDC memory handle "
3643 		    "(mhdl=%p, buf=%p, err=%d)\n",
3644 		    vdcp->instance, (void *)mhdl, (void *)vaddr, rv);
3645 		if (ldep->align_addr) {
3646 			kmem_free(ldep->align_addr,
3647 			    sizeof (caddr_t) * P2ROUNDUP(nbytes, 8));
3648 			ldep->align_addr = NULL;
3649 		}
3650 		return (EAGAIN);
3651 	}
3652 
3653 	/*
3654 	 * Get the other cookies (if any).
3655 	 */
3656 	for (i = 1; i < dep->payload.ncookies; i++) {
3657 		rv = ldc_mem_nextcookie(mhdl, &dep->payload.cookie[i]);
3658 		if (rv != 0) {
3659 			(void) ldc_mem_unbind_handle(mhdl);
3660 			DMSG(vdcp, 0, "?[%d] Failed to get next cookie "
3661 			    "(mhdl=%lx cnum=%d), err=%d",
3662 			    vdcp->instance, mhdl, i, rv);
3663 			if (ldep->align_addr) {
3664 				kmem_free(ldep->align_addr,
3665 				    sizeof (caddr_t) * ldep->nbytes);
3666 				ldep->align_addr = NULL;
3667 			}
3668 			return (EAGAIN);
3669 		}
3670 	}
3671 
3672 	return (rv);
3673 }
3674 
3675 /*
3676  * Interrupt handlers for messages from LDC
3677  */
3678 
3679 /*
3680  * Function:
3681  *	vdc_handle_cb()
3682  *
3683  * Description:
3684  *
3685  * Arguments:
3686  *	event	- Type of event (LDC_EVT_xxx) that triggered the callback
3687  *	arg	- soft state pointer for this instance of the device driver.
3688  *
3689  * Return Code:
3690  *	0	- Success
3691  */
3692 static uint_t
3693 vdc_handle_cb(uint64_t event, caddr_t arg)
3694 {
3695 	ldc_status_t	ldc_state;
3696 	int		rv = 0;
3697 	vdc_server_t	*srvr = (vdc_server_t *)(void *)arg;
3698 	vdc_t		*vdc = srvr->vdcp;
3699 
3700 	ASSERT(vdc != NULL);
3701 
3702 	DMSG(vdc, 1, "evt=%lx seqID=%ld\n", event, vdc->seq_num);
3703 
3704 	/* If callback is not for the current server, ignore it */
3705 	mutex_enter(&vdc->lock);
3706 
3707 	if (vdc->curr_server != srvr) {
3708 		DMSG(vdc, 0, "[%d] Ignoring event 0x%lx for port@%ld\n",
3709 		    vdc->instance, event, srvr->id);
3710 		mutex_exit(&vdc->lock);
3711 		return (LDC_SUCCESS);
3712 	}
3713 
3714 	/*
3715 	 * Depending on the type of event that triggered this callback,
3716 	 * we modify the handshake state or read the data.
3717 	 *
3718 	 * NOTE: not done as a switch() as event could be triggered by
3719 	 * a state change and a read request. Also the ordering	of the
3720 	 * check for the event types is deliberate.
3721 	 */
3722 	if (event & LDC_EVT_UP) {
3723 		DMSG(vdc, 0, "[%d] Received LDC_EVT_UP\n", vdc->instance);
3724 
3725 		/* get LDC state */
3726 		rv = ldc_status(srvr->ldc_handle, &ldc_state);
3727 		if (rv != 0) {
3728 			DMSG(vdc, 0, "[%d] Couldn't get LDC status %d",
3729 			    vdc->instance, rv);
3730 			mutex_exit(&vdc->lock);
3731 			return (LDC_SUCCESS);
3732 		}
3733 		if (srvr->ldc_state != LDC_UP &&
3734 		    ldc_state == LDC_UP) {
3735 			/*
3736 			 * Reset the transaction sequence numbers when
3737 			 * LDC comes up. We then kick off the handshake
3738 			 * negotiation with the vDisk server.
3739 			 */
3740 			vdc->seq_num = 1;
3741 			vdc->seq_num_reply = 0;
3742 			vdc->io_pending = B_TRUE;
3743 			srvr->ldc_state = ldc_state;
3744 			cv_signal(&vdc->initwait_cv);
3745 			cv_signal(&vdc->io_pending_cv);
3746 		}
3747 	}
3748 
3749 	if (event & LDC_EVT_READ) {
3750 		DMSG(vdc, 1, "[%d] Received LDC_EVT_READ\n", vdc->instance);
3751 		mutex_enter(&vdc->read_lock);
3752 		cv_signal(&vdc->read_cv);
3753 		vdc->read_state = VDC_READ_PENDING;
3754 		mutex_exit(&vdc->read_lock);
3755 		mutex_exit(&vdc->lock);
3756 
3757 		/* that's all we have to do - no need to handle DOWN/RESET */
3758 		return (LDC_SUCCESS);
3759 	}
3760 
3761 	if (event & (LDC_EVT_RESET|LDC_EVT_DOWN)) {
3762 
3763 		DMSG(vdc, 0, "[%d] Received LDC RESET event\n", vdc->instance);
3764 
3765 		/*
3766 		 * Need to wake up any readers so they will
3767 		 * detect that a reset has occurred.
3768 		 */
3769 		mutex_enter(&vdc->read_lock);
3770 		if ((vdc->read_state == VDC_READ_WAITING) ||
3771 		    (vdc->read_state == VDC_READ_RESET))
3772 			cv_signal(&vdc->read_cv);
3773 		vdc->read_state = VDC_READ_RESET;
3774 		mutex_exit(&vdc->read_lock);
3775 
3776 		/* wake up any threads waiting for connection to come up */
3777 		if (vdc->state == VDC_STATE_INIT_WAITING) {
3778 			vdc->state = VDC_STATE_RESETTING;
3779 			cv_signal(&vdc->initwait_cv);
3780 		} else if (vdc->state == VDC_STATE_FAILED) {
3781 			vdc->io_pending = B_TRUE;
3782 			cv_signal(&vdc->io_pending_cv);
3783 		}
3784 
3785 	}
3786 
3787 	mutex_exit(&vdc->lock);
3788 
3789 	if (event & ~(LDC_EVT_UP | LDC_EVT_RESET | LDC_EVT_DOWN | LDC_EVT_READ))
3790 		DMSG(vdc, 0, "![%d] Unexpected LDC event (%lx) received",
3791 		    vdc->instance, event);
3792 
3793 	return (LDC_SUCCESS);
3794 }
3795 
3796 /*
3797  * Function:
3798  *	vdc_wait_for_response()
3799  *
3800  * Description:
3801  *	Block waiting for a response from the server. If there is
3802  *	no data the thread block on the read_cv that is signalled
3803  *	by the callback when an EVT_READ occurs.
3804  *
3805  * Arguments:
3806  *	vdcp	- soft state pointer for this instance of the device driver.
3807  *
3808  * Return Code:
3809  *	0	- Success
3810  */
3811 static int
3812 vdc_wait_for_response(vdc_t *vdcp, vio_msg_t *msgp)
3813 {
3814 	size_t		nbytes = sizeof (*msgp);
3815 	int		status;
3816 
3817 	ASSERT(vdcp != NULL);
3818 
3819 	DMSG(vdcp, 1, "[%d] Entered\n", vdcp->instance);
3820 
3821 	status = vdc_recv(vdcp, msgp, &nbytes);
3822 	DMSG(vdcp, 3, "vdc_read() done.. status=0x%x size=0x%x\n",
3823 	    status, (int)nbytes);
3824 	if (status) {
3825 		DMSG(vdcp, 0, "?[%d] Error %d reading LDC msg\n",
3826 		    vdcp->instance, status);
3827 		return (status);
3828 	}
3829 
3830 	if (nbytes < sizeof (vio_msg_tag_t)) {
3831 		DMSG(vdcp, 0, "?[%d] Expect %lu bytes; recv'd %lu\n",
3832 		    vdcp->instance, sizeof (vio_msg_tag_t), nbytes);
3833 		return (ENOMSG);
3834 	}
3835 
3836 	DMSG(vdcp, 2, "[%d] (%x/%x/%x)\n", vdcp->instance,
3837 	    msgp->tag.vio_msgtype,
3838 	    msgp->tag.vio_subtype,
3839 	    msgp->tag.vio_subtype_env);
3840 
3841 	/*
3842 	 * Verify the Session ID of the message
3843 	 *
3844 	 * Every message after the Version has been negotiated should
3845 	 * have the correct session ID set.
3846 	 */
3847 	if ((msgp->tag.vio_sid != vdcp->session_id) &&
3848 	    (msgp->tag.vio_subtype_env != VIO_VER_INFO)) {
3849 		DMSG(vdcp, 0, "[%d] Invalid SID: received 0x%x, "
3850 		    "expected 0x%lx [seq num %lx @ %d]",
3851 		    vdcp->instance, msgp->tag.vio_sid,
3852 		    vdcp->session_id,
3853 		    ((vio_dring_msg_t *)msgp)->seq_num,
3854 		    ((vio_dring_msg_t *)msgp)->start_idx);
3855 		return (ENOMSG);
3856 	}
3857 	return (0);
3858 }
3859 
3860 
3861 /*
3862  * Function:
3863  *	vdc_resubmit_backup_dring()
3864  *
3865  * Description:
3866  *	Resubmit each descriptor in the backed up dring to
3867  * 	vDisk server. The Dring was backed up during connection
3868  *	reset.
3869  *
3870  * Arguments:
3871  *	vdcp	- soft state pointer for this instance of the device driver.
3872  *
3873  * Return Code:
3874  *	0	- Success
3875  */
3876 static int
3877 vdc_resubmit_backup_dring(vdc_t *vdcp)
3878 {
3879 	int		processed = 0;
3880 	int		count;
3881 	int		b_idx;
3882 	int		rv = 0;
3883 	int		dring_size;
3884 	vdc_local_desc_t	*curr_ldep;
3885 
3886 	ASSERT(MUTEX_NOT_HELD(&vdcp->lock));
3887 	ASSERT(vdcp->state == VDC_STATE_HANDLE_PENDING);
3888 
3889 	if (vdcp->local_dring_backup == NULL) {
3890 		/* the pending requests have already been processed */
3891 		return (0);
3892 	}
3893 
3894 	DMSG(vdcp, 1, "restoring pending dring entries (len=%d, tail=%d)\n",
3895 	    vdcp->local_dring_backup_len, vdcp->local_dring_backup_tail);
3896 
3897 	/*
3898 	 * Walk the backup copy of the local descriptor ring and
3899 	 * resubmit all the outstanding transactions.
3900 	 */
3901 	b_idx = vdcp->local_dring_backup_tail;
3902 	for (count = 0; count < vdcp->local_dring_backup_len; count++) {
3903 
3904 		curr_ldep = &(vdcp->local_dring_backup[b_idx]);
3905 
3906 		/* only resubmit outstanding transactions */
3907 		if (!curr_ldep->is_free) {
3908 
3909 			DMSG(vdcp, 1, "resubmitting entry idx=%x\n", b_idx);
3910 
3911 			rv = vdc_do_op(vdcp, curr_ldep->operation,
3912 			    curr_ldep->addr, curr_ldep->nbytes,
3913 			    curr_ldep->slice, curr_ldep->offset,
3914 			    curr_ldep->buf, curr_ldep->dir,
3915 			    curr_ldep->flags & ~VDC_OP_STATE_RUNNING);
3916 
3917 			if (rv) {
3918 				DMSG(vdcp, 1, "[%d] resubmit entry %d failed\n",
3919 				    vdcp->instance, b_idx);
3920 				goto done;
3921 			}
3922 
3923 			/*
3924 			 * Mark this entry as free so that we will not resubmit
3925 			 * this "done" request again, if we were to use the same
3926 			 * backup_dring again in future. This could happen when
3927 			 * a reset happens while processing the backup_dring.
3928 			 */
3929 			curr_ldep->is_free = B_TRUE;
3930 			processed++;
3931 		}
3932 
3933 		/* get the next element to submit */
3934 		if (++b_idx >= vdcp->local_dring_backup_len)
3935 			b_idx = 0;
3936 	}
3937 
3938 	/* all done - now clear up pending dring copy */
3939 	dring_size = vdcp->local_dring_backup_len *
3940 	    sizeof (vdcp->local_dring_backup[0]);
3941 
3942 	(void) kmem_free(vdcp->local_dring_backup, dring_size);
3943 
3944 	vdcp->local_dring_backup = NULL;
3945 
3946 done:
3947 	DTRACE_PROBE2(processed, int, processed, vdc_t *, vdcp);
3948 
3949 	return (rv);
3950 }
3951 
3952 /*
3953  * Function:
3954  *	vdc_cancel_backup_dring
3955  *
3956  * Description:
3957  *	Cancel each descriptor in the backed up dring to vDisk server.
3958  *	The Dring was backed up during connection reset.
3959  *
3960  * Arguments:
3961  *	vdcp	- soft state pointer for this instance of the device driver.
3962  *
3963  * Return Code:
3964  *	None
3965  */
3966 void
3967 vdc_cancel_backup_dring(vdc_t *vdcp)
3968 {
3969 	vdc_local_desc_t *ldep;
3970 	struct buf 	*bufp;
3971 	int		count;
3972 	int		b_idx;
3973 	int		dring_size;
3974 	int		cancelled = 0;
3975 
3976 	ASSERT(MUTEX_HELD(&vdcp->lock));
3977 	ASSERT(vdcp->state == VDC_STATE_FAILED);
3978 
3979 	if (vdcp->local_dring_backup == NULL) {
3980 		/* the pending requests have already been processed */
3981 		return;
3982 	}
3983 
3984 	DMSG(vdcp, 1, "cancelling pending dring entries (len=%d, tail=%d)\n",
3985 	    vdcp->local_dring_backup_len, vdcp->local_dring_backup_tail);
3986 
3987 	/*
3988 	 * Walk the backup copy of the local descriptor ring and
3989 	 * cancel all the outstanding transactions.
3990 	 */
3991 	b_idx = vdcp->local_dring_backup_tail;
3992 	for (count = 0; count < vdcp->local_dring_backup_len; count++) {
3993 
3994 		ldep = &(vdcp->local_dring_backup[b_idx]);
3995 
3996 		/* only cancel outstanding transactions */
3997 		if (!ldep->is_free) {
3998 
3999 			DMSG(vdcp, 1, "cancelling entry idx=%x\n", b_idx);
4000 			cancelled++;
4001 
4002 			/*
4003 			 * All requests have already been cleared from the
4004 			 * local descriptor ring and the LDC channel has been
4005 			 * reset so we will never get any reply for these
4006 			 * requests. Now we just have to notify threads waiting
4007 			 * for replies that the request has failed.
4008 			 */
4009 			bufp = ldep->buf;
4010 			ASSERT(bufp != NULL);
4011 			bufp->b_resid = bufp->b_bcount;
4012 			if (ldep->operation == VD_OP_BREAD ||
4013 			    ldep->operation == VD_OP_BWRITE) {
4014 				VD_UPDATE_ERR_STATS(vdcp, vd_softerrs);
4015 				VD_KSTAT_RUNQ_EXIT(vdcp);
4016 				DTRACE_IO1(done, buf_t *, bufp);
4017 			}
4018 			bioerror(bufp, EIO);
4019 			biodone(bufp);
4020 		}
4021 
4022 		/* get the next element to cancel */
4023 		if (++b_idx >= vdcp->local_dring_backup_len)
4024 			b_idx = 0;
4025 	}
4026 
4027 	/* all done - now clear up pending dring copy */
4028 	dring_size = vdcp->local_dring_backup_len *
4029 	    sizeof (vdcp->local_dring_backup[0]);
4030 
4031 	(void) kmem_free(vdcp->local_dring_backup, dring_size);
4032 
4033 	vdcp->local_dring_backup = NULL;
4034 
4035 	DTRACE_PROBE2(cancelled, int, cancelled, vdc_t *, vdcp);
4036 }
4037 
4038 /*
4039  * Function:
4040  *	vdc_connection_timeout
4041  *
4042  * Description:
4043  *	This function is invoked if the timeout set to establish the connection
4044  *	with vds expires. This will happen if we spend too much time in the
4045  *	VDC_STATE_INIT_WAITING or VDC_STATE_NEGOTIATE states.
4046  *
4047  *	If the timeout does not expire, it will be cancelled when we reach the
4048  *	VDC_STATE_HANDLE_PENDING, VDC_STATE_FAILED or VDC_STATE_DETACH state.
4049  *	This function can also be invoked while we are in those states, in
4050  *	which case we do nothing because the timeout is being cancelled.
4051  *
4052  * Arguments:
4053  *	arg	- argument of the timeout function actually a soft state
4054  *		  pointer for the instance of the device driver.
4055  *
4056  * Return Code:
4057  *	None
4058  */
4059 void
4060 vdc_connection_timeout(void *arg)
4061 {
4062 	vdc_t 		*vdcp = (vdc_t *)arg;
4063 
4064 	mutex_enter(&vdcp->lock);
4065 
4066 	if (vdcp->state == VDC_STATE_HANDLE_PENDING ||
4067 	    vdcp->state == VDC_STATE_DETACH ||
4068 	    vdcp->state == VDC_STATE_FAILED) {
4069 		/*
4070 		 * The connection has just been re-established, has failed or
4071 		 * we are detaching.
4072 		 */
4073 		vdcp->ctimeout_reached = B_FALSE;
4074 	} else {
4075 		vdcp->ctimeout_reached = B_TRUE;
4076 	}
4077 
4078 	mutex_exit(&vdcp->lock);
4079 }
4080 
4081 /*
4082  * Function:
4083  *	vdc_backup_local_dring()
4084  *
4085  * Description:
4086  *	Backup the current dring in the event of a reset. The Dring
4087  *	transactions will be resubmitted to the server when the
4088  *	connection is restored.
4089  *
4090  * Arguments:
4091  *	vdcp	- soft state pointer for this instance of the device driver.
4092  *
4093  * Return Code:
4094  *	NONE
4095  */
4096 static void
4097 vdc_backup_local_dring(vdc_t *vdcp)
4098 {
4099 	int dring_size;
4100 
4101 	ASSERT(MUTEX_HELD(&vdcp->lock));
4102 	ASSERT(vdcp->state == VDC_STATE_RESETTING);
4103 
4104 	/*
4105 	 * If the backup dring is stil around, it means
4106 	 * that the last restore did not complete. However,
4107 	 * since we never got back into the running state,
4108 	 * the backup copy we have is still valid.
4109 	 */
4110 	if (vdcp->local_dring_backup != NULL) {
4111 		DMSG(vdcp, 1, "reusing local descriptor ring backup "
4112 		    "(len=%d, tail=%d)\n", vdcp->local_dring_backup_len,
4113 		    vdcp->local_dring_backup_tail);
4114 		return;
4115 	}
4116 
4117 	/*
4118 	 * The backup dring can be NULL and the local dring may not be
4119 	 * initialized. This can happen if we had a reset while establishing
4120 	 * a new connection but after the connection has timed out. In that
4121 	 * case the backup dring is NULL because the requests have been
4122 	 * cancelled and the request occured before the local dring is
4123 	 * initialized.
4124 	 */
4125 	if (!(vdcp->initialized & VDC_DRING_LOCAL))
4126 		return;
4127 
4128 	DMSG(vdcp, 1, "backing up the local descriptor ring (len=%d, "
4129 	    "tail=%d)\n", vdcp->dring_len, vdcp->dring_curr_idx);
4130 
4131 	dring_size = vdcp->dring_len * sizeof (vdcp->local_dring[0]);
4132 
4133 	vdcp->local_dring_backup = kmem_alloc(dring_size, KM_SLEEP);
4134 	bcopy(vdcp->local_dring, vdcp->local_dring_backup, dring_size);
4135 
4136 	vdcp->local_dring_backup_tail = vdcp->dring_curr_idx;
4137 	vdcp->local_dring_backup_len = vdcp->dring_len;
4138 }
4139 
4140 static void
4141 vdc_switch_server(vdc_t *vdcp)
4142 {
4143 	int		rv;
4144 	vdc_server_t 	*curr_server, *new_server;
4145 
4146 	ASSERT(MUTEX_HELD(&vdcp->lock));
4147 
4148 	/* if there is only one server return back */
4149 	if (vdcp->num_servers == 1) {
4150 		return;
4151 	}
4152 
4153 	/* Get current and next server */
4154 	curr_server = vdcp->curr_server;
4155 	new_server =
4156 	    (curr_server->next) ? curr_server->next : vdcp->server_list;
4157 	ASSERT(curr_server != new_server);
4158 
4159 	/* bring current server's channel down */
4160 	rv = ldc_down(curr_server->ldc_handle);
4161 	if (rv) {
4162 		DMSG(vdcp, 0, "[%d] Cannot bring channel down, port %ld\n",
4163 		    vdcp->instance, curr_server->id);
4164 		return;
4165 	}
4166 
4167 	/* switch the server */
4168 	vdcp->curr_server = new_server;
4169 
4170 	DMSG(vdcp, 0, "[%d] Switched to next vdisk server, port@%ld, ldc@%ld\n",
4171 	    vdcp->instance, vdcp->curr_server->id, vdcp->curr_server->ldc_id);
4172 }
4173 
4174 static void
4175 vdc_print_svc_status(vdc_t *vdcp)
4176 {
4177 	int instance;
4178 	uint64_t ldc_id, port_id;
4179 	vdc_service_state_t svc_state;
4180 
4181 	ASSERT(mutex_owned(&vdcp->lock));
4182 
4183 	svc_state = vdcp->curr_server->svc_state;
4184 
4185 	if (vdcp->curr_server->log_state == svc_state)
4186 		return;
4187 
4188 	instance = vdcp->instance;
4189 	ldc_id = vdcp->curr_server->ldc_id;
4190 	port_id = vdcp->curr_server->id;
4191 
4192 	switch (svc_state) {
4193 
4194 	case VDC_SERVICE_OFFLINE:
4195 		cmn_err(CE_CONT, "?vdisk@%d is offline\n", instance);
4196 		break;
4197 
4198 	case VDC_SERVICE_CONNECTED:
4199 		cmn_err(CE_CONT, "?vdisk@%d is connected using ldc@%ld,%ld\n",
4200 		    instance, ldc_id, port_id);
4201 		break;
4202 
4203 	case VDC_SERVICE_ONLINE:
4204 		cmn_err(CE_CONT, "?vdisk@%d is online using ldc@%ld,%ld\n",
4205 		    instance, ldc_id, port_id);
4206 		break;
4207 
4208 	case VDC_SERVICE_FAILED:
4209 		cmn_err(CE_CONT, "?vdisk@%d access to service failed "
4210 		    "using ldc@%ld,%ld\n", instance, ldc_id, port_id);
4211 		break;
4212 
4213 	case VDC_SERVICE_FAULTED:
4214 		cmn_err(CE_CONT, "?vdisk@%d access to backend failed "
4215 		    "using ldc@%ld,%ld\n", instance, ldc_id, port_id);
4216 		break;
4217 
4218 	default:
4219 		ASSERT(0);
4220 		break;
4221 	}
4222 
4223 	vdcp->curr_server->log_state = svc_state;
4224 }
4225 
4226 /* -------------------------------------------------------------------------- */
4227 
4228 /*
4229  * The following functions process the incoming messages from vds
4230  */
4231 
4232 /*
4233  * Function:
4234  *      vdc_process_msg_thread()
4235  *
4236  * Description:
4237  *
4238  *	Main VDC message processing thread. Each vDisk instance
4239  * 	consists of a copy of this thread. This thread triggers
4240  * 	all the handshakes and data exchange with the server. It
4241  * 	also handles all channel resets
4242  *
4243  * Arguments:
4244  *      vdc     - soft state pointer for this instance of the device driver.
4245  *
4246  * Return Code:
4247  *      None
4248  */
4249 static void
4250 vdc_process_msg_thread(vdc_t *vdcp)
4251 {
4252 	int		status;
4253 	int		ctimeout;
4254 	timeout_id_t	tmid = 0;
4255 	clock_t		ldcup_timeout = 0;
4256 	vdc_server_t	*srvr;
4257 	vdc_service_state_t svc_state;
4258 
4259 	mutex_enter(&vdcp->lock);
4260 
4261 	for (;;) {
4262 
4263 #define	Q(_s)	(vdcp->state == _s) ? #_s :
4264 		DMSG(vdcp, 3, "state = %d (%s)\n", vdcp->state,
4265 		    Q(VDC_STATE_INIT)
4266 		    Q(VDC_STATE_INIT_WAITING)
4267 		    Q(VDC_STATE_NEGOTIATE)
4268 		    Q(VDC_STATE_HANDLE_PENDING)
4269 		    Q(VDC_STATE_FAULTED)
4270 		    Q(VDC_STATE_FAILED)
4271 		    Q(VDC_STATE_RUNNING)
4272 		    Q(VDC_STATE_RESETTING)
4273 		    Q(VDC_STATE_DETACH)
4274 		    "UNKNOWN");
4275 
4276 		switch (vdcp->state) {
4277 		case VDC_STATE_INIT:
4278 
4279 			/*
4280 			 * If requested, start a timeout to check if the
4281 			 * connection with vds is established in the
4282 			 * specified delay. If the timeout expires, we
4283 			 * will cancel any pending request.
4284 			 *
4285 			 * If some reset have occurred while establishing
4286 			 * the connection, we already have a timeout armed
4287 			 * and in that case we don't need to arm a new one.
4288 			 *
4289 			 * The same rule applies when there are multiple vds'.
4290 			 * If either a connection cannot be established or
4291 			 * the handshake times out, the connection thread will
4292 			 * try another server. The 'ctimeout' will report
4293 			 * back an error after it expires irrespective of
4294 			 * whether the vdisk is trying to connect to just
4295 			 * one or multiple servers.
4296 			 */
4297 			ctimeout = (vdc_timeout != 0)?
4298 			    vdc_timeout : vdcp->curr_server->ctimeout;
4299 
4300 			if (ctimeout != 0 && tmid == 0) {
4301 				tmid = timeout(vdc_connection_timeout, vdcp,
4302 				    ctimeout * drv_usectohz(MICROSEC));
4303 			}
4304 
4305 			/* Switch to STATE_DETACH if drv is detaching */
4306 			if (vdcp->lifecycle == VDC_LC_DETACHING) {
4307 				vdcp->state = VDC_STATE_DETACH;
4308 				break;
4309 			}
4310 
4311 			/* Check if the timeout has been reached */
4312 			if (vdcp->ctimeout_reached) {
4313 				ASSERT(tmid != 0);
4314 				tmid = 0;
4315 				vdcp->state = VDC_STATE_FAILED;
4316 				break;
4317 			}
4318 
4319 			/* Check if we are re-initializing repeatedly */
4320 			if (vdcp->hshake_cnt > vdc_hshake_retries &&
4321 			    vdcp->lifecycle != VDC_LC_ONLINE) {
4322 
4323 				DMSG(vdcp, 0, "[%d] too many handshakes,cnt=%d",
4324 				    vdcp->instance, vdcp->hshake_cnt);
4325 				vdcp->state = VDC_STATE_FAILED;
4326 				break;
4327 			}
4328 
4329 			/* Switch server */
4330 			if (vdcp->hshake_cnt > 0)
4331 				vdc_switch_server(vdcp);
4332 			vdcp->hshake_cnt++;
4333 
4334 			/* Bring up connection with vds via LDC */
4335 			status = vdc_start_ldc_connection(vdcp);
4336 			if (status != EINVAL) {
4337 				vdcp->state = VDC_STATE_INIT_WAITING;
4338 			} else {
4339 				vdcp->curr_server->svc_state =
4340 				    VDC_SERVICE_FAILED;
4341 				vdc_print_svc_status(vdcp);
4342 			}
4343 			break;
4344 
4345 		case VDC_STATE_INIT_WAITING:
4346 
4347 			/* if channel is UP, start negotiation */
4348 			if (vdcp->curr_server->ldc_state == LDC_UP) {
4349 				vdcp->state = VDC_STATE_NEGOTIATE;
4350 				break;
4351 			}
4352 
4353 			/*
4354 			 * Wait for LDC_UP. If it times out and we have multiple
4355 			 * servers then we will retry using a different server.
4356 			 */
4357 			ldcup_timeout = ddi_get_lbolt() + (vdc_ldcup_timeout *
4358 			    drv_usectohz(MICROSEC));
4359 			status = cv_timedwait(&vdcp->initwait_cv, &vdcp->lock,
4360 			    ldcup_timeout);
4361 			if (status == -1 &&
4362 			    vdcp->state == VDC_STATE_INIT_WAITING &&
4363 			    vdcp->curr_server->ldc_state != LDC_UP) {
4364 				/* timed out & still waiting */
4365 				vdcp->curr_server->svc_state =
4366 				    VDC_SERVICE_FAILED;
4367 				vdc_print_svc_status(vdcp);
4368 				vdcp->state = VDC_STATE_INIT;
4369 				break;
4370 			}
4371 
4372 			if (vdcp->state != VDC_STATE_INIT_WAITING) {
4373 				DMSG(vdcp, 0,
4374 				    "state moved to %d out from under us...\n",
4375 				    vdcp->state);
4376 			}
4377 			break;
4378 
4379 		case VDC_STATE_NEGOTIATE:
4380 			switch (status = vdc_ver_negotiation(vdcp)) {
4381 			case 0:
4382 				break;
4383 			default:
4384 				DMSG(vdcp, 0, "ver negotiate failed (%d)..\n",
4385 				    status);
4386 				goto reset;
4387 			}
4388 
4389 			switch (status = vdc_attr_negotiation(vdcp)) {
4390 			case 0:
4391 				break;
4392 			default:
4393 				DMSG(vdcp, 0, "attr negotiate failed (%d)..\n",
4394 				    status);
4395 				goto reset;
4396 			}
4397 
4398 			switch (status = vdc_dring_negotiation(vdcp)) {
4399 			case 0:
4400 				break;
4401 			default:
4402 				DMSG(vdcp, 0, "dring negotiate failed (%d)..\n",
4403 				    status);
4404 				goto reset;
4405 			}
4406 
4407 			switch (status = vdc_rdx_exchange(vdcp)) {
4408 			case 0:
4409 				vdcp->state = VDC_STATE_HANDLE_PENDING;
4410 				goto done;
4411 			default:
4412 				DMSG(vdcp, 0, "RDX xchg failed ..(%d)\n",
4413 				    status);
4414 				goto reset;
4415 			}
4416 reset:
4417 			DMSG(vdcp, 0, "negotiation failed: resetting (%d)\n",
4418 			    status);
4419 			vdcp->state = VDC_STATE_RESETTING;
4420 			vdcp->self_reset = B_TRUE;
4421 			vdcp->curr_server->svc_state = VDC_SERVICE_FAILED;
4422 			vdc_print_svc_status(vdcp);
4423 done:
4424 			DMSG(vdcp, 0, "negotiation complete (state=0x%x)...\n",
4425 			    vdcp->state);
4426 			break;
4427 
4428 		case VDC_STATE_HANDLE_PENDING:
4429 
4430 			DMSG(vdcp, 0, "[%d] connection to service domain is up",
4431 			    vdcp->instance);
4432 			vdcp->curr_server->svc_state = VDC_SERVICE_CONNECTED;
4433 
4434 			mutex_exit(&vdcp->lock);
4435 
4436 			/*
4437 			 * If we have multiple servers, check that the backend
4438 			 * is effectively available before resubmitting any IO.
4439 			 */
4440 			if (vdcp->num_servers > 1 &&
4441 			    vdc_eio_check(vdcp, 0) != 0) {
4442 				mutex_enter(&vdcp->lock);
4443 				vdcp->curr_server->svc_state =
4444 				    VDC_SERVICE_FAULTED;
4445 				vdcp->state = VDC_STATE_FAULTED;
4446 				break;
4447 			}
4448 
4449 			if (tmid != 0) {
4450 				(void) untimeout(tmid);
4451 				tmid = 0;
4452 				vdcp->ctimeout_reached = B_FALSE;
4453 			}
4454 
4455 			/*
4456 			 * Setup devid
4457 			 */
4458 			(void) vdc_setup_devid(vdcp);
4459 
4460 			status = vdc_resubmit_backup_dring(vdcp);
4461 
4462 			mutex_enter(&vdcp->lock);
4463 
4464 			if (status) {
4465 				vdcp->state = VDC_STATE_RESETTING;
4466 				vdcp->self_reset = B_TRUE;
4467 				vdcp->curr_server->svc_state =
4468 				    VDC_SERVICE_FAILED;
4469 				vdc_print_svc_status(vdcp);
4470 			} else {
4471 				vdcp->state = VDC_STATE_RUNNING;
4472 			}
4473 			break;
4474 
4475 		case VDC_STATE_FAULTED:
4476 			/*
4477 			 * Server is faulted because the backend is unavailable.
4478 			 * If all servers are faulted then we mark the service
4479 			 * as failed, otherwise we reset to switch to another
4480 			 * server.
4481 			 */
4482 			vdc_print_svc_status(vdcp);
4483 
4484 			/* check if all servers are faulted */
4485 			for (srvr = vdcp->server_list; srvr != NULL;
4486 			    srvr = srvr->next) {
4487 				svc_state = srvr->svc_state;
4488 				if (svc_state != VDC_SERVICE_FAULTED)
4489 					break;
4490 			}
4491 
4492 			if (srvr != NULL) {
4493 				vdcp->state = VDC_STATE_RESETTING;
4494 				vdcp->self_reset = B_TRUE;
4495 			} else {
4496 				vdcp->state = VDC_STATE_FAILED;
4497 			}
4498 			break;
4499 
4500 		case VDC_STATE_FAILED:
4501 			/*
4502 			 * We reach this state when we are unable to access the
4503 			 * backend from any server, either because of a maximum
4504 			 * connection retries or timeout, or because the backend
4505 			 * is unavailable.
4506 			 *
4507 			 * Then we cancel the backup DRing so that errors get
4508 			 * reported and we wait for a new I/O before attempting
4509 			 * another connection.
4510 			 */
4511 			cmn_err(CE_NOTE, "vdisk@%d disk access failed",
4512 			    vdcp->instance);
4513 
4514 			/* cancel any timeout */
4515 			if (tmid != 0) {
4516 				(void) untimeout(tmid);
4517 				tmid = 0;
4518 			}
4519 
4520 			/* cancel pending I/Os */
4521 			cv_broadcast(&vdcp->running_cv);
4522 			vdc_cancel_backup_dring(vdcp);
4523 
4524 			/* wait for new I/O */
4525 			while (!vdcp->io_pending)
4526 				cv_wait(&vdcp->io_pending_cv, &vdcp->lock);
4527 
4528 			/*
4529 			 * There's a new IO pending. Try to re-establish a
4530 			 * connection. Mark all services as offline, so that
4531 			 * we don't stop again before having retried all
4532 			 * servers.
4533 			 */
4534 			for (srvr = vdcp->server_list; srvr != NULL;
4535 			    srvr = srvr->next) {
4536 				srvr->svc_state = VDC_SERVICE_OFFLINE;
4537 			}
4538 
4539 			/* reset variables */
4540 			vdcp->hshake_cnt = 0;
4541 			vdcp->ctimeout_reached = B_FALSE;
4542 
4543 			vdcp->state = VDC_STATE_RESETTING;
4544 			vdcp->self_reset = B_TRUE;
4545 			break;
4546 
4547 		/* enter running state */
4548 		case VDC_STATE_RUNNING:
4549 			/*
4550 			 * Signal anyone waiting for the connection
4551 			 * to come on line.
4552 			 */
4553 			vdcp->hshake_cnt = 0;
4554 			cv_broadcast(&vdcp->running_cv);
4555 
4556 			/* backend has to be checked after reset */
4557 			if (vdcp->failfast_interval != 0 ||
4558 			    vdcp->num_servers > 1)
4559 				cv_signal(&vdcp->eio_cv);
4560 
4561 			/* ownership is lost during reset */
4562 			if (vdcp->ownership & VDC_OWNERSHIP_WANTED)
4563 				vdcp->ownership |= VDC_OWNERSHIP_RESET;
4564 			cv_signal(&vdcp->ownership_cv);
4565 
4566 			vdcp->curr_server->svc_state = VDC_SERVICE_ONLINE;
4567 			vdc_print_svc_status(vdcp);
4568 
4569 			mutex_exit(&vdcp->lock);
4570 
4571 			for (;;) {
4572 				vio_msg_t msg;
4573 				status = vdc_wait_for_response(vdcp, &msg);
4574 				if (status) break;
4575 
4576 				DMSG(vdcp, 1, "[%d] new pkt(s) available\n",
4577 				    vdcp->instance);
4578 				status = vdc_process_data_msg(vdcp, &msg);
4579 				if (status) {
4580 					DMSG(vdcp, 1, "[%d] process_data_msg "
4581 					    "returned err=%d\n", vdcp->instance,
4582 					    status);
4583 					break;
4584 				}
4585 
4586 			}
4587 
4588 			mutex_enter(&vdcp->lock);
4589 
4590 			/* all servers are now offline */
4591 			for (srvr = vdcp->server_list; srvr != NULL;
4592 			    srvr = srvr->next) {
4593 				srvr->svc_state = VDC_SERVICE_OFFLINE;
4594 				srvr->log_state = VDC_SERVICE_NONE;
4595 			}
4596 
4597 			vdc_print_svc_status(vdcp);
4598 
4599 			vdcp->state = VDC_STATE_RESETTING;
4600 			vdcp->self_reset = B_TRUE;
4601 			break;
4602 
4603 		case VDC_STATE_RESETTING:
4604 			/*
4605 			 * When we reach this state, we either come from the
4606 			 * VDC_STATE_RUNNING state and we can have pending
4607 			 * request but no timeout is armed; or we come from
4608 			 * the VDC_STATE_INIT_WAITING, VDC_NEGOTIATE or
4609 			 * VDC_HANDLE_PENDING state and there is no pending
4610 			 * request or pending requests have already been copied
4611 			 * into the backup dring. So we can safely keep the
4612 			 * connection timeout armed while we are in this state.
4613 			 */
4614 
4615 			DMSG(vdcp, 0, "Initiating channel reset "
4616 			    "(pending = %d)\n", (int)vdcp->threads_pending);
4617 
4618 			if (vdcp->self_reset) {
4619 				DMSG(vdcp, 0,
4620 				    "[%d] calling stop_ldc_connection.\n",
4621 				    vdcp->instance);
4622 				status = vdc_stop_ldc_connection(vdcp);
4623 				vdcp->self_reset = B_FALSE;
4624 			}
4625 
4626 			/*
4627 			 * Wait for all threads currently waiting
4628 			 * for a free dring entry to use.
4629 			 */
4630 			while (vdcp->threads_pending) {
4631 				cv_broadcast(&vdcp->membind_cv);
4632 				cv_broadcast(&vdcp->dring_free_cv);
4633 				mutex_exit(&vdcp->lock);
4634 				/* give the waiters enough time to wake up */
4635 				delay(vdc_hz_min_ldc_delay);
4636 				mutex_enter(&vdcp->lock);
4637 			}
4638 
4639 			ASSERT(vdcp->threads_pending == 0);
4640 
4641 			/* Sanity check that no thread is receiving */
4642 			ASSERT(vdcp->read_state != VDC_READ_WAITING);
4643 
4644 			vdcp->read_state = VDC_READ_IDLE;
4645 			vdcp->io_pending = B_FALSE;
4646 
4647 			/*
4648 			 * Cleanup any pending eio. These I/Os are going to
4649 			 * be resubmitted.
4650 			 */
4651 			vdc_eio_unqueue(vdcp, 0, B_FALSE);
4652 
4653 			vdc_backup_local_dring(vdcp);
4654 
4655 			/* cleanup the old d-ring */
4656 			vdc_destroy_descriptor_ring(vdcp);
4657 
4658 			/* go and start again */
4659 			vdcp->state = VDC_STATE_INIT;
4660 
4661 			break;
4662 
4663 		case VDC_STATE_DETACH:
4664 			DMSG(vdcp, 0, "[%d] Reset thread exit cleanup ..\n",
4665 			    vdcp->instance);
4666 
4667 			/* cancel any pending timeout */
4668 			mutex_exit(&vdcp->lock);
4669 			if (tmid != 0) {
4670 				(void) untimeout(tmid);
4671 				tmid = 0;
4672 			}
4673 			mutex_enter(&vdcp->lock);
4674 
4675 			/*
4676 			 * Signal anyone waiting for connection
4677 			 * to come online
4678 			 */
4679 			cv_broadcast(&vdcp->running_cv);
4680 
4681 			while (vdcp->sync_op_cnt > 0) {
4682 				cv_broadcast(&vdcp->sync_blocked_cv);
4683 				mutex_exit(&vdcp->lock);
4684 				/* give the waiters enough time to wake up */
4685 				delay(vdc_hz_min_ldc_delay);
4686 				mutex_enter(&vdcp->lock);
4687 			}
4688 
4689 			mutex_exit(&vdcp->lock);
4690 
4691 			DMSG(vdcp, 0, "[%d] Msg processing thread exiting ..\n",
4692 			    vdcp->instance);
4693 			thread_exit();
4694 			break;
4695 		}
4696 	}
4697 }
4698 
4699 
4700 /*
4701  * Function:
4702  *	vdc_process_data_msg()
4703  *
4704  * Description:
4705  *	This function is called by the message processing thread each time
4706  *	a message with a msgtype of VIO_TYPE_DATA is received. It will either
4707  *	be an ACK or NACK from vds[1] which vdc handles as follows.
4708  *		ACK	- wake up the waiting thread
4709  *		NACK	- resend any messages necessary
4710  *
4711  *	[1] Although the message format allows it, vds should not send a
4712  *	    VIO_SUBTYPE_INFO message to vdc asking it to read data; if for
4713  *	    some bizarre reason it does, vdc will reset the connection.
4714  *
4715  * Arguments:
4716  *	vdc	- soft state pointer for this instance of the device driver.
4717  *	msg	- the LDC message sent by vds
4718  *
4719  * Return Code:
4720  *	0	- Success.
4721  *	> 0	- error value returned by LDC
4722  */
4723 static int
4724 vdc_process_data_msg(vdc_t *vdcp, vio_msg_t *msg)
4725 {
4726 	int			status = 0;
4727 	vio_dring_msg_t		*dring_msg;
4728 	vdc_local_desc_t	*ldep = NULL;
4729 	int			start, end;
4730 	int			idx;
4731 	int			op;
4732 
4733 	dring_msg = (vio_dring_msg_t *)msg;
4734 
4735 	ASSERT(msg->tag.vio_msgtype == VIO_TYPE_DATA);
4736 	ASSERT(vdcp != NULL);
4737 
4738 	mutex_enter(&vdcp->lock);
4739 
4740 	/*
4741 	 * Check to see if the message has bogus data
4742 	 */
4743 	idx = start = dring_msg->start_idx;
4744 	end = dring_msg->end_idx;
4745 	if ((start >= vdcp->dring_len) ||
4746 	    (end >= vdcp->dring_len) || (end < -1)) {
4747 		/*
4748 		 * Update the I/O statistics to indicate that an error ocurred.
4749 		 * No need to update the wait/run queues as no specific read or
4750 		 * write request is being completed in response to this 'msg'.
4751 		 */
4752 		VD_UPDATE_ERR_STATS(vdcp, vd_softerrs);
4753 		DMSG(vdcp, 0, "[%d] Bogus ACK data : start %d, end %d\n",
4754 		    vdcp->instance, start, end);
4755 		mutex_exit(&vdcp->lock);
4756 		return (EINVAL);
4757 	}
4758 
4759 	/*
4760 	 * Verify that the sequence number is what vdc expects.
4761 	 */
4762 	switch (vdc_verify_seq_num(vdcp, dring_msg)) {
4763 	case VDC_SEQ_NUM_TODO:
4764 		break;	/* keep processing this message */
4765 	case VDC_SEQ_NUM_SKIP:
4766 		mutex_exit(&vdcp->lock);
4767 		return (0);
4768 	case VDC_SEQ_NUM_INVALID:
4769 		/*
4770 		 * Update the I/O statistics to indicate that an error ocurred.
4771 		 * No need to update the wait/run queues as no specific read or
4772 		 * write request is being completed in response to this 'msg'.
4773 		 */
4774 		VD_UPDATE_ERR_STATS(vdcp, vd_softerrs);
4775 		DMSG(vdcp, 0, "[%d] invalid seqno\n", vdcp->instance);
4776 		mutex_exit(&vdcp->lock);
4777 		return (ENXIO);
4778 	}
4779 
4780 	if (msg->tag.vio_subtype == VIO_SUBTYPE_NACK) {
4781 		/*
4782 		 * Update the I/O statistics to indicate that an error ocurred.
4783 		 *
4784 		 * We need to update the run queue if a read or write request
4785 		 * is being NACKed - otherwise there will appear to be an
4786 		 * indefinite outstanding request and statistics reported by
4787 		 * iostat(1M) will be incorrect. The transaction will be
4788 		 * resubmitted from the backup DRing following the reset
4789 		 * and the wait/run queues will be entered again.
4790 		 */
4791 		ldep = &vdcp->local_dring[idx];
4792 		op = ldep->operation;
4793 		if ((op == VD_OP_BREAD) || (op == VD_OP_BWRITE)) {
4794 			DTRACE_IO1(done, buf_t *, ldep->buf);
4795 			VD_KSTAT_RUNQ_EXIT(vdcp);
4796 		}
4797 		VD_UPDATE_ERR_STATS(vdcp, vd_softerrs);
4798 		VDC_DUMP_DRING_MSG(dring_msg);
4799 		DMSG(vdcp, 0, "[%d] DATA NACK\n", vdcp->instance);
4800 		mutex_exit(&vdcp->lock);
4801 		return (EIO);
4802 
4803 	} else if (msg->tag.vio_subtype == VIO_SUBTYPE_INFO) {
4804 		/*
4805 		 * Update the I/O statistics to indicate that an error occurred.
4806 		 * No need to update the wait/run queues as no specific read or
4807 		 * write request is being completed in response to this 'msg'.
4808 		 */
4809 		VD_UPDATE_ERR_STATS(vdcp, vd_protoerrs);
4810 		mutex_exit(&vdcp->lock);
4811 		return (EPROTO);
4812 	}
4813 
4814 	DMSG(vdcp, 1, ": start %d end %d\n", start, end);
4815 	ASSERT(start == end);
4816 
4817 	ldep = &vdcp->local_dring[idx];
4818 
4819 	DMSG(vdcp, 1, ": state 0x%x\n", ldep->dep->hdr.dstate);
4820 
4821 	if (ldep->dep->hdr.dstate == VIO_DESC_DONE) {
4822 		struct buf *bufp;
4823 
4824 		status = ldep->dep->payload.status;
4825 
4826 		bufp = ldep->buf;
4827 		ASSERT(bufp != NULL);
4828 
4829 		bufp->b_resid = bufp->b_bcount - ldep->dep->payload.nbytes;
4830 		bioerror(bufp, status);
4831 
4832 		if (status != 0) {
4833 			DMSG(vdcp, 1, "I/O status=%d\n", status);
4834 		}
4835 
4836 		DMSG(vdcp, 1,
4837 		    "I/O complete req=%ld bytes resp=%ld bytes\n",
4838 		    bufp->b_bcount, ldep->dep->payload.nbytes);
4839 
4840 		/*
4841 		 * If the request has failed and we have multiple servers or
4842 		 * failfast is enabled then we will have to defer the completion
4843 		 * of the request until we have checked that the vdisk backend
4844 		 * is effectively available (if multiple server) or that there
4845 		 * is no reservation conflict (if failfast).
4846 		 */
4847 		if ((status != 0 &&
4848 		    (vdcp->num_servers > 1 &&
4849 		    (ldep->flags & VDC_OP_ERRCHK_BACKEND)) ||
4850 		    (vdcp->failfast_interval != 0 &&
4851 		    (ldep->flags & VDC_OP_ERRCHK_CONFLICT)))) {
4852 			/*
4853 			 * The I/O has failed and we need to check the error.
4854 			 */
4855 			(void) vdc_eio_queue(vdcp, idx);
4856 		} else {
4857 			op = ldep->operation;
4858 			if (op == VD_OP_BREAD || op == VD_OP_BWRITE) {
4859 				if (status == 0) {
4860 					VD_UPDATE_IO_STATS(vdcp, op,
4861 					    ldep->dep->payload.nbytes);
4862 				} else {
4863 					VD_UPDATE_ERR_STATS(vdcp, vd_softerrs);
4864 				}
4865 				VD_KSTAT_RUNQ_EXIT(vdcp);
4866 				DTRACE_IO1(done, buf_t *, bufp);
4867 			}
4868 			(void) vdc_depopulate_descriptor(vdcp, idx);
4869 			biodone(bufp);
4870 		}
4871 	}
4872 
4873 	/* let the arrival signal propogate */
4874 	mutex_exit(&vdcp->lock);
4875 
4876 	/* probe gives the count of how many entries were processed */
4877 	DTRACE_PROBE2(processed, int, 1, vdc_t *, vdcp);
4878 
4879 	return (0);
4880 }
4881 
4882 
4883 /*
4884  * Function:
4885  *	vdc_handle_ver_msg()
4886  *
4887  * Description:
4888  *
4889  * Arguments:
4890  *	vdc	- soft state pointer for this instance of the device driver.
4891  *	ver_msg	- LDC message sent by vDisk server
4892  *
4893  * Return Code:
4894  *	0	- Success
4895  */
4896 static int
4897 vdc_handle_ver_msg(vdc_t *vdc, vio_ver_msg_t *ver_msg)
4898 {
4899 	int status = 0;
4900 
4901 	ASSERT(vdc != NULL);
4902 	ASSERT(mutex_owned(&vdc->lock));
4903 
4904 	if (ver_msg->tag.vio_subtype_env != VIO_VER_INFO) {
4905 		return (EPROTO);
4906 	}
4907 
4908 	if (ver_msg->dev_class != VDEV_DISK_SERVER) {
4909 		return (EINVAL);
4910 	}
4911 
4912 	switch (ver_msg->tag.vio_subtype) {
4913 	case VIO_SUBTYPE_ACK:
4914 		/*
4915 		 * We check to see if the version returned is indeed supported
4916 		 * (The server may have also adjusted the minor number downwards
4917 		 * and if so 'ver_msg' will contain the actual version agreed)
4918 		 */
4919 		if (vdc_is_supported_version(ver_msg)) {
4920 			vdc->ver.major = ver_msg->ver_major;
4921 			vdc->ver.minor = ver_msg->ver_minor;
4922 			ASSERT(vdc->ver.major > 0);
4923 		} else {
4924 			status = EPROTO;
4925 		}
4926 		break;
4927 
4928 	case VIO_SUBTYPE_NACK:
4929 		/*
4930 		 * call vdc_is_supported_version() which will return the next
4931 		 * supported version (if any) in 'ver_msg'
4932 		 */
4933 		(void) vdc_is_supported_version(ver_msg);
4934 		if (ver_msg->ver_major > 0) {
4935 			size_t len = sizeof (*ver_msg);
4936 
4937 			ASSERT(vdc->ver.major > 0);
4938 
4939 			/* reset the necessary fields and resend */
4940 			ver_msg->tag.vio_subtype = VIO_SUBTYPE_INFO;
4941 			ver_msg->dev_class = VDEV_DISK;
4942 
4943 			status = vdc_send(vdc, (caddr_t)ver_msg, &len);
4944 			DMSG(vdc, 0, "[%d] Resend VER info (LDC status = %d)\n",
4945 			    vdc->instance, status);
4946 			if (len != sizeof (*ver_msg))
4947 				status = EBADMSG;
4948 		} else {
4949 			DMSG(vdc, 0, "[%d] No common version with vDisk server",
4950 			    vdc->instance);
4951 			status = ENOTSUP;
4952 		}
4953 
4954 		break;
4955 	case VIO_SUBTYPE_INFO:
4956 		/*
4957 		 * Handle the case where vds starts handshake
4958 		 * (for now only vdc is the instigator)
4959 		 */
4960 		status = ENOTSUP;
4961 		break;
4962 
4963 	default:
4964 		status = EINVAL;
4965 		break;
4966 	}
4967 
4968 	return (status);
4969 }
4970 
4971 /*
4972  * Function:
4973  *	vdc_handle_attr_msg()
4974  *
4975  * Description:
4976  *
4977  * Arguments:
4978  *	vdc	- soft state pointer for this instance of the device driver.
4979  *	attr_msg	- LDC message sent by vDisk server
4980  *
4981  * Return Code:
4982  *	0	- Success
4983  */
4984 static int
4985 vdc_handle_attr_msg(vdc_t *vdc, vd_attr_msg_t *attr_msg)
4986 {
4987 	int status = 0;
4988 	vd_disk_type_t old_type;
4989 
4990 	ASSERT(vdc != NULL);
4991 	ASSERT(mutex_owned(&vdc->lock));
4992 
4993 	if (attr_msg->tag.vio_subtype_env != VIO_ATTR_INFO) {
4994 		return (EPROTO);
4995 	}
4996 
4997 	switch (attr_msg->tag.vio_subtype) {
4998 	case VIO_SUBTYPE_ACK:
4999 		/*
5000 		 * We now verify the attributes sent by vds.
5001 		 */
5002 		if (attr_msg->vdisk_size == 0) {
5003 			DMSG(vdc, 0, "[%d] Invalid disk size from vds",
5004 			    vdc->instance);
5005 			status = EINVAL;
5006 			break;
5007 		}
5008 
5009 		if (attr_msg->max_xfer_sz == 0) {
5010 			DMSG(vdc, 0, "[%d] Invalid transfer size from vds",
5011 			    vdc->instance);
5012 			status = EINVAL;
5013 			break;
5014 		}
5015 
5016 		if (attr_msg->vdisk_size == VD_SIZE_UNKNOWN) {
5017 			DMSG(vdc, 0, "[%d] Unknown disk size from vds",
5018 			    vdc->instance);
5019 			attr_msg->vdisk_size = 0;
5020 		}
5021 
5022 		/* update the VIO block size */
5023 		if (attr_msg->vdisk_block_size > 0 &&
5024 		    vdc_update_vio_bsize(vdc,
5025 		    attr_msg->vdisk_block_size) != 0) {
5026 			DMSG(vdc, 0, "[%d] Invalid block size (%u) from vds",
5027 			    vdc->instance, attr_msg->vdisk_block_size);
5028 			status = EINVAL;
5029 			break;
5030 		}
5031 
5032 		/* update disk, block and transfer sizes */
5033 		old_type = vdc->vdisk_type;
5034 		vdc_update_size(vdc, attr_msg->vdisk_size,
5035 		    attr_msg->vdisk_block_size, attr_msg->max_xfer_sz);
5036 		vdc->vdisk_type = attr_msg->vdisk_type;
5037 		vdc->operations = attr_msg->operations;
5038 		if (vio_ver_is_supported(vdc->ver, 1, 1))
5039 			vdc->vdisk_media = attr_msg->vdisk_media;
5040 		else
5041 			vdc->vdisk_media = 0;
5042 
5043 		DMSG(vdc, 0, "[%d] max_xfer_sz: sent %lx acked %lx\n",
5044 		    vdc->instance, vdc->max_xfer_sz, attr_msg->max_xfer_sz);
5045 		DMSG(vdc, 0, "[%d] vdisk_block_size: sent %lx acked %x\n",
5046 		    vdc->instance, vdc->vdisk_bsize,
5047 		    attr_msg->vdisk_block_size);
5048 
5049 		if ((attr_msg->xfer_mode != VIO_DRING_MODE_V1_0) ||
5050 		    (attr_msg->vdisk_size > INT64_MAX) ||
5051 		    (attr_msg->operations == 0) ||
5052 		    (attr_msg->vdisk_type > VD_DISK_TYPE_DISK)) {
5053 			DMSG(vdc, 0, "[%d] Invalid attributes from vds",
5054 			    vdc->instance);
5055 			status = EINVAL;
5056 			break;
5057 		}
5058 
5059 		/*
5060 		 * Now that we have received all attributes we can create a
5061 		 * fake geometry for the disk.
5062 		 */
5063 		vdc_create_fake_geometry(vdc);
5064 
5065 		/*
5066 		 * If the disk type was previously unknown and device nodes
5067 		 * were created then the driver would have created 8 device
5068 		 * nodes. If we now find out that this is a single-slice disk
5069 		 * then we need to re-create the appropriate device nodes.
5070 		 */
5071 		if (old_type == VD_DISK_TYPE_UNK &&
5072 		    (vdc->initialized & VDC_MINOR) &&
5073 		    vdc->vdisk_type == VD_DISK_TYPE_SLICE) {
5074 			ddi_remove_minor_node(vdc->dip, NULL);
5075 			(void) devfs_clean(ddi_get_parent(vdc->dip),
5076 			    NULL, DV_CLEAN_FORCE);
5077 			if (vdc_create_device_nodes(vdc) != 0) {
5078 				DMSG(vdc, 0, "![%d] Failed to update "
5079 				    "device nodes", vdc->instance);
5080 			}
5081 		}
5082 
5083 		break;
5084 
5085 	case VIO_SUBTYPE_NACK:
5086 		/*
5087 		 * vds could not handle the attributes we sent so we
5088 		 * stop negotiating.
5089 		 */
5090 		status = EPROTO;
5091 		break;
5092 
5093 	case VIO_SUBTYPE_INFO:
5094 		/*
5095 		 * Handle the case where vds starts the handshake
5096 		 * (for now; vdc is the only supported instigatior)
5097 		 */
5098 		status = ENOTSUP;
5099 		break;
5100 
5101 	default:
5102 		status = ENOTSUP;
5103 		break;
5104 	}
5105 
5106 	return (status);
5107 }
5108 
5109 /*
5110  * Function:
5111  *	vdc_handle_dring_reg_msg()
5112  *
5113  * Description:
5114  *
5115  * Arguments:
5116  *	vdc		- soft state pointer for this instance of the driver.
5117  *	dring_msg	- LDC message sent by vDisk server
5118  *
5119  * Return Code:
5120  *	0	- Success
5121  */
5122 static int
5123 vdc_handle_dring_reg_msg(vdc_t *vdc, vio_dring_reg_msg_t *dring_msg)
5124 {
5125 	int		status = 0;
5126 
5127 	ASSERT(vdc != NULL);
5128 	ASSERT(mutex_owned(&vdc->lock));
5129 
5130 	if (dring_msg->tag.vio_subtype_env != VIO_DRING_REG) {
5131 		return (EPROTO);
5132 	}
5133 
5134 	switch (dring_msg->tag.vio_subtype) {
5135 	case VIO_SUBTYPE_ACK:
5136 		/* save the received dring_ident */
5137 		vdc->dring_ident = dring_msg->dring_ident;
5138 		DMSG(vdc, 0, "[%d] Received dring ident=0x%lx\n",
5139 		    vdc->instance, vdc->dring_ident);
5140 		break;
5141 
5142 	case VIO_SUBTYPE_NACK:
5143 		/*
5144 		 * vds could not handle the DRing info we sent so we
5145 		 * stop negotiating.
5146 		 */
5147 		DMSG(vdc, 0, "[%d] server could not register DRing\n",
5148 		    vdc->instance);
5149 		status = EPROTO;
5150 		break;
5151 
5152 	case VIO_SUBTYPE_INFO:
5153 		/*
5154 		 * Handle the case where vds starts handshake
5155 		 * (for now only vdc is the instigatior)
5156 		 */
5157 		status = ENOTSUP;
5158 		break;
5159 	default:
5160 		status = ENOTSUP;
5161 	}
5162 
5163 	return (status);
5164 }
5165 
5166 /*
5167  * Function:
5168  *	vdc_verify_seq_num()
5169  *
5170  * Description:
5171  *	This functions verifies that the sequence number sent back by the vDisk
5172  *	server with the latest message is what is expected (i.e. it is greater
5173  *	than the last seq num sent by the vDisk server and less than or equal
5174  *	to the last seq num generated by vdc).
5175  *
5176  *	It then checks the request ID to see if any requests need processing
5177  *	in the DRing.
5178  *
5179  * Arguments:
5180  *	vdc		- soft state pointer for this instance of the driver.
5181  *	dring_msg	- pointer to the LDC message sent by vds
5182  *
5183  * Return Code:
5184  *	VDC_SEQ_NUM_TODO	- Message needs to be processed
5185  *	VDC_SEQ_NUM_SKIP	- Message has already been processed
5186  *	VDC_SEQ_NUM_INVALID	- The seq numbers are so out of sync,
5187  *				  vdc cannot deal with them
5188  */
5189 static int
5190 vdc_verify_seq_num(vdc_t *vdc, vio_dring_msg_t *dring_msg)
5191 {
5192 	ASSERT(vdc != NULL);
5193 	ASSERT(dring_msg != NULL);
5194 	ASSERT(mutex_owned(&vdc->lock));
5195 
5196 	/*
5197 	 * Check to see if the messages were responded to in the correct
5198 	 * order by vds.
5199 	 */
5200 	if ((dring_msg->seq_num <= vdc->seq_num_reply) ||
5201 	    (dring_msg->seq_num > vdc->seq_num)) {
5202 		DMSG(vdc, 0, "?[%d] Bogus sequence_number %lu: "
5203 		    "%lu > expected <= %lu (last proc req %lu sent %lu)\n",
5204 		    vdc->instance, dring_msg->seq_num,
5205 		    vdc->seq_num_reply, vdc->seq_num,
5206 		    vdc->req_id_proc, vdc->req_id);
5207 		return (VDC_SEQ_NUM_INVALID);
5208 	}
5209 	vdc->seq_num_reply = dring_msg->seq_num;
5210 
5211 	if (vdc->req_id_proc < vdc->req_id)
5212 		return (VDC_SEQ_NUM_TODO);
5213 	else
5214 		return (VDC_SEQ_NUM_SKIP);
5215 }
5216 
5217 
5218 /*
5219  * Function:
5220  *	vdc_is_supported_version()
5221  *
5222  * Description:
5223  *	This routine checks if the major/minor version numbers specified in
5224  *	'ver_msg' are supported. If not it finds the next version that is
5225  *	in the supported version list 'vdc_version[]' and sets the fields in
5226  *	'ver_msg' to those values
5227  *
5228  * Arguments:
5229  *	ver_msg	- LDC message sent by vDisk server
5230  *
5231  * Return Code:
5232  *	B_TRUE	- Success
5233  *	B_FALSE	- Version not supported
5234  */
5235 static boolean_t
5236 vdc_is_supported_version(vio_ver_msg_t *ver_msg)
5237 {
5238 	int vdc_num_versions = sizeof (vdc_version) / sizeof (vdc_version[0]);
5239 
5240 	for (int i = 0; i < vdc_num_versions; i++) {
5241 		ASSERT(vdc_version[i].major > 0);
5242 		ASSERT((i == 0) ||
5243 		    (vdc_version[i].major < vdc_version[i-1].major));
5244 
5245 		/*
5246 		 * If the major versions match, adjust the minor version, if
5247 		 * necessary, down to the highest value supported by this
5248 		 * client. The server should support all minor versions lower
5249 		 * than the value it sent
5250 		 */
5251 		if (ver_msg->ver_major == vdc_version[i].major) {
5252 			if (ver_msg->ver_minor > vdc_version[i].minor) {
5253 				DMSGX(0,
5254 				    "Adjusting minor version from %u to %u",
5255 				    ver_msg->ver_minor, vdc_version[i].minor);
5256 				ver_msg->ver_minor = vdc_version[i].minor;
5257 			}
5258 			return (B_TRUE);
5259 		}
5260 
5261 		/*
5262 		 * If the message contains a higher major version number, set
5263 		 * the message's major/minor versions to the current values
5264 		 * and return false, so this message will get resent with
5265 		 * these values, and the server will potentially try again
5266 		 * with the same or a lower version
5267 		 */
5268 		if (ver_msg->ver_major > vdc_version[i].major) {
5269 			ver_msg->ver_major = vdc_version[i].major;
5270 			ver_msg->ver_minor = vdc_version[i].minor;
5271 			DMSGX(0, "Suggesting major/minor (0x%x/0x%x)\n",
5272 			    ver_msg->ver_major, ver_msg->ver_minor);
5273 
5274 			return (B_FALSE);
5275 		}
5276 
5277 		/*
5278 		 * Otherwise, the message's major version is less than the
5279 		 * current major version, so continue the loop to the next
5280 		 * (lower) supported version
5281 		 */
5282 	}
5283 
5284 	/*
5285 	 * No common version was found; "ground" the version pair in the
5286 	 * message to terminate negotiation
5287 	 */
5288 	ver_msg->ver_major = 0;
5289 	ver_msg->ver_minor = 0;
5290 
5291 	return (B_FALSE);
5292 }
5293 /* -------------------------------------------------------------------------- */
5294 
5295 /*
5296  * DKIO(7) support
5297  */
5298 
5299 typedef struct vdc_dk_arg {
5300 	struct dk_callback	dkc;
5301 	int			mode;
5302 	dev_t			dev;
5303 	vdc_t			*vdc;
5304 } vdc_dk_arg_t;
5305 
5306 /*
5307  * Function:
5308  * 	vdc_dkio_flush_cb()
5309  *
5310  * Description:
5311  *	This routine is a callback for DKIOCFLUSHWRITECACHE which can be called
5312  *	by kernel code.
5313  *
5314  * Arguments:
5315  *	arg	- a pointer to a vdc_dk_arg_t structure.
5316  */
5317 void
5318 vdc_dkio_flush_cb(void *arg)
5319 {
5320 	struct vdc_dk_arg	*dk_arg = (struct vdc_dk_arg *)arg;
5321 	struct dk_callback	*dkc = NULL;
5322 	vdc_t			*vdc = NULL;
5323 	int			rv;
5324 
5325 	if (dk_arg == NULL) {
5326 		cmn_err(CE_NOTE, "?[Unk] DKIOCFLUSHWRITECACHE arg is NULL\n");
5327 		return;
5328 	}
5329 	dkc = &dk_arg->dkc;
5330 	vdc = dk_arg->vdc;
5331 	ASSERT(vdc != NULL);
5332 
5333 	rv = vdc_do_sync_op(vdc, VD_OP_FLUSH, NULL, 0,
5334 	    VDCPART(dk_arg->dev), 0, VIO_both_dir, B_TRUE);
5335 	if (rv != 0) {
5336 		DMSG(vdc, 0, "[%d] DKIOCFLUSHWRITECACHE failed %d : model %x\n",
5337 		    vdc->instance, rv,
5338 		    ddi_model_convert_from(dk_arg->mode & FMODELS));
5339 	}
5340 
5341 	/*
5342 	 * Trigger the call back to notify the caller the the ioctl call has
5343 	 * been completed.
5344 	 */
5345 	if ((dk_arg->mode & FKIOCTL) &&
5346 	    (dkc != NULL) &&
5347 	    (dkc->dkc_callback != NULL)) {
5348 		ASSERT(dkc->dkc_cookie != NULL);
5349 		(*dkc->dkc_callback)(dkc->dkc_cookie, rv);
5350 	}
5351 
5352 	/* Indicate that one less DKIO write flush is outstanding */
5353 	mutex_enter(&vdc->lock);
5354 	vdc->dkio_flush_pending--;
5355 	ASSERT(vdc->dkio_flush_pending >= 0);
5356 	mutex_exit(&vdc->lock);
5357 
5358 	/* free the mem that was allocated when the callback was dispatched */
5359 	kmem_free(arg, sizeof (vdc_dk_arg_t));
5360 }
5361 
5362 /*
5363  * Function:
5364  * 	vdc_dkio_gapart()
5365  *
5366  * Description:
5367  *	This function implements the DKIOCGAPART ioctl.
5368  *
5369  * Arguments:
5370  *	vdc	- soft state pointer
5371  *	arg	- a pointer to a dk_map[NDKMAP] or dk_map32[NDKMAP] structure
5372  *	flag	- ioctl flags
5373  */
5374 static int
5375 vdc_dkio_gapart(vdc_t *vdc, caddr_t arg, int flag)
5376 {
5377 	struct dk_geom *geom;
5378 	struct extvtoc *vtoc;
5379 	union {
5380 		struct dk_map map[NDKMAP];
5381 		struct dk_map32 map32[NDKMAP];
5382 	} data;
5383 	int i, rv, size;
5384 
5385 	mutex_enter(&vdc->lock);
5386 
5387 	if ((rv = vdc_validate_geometry(vdc)) != 0) {
5388 		mutex_exit(&vdc->lock);
5389 		return (rv);
5390 	}
5391 
5392 	if (vdc->vdisk_size > VD_OLDVTOC_LIMIT) {
5393 		mutex_exit(&vdc->lock);
5394 		return (EOVERFLOW);
5395 	}
5396 
5397 	vtoc = vdc->vtoc;
5398 	geom = vdc->geom;
5399 
5400 	if (ddi_model_convert_from(flag & FMODELS) == DDI_MODEL_ILP32) {
5401 
5402 		for (i = 0; i < vtoc->v_nparts; i++) {
5403 			data.map32[i].dkl_cylno = vtoc->v_part[i].p_start /
5404 			    (geom->dkg_nhead * geom->dkg_nsect);
5405 			data.map32[i].dkl_nblk = vtoc->v_part[i].p_size;
5406 		}
5407 		size = NDKMAP * sizeof (struct dk_map32);
5408 
5409 	} else {
5410 
5411 		for (i = 0; i < vtoc->v_nparts; i++) {
5412 			data.map[i].dkl_cylno = vtoc->v_part[i].p_start /
5413 			    (geom->dkg_nhead * geom->dkg_nsect);
5414 			data.map[i].dkl_nblk = vtoc->v_part[i].p_size;
5415 		}
5416 		size = NDKMAP * sizeof (struct dk_map);
5417 
5418 	}
5419 
5420 	mutex_exit(&vdc->lock);
5421 
5422 	if (ddi_copyout(&data, arg, size, flag) != 0)
5423 		return (EFAULT);
5424 
5425 	return (0);
5426 }
5427 
5428 /*
5429  * Function:
5430  * 	vdc_dkio_partition()
5431  *
5432  * Description:
5433  *	This function implements the DKIOCPARTITION ioctl.
5434  *
5435  * Arguments:
5436  *	vdc	- soft state pointer
5437  *	arg	- a pointer to a struct partition64 structure
5438  *	flag	- ioctl flags
5439  */
5440 static int
5441 vdc_dkio_partition(vdc_t *vdc, caddr_t arg, int flag)
5442 {
5443 	struct partition64 p64;
5444 	efi_gpt_t *gpt;
5445 	efi_gpe_t *gpe;
5446 	vd_efi_dev_t edev;
5447 	uint_t partno;
5448 	int rv;
5449 
5450 	if (ddi_copyin(arg, &p64, sizeof (struct partition64), flag)) {
5451 		return (EFAULT);
5452 	}
5453 
5454 	VDC_EFI_DEV_SET(edev, vdc, vd_process_efi_ioctl);
5455 
5456 	if ((rv = vd_efi_alloc_and_read(&edev, &gpt, &gpe)) != 0) {
5457 		return (rv);
5458 	}
5459 
5460 	partno = p64.p_partno;
5461 
5462 	if (partno >= gpt->efi_gpt_NumberOfPartitionEntries) {
5463 		vd_efi_free(&edev, gpt, gpe);
5464 		return (ESRCH);
5465 	}
5466 
5467 	bcopy(&gpe[partno].efi_gpe_PartitionTypeGUID, &p64.p_type,
5468 	    sizeof (struct uuid));
5469 	p64.p_start = gpe[partno].efi_gpe_StartingLBA;
5470 	p64.p_size = gpe[partno].efi_gpe_EndingLBA - p64.p_start + 1;
5471 
5472 	if (ddi_copyout(&p64, arg, sizeof (struct partition64), flag)) {
5473 		vd_efi_free(&edev, gpt, gpe);
5474 		return (EFAULT);
5475 	}
5476 
5477 	vd_efi_free(&edev, gpt, gpe);
5478 	return (0);
5479 }
5480 
5481 /*
5482  * Function:
5483  * 	vdc_dioctl_rwcmd()
5484  *
5485  * Description:
5486  *	This function implements the DIOCTL_RWCMD ioctl. This ioctl is used
5487  *	for DKC_DIRECT disks to read or write at an absolute disk offset.
5488  *
5489  * Arguments:
5490  *	dev	- device
5491  *	arg	- a pointer to a dadkio_rwcmd or dadkio_rwcmd32 structure
5492  *	flag	- ioctl flags
5493  */
5494 static int
5495 vdc_dioctl_rwcmd(vdc_t *vdc, caddr_t arg, int flag)
5496 {
5497 	struct dadkio_rwcmd32 rwcmd32;
5498 	struct dadkio_rwcmd rwcmd;
5499 	struct iovec aiov;
5500 	struct uio auio;
5501 	int rw, status;
5502 	struct buf *buf;
5503 
5504 	if (ddi_model_convert_from(flag & FMODELS) == DDI_MODEL_ILP32) {
5505 		if (ddi_copyin((caddr_t)arg, (caddr_t)&rwcmd32,
5506 		    sizeof (struct dadkio_rwcmd32), flag)) {
5507 			return (EFAULT);
5508 		}
5509 		rwcmd.cmd = rwcmd32.cmd;
5510 		rwcmd.flags = rwcmd32.flags;
5511 		rwcmd.blkaddr = (daddr_t)rwcmd32.blkaddr;
5512 		rwcmd.buflen = rwcmd32.buflen;
5513 		rwcmd.bufaddr = (caddr_t)(uintptr_t)rwcmd32.bufaddr;
5514 	} else {
5515 		if (ddi_copyin((caddr_t)arg, (caddr_t)&rwcmd,
5516 		    sizeof (struct dadkio_rwcmd), flag)) {
5517 			return (EFAULT);
5518 		}
5519 	}
5520 
5521 	switch (rwcmd.cmd) {
5522 	case DADKIO_RWCMD_READ:
5523 		rw = B_READ;
5524 		break;
5525 	case DADKIO_RWCMD_WRITE:
5526 		rw = B_WRITE;
5527 		break;
5528 	default:
5529 		return (EINVAL);
5530 	}
5531 
5532 	bzero((caddr_t)&aiov, sizeof (struct iovec));
5533 	aiov.iov_base   = rwcmd.bufaddr;
5534 	aiov.iov_len    = rwcmd.buflen;
5535 
5536 	bzero((caddr_t)&auio, sizeof (struct uio));
5537 	auio.uio_iov    = &aiov;
5538 	auio.uio_iovcnt = 1;
5539 	auio.uio_loffset = rwcmd.blkaddr * vdc->vdisk_bsize;
5540 	auio.uio_resid  = rwcmd.buflen;
5541 	auio.uio_segflg = flag & FKIOCTL ? UIO_SYSSPACE : UIO_USERSPACE;
5542 
5543 	buf = kmem_alloc(sizeof (buf_t), KM_SLEEP);
5544 	bioinit(buf);
5545 	/*
5546 	 * We use the private field of buf to specify that this is an
5547 	 * I/O using an absolute offset.
5548 	 */
5549 	buf->b_private = (void *)VD_SLICE_NONE;
5550 
5551 	status = physio(vdc_strategy, buf, VD_MAKE_DEV(vdc->instance, 0),
5552 	    rw, vdc_min, &auio);
5553 
5554 	biofini(buf);
5555 	kmem_free(buf, sizeof (buf_t));
5556 
5557 	return (status);
5558 }
5559 
5560 /*
5561  * Allocate a buffer for a VD_OP_SCSICMD operation. The size of the allocated
5562  * buffer is returned in alloc_len.
5563  */
5564 static vd_scsi_t *
5565 vdc_scsi_alloc(int cdb_len, int sense_len, int datain_len, int dataout_len,
5566     int *alloc_len)
5567 {
5568 	vd_scsi_t *vd_scsi;
5569 	int vd_scsi_len = VD_SCSI_SIZE;
5570 
5571 	vd_scsi_len += P2ROUNDUP(cdb_len, sizeof (uint64_t));
5572 	vd_scsi_len += P2ROUNDUP(sense_len, sizeof (uint64_t));
5573 	vd_scsi_len += P2ROUNDUP(datain_len, sizeof (uint64_t));
5574 	vd_scsi_len += P2ROUNDUP(dataout_len, sizeof (uint64_t));
5575 
5576 	ASSERT(vd_scsi_len % sizeof (uint64_t) == 0);
5577 
5578 	vd_scsi = kmem_zalloc(vd_scsi_len, KM_SLEEP);
5579 
5580 	vd_scsi->cdb_len = cdb_len;
5581 	vd_scsi->sense_len = sense_len;
5582 	vd_scsi->datain_len = datain_len;
5583 	vd_scsi->dataout_len = dataout_len;
5584 
5585 	*alloc_len = vd_scsi_len;
5586 
5587 	return (vd_scsi);
5588 }
5589 
5590 /*
5591  * Convert the status of a SCSI command to a Solaris return code.
5592  *
5593  * Arguments:
5594  *	vd_scsi		- The SCSI operation buffer.
5595  *	log_error	- indicate if an error message should be logged.
5596  *
5597  * Note that our SCSI error messages are rather primitive for the moment
5598  * and could be improved by decoding some data like the SCSI command and
5599  * the sense key.
5600  *
5601  * Return value:
5602  *	0		- Status is good.
5603  *	EACCES		- Status reports a reservation conflict.
5604  *	ENOTSUP		- Status reports a check condition and sense key
5605  *			  reports an illegal request.
5606  *	EIO		- Any other status.
5607  */
5608 static int
5609 vdc_scsi_status(vdc_t *vdc, vd_scsi_t *vd_scsi, boolean_t log_error)
5610 {
5611 	int rv;
5612 	char path_str[MAXPATHLEN];
5613 	char panic_str[VDC_RESV_CONFLICT_FMT_LEN + MAXPATHLEN];
5614 	union scsi_cdb *cdb;
5615 	struct scsi_extended_sense *sense;
5616 
5617 	if (vd_scsi->cmd_status == STATUS_GOOD)
5618 		/* no error */
5619 		return (0);
5620 
5621 	/* when the tunable vdc_scsi_log_error is true we log all errors */
5622 	if (vdc_scsi_log_error)
5623 		log_error = B_TRUE;
5624 
5625 	if (log_error) {
5626 		cmn_err(CE_WARN, "%s (vdc%d):\tError for Command: 0x%x)\n",
5627 		    ddi_pathname(vdc->dip, path_str), vdc->instance,
5628 		    GETCMD(VD_SCSI_DATA_CDB(vd_scsi)));
5629 	}
5630 
5631 	/* default returned value */
5632 	rv = EIO;
5633 
5634 	switch (vd_scsi->cmd_status) {
5635 
5636 	case STATUS_CHECK:
5637 	case STATUS_TERMINATED:
5638 		if (log_error)
5639 			cmn_err(CE_CONT, "\tCheck Condition Error\n");
5640 
5641 		/* check sense buffer */
5642 		if (vd_scsi->sense_len == 0 ||
5643 		    vd_scsi->sense_status != STATUS_GOOD) {
5644 			if (log_error)
5645 				cmn_err(CE_CONT, "\tNo Sense Data Available\n");
5646 			break;
5647 		}
5648 
5649 		sense = VD_SCSI_DATA_SENSE(vd_scsi);
5650 
5651 		if (log_error) {
5652 			cmn_err(CE_CONT, "\tSense Key:  0x%x\n"
5653 			    "\tASC: 0x%x, ASCQ: 0x%x\n",
5654 			    scsi_sense_key((uint8_t *)sense),
5655 			    scsi_sense_asc((uint8_t *)sense),
5656 			    scsi_sense_ascq((uint8_t *)sense));
5657 		}
5658 
5659 		if (scsi_sense_key((uint8_t *)sense) == KEY_ILLEGAL_REQUEST)
5660 			rv = ENOTSUP;
5661 		break;
5662 
5663 	case STATUS_BUSY:
5664 		if (log_error)
5665 			cmn_err(CE_NOTE, "\tDevice Busy\n");
5666 		break;
5667 
5668 	case STATUS_RESERVATION_CONFLICT:
5669 		/*
5670 		 * If the command was PERSISTENT_RESERVATION_[IN|OUT] then
5671 		 * reservation conflict could be due to various reasons like
5672 		 * incorrect keys, not registered or not reserved etc. So,
5673 		 * we should not panic in that case.
5674 		 */
5675 		cdb = VD_SCSI_DATA_CDB(vd_scsi);
5676 		if (vdc->failfast_interval != 0 &&
5677 		    cdb->scc_cmd != SCMD_PERSISTENT_RESERVE_IN &&
5678 		    cdb->scc_cmd != SCMD_PERSISTENT_RESERVE_OUT) {
5679 			/* failfast is enabled so we have to panic */
5680 			(void) snprintf(panic_str, sizeof (panic_str),
5681 			    VDC_RESV_CONFLICT_FMT_STR "%s",
5682 			    ddi_pathname(vdc->dip, path_str));
5683 			panic(panic_str);
5684 		}
5685 		if (log_error)
5686 			cmn_err(CE_NOTE, "\tReservation Conflict\n");
5687 		rv = EACCES;
5688 		break;
5689 
5690 	case STATUS_QFULL:
5691 		if (log_error)
5692 			cmn_err(CE_NOTE, "\tQueue Full\n");
5693 		break;
5694 
5695 	case STATUS_MET:
5696 	case STATUS_INTERMEDIATE:
5697 	case STATUS_SCSI2:
5698 	case STATUS_INTERMEDIATE_MET:
5699 	case STATUS_ACA_ACTIVE:
5700 		if (log_error)
5701 			cmn_err(CE_CONT,
5702 			    "\tUnexpected SCSI status received: 0x%x\n",
5703 			    vd_scsi->cmd_status);
5704 		break;
5705 
5706 	default:
5707 		if (log_error)
5708 			cmn_err(CE_CONT,
5709 			    "\tInvalid SCSI status received: 0x%x\n",
5710 			    vd_scsi->cmd_status);
5711 		break;
5712 	}
5713 
5714 	return (rv);
5715 }
5716 
5717 /*
5718  * Implemented the USCSICMD uscsi(7I) ioctl. This ioctl is converted to
5719  * a VD_OP_SCSICMD operation which is sent to the vdisk server. If a SCSI
5720  * reset is requested (i.e. a flag USCSI_RESET* is set) then the ioctl is
5721  * converted to a VD_OP_RESET operation.
5722  */
5723 static int
5724 vdc_uscsi_cmd(vdc_t *vdc, caddr_t arg, int mode)
5725 {
5726 	struct uscsi_cmd 	uscsi;
5727 	struct uscsi_cmd32	uscsi32;
5728 	vd_scsi_t 		*vd_scsi;
5729 	int 			vd_scsi_len;
5730 	union scsi_cdb		*cdb;
5731 	struct scsi_extended_sense *sense;
5732 	char 			*datain, *dataout;
5733 	size_t			cdb_len, datain_len, dataout_len, sense_len;
5734 	int 			rv;
5735 
5736 	if (ddi_model_convert_from(mode & FMODELS) == DDI_MODEL_ILP32) {
5737 		if (ddi_copyin(arg, &uscsi32, sizeof (struct uscsi_cmd32),
5738 		    mode) != 0)
5739 			return (EFAULT);
5740 		uscsi_cmd32touscsi_cmd((&uscsi32), (&uscsi));
5741 	} else {
5742 		if (ddi_copyin(arg, &uscsi, sizeof (struct uscsi_cmd),
5743 		    mode) != 0)
5744 			return (EFAULT);
5745 	}
5746 
5747 	/* a uscsi reset is converted to a VD_OP_RESET operation */
5748 	if (uscsi.uscsi_flags & (USCSI_RESET | USCSI_RESET_LUN |
5749 	    USCSI_RESET_ALL)) {
5750 		rv = vdc_do_sync_op(vdc, VD_OP_RESET, NULL, 0, 0, 0,
5751 		    VIO_both_dir, B_TRUE);
5752 		return (rv);
5753 	}
5754 
5755 	/* cdb buffer length */
5756 	cdb_len = uscsi.uscsi_cdblen;
5757 
5758 	/* data in and out buffers length */
5759 	if (uscsi.uscsi_flags & USCSI_READ) {
5760 		datain_len = uscsi.uscsi_buflen;
5761 		dataout_len = 0;
5762 	} else {
5763 		datain_len = 0;
5764 		dataout_len = uscsi.uscsi_buflen;
5765 	}
5766 
5767 	/* sense buffer length */
5768 	if (uscsi.uscsi_flags & USCSI_RQENABLE)
5769 		sense_len = uscsi.uscsi_rqlen;
5770 	else
5771 		sense_len = 0;
5772 
5773 	/* allocate buffer for the VD_SCSICMD_OP operation */
5774 	vd_scsi = vdc_scsi_alloc(cdb_len, sense_len, datain_len, dataout_len,
5775 	    &vd_scsi_len);
5776 
5777 	/*
5778 	 * The documentation of USCSI_ISOLATE and USCSI_DIAGNOSE is very vague,
5779 	 * but basically they prevent a SCSI command from being retried in case
5780 	 * of an error.
5781 	 */
5782 	if ((uscsi.uscsi_flags & USCSI_ISOLATE) ||
5783 	    (uscsi.uscsi_flags & USCSI_DIAGNOSE))
5784 		vd_scsi->options |= VD_SCSI_OPT_NORETRY;
5785 
5786 	/* set task attribute */
5787 	if (uscsi.uscsi_flags & USCSI_NOTAG) {
5788 		vd_scsi->task_attribute = 0;
5789 	} else {
5790 		if (uscsi.uscsi_flags & USCSI_HEAD)
5791 			vd_scsi->task_attribute = VD_SCSI_TASK_ACA;
5792 		else if (uscsi.uscsi_flags & USCSI_HTAG)
5793 			vd_scsi->task_attribute = VD_SCSI_TASK_HQUEUE;
5794 		else if (uscsi.uscsi_flags & USCSI_OTAG)
5795 			vd_scsi->task_attribute = VD_SCSI_TASK_ORDERED;
5796 		else
5797 			vd_scsi->task_attribute = 0;
5798 	}
5799 
5800 	/* set timeout */
5801 	vd_scsi->timeout = uscsi.uscsi_timeout;
5802 
5803 	/* copy-in cdb data */
5804 	cdb = VD_SCSI_DATA_CDB(vd_scsi);
5805 	if (ddi_copyin(uscsi.uscsi_cdb, cdb, cdb_len, mode) != 0) {
5806 		rv = EFAULT;
5807 		goto done;
5808 	}
5809 
5810 	/* keep a pointer to the sense buffer */
5811 	sense = VD_SCSI_DATA_SENSE(vd_scsi);
5812 
5813 	/* keep a pointer to the data-in buffer */
5814 	datain = (char *)VD_SCSI_DATA_IN(vd_scsi);
5815 
5816 	/* copy-in request data to the data-out buffer */
5817 	dataout = (char *)VD_SCSI_DATA_OUT(vd_scsi);
5818 	if (!(uscsi.uscsi_flags & USCSI_READ)) {
5819 		if (ddi_copyin(uscsi.uscsi_bufaddr, dataout, dataout_len,
5820 		    mode)) {
5821 			rv = EFAULT;
5822 			goto done;
5823 		}
5824 	}
5825 
5826 	/* submit the request */
5827 	rv = vdc_do_sync_op(vdc, VD_OP_SCSICMD, (caddr_t)vd_scsi, vd_scsi_len,
5828 	    0, 0, VIO_both_dir, B_FALSE);
5829 
5830 	if (rv != 0)
5831 		goto done;
5832 
5833 	/* update scsi status */
5834 	uscsi.uscsi_status = vd_scsi->cmd_status;
5835 
5836 	/* update sense data */
5837 	if ((uscsi.uscsi_flags & USCSI_RQENABLE) &&
5838 	    (uscsi.uscsi_status == STATUS_CHECK ||
5839 	    uscsi.uscsi_status == STATUS_TERMINATED)) {
5840 
5841 		uscsi.uscsi_rqstatus = vd_scsi->sense_status;
5842 
5843 		if (uscsi.uscsi_rqstatus == STATUS_GOOD) {
5844 			uscsi.uscsi_rqresid = uscsi.uscsi_rqlen -
5845 			    vd_scsi->sense_len;
5846 			if (ddi_copyout(sense, uscsi.uscsi_rqbuf,
5847 			    vd_scsi->sense_len, mode) != 0) {
5848 				rv = EFAULT;
5849 				goto done;
5850 			}
5851 		}
5852 	}
5853 
5854 	/* update request data */
5855 	if (uscsi.uscsi_status == STATUS_GOOD) {
5856 		if (uscsi.uscsi_flags & USCSI_READ) {
5857 			uscsi.uscsi_resid = uscsi.uscsi_buflen -
5858 			    vd_scsi->datain_len;
5859 			if (ddi_copyout(datain, uscsi.uscsi_bufaddr,
5860 			    vd_scsi->datain_len, mode) != 0) {
5861 				rv = EFAULT;
5862 				goto done;
5863 			}
5864 		} else {
5865 			uscsi.uscsi_resid = uscsi.uscsi_buflen -
5866 			    vd_scsi->dataout_len;
5867 		}
5868 	}
5869 
5870 	/* copy-out result */
5871 	if (ddi_model_convert_from(mode & FMODELS) == DDI_MODEL_ILP32) {
5872 		uscsi_cmdtouscsi_cmd32((&uscsi), (&uscsi32));
5873 		if (ddi_copyout(&uscsi32, arg, sizeof (struct uscsi_cmd32),
5874 		    mode) != 0) {
5875 			rv = EFAULT;
5876 			goto done;
5877 		}
5878 	} else {
5879 		if (ddi_copyout(&uscsi, arg, sizeof (struct uscsi_cmd),
5880 		    mode) != 0) {
5881 			rv = EFAULT;
5882 			goto done;
5883 		}
5884 	}
5885 
5886 	/* get the return code from the SCSI command status */
5887 	rv = vdc_scsi_status(vdc, vd_scsi,
5888 	    !(uscsi.uscsi_flags & USCSI_SILENT));
5889 
5890 done:
5891 	kmem_free(vd_scsi, vd_scsi_len);
5892 	return (rv);
5893 }
5894 
5895 /*
5896  * Create a VD_OP_SCSICMD buffer for a SCSI PERSISTENT IN command.
5897  *
5898  * Arguments:
5899  *	cmd		- SCSI PERSISTENT IN command
5900  *	len		- length of the SCSI input buffer
5901  *	vd_scsi_len	- return the length of the allocated buffer
5902  *
5903  * Returned Value:
5904  *	a pointer to the allocated VD_OP_SCSICMD buffer.
5905  */
5906 static vd_scsi_t *
5907 vdc_scsi_alloc_persistent_in(uchar_t cmd, int len, int *vd_scsi_len)
5908 {
5909 	int cdb_len, sense_len, datain_len, dataout_len;
5910 	vd_scsi_t *vd_scsi;
5911 	union scsi_cdb *cdb;
5912 
5913 	cdb_len = CDB_GROUP1;
5914 	sense_len = sizeof (struct scsi_extended_sense);
5915 	datain_len = len;
5916 	dataout_len = 0;
5917 
5918 	vd_scsi = vdc_scsi_alloc(cdb_len, sense_len, datain_len, dataout_len,
5919 	    vd_scsi_len);
5920 
5921 	cdb = VD_SCSI_DATA_CDB(vd_scsi);
5922 
5923 	/* set cdb */
5924 	cdb->scc_cmd = SCMD_PERSISTENT_RESERVE_IN;
5925 	cdb->cdb_opaque[1] = cmd;
5926 	FORMG1COUNT(cdb, datain_len);
5927 
5928 	vd_scsi->timeout = vdc_scsi_timeout;
5929 
5930 	return (vd_scsi);
5931 }
5932 
5933 /*
5934  * Create a VD_OP_SCSICMD buffer for a SCSI PERSISTENT OUT command.
5935  *
5936  * Arguments:
5937  *	cmd		- SCSI PERSISTENT OUT command
5938  *	len		- length of the SCSI output buffer
5939  *	vd_scsi_len	- return the length of the allocated buffer
5940  *
5941  * Returned Code:
5942  *	a pointer to the allocated VD_OP_SCSICMD buffer.
5943  */
5944 static vd_scsi_t *
5945 vdc_scsi_alloc_persistent_out(uchar_t cmd, int len, int *vd_scsi_len)
5946 {
5947 	int cdb_len, sense_len, datain_len, dataout_len;
5948 	vd_scsi_t *vd_scsi;
5949 	union scsi_cdb *cdb;
5950 
5951 	cdb_len = CDB_GROUP1;
5952 	sense_len = sizeof (struct scsi_extended_sense);
5953 	datain_len = 0;
5954 	dataout_len = len;
5955 
5956 	vd_scsi = vdc_scsi_alloc(cdb_len, sense_len, datain_len, dataout_len,
5957 	    vd_scsi_len);
5958 
5959 	cdb = VD_SCSI_DATA_CDB(vd_scsi);
5960 
5961 	/* set cdb */
5962 	cdb->scc_cmd = SCMD_PERSISTENT_RESERVE_OUT;
5963 	cdb->cdb_opaque[1] = cmd;
5964 	FORMG1COUNT(cdb, dataout_len);
5965 
5966 	vd_scsi->timeout = vdc_scsi_timeout;
5967 
5968 	return (vd_scsi);
5969 }
5970 
5971 /*
5972  * Implement the MHIOCGRP_INKEYS mhd(7i) ioctl. The ioctl is converted
5973  * to a SCSI PERSISTENT IN READ KEYS command which is sent to the vdisk
5974  * server with a VD_OP_SCSICMD operation.
5975  */
5976 static int
5977 vdc_mhd_inkeys(vdc_t *vdc, caddr_t arg, int mode)
5978 {
5979 	vd_scsi_t *vd_scsi;
5980 	mhioc_inkeys_t inkeys;
5981 	mhioc_key_list_t klist;
5982 	struct mhioc_inkeys32 inkeys32;
5983 	struct mhioc_key_list32 klist32;
5984 	sd_prin_readkeys_t *scsi_keys;
5985 	void *user_keys;
5986 	int vd_scsi_len;
5987 	int listsize, listlen, rv;
5988 
5989 	/* copyin arguments */
5990 	if (ddi_model_convert_from(mode & FMODELS) == DDI_MODEL_ILP32) {
5991 		rv = ddi_copyin(arg, &inkeys32, sizeof (inkeys32), mode);
5992 		if (rv != 0)
5993 			return (EFAULT);
5994 
5995 		rv = ddi_copyin((caddr_t)(uintptr_t)inkeys32.li, &klist32,
5996 		    sizeof (klist32), mode);
5997 		if (rv != 0)
5998 			return (EFAULT);
5999 
6000 		listsize = klist32.listsize;
6001 	} else {
6002 		rv = ddi_copyin(arg, &inkeys, sizeof (inkeys), mode);
6003 		if (rv != 0)
6004 			return (EFAULT);
6005 
6006 		rv = ddi_copyin(inkeys.li, &klist, sizeof (klist), mode);
6007 		if (rv != 0)
6008 			return (EFAULT);
6009 
6010 		listsize = klist.listsize;
6011 	}
6012 
6013 	/* build SCSI VD_OP request */
6014 	vd_scsi = vdc_scsi_alloc_persistent_in(SD_READ_KEYS,
6015 	    sizeof (sd_prin_readkeys_t) - sizeof (caddr_t) +
6016 	    (sizeof (mhioc_resv_key_t) * listsize), &vd_scsi_len);
6017 
6018 	scsi_keys = (sd_prin_readkeys_t *)VD_SCSI_DATA_IN(vd_scsi);
6019 
6020 	/* submit the request */
6021 	rv = vdc_do_sync_op(vdc, VD_OP_SCSICMD, (caddr_t)vd_scsi, vd_scsi_len,
6022 	    0, 0, VIO_both_dir, B_FALSE);
6023 
6024 	if (rv != 0)
6025 		goto done;
6026 
6027 	listlen = scsi_keys->len / MHIOC_RESV_KEY_SIZE;
6028 
6029 	if (ddi_model_convert_from(mode & FMODELS) == DDI_MODEL_ILP32) {
6030 		inkeys32.generation = scsi_keys->generation;
6031 		rv = ddi_copyout(&inkeys32, arg, sizeof (inkeys32), mode);
6032 		if (rv != 0) {
6033 			rv = EFAULT;
6034 			goto done;
6035 		}
6036 
6037 		klist32.listlen = listlen;
6038 		rv = ddi_copyout(&klist32, (caddr_t)(uintptr_t)inkeys32.li,
6039 		    sizeof (klist32), mode);
6040 		if (rv != 0) {
6041 			rv = EFAULT;
6042 			goto done;
6043 		}
6044 
6045 		user_keys = (caddr_t)(uintptr_t)klist32.list;
6046 	} else {
6047 		inkeys.generation = scsi_keys->generation;
6048 		rv = ddi_copyout(&inkeys, arg, sizeof (inkeys), mode);
6049 		if (rv != 0) {
6050 			rv = EFAULT;
6051 			goto done;
6052 		}
6053 
6054 		klist.listlen = listlen;
6055 		rv = ddi_copyout(&klist, inkeys.li, sizeof (klist), mode);
6056 		if (rv != 0) {
6057 			rv = EFAULT;
6058 			goto done;
6059 		}
6060 
6061 		user_keys = klist.list;
6062 	}
6063 
6064 	/* copy out keys */
6065 	if (listlen > 0 && listsize > 0) {
6066 		if (listsize < listlen)
6067 			listlen = listsize;
6068 		rv = ddi_copyout(&scsi_keys->keylist, user_keys,
6069 		    listlen * MHIOC_RESV_KEY_SIZE, mode);
6070 		if (rv != 0)
6071 			rv = EFAULT;
6072 	}
6073 
6074 	if (rv == 0)
6075 		rv = vdc_scsi_status(vdc, vd_scsi, B_FALSE);
6076 
6077 done:
6078 	kmem_free(vd_scsi, vd_scsi_len);
6079 
6080 	return (rv);
6081 }
6082 
6083 /*
6084  * Implement the MHIOCGRP_INRESV mhd(7i) ioctl. The ioctl is converted
6085  * to a SCSI PERSISTENT IN READ RESERVATION command which is sent to
6086  * the vdisk server with a VD_OP_SCSICMD operation.
6087  */
6088 static int
6089 vdc_mhd_inresv(vdc_t *vdc, caddr_t arg, int mode)
6090 {
6091 	vd_scsi_t *vd_scsi;
6092 	mhioc_inresvs_t inresv;
6093 	mhioc_resv_desc_list_t rlist;
6094 	struct mhioc_inresvs32 inresv32;
6095 	struct mhioc_resv_desc_list32 rlist32;
6096 	mhioc_resv_desc_t mhd_resv;
6097 	sd_prin_readresv_t *scsi_resv;
6098 	sd_readresv_desc_t *resv;
6099 	mhioc_resv_desc_t *user_resv;
6100 	int vd_scsi_len;
6101 	int listsize, listlen, i, rv;
6102 
6103 	/* copyin arguments */
6104 	if (ddi_model_convert_from(mode & FMODELS) == DDI_MODEL_ILP32) {
6105 		rv = ddi_copyin(arg, &inresv32, sizeof (inresv32), mode);
6106 		if (rv != 0)
6107 			return (EFAULT);
6108 
6109 		rv = ddi_copyin((caddr_t)(uintptr_t)inresv32.li, &rlist32,
6110 		    sizeof (rlist32), mode);
6111 		if (rv != 0)
6112 			return (EFAULT);
6113 
6114 		listsize = rlist32.listsize;
6115 	} else {
6116 		rv = ddi_copyin(arg, &inresv, sizeof (inresv), mode);
6117 		if (rv != 0)
6118 			return (EFAULT);
6119 
6120 		rv = ddi_copyin(inresv.li, &rlist, sizeof (rlist), mode);
6121 		if (rv != 0)
6122 			return (EFAULT);
6123 
6124 		listsize = rlist.listsize;
6125 	}
6126 
6127 	/* build SCSI VD_OP request */
6128 	vd_scsi = vdc_scsi_alloc_persistent_in(SD_READ_RESV,
6129 	    sizeof (sd_prin_readresv_t) - sizeof (caddr_t) +
6130 	    (SCSI3_RESV_DESC_LEN * listsize), &vd_scsi_len);
6131 
6132 	scsi_resv = (sd_prin_readresv_t *)VD_SCSI_DATA_IN(vd_scsi);
6133 
6134 	/* submit the request */
6135 	rv = vdc_do_sync_op(vdc, VD_OP_SCSICMD, (caddr_t)vd_scsi, vd_scsi_len,
6136 	    0, 0, VIO_both_dir, B_FALSE);
6137 
6138 	if (rv != 0)
6139 		goto done;
6140 
6141 	listlen = scsi_resv->len / SCSI3_RESV_DESC_LEN;
6142 
6143 	if (ddi_model_convert_from(mode & FMODELS) == DDI_MODEL_ILP32) {
6144 		inresv32.generation = scsi_resv->generation;
6145 		rv = ddi_copyout(&inresv32, arg, sizeof (inresv32), mode);
6146 		if (rv != 0) {
6147 			rv = EFAULT;
6148 			goto done;
6149 		}
6150 
6151 		rlist32.listlen = listlen;
6152 		rv = ddi_copyout(&rlist32, (caddr_t)(uintptr_t)inresv32.li,
6153 		    sizeof (rlist32), mode);
6154 		if (rv != 0) {
6155 			rv = EFAULT;
6156 			goto done;
6157 		}
6158 
6159 		user_resv = (mhioc_resv_desc_t *)(uintptr_t)rlist32.list;
6160 	} else {
6161 		inresv.generation = scsi_resv->generation;
6162 		rv = ddi_copyout(&inresv, arg, sizeof (inresv), mode);
6163 		if (rv != 0) {
6164 			rv = EFAULT;
6165 			goto done;
6166 		}
6167 
6168 		rlist.listlen = listlen;
6169 		rv = ddi_copyout(&rlist, inresv.li, sizeof (rlist), mode);
6170 		if (rv != 0) {
6171 			rv = EFAULT;
6172 			goto done;
6173 		}
6174 
6175 		user_resv = rlist.list;
6176 	}
6177 
6178 	/* copy out reservations */
6179 	if (listsize > 0 && listlen > 0) {
6180 		if (listsize < listlen)
6181 			listlen = listsize;
6182 		resv = (sd_readresv_desc_t *)&scsi_resv->readresv_desc;
6183 
6184 		for (i = 0; i < listlen; i++) {
6185 			mhd_resv.type = resv->type;
6186 			mhd_resv.scope = resv->scope;
6187 			mhd_resv.scope_specific_addr =
6188 			    BE_32(resv->scope_specific_addr);
6189 			bcopy(&resv->resvkey, &mhd_resv.key,
6190 			    MHIOC_RESV_KEY_SIZE);
6191 
6192 			rv = ddi_copyout(&mhd_resv, user_resv,
6193 			    sizeof (mhd_resv), mode);
6194 			if (rv != 0) {
6195 				rv = EFAULT;
6196 				goto done;
6197 			}
6198 			resv++;
6199 			user_resv++;
6200 		}
6201 	}
6202 
6203 	if (rv == 0)
6204 		rv = vdc_scsi_status(vdc, vd_scsi, B_FALSE);
6205 
6206 done:
6207 	kmem_free(vd_scsi, vd_scsi_len);
6208 	return (rv);
6209 }
6210 
6211 /*
6212  * Implement the MHIOCGRP_REGISTER mhd(7i) ioctl. The ioctl is converted
6213  * to a SCSI PERSISTENT OUT REGISTER command which is sent to the vdisk
6214  * server with a VD_OP_SCSICMD operation.
6215  */
6216 static int
6217 vdc_mhd_register(vdc_t *vdc, caddr_t arg, int mode)
6218 {
6219 	vd_scsi_t *vd_scsi;
6220 	sd_prout_t *scsi_prout;
6221 	mhioc_register_t mhd_reg;
6222 	int vd_scsi_len, rv;
6223 
6224 	/* copyin arguments */
6225 	rv = ddi_copyin(arg, &mhd_reg, sizeof (mhd_reg), mode);
6226 	if (rv != 0)
6227 		return (EFAULT);
6228 
6229 	/* build SCSI VD_OP request */
6230 	vd_scsi = vdc_scsi_alloc_persistent_out(SD_SCSI3_REGISTER,
6231 	    sizeof (sd_prout_t), &vd_scsi_len);
6232 
6233 	/* set parameters */
6234 	scsi_prout = (sd_prout_t *)VD_SCSI_DATA_OUT(vd_scsi);
6235 	bcopy(mhd_reg.oldkey.key, scsi_prout->res_key, MHIOC_RESV_KEY_SIZE);
6236 	bcopy(mhd_reg.newkey.key, scsi_prout->service_key, MHIOC_RESV_KEY_SIZE);
6237 	scsi_prout->aptpl = (uchar_t)mhd_reg.aptpl;
6238 
6239 	/* submit the request */
6240 	rv = vdc_do_sync_op(vdc, VD_OP_SCSICMD, (caddr_t)vd_scsi, vd_scsi_len,
6241 	    0, 0, VIO_both_dir, B_FALSE);
6242 
6243 	if (rv == 0)
6244 		rv = vdc_scsi_status(vdc, vd_scsi, B_FALSE);
6245 
6246 	kmem_free(vd_scsi, vd_scsi_len);
6247 	return (rv);
6248 }
6249 
6250 /*
6251  * Implement the MHIOCGRP_RESERVE mhd(7i) ioctl. The ioctl is converted
6252  * to a SCSI PERSISTENT OUT RESERVE command which is sent to the vdisk
6253  * server with a VD_OP_SCSICMD operation.
6254  */
6255 static int
6256 vdc_mhd_reserve(vdc_t *vdc, caddr_t arg, int mode)
6257 {
6258 	union scsi_cdb *cdb;
6259 	vd_scsi_t *vd_scsi;
6260 	sd_prout_t *scsi_prout;
6261 	mhioc_resv_desc_t mhd_resv;
6262 	int vd_scsi_len, rv;
6263 
6264 	/* copyin arguments */
6265 	rv = ddi_copyin(arg, &mhd_resv, sizeof (mhd_resv), mode);
6266 	if (rv != 0)
6267 		return (EFAULT);
6268 
6269 	/* build SCSI VD_OP request */
6270 	vd_scsi = vdc_scsi_alloc_persistent_out(SD_SCSI3_RESERVE,
6271 	    sizeof (sd_prout_t), &vd_scsi_len);
6272 
6273 	/* set parameters */
6274 	cdb = VD_SCSI_DATA_CDB(vd_scsi);
6275 	scsi_prout = (sd_prout_t *)VD_SCSI_DATA_OUT(vd_scsi);
6276 	bcopy(mhd_resv.key.key, scsi_prout->res_key, MHIOC_RESV_KEY_SIZE);
6277 	scsi_prout->scope_address = mhd_resv.scope_specific_addr;
6278 	cdb->cdb_opaque[2] = mhd_resv.type;
6279 
6280 	/* submit the request */
6281 	rv = vdc_do_sync_op(vdc, VD_OP_SCSICMD, (caddr_t)vd_scsi, vd_scsi_len,
6282 	    0, 0, VIO_both_dir, B_FALSE);
6283 
6284 	if (rv == 0)
6285 		rv = vdc_scsi_status(vdc, vd_scsi, B_FALSE);
6286 
6287 	kmem_free(vd_scsi, vd_scsi_len);
6288 	return (rv);
6289 }
6290 
6291 /*
6292  * Implement the MHIOCGRP_PREEMPTANDABORT mhd(7i) ioctl. The ioctl is
6293  * converted to a SCSI PERSISTENT OUT PREEMPT AND ABORT command which
6294  * is sent to the vdisk server with a VD_OP_SCSICMD operation.
6295  */
6296 static int
6297 vdc_mhd_preemptabort(vdc_t *vdc, caddr_t arg, int mode)
6298 {
6299 	union scsi_cdb *cdb;
6300 	vd_scsi_t *vd_scsi;
6301 	sd_prout_t *scsi_prout;
6302 	mhioc_preemptandabort_t mhd_preempt;
6303 	int vd_scsi_len, rv;
6304 
6305 	/* copyin arguments */
6306 	rv = ddi_copyin(arg, &mhd_preempt, sizeof (mhd_preempt), mode);
6307 	if (rv != 0)
6308 		return (EFAULT);
6309 
6310 	/* build SCSI VD_OP request */
6311 	vd_scsi = vdc_scsi_alloc_persistent_out(SD_SCSI3_PREEMPTANDABORT,
6312 	    sizeof (sd_prout_t), &vd_scsi_len);
6313 
6314 	/* set parameters */
6315 	vd_scsi->task_attribute = VD_SCSI_TASK_ACA;
6316 	cdb = VD_SCSI_DATA_CDB(vd_scsi);
6317 	scsi_prout = (sd_prout_t *)VD_SCSI_DATA_OUT(vd_scsi);
6318 	bcopy(mhd_preempt.resvdesc.key.key, scsi_prout->res_key,
6319 	    MHIOC_RESV_KEY_SIZE);
6320 	bcopy(mhd_preempt.victim_key.key, scsi_prout->service_key,
6321 	    MHIOC_RESV_KEY_SIZE);
6322 	scsi_prout->scope_address = mhd_preempt.resvdesc.scope_specific_addr;
6323 	cdb->cdb_opaque[2] = mhd_preempt.resvdesc.type;
6324 
6325 	/* submit the request */
6326 	rv = vdc_do_sync_op(vdc, VD_OP_SCSICMD, (caddr_t)vd_scsi, vd_scsi_len,
6327 	    0, 0, VIO_both_dir, B_FALSE);
6328 
6329 	if (rv == 0)
6330 		rv = vdc_scsi_status(vdc, vd_scsi, B_FALSE);
6331 
6332 	kmem_free(vd_scsi, vd_scsi_len);
6333 	return (rv);
6334 }
6335 
6336 /*
6337  * Implement the MHIOCGRP_REGISTERANDIGNOREKEY mhd(7i) ioctl. The ioctl
6338  * is converted to a SCSI PERSISTENT OUT REGISTER AND IGNORE EXISTING KEY
6339  * command which is sent to the vdisk server with a VD_OP_SCSICMD operation.
6340  */
6341 static int
6342 vdc_mhd_registerignore(vdc_t *vdc, caddr_t arg, int mode)
6343 {
6344 	vd_scsi_t *vd_scsi;
6345 	sd_prout_t *scsi_prout;
6346 	mhioc_registerandignorekey_t mhd_regi;
6347 	int vd_scsi_len, rv;
6348 
6349 	/* copyin arguments */
6350 	rv = ddi_copyin(arg, &mhd_regi, sizeof (mhd_regi), mode);
6351 	if (rv != 0)
6352 		return (EFAULT);
6353 
6354 	/* build SCSI VD_OP request */
6355 	vd_scsi = vdc_scsi_alloc_persistent_out(SD_SCSI3_REGISTERANDIGNOREKEY,
6356 	    sizeof (sd_prout_t), &vd_scsi_len);
6357 
6358 	/* set parameters */
6359 	scsi_prout = (sd_prout_t *)VD_SCSI_DATA_OUT(vd_scsi);
6360 	bcopy(mhd_regi.newkey.key, scsi_prout->service_key,
6361 	    MHIOC_RESV_KEY_SIZE);
6362 	scsi_prout->aptpl = (uchar_t)mhd_regi.aptpl;
6363 
6364 	/* submit the request */
6365 	rv = vdc_do_sync_op(vdc, VD_OP_SCSICMD, (caddr_t)vd_scsi, vd_scsi_len,
6366 	    0, 0, VIO_both_dir, B_FALSE);
6367 
6368 	if (rv == 0)
6369 		rv = vdc_scsi_status(vdc, vd_scsi, B_FALSE);
6370 
6371 	kmem_free(vd_scsi, vd_scsi_len);
6372 	return (rv);
6373 }
6374 
6375 /*
6376  * This function is used to send a (simple) SCSI command and check errors.
6377  */
6378 static int
6379 vdc_eio_scsi_cmd(vdc_t *vdc, uchar_t scmd, int flags)
6380 {
6381 	int cdb_len, sense_len, vd_scsi_len;
6382 	vd_scsi_t *vd_scsi;
6383 	union scsi_cdb *cdb;
6384 	int rv;
6385 
6386 	ASSERT(scmd == SCMD_TEST_UNIT_READY || scmd == SCMD_WRITE_G1);
6387 
6388 	if (scmd == SCMD_WRITE_G1)
6389 		cdb_len = CDB_GROUP1;
6390 	else
6391 		cdb_len = CDB_GROUP0;
6392 
6393 	sense_len = sizeof (struct scsi_extended_sense);
6394 
6395 	vd_scsi = vdc_scsi_alloc(cdb_len, sense_len, 0, 0, &vd_scsi_len);
6396 
6397 	/* set cdb */
6398 	cdb = VD_SCSI_DATA_CDB(vd_scsi);
6399 	cdb->scc_cmd = scmd;
6400 
6401 	vd_scsi->timeout = vdc_scsi_timeout;
6402 
6403 	/*
6404 	 * Submit the request. Note the operation should not request that any
6405 	 * error is checked because this function is precisely called when
6406 	 * checking errors.
6407 	 */
6408 	ASSERT((flags & VDC_OP_ERRCHK) == 0);
6409 
6410 	rv = vdc_do_op(vdc, VD_OP_SCSICMD, (caddr_t)vd_scsi, vd_scsi_len,
6411 	    0, 0, NULL, VIO_both_dir, flags);
6412 
6413 	if (rv == 0)
6414 		rv = vdc_scsi_status(vdc, vd_scsi, B_FALSE);
6415 
6416 	kmem_free(vd_scsi, vd_scsi_len);
6417 	return (rv);
6418 }
6419 
6420 /*
6421  * This function is used to check if a SCSI backend is accessible. It will
6422  * also detect reservation conflict if failfast is enabled, and panic the
6423  * system in that case.
6424  *
6425  * Returned Code:
6426  *	0	- disk is accessible
6427  *	!= 0	- disk is inaccessible or unable to check if disk is accessible
6428  */
6429 static int
6430 vdc_eio_scsi_check(vdc_t *vdc, int flags)
6431 {
6432 	int failure = 0;
6433 	int rv;
6434 
6435 	/*
6436 	 * Send a TEST UNIT READY command. The command will panic
6437 	 * the system if it fails with a reservation conflict and
6438 	 * failfast is enabled. If there is a reservation conflict
6439 	 * and failfast is not enabled then the function will return
6440 	 * EACCES. In that case, there's no problem with accessing
6441 	 * the backend, it is just reserved.
6442 	 */
6443 	rv = vdc_eio_scsi_cmd(vdc, SCMD_TEST_UNIT_READY, flags);
6444 	if (rv != 0 && rv != EACCES)
6445 		failure++;
6446 
6447 	/* we don't need to do more checking if failfast is not enabled */
6448 	if (vdc->failfast_interval == 0)
6449 		return (failure);
6450 
6451 	/*
6452 	 * With SPC-3 compliant devices TEST UNIT READY will succeed on
6453 	 * a reserved device, so we also do a WRITE(10) of zero byte in
6454 	 * order to provoke a Reservation Conflict status on those newer
6455 	 * devices.
6456 	 */
6457 	if (vdc_eio_scsi_cmd(vdc, SCMD_WRITE_G1, flags) != 0)
6458 		failure++;
6459 
6460 	return (failure);
6461 }
6462 
6463 /*
6464  * This function is used to check if a backend is effectively accessible.
6465  *
6466  * Returned Code:
6467  *	0	- disk is accessible
6468  *	!= 0	- disk is inaccessible or unable to check if disk is accessible
6469  */
6470 static int
6471 vdc_eio_check(vdc_t *vdc, int flags)
6472 {
6473 	char *buffer;
6474 	diskaddr_t blkno;
6475 	int rv;
6476 
6477 	ASSERT((flags & VDC_OP_ERRCHK) == 0);
6478 
6479 	if (VD_OP_SUPPORTED(vdc->operations, VD_OP_SCSICMD))
6480 		return (vdc_eio_scsi_check(vdc, flags));
6481 
6482 	ASSERT(vdc->failfast_interval == 0);
6483 
6484 	/*
6485 	 * If the backend does not support SCSI operations then we simply
6486 	 * check if the backend is accessible by reading some data blocks.
6487 	 * We first try to read a random block, to try to avoid getting
6488 	 * a block that might have been cached on the service domain. Then
6489 	 * we try the last block, and finally the first block.
6490 	 *
6491 	 * We return success as soon as we are able to read any block.
6492 	 */
6493 	buffer = kmem_alloc(vdc->vdisk_bsize, KM_SLEEP);
6494 
6495 	if (vdc->vdisk_size > 0) {
6496 
6497 		/* try a random block */
6498 		(void) random_get_pseudo_bytes((uint8_t *)&blkno,
6499 		    sizeof (diskaddr_t));
6500 		blkno = blkno % vdc->vdisk_size;
6501 		rv = vdc_do_op(vdc, VD_OP_BREAD, (caddr_t)buffer,
6502 		    vdc->vdisk_bsize, VD_SLICE_NONE, blkno, NULL,
6503 		    VIO_read_dir, flags);
6504 
6505 		if (rv == 0)
6506 			goto done;
6507 
6508 		/* try the last block */
6509 		blkno = vdc->vdisk_size - 1;
6510 		rv = vdc_do_op(vdc, VD_OP_BREAD, (caddr_t)buffer,
6511 		    vdc->vdisk_bsize, VD_SLICE_NONE, blkno, NULL,
6512 		    VIO_read_dir, flags);
6513 
6514 		if (rv == 0)
6515 			goto done;
6516 	}
6517 
6518 	/* try block 0 */
6519 	blkno = 0;
6520 	rv = vdc_do_op(vdc, VD_OP_BREAD, (caddr_t)buffer, vdc->vdisk_bsize,
6521 	    VD_SLICE_NONE, blkno, NULL, VIO_read_dir, flags);
6522 
6523 done:
6524 	kmem_free(buffer, vdc->vdisk_bsize);
6525 	return (rv);
6526 }
6527 
6528 /*
6529  * Add a pending I/O to the eio queue. An I/O is added to this queue
6530  * when it has failed and failfast is enabled or the vdisk has multiple
6531  * servers. It will then be handled by the eio thread (vdc_eio_thread).
6532  * The eio queue is ordered starting with the most recent I/O added.
6533  */
6534 static vdc_io_t *
6535 vdc_eio_queue(vdc_t *vdc, int index)
6536 {
6537 	vdc_io_t *vio;
6538 
6539 	ASSERT(MUTEX_HELD(&vdc->lock));
6540 
6541 	vio = kmem_alloc(sizeof (vdc_io_t), KM_SLEEP);
6542 	vio->vio_next = vdc->eio_queue;
6543 	vio->vio_index = index;
6544 	vio->vio_qtime = ddi_get_lbolt();
6545 
6546 	vdc->eio_queue = vio;
6547 
6548 	/* notify the eio thread that a new I/O is queued */
6549 	cv_signal(&vdc->eio_cv);
6550 
6551 	return (vio);
6552 }
6553 
6554 /*
6555  * Remove I/Os added before the indicated deadline from the eio queue. A
6556  * deadline of 0 means that all I/Os have to be unqueued. The complete_io
6557  * boolean specifies if unqueued I/Os should be marked as completed or not.
6558  */
6559 static void
6560 vdc_eio_unqueue(vdc_t *vdc, clock_t deadline, boolean_t complete_io)
6561 {
6562 	struct buf *buf;
6563 	vdc_io_t *vio, *vio_tmp;
6564 	int index, op;
6565 
6566 	ASSERT(MUTEX_HELD(&vdc->lock));
6567 
6568 	vio_tmp = NULL;
6569 	vio = vdc->eio_queue;
6570 
6571 	if (deadline != 0) {
6572 		/*
6573 		 * Skip any io queued after the deadline. The eio queue is
6574 		 * ordered starting with the last I/O added to the queue.
6575 		 */
6576 		while (vio != NULL && vio->vio_qtime > deadline) {
6577 			vio_tmp = vio;
6578 			vio = vio->vio_next;
6579 		}
6580 	}
6581 
6582 	if (vio == NULL)
6583 		/* nothing to unqueue */
6584 		return;
6585 
6586 	/* update the queue */
6587 	if (vio_tmp == NULL)
6588 		vdc->eio_queue = NULL;
6589 	else
6590 		vio_tmp->vio_next = NULL;
6591 
6592 	/*
6593 	 * Free and complete unqueued I/Os if this was requested. All I/Os
6594 	 * have a block I/O data transfer structure (buf) and they are
6595 	 * completed by calling biodone().
6596 	 */
6597 	while (vio != NULL) {
6598 		vio_tmp = vio->vio_next;
6599 
6600 		if (complete_io) {
6601 			index = vio->vio_index;
6602 			op = vdc->local_dring[index].operation;
6603 			buf = vdc->local_dring[index].buf;
6604 			(void) vdc_depopulate_descriptor(vdc, index);
6605 			ASSERT(buf->b_flags & B_ERROR);
6606 			if (op == VD_OP_BREAD || op == VD_OP_BWRITE) {
6607 				VD_UPDATE_ERR_STATS(vdc, vd_softerrs);
6608 				VD_KSTAT_RUNQ_EXIT(vdc);
6609 				DTRACE_IO1(done, buf_t *, buf);
6610 			}
6611 			biodone(buf);
6612 		}
6613 
6614 		kmem_free(vio, sizeof (vdc_io_t));
6615 		vio = vio_tmp;
6616 	}
6617 }
6618 
6619 /*
6620  * Error I/O Thread.  There is one eio thread for each virtual disk that
6621  * has multiple servers or for which failfast is enabled. Failfast can only
6622  * be enabled for vdisk supporting SCSI commands.
6623  *
6624  * While failfast is enabled, the eio thread sends a TEST UNIT READY
6625  * and a zero size WRITE(10) SCSI commands on a regular basis to check that
6626  * we still have access to the disk. If a command fails with a RESERVATION
6627  * CONFLICT error then the system will immediatly panic.
6628  *
6629  * The eio thread is also woken up when an I/O has failed. It then checks
6630  * the access to the disk to ensure that the I/O failure was not due to a
6631  * reservation conflict or to the backend been inaccessible.
6632  *
6633  */
6634 static void
6635 vdc_eio_thread(void *arg)
6636 {
6637 	int status;
6638 	vdc_t *vdc = (vdc_t *)arg;
6639 	clock_t starttime, timeout = drv_usectohz(vdc->failfast_interval);
6640 
6641 	mutex_enter(&vdc->lock);
6642 
6643 	while (vdc->failfast_interval != 0 || vdc->num_servers > 1) {
6644 		/*
6645 		 * Wait if there is nothing in the eio queue or if the state
6646 		 * is not VDC_STATE_RUNNING.
6647 		 */
6648 		if (vdc->eio_queue == NULL || vdc->state != VDC_STATE_RUNNING) {
6649 			if (vdc->failfast_interval != 0) {
6650 				timeout = ddi_get_lbolt() +
6651 				    drv_usectohz(vdc->failfast_interval);
6652 				(void) cv_timedwait(&vdc->eio_cv, &vdc->lock,
6653 				    timeout);
6654 			} else {
6655 				ASSERT(vdc->num_servers > 1);
6656 				(void) cv_wait(&vdc->eio_cv, &vdc->lock);
6657 			}
6658 
6659 			if (vdc->state != VDC_STATE_RUNNING)
6660 				continue;
6661 		}
6662 
6663 		mutex_exit(&vdc->lock);
6664 
6665 		starttime = ddi_get_lbolt();
6666 
6667 		/* check error */
6668 		status = vdc_eio_check(vdc, VDC_OP_STATE_RUNNING);
6669 
6670 		mutex_enter(&vdc->lock);
6671 		/*
6672 		 * We have dropped the lock to check the backend so we have
6673 		 * to check that the eio thread is still enabled.
6674 		 */
6675 		if (vdc->failfast_interval == 0 && vdc->num_servers <= 1)
6676 			break;
6677 
6678 		/*
6679 		 * If the eio queue is empty or we are not in running state
6680 		 * anymore then there is nothing to do.
6681 		 */
6682 		if (vdc->state != VDC_STATE_RUNNING || vdc->eio_queue == NULL)
6683 			continue;
6684 
6685 		if (status == 0) {
6686 			/*
6687 			 * The backend access has been successfully checked,
6688 			 * we can complete any I/O queued before the last check.
6689 			 */
6690 			vdc_eio_unqueue(vdc, starttime, B_TRUE);
6691 
6692 		} else if (vdc->num_servers > 1) {
6693 			/*
6694 			 * The backend is inaccessible for a disk with multiple
6695 			 * servers. So we force a reset to switch to another
6696 			 * server. The reset will also clear the eio queue and
6697 			 * resubmit all pending I/Os.
6698 			 */
6699 			mutex_enter(&vdc->read_lock);
6700 			vdc->read_state = VDC_READ_RESET;
6701 			cv_signal(&vdc->read_cv);
6702 			mutex_exit(&vdc->read_lock);
6703 		}
6704 	}
6705 
6706 	/*
6707 	 * The thread is being stopped so we can complete any queued I/O.
6708 	 */
6709 	vdc_eio_unqueue(vdc, 0, B_TRUE);
6710 	vdc->eio_thread = NULL;
6711 	mutex_exit(&vdc->lock);
6712 	thread_exit();
6713 }
6714 
6715 /*
6716  * Implement the MHIOCENFAILFAST mhd(7i) ioctl.
6717  */
6718 static int
6719 vdc_failfast(vdc_t *vdc, caddr_t arg, int mode)
6720 {
6721 	unsigned int mh_time;
6722 
6723 	if (ddi_copyin((void *)arg, &mh_time, sizeof (int), mode))
6724 		return (EFAULT);
6725 
6726 	mutex_enter(&vdc->lock);
6727 	if (mh_time != 0 && vdc->eio_thread == NULL) {
6728 		vdc->eio_thread = thread_create(NULL, 0,
6729 		    vdc_eio_thread, vdc, 0, &p0, TS_RUN,
6730 		    v.v_maxsyspri - 2);
6731 	}
6732 
6733 	vdc->failfast_interval = ((long)mh_time) * MILLISEC;
6734 	cv_signal(&vdc->eio_cv);
6735 	mutex_exit(&vdc->lock);
6736 
6737 	return (0);
6738 }
6739 
6740 /*
6741  * Implement the MHIOCTKOWN and MHIOCRELEASE mhd(7i) ioctls. These ioctls are
6742  * converted to VD_OP_SET_ACCESS operations.
6743  */
6744 static int
6745 vdc_access_set(vdc_t *vdc, uint64_t flags)
6746 {
6747 	int rv;
6748 
6749 	/* submit owership command request */
6750 	rv = vdc_do_sync_op(vdc, VD_OP_SET_ACCESS, (caddr_t)&flags,
6751 	    sizeof (uint64_t), 0, 0, VIO_both_dir, B_TRUE);
6752 
6753 	return (rv);
6754 }
6755 
6756 /*
6757  * Implement the MHIOCSTATUS mhd(7i) ioctl. This ioctl is converted to a
6758  * VD_OP_GET_ACCESS operation.
6759  */
6760 static int
6761 vdc_access_get(vdc_t *vdc, uint64_t *status)
6762 {
6763 	int rv;
6764 
6765 	/* submit owership command request */
6766 	rv = vdc_do_sync_op(vdc, VD_OP_GET_ACCESS, (caddr_t)status,
6767 	    sizeof (uint64_t), 0, 0, VIO_both_dir, B_TRUE);
6768 
6769 	return (rv);
6770 }
6771 
6772 /*
6773  * Disk Ownership Thread.
6774  *
6775  * When we have taken the ownership of a disk, this thread waits to be
6776  * notified when the LDC channel is reset so that it can recover the
6777  * ownership.
6778  *
6779  * Note that the thread handling the LDC reset (vdc_process_msg_thread())
6780  * can not be used to do the ownership recovery because it has to be
6781  * running to handle the reply message to the ownership operation.
6782  */
6783 static void
6784 vdc_ownership_thread(void *arg)
6785 {
6786 	vdc_t *vdc = (vdc_t *)arg;
6787 	clock_t timeout;
6788 	uint64_t status;
6789 
6790 	mutex_enter(&vdc->ownership_lock);
6791 	mutex_enter(&vdc->lock);
6792 
6793 	while (vdc->ownership & VDC_OWNERSHIP_WANTED) {
6794 
6795 		if ((vdc->ownership & VDC_OWNERSHIP_RESET) ||
6796 		    !(vdc->ownership & VDC_OWNERSHIP_GRANTED)) {
6797 			/*
6798 			 * There was a reset so the ownership has been lost,
6799 			 * try to recover. We do this without using the preempt
6800 			 * option so that we don't steal the ownership from
6801 			 * someone who has preempted us.
6802 			 */
6803 			DMSG(vdc, 0, "[%d] Ownership lost, recovering",
6804 			    vdc->instance);
6805 
6806 			vdc->ownership &= ~(VDC_OWNERSHIP_RESET |
6807 			    VDC_OWNERSHIP_GRANTED);
6808 
6809 			mutex_exit(&vdc->lock);
6810 
6811 			status = vdc_access_set(vdc, VD_ACCESS_SET_EXCLUSIVE |
6812 			    VD_ACCESS_SET_PRESERVE);
6813 
6814 			mutex_enter(&vdc->lock);
6815 
6816 			if (status == 0) {
6817 				DMSG(vdc, 0, "[%d] Ownership recovered",
6818 				    vdc->instance);
6819 				vdc->ownership |= VDC_OWNERSHIP_GRANTED;
6820 			} else {
6821 				DMSG(vdc, 0, "[%d] Fail to recover ownership",
6822 				    vdc->instance);
6823 			}
6824 
6825 		}
6826 
6827 		/*
6828 		 * If we have the ownership then we just wait for an event
6829 		 * to happen (LDC reset), otherwise we will retry to recover
6830 		 * after a delay.
6831 		 */
6832 		if (vdc->ownership & VDC_OWNERSHIP_GRANTED)
6833 			timeout = 0;
6834 		else
6835 			timeout = drv_usectohz(vdc_ownership_delay);
6836 
6837 		/* Release the ownership_lock and wait on the vdc lock */
6838 		mutex_exit(&vdc->ownership_lock);
6839 
6840 		if (timeout == 0)
6841 			(void) cv_wait(&vdc->ownership_cv, &vdc->lock);
6842 		else
6843 			(void) cv_reltimedwait(&vdc->ownership_cv, &vdc->lock,
6844 			    timeout, TR_CLOCK_TICK);
6845 
6846 		mutex_exit(&vdc->lock);
6847 
6848 		mutex_enter(&vdc->ownership_lock);
6849 		mutex_enter(&vdc->lock);
6850 	}
6851 
6852 	vdc->ownership_thread = NULL;
6853 	mutex_exit(&vdc->lock);
6854 	mutex_exit(&vdc->ownership_lock);
6855 
6856 	thread_exit();
6857 }
6858 
6859 static void
6860 vdc_ownership_update(vdc_t *vdc, int ownership_flags)
6861 {
6862 	ASSERT(MUTEX_HELD(&vdc->ownership_lock));
6863 
6864 	mutex_enter(&vdc->lock);
6865 	vdc->ownership = ownership_flags;
6866 	if ((vdc->ownership & VDC_OWNERSHIP_WANTED) &&
6867 	    vdc->ownership_thread == NULL) {
6868 		/* start ownership thread */
6869 		vdc->ownership_thread = thread_create(NULL, 0,
6870 		    vdc_ownership_thread, vdc, 0, &p0, TS_RUN,
6871 		    v.v_maxsyspri - 2);
6872 	} else {
6873 		/* notify the ownership thread */
6874 		cv_signal(&vdc->ownership_cv);
6875 	}
6876 	mutex_exit(&vdc->lock);
6877 }
6878 
6879 /*
6880  * Get the size and the block size of a virtual disk from the vdisk server.
6881  */
6882 static int
6883 vdc_get_capacity(vdc_t *vdc, size_t *dsk_size, size_t *blk_size)
6884 {
6885 	int rv = 0;
6886 	size_t alloc_len;
6887 	vd_capacity_t *vd_cap;
6888 
6889 	ASSERT(MUTEX_NOT_HELD(&vdc->lock));
6890 
6891 	alloc_len = P2ROUNDUP(sizeof (vd_capacity_t), sizeof (uint64_t));
6892 
6893 	vd_cap = kmem_zalloc(alloc_len, KM_SLEEP);
6894 
6895 	rv = vdc_do_sync_op(vdc, VD_OP_GET_CAPACITY, (caddr_t)vd_cap, alloc_len,
6896 	    0, 0, VIO_both_dir, B_TRUE);
6897 
6898 	*dsk_size = vd_cap->vdisk_size;
6899 	*blk_size = vd_cap->vdisk_block_size;
6900 
6901 	kmem_free(vd_cap, alloc_len);
6902 	return (rv);
6903 }
6904 
6905 /*
6906  * Check the disk capacity. Disk size information is updated if size has
6907  * changed.
6908  *
6909  * Return 0 if the disk capacity is available, or non-zero if it is not.
6910  */
6911 static int
6912 vdc_check_capacity(vdc_t *vdc)
6913 {
6914 	size_t dsk_size, blk_size;
6915 	int rv;
6916 
6917 	/*
6918 	 * If the vdisk does not support the VD_OP_GET_CAPACITY operation
6919 	 * then the disk capacity has been retrieved during the handshake
6920 	 * and there's nothing more to do here.
6921 	 */
6922 	if (!VD_OP_SUPPORTED(vdc->operations, VD_OP_GET_CAPACITY))
6923 		return (0);
6924 
6925 	if ((rv = vdc_get_capacity(vdc, &dsk_size, &blk_size)) != 0)
6926 		return (rv);
6927 
6928 	if (dsk_size == VD_SIZE_UNKNOWN || dsk_size == 0 || blk_size == 0)
6929 		return (EINVAL);
6930 
6931 	mutex_enter(&vdc->lock);
6932 	/*
6933 	 * First try to update the VIO block size (which is the same as the
6934 	 * vdisk block size). If this returns an error then that means that
6935 	 * we can not use that block size so basically the vdisk is unusable
6936 	 * and we return an error.
6937 	 */
6938 	rv = vdc_update_vio_bsize(vdc, blk_size);
6939 	if (rv == 0)
6940 		vdc_update_size(vdc, dsk_size, blk_size, vdc->max_xfer_sz);
6941 
6942 	mutex_exit(&vdc->lock);
6943 
6944 	return (rv);
6945 }
6946 
6947 /*
6948  * This structure is used in the DKIO(7I) array below.
6949  */
6950 typedef struct vdc_dk_ioctl {
6951 	uint8_t		op;		/* VD_OP_XXX value */
6952 	int		cmd;		/* Solaris ioctl operation number */
6953 	size_t		nbytes;		/* size of structure to be copied */
6954 
6955 	/* function to convert between vDisk and Solaris structure formats */
6956 	int	(*convert)(vdc_t *vdc, void *vd_buf, void *ioctl_arg,
6957 	    int mode, int dir);
6958 } vdc_dk_ioctl_t;
6959 
6960 /*
6961  * Subset of DKIO(7I) operations currently supported
6962  */
6963 static vdc_dk_ioctl_t	dk_ioctl[] = {
6964 	{VD_OP_FLUSH,		DKIOCFLUSHWRITECACHE,	0,
6965 		vdc_null_copy_func},
6966 	{VD_OP_GET_WCE,		DKIOCGETWCE,		sizeof (int),
6967 		vdc_get_wce_convert},
6968 	{VD_OP_SET_WCE,		DKIOCSETWCE,		sizeof (int),
6969 		vdc_set_wce_convert},
6970 	{VD_OP_GET_VTOC,	DKIOCGVTOC,		sizeof (vd_vtoc_t),
6971 		vdc_get_vtoc_convert},
6972 	{VD_OP_SET_VTOC,	DKIOCSVTOC,		sizeof (vd_vtoc_t),
6973 		vdc_set_vtoc_convert},
6974 	{VD_OP_GET_VTOC,	DKIOCGEXTVTOC,		sizeof (vd_vtoc_t),
6975 		vdc_get_extvtoc_convert},
6976 	{VD_OP_SET_VTOC,	DKIOCSEXTVTOC,		sizeof (vd_vtoc_t),
6977 		vdc_set_extvtoc_convert},
6978 	{VD_OP_GET_DISKGEOM,	DKIOCGGEOM,		sizeof (vd_geom_t),
6979 		vdc_get_geom_convert},
6980 	{VD_OP_GET_DISKGEOM,	DKIOCG_PHYGEOM,		sizeof (vd_geom_t),
6981 		vdc_get_geom_convert},
6982 	{VD_OP_GET_DISKGEOM, 	DKIOCG_VIRTGEOM,	sizeof (vd_geom_t),
6983 		vdc_get_geom_convert},
6984 	{VD_OP_SET_DISKGEOM,	DKIOCSGEOM,		sizeof (vd_geom_t),
6985 		vdc_set_geom_convert},
6986 	{VD_OP_GET_EFI,		DKIOCGETEFI,		0,
6987 		vdc_get_efi_convert},
6988 	{VD_OP_SET_EFI,		DKIOCSETEFI,		0,
6989 		vdc_set_efi_convert},
6990 
6991 	/* DIOCTL_RWCMD is converted to a read or a write */
6992 	{0, DIOCTL_RWCMD,  sizeof (struct dadkio_rwcmd), NULL},
6993 
6994 	/* mhd(7I) non-shared multihost disks ioctls */
6995 	{0, MHIOCTKOWN,				0, vdc_null_copy_func},
6996 	{0, MHIOCRELEASE,			0, vdc_null_copy_func},
6997 	{0, MHIOCSTATUS,			0, vdc_null_copy_func},
6998 	{0, MHIOCQRESERVE,			0, vdc_null_copy_func},
6999 
7000 	/* mhd(7I) shared multihost disks ioctls */
7001 	{0, MHIOCGRP_INKEYS,			0, vdc_null_copy_func},
7002 	{0, MHIOCGRP_INRESV,			0, vdc_null_copy_func},
7003 	{0, MHIOCGRP_REGISTER,			0, vdc_null_copy_func},
7004 	{0, MHIOCGRP_RESERVE, 			0, vdc_null_copy_func},
7005 	{0, MHIOCGRP_PREEMPTANDABORT,		0, vdc_null_copy_func},
7006 	{0, MHIOCGRP_REGISTERANDIGNOREKEY,	0, vdc_null_copy_func},
7007 
7008 	/* mhd(7I) failfast ioctl */
7009 	{0, MHIOCENFAILFAST,			0, vdc_null_copy_func},
7010 
7011 	/*
7012 	 * These particular ioctls are not sent to the server - vdc fakes up
7013 	 * the necessary info.
7014 	 */
7015 	{0, DKIOCINFO, sizeof (struct dk_cinfo), vdc_null_copy_func},
7016 	{0, DKIOCGMEDIAINFO, sizeof (struct dk_minfo), vdc_null_copy_func},
7017 	{0, USCSICMD,	sizeof (struct uscsi_cmd), vdc_null_copy_func},
7018 	{0, DKIOCPARTITION, 0, vdc_null_copy_func },
7019 	{0, DKIOCGAPART, 0, vdc_null_copy_func },
7020 	{0, DKIOCREMOVABLE, 0, vdc_null_copy_func},
7021 	{0, CDROMREADOFFSET, 0, vdc_null_copy_func}
7022 };
7023 
7024 /*
7025  * This function handles ioctl requests from the vd_efi_alloc_and_read()
7026  * function and forward them to the vdisk.
7027  */
7028 static int
7029 vd_process_efi_ioctl(void *vdisk, int cmd, uintptr_t arg)
7030 {
7031 	vdc_t *vdc = (vdc_t *)vdisk;
7032 	dev_t dev;
7033 	int rval;
7034 
7035 	dev = makedevice(ddi_driver_major(vdc->dip),
7036 	    VD_MAKE_DEV(vdc->instance, 0));
7037 
7038 	return (vd_process_ioctl(dev, cmd, (caddr_t)arg, FKIOCTL, &rval));
7039 }
7040 
7041 /*
7042  * Function:
7043  *	vd_process_ioctl()
7044  *
7045  * Description:
7046  *	This routine processes disk specific ioctl calls
7047  *
7048  * Arguments:
7049  *	dev	- the device number
7050  *	cmd	- the operation [dkio(7I)] to be processed
7051  *	arg	- pointer to user provided structure
7052  *		  (contains data to be set or reference parameter for get)
7053  *	mode	- bit flag, indicating open settings, 32/64 bit type, etc
7054  *	rvalp	- pointer to return value for calling process.
7055  *
7056  * Return Code:
7057  *	0
7058  *	EFAULT
7059  *	ENXIO
7060  *	EIO
7061  *	ENOTSUP
7062  */
7063 static int
7064 vd_process_ioctl(dev_t dev, int cmd, caddr_t arg, int mode, int *rvalp)
7065 {
7066 	int		instance = VDCUNIT(dev);
7067 	vdc_t		*vdc = NULL;
7068 	int		rv = -1;
7069 	int		idx = 0;		/* index into dk_ioctl[] */
7070 	size_t		len = 0;		/* #bytes to send to vds */
7071 	size_t		alloc_len = 0;		/* #bytes to allocate mem for */
7072 	caddr_t		mem_p = NULL;
7073 	size_t		nioctls = (sizeof (dk_ioctl)) / (sizeof (dk_ioctl[0]));
7074 	vdc_dk_ioctl_t	*iop;
7075 
7076 	vdc = ddi_get_soft_state(vdc_state, instance);
7077 	if (vdc == NULL) {
7078 		cmn_err(CE_NOTE, "![%d] Could not get soft state structure",
7079 		    instance);
7080 		return (ENXIO);
7081 	}
7082 
7083 	DMSG(vdc, 0, "[%d] Processing ioctl(%x) for dev %lx : model %x\n",
7084 	    instance, cmd, dev, ddi_model_convert_from(mode & FMODELS));
7085 
7086 	if (rvalp != NULL) {
7087 		/* the return value of the ioctl is 0 by default */
7088 		*rvalp = 0;
7089 	}
7090 
7091 	/*
7092 	 * Validate the ioctl operation to be performed.
7093 	 *
7094 	 * If we have looped through the array without finding a match then we
7095 	 * don't support this ioctl.
7096 	 */
7097 	for (idx = 0; idx < nioctls; idx++) {
7098 		if (cmd == dk_ioctl[idx].cmd)
7099 			break;
7100 	}
7101 
7102 	if (idx >= nioctls) {
7103 		DMSG(vdc, 0, "[%d] Unsupported ioctl (0x%x)\n",
7104 		    vdc->instance, cmd);
7105 		return (ENOTSUP);
7106 	}
7107 
7108 	iop = &(dk_ioctl[idx]);
7109 
7110 	if (cmd == DKIOCGETEFI || cmd == DKIOCSETEFI) {
7111 		/* size is not fixed for EFI ioctls, it depends on ioctl arg */
7112 		dk_efi_t	dk_efi;
7113 
7114 		rv = ddi_copyin(arg, &dk_efi, sizeof (dk_efi_t), mode);
7115 		if (rv != 0)
7116 			return (EFAULT);
7117 
7118 		len = sizeof (vd_efi_t) - 1 + dk_efi.dki_length;
7119 	} else {
7120 		len = iop->nbytes;
7121 	}
7122 
7123 	/* check if the ioctl is applicable */
7124 	switch (cmd) {
7125 	case CDROMREADOFFSET:
7126 	case DKIOCREMOVABLE:
7127 		return (ENOTTY);
7128 
7129 	case USCSICMD:
7130 	case MHIOCTKOWN:
7131 	case MHIOCSTATUS:
7132 	case MHIOCQRESERVE:
7133 	case MHIOCRELEASE:
7134 	case MHIOCGRP_INKEYS:
7135 	case MHIOCGRP_INRESV:
7136 	case MHIOCGRP_REGISTER:
7137 	case MHIOCGRP_RESERVE:
7138 	case MHIOCGRP_PREEMPTANDABORT:
7139 	case MHIOCGRP_REGISTERANDIGNOREKEY:
7140 	case MHIOCENFAILFAST:
7141 		if (vdc->cinfo == NULL)
7142 			return (ENXIO);
7143 		if (vdc->cinfo->dki_ctype != DKC_SCSI_CCS)
7144 			return (ENOTTY);
7145 		break;
7146 
7147 	case DIOCTL_RWCMD:
7148 		if (vdc->cinfo == NULL)
7149 			return (ENXIO);
7150 		if (vdc->cinfo->dki_ctype != DKC_DIRECT)
7151 			return (ENOTTY);
7152 		break;
7153 
7154 	case DKIOCINFO:
7155 		if (vdc->cinfo == NULL)
7156 			return (ENXIO);
7157 		break;
7158 
7159 	case DKIOCGMEDIAINFO:
7160 		if (vdc->minfo == NULL)
7161 			return (ENXIO);
7162 		if (vdc_check_capacity(vdc) != 0)
7163 			/* disk capacity is not available */
7164 			return (EIO);
7165 		break;
7166 	}
7167 
7168 	/*
7169 	 * Deal with ioctls which require a processing different than
7170 	 * converting ioctl arguments and sending a corresponding
7171 	 * VD operation.
7172 	 */
7173 	switch (cmd) {
7174 
7175 	case USCSICMD:
7176 	{
7177 		return (vdc_uscsi_cmd(vdc, arg, mode));
7178 	}
7179 
7180 	case MHIOCTKOWN:
7181 	{
7182 		mutex_enter(&vdc->ownership_lock);
7183 		/*
7184 		 * We have to set VDC_OWNERSHIP_WANTED now so that the ownership
7185 		 * can be flagged with VDC_OWNERSHIP_RESET if the LDC is reset
7186 		 * while we are processing the ioctl.
7187 		 */
7188 		vdc_ownership_update(vdc, VDC_OWNERSHIP_WANTED);
7189 
7190 		rv = vdc_access_set(vdc, VD_ACCESS_SET_EXCLUSIVE |
7191 		    VD_ACCESS_SET_PREEMPT | VD_ACCESS_SET_PRESERVE);
7192 		if (rv == 0) {
7193 			vdc_ownership_update(vdc, VDC_OWNERSHIP_WANTED |
7194 			    VDC_OWNERSHIP_GRANTED);
7195 		} else {
7196 			vdc_ownership_update(vdc, VDC_OWNERSHIP_NONE);
7197 		}
7198 		mutex_exit(&vdc->ownership_lock);
7199 		return (rv);
7200 	}
7201 
7202 	case MHIOCRELEASE:
7203 	{
7204 		mutex_enter(&vdc->ownership_lock);
7205 		rv = vdc_access_set(vdc, VD_ACCESS_SET_CLEAR);
7206 		if (rv == 0) {
7207 			vdc_ownership_update(vdc, VDC_OWNERSHIP_NONE);
7208 		}
7209 		mutex_exit(&vdc->ownership_lock);
7210 		return (rv);
7211 	}
7212 
7213 	case MHIOCSTATUS:
7214 	{
7215 		uint64_t status;
7216 
7217 		rv = vdc_access_get(vdc, &status);
7218 		if (rv == 0 && rvalp != NULL)
7219 			*rvalp = (status & VD_ACCESS_ALLOWED)? 0 : 1;
7220 		return (rv);
7221 	}
7222 
7223 	case MHIOCQRESERVE:
7224 	{
7225 		rv = vdc_access_set(vdc, VD_ACCESS_SET_EXCLUSIVE);
7226 		return (rv);
7227 	}
7228 
7229 	case MHIOCGRP_INKEYS:
7230 	{
7231 		return (vdc_mhd_inkeys(vdc, arg, mode));
7232 	}
7233 
7234 	case MHIOCGRP_INRESV:
7235 	{
7236 		return (vdc_mhd_inresv(vdc, arg, mode));
7237 	}
7238 
7239 	case MHIOCGRP_REGISTER:
7240 	{
7241 		return (vdc_mhd_register(vdc, arg, mode));
7242 	}
7243 
7244 	case MHIOCGRP_RESERVE:
7245 	{
7246 		return (vdc_mhd_reserve(vdc, arg, mode));
7247 	}
7248 
7249 	case MHIOCGRP_PREEMPTANDABORT:
7250 	{
7251 		return (vdc_mhd_preemptabort(vdc, arg, mode));
7252 	}
7253 
7254 	case MHIOCGRP_REGISTERANDIGNOREKEY:
7255 	{
7256 		return (vdc_mhd_registerignore(vdc, arg, mode));
7257 	}
7258 
7259 	case MHIOCENFAILFAST:
7260 	{
7261 		rv = vdc_failfast(vdc, arg, mode);
7262 		return (rv);
7263 	}
7264 
7265 	case DIOCTL_RWCMD:
7266 	{
7267 		return (vdc_dioctl_rwcmd(vdc, arg, mode));
7268 	}
7269 
7270 	case DKIOCGAPART:
7271 	{
7272 		return (vdc_dkio_gapart(vdc, arg, mode));
7273 	}
7274 
7275 	case DKIOCPARTITION:
7276 	{
7277 		return (vdc_dkio_partition(vdc, arg, mode));
7278 	}
7279 
7280 	case DKIOCINFO:
7281 	{
7282 		struct dk_cinfo	cinfo;
7283 
7284 		bcopy(vdc->cinfo, &cinfo, sizeof (struct dk_cinfo));
7285 		cinfo.dki_partition = VDCPART(dev);
7286 
7287 		rv = ddi_copyout(&cinfo, (void *)arg,
7288 		    sizeof (struct dk_cinfo), mode);
7289 		if (rv != 0)
7290 			return (EFAULT);
7291 
7292 		return (0);
7293 	}
7294 
7295 	case DKIOCGMEDIAINFO:
7296 	{
7297 		ASSERT(vdc->vdisk_size != 0);
7298 		ASSERT(vdc->minfo->dki_capacity != 0);
7299 		rv = ddi_copyout(vdc->minfo, (void *)arg,
7300 		    sizeof (struct dk_minfo), mode);
7301 		if (rv != 0)
7302 			return (EFAULT);
7303 
7304 		return (0);
7305 	}
7306 
7307 	case DKIOCFLUSHWRITECACHE:
7308 		{
7309 			struct dk_callback *dkc =
7310 			    (struct dk_callback *)(uintptr_t)arg;
7311 			vdc_dk_arg_t	*dkarg = NULL;
7312 
7313 			DMSG(vdc, 1, "[%d] Flush W$: mode %x\n",
7314 			    instance, mode);
7315 
7316 			/*
7317 			 * If arg is NULL, then there is no callback function
7318 			 * registered and the call operates synchronously; we
7319 			 * break and continue with the rest of the function and
7320 			 * wait for vds to return (i.e. after the request to
7321 			 * vds returns successfully, all writes completed prior
7322 			 * to the ioctl will have been flushed from the disk
7323 			 * write cache to persistent media.
7324 			 *
7325 			 * If a callback function is registered, we dispatch
7326 			 * the request on a task queue and return immediately.
7327 			 * The callback will deal with informing the calling
7328 			 * thread that the flush request is completed.
7329 			 */
7330 			if (dkc == NULL)
7331 				break;
7332 
7333 			/*
7334 			 * the asynchronous callback is only supported if
7335 			 * invoked from within the kernel
7336 			 */
7337 			if ((mode & FKIOCTL) == 0)
7338 				return (ENOTSUP);
7339 
7340 			dkarg = kmem_zalloc(sizeof (vdc_dk_arg_t), KM_SLEEP);
7341 
7342 			dkarg->mode = mode;
7343 			dkarg->dev = dev;
7344 			bcopy(dkc, &dkarg->dkc, sizeof (*dkc));
7345 
7346 			mutex_enter(&vdc->lock);
7347 			vdc->dkio_flush_pending++;
7348 			dkarg->vdc = vdc;
7349 			mutex_exit(&vdc->lock);
7350 
7351 			/* put the request on a task queue */
7352 			rv = taskq_dispatch(system_taskq, vdc_dkio_flush_cb,
7353 			    (void *)dkarg, DDI_SLEEP);
7354 			if (rv == NULL) {
7355 				/* clean up if dispatch fails */
7356 				mutex_enter(&vdc->lock);
7357 				vdc->dkio_flush_pending--;
7358 				mutex_exit(&vdc->lock);
7359 				kmem_free(dkarg, sizeof (vdc_dk_arg_t));
7360 			}
7361 
7362 			return (rv == NULL ? ENOMEM : 0);
7363 		}
7364 	}
7365 
7366 	/* catch programming error in vdc - should be a VD_OP_XXX ioctl */
7367 	ASSERT(iop->op != 0);
7368 
7369 	/* check if the vDisk server handles the operation for this vDisk */
7370 	if (VD_OP_SUPPORTED(vdc->operations, iop->op) == B_FALSE) {
7371 		DMSG(vdc, 0, "[%d] Unsupported VD_OP operation (0x%x)\n",
7372 		    vdc->instance, iop->op);
7373 		return (ENOTSUP);
7374 	}
7375 
7376 	/* LDC requires that the memory being mapped is 8-byte aligned */
7377 	alloc_len = P2ROUNDUP(len, sizeof (uint64_t));
7378 	DMSG(vdc, 1, "[%d] struct size %ld alloc %ld\n",
7379 	    instance, len, alloc_len);
7380 
7381 	if (alloc_len > 0)
7382 		mem_p = kmem_zalloc(alloc_len, KM_SLEEP);
7383 
7384 	/*
7385 	 * Call the conversion function for this ioctl which, if necessary,
7386 	 * converts from the Solaris format to the format ARC'ed
7387 	 * as part of the vDisk protocol (FWARC 2006/195)
7388 	 */
7389 	ASSERT(iop->convert != NULL);
7390 	rv = (iop->convert)(vdc, arg, mem_p, mode, VD_COPYIN);
7391 	if (rv != 0) {
7392 		DMSG(vdc, 0, "[%d] convert func returned %d for ioctl 0x%x\n",
7393 		    instance, rv, cmd);
7394 		if (mem_p != NULL)
7395 			kmem_free(mem_p, alloc_len);
7396 		return (rv);
7397 	}
7398 
7399 	/*
7400 	 * send request to vds to service the ioctl.
7401 	 */
7402 	rv = vdc_do_sync_op(vdc, iop->op, mem_p, alloc_len,
7403 	    VDCPART(dev), 0, VIO_both_dir, B_TRUE);
7404 
7405 	if (rv != 0) {
7406 		/*
7407 		 * This is not necessarily an error. The ioctl could
7408 		 * be returning a value such as ENOTTY to indicate
7409 		 * that the ioctl is not applicable.
7410 		 */
7411 		DMSG(vdc, 0, "[%d] vds returned %d for ioctl 0x%x\n",
7412 		    instance, rv, cmd);
7413 		if (mem_p != NULL)
7414 			kmem_free(mem_p, alloc_len);
7415 
7416 		return (rv);
7417 	}
7418 
7419 	/*
7420 	 * Call the conversion function (if it exists) for this ioctl
7421 	 * which converts from the format ARC'ed as part of the vDisk
7422 	 * protocol (FWARC 2006/195) back to a format understood by
7423 	 * the rest of Solaris.
7424 	 */
7425 	rv = (iop->convert)(vdc, mem_p, arg, mode, VD_COPYOUT);
7426 	if (rv != 0) {
7427 		DMSG(vdc, 0, "[%d] convert func returned %d for ioctl 0x%x\n",
7428 		    instance, rv, cmd);
7429 		if (mem_p != NULL)
7430 			kmem_free(mem_p, alloc_len);
7431 		return (rv);
7432 	}
7433 
7434 	if (mem_p != NULL)
7435 		kmem_free(mem_p, alloc_len);
7436 
7437 	return (rv);
7438 }
7439 
7440 /*
7441  * Function:
7442  *
7443  * Description:
7444  *	This is an empty conversion function used by ioctl calls which
7445  *	do not need to convert the data being passed in/out to userland
7446  */
7447 static int
7448 vdc_null_copy_func(vdc_t *vdc, void *from, void *to, int mode, int dir)
7449 {
7450 	_NOTE(ARGUNUSED(vdc))
7451 	_NOTE(ARGUNUSED(from))
7452 	_NOTE(ARGUNUSED(to))
7453 	_NOTE(ARGUNUSED(mode))
7454 	_NOTE(ARGUNUSED(dir))
7455 
7456 	return (0);
7457 }
7458 
7459 static int
7460 vdc_get_wce_convert(vdc_t *vdc, void *from, void *to,
7461     int mode, int dir)
7462 {
7463 	_NOTE(ARGUNUSED(vdc))
7464 
7465 	if (dir == VD_COPYIN)
7466 		return (0);		/* nothing to do */
7467 
7468 	if (ddi_copyout(from, to, sizeof (int), mode) != 0)
7469 		return (EFAULT);
7470 
7471 	return (0);
7472 }
7473 
7474 static int
7475 vdc_set_wce_convert(vdc_t *vdc, void *from, void *to,
7476     int mode, int dir)
7477 {
7478 	_NOTE(ARGUNUSED(vdc))
7479 
7480 	if (dir == VD_COPYOUT)
7481 		return (0);		/* nothing to do */
7482 
7483 	if (ddi_copyin(from, to, sizeof (int), mode) != 0)
7484 		return (EFAULT);
7485 
7486 	return (0);
7487 }
7488 
7489 /*
7490  * Function:
7491  *	vdc_get_vtoc_convert()
7492  *
7493  * Description:
7494  *	This routine performs the necessary convertions from the DKIOCGVTOC
7495  *	Solaris structure to the format defined in FWARC 2006/195.
7496  *
7497  *	In the struct vtoc definition, the timestamp field is marked as not
7498  *	supported so it is not part of vDisk protocol (FWARC 2006/195).
7499  *	However SVM uses that field to check it can write into the VTOC,
7500  *	so we fake up the info of that field.
7501  *
7502  * Arguments:
7503  *	vdc	- the vDisk client
7504  *	from	- the buffer containing the data to be copied from
7505  *	to	- the buffer to be copied to
7506  *	mode	- flags passed to ioctl() call
7507  *	dir	- the "direction" of the copy - VD_COPYIN or VD_COPYOUT
7508  *
7509  * Return Code:
7510  *	0	- Success
7511  *	ENXIO	- incorrect buffer passed in.
7512  *	EFAULT	- ddi_copyout routine encountered an error.
7513  */
7514 static int
7515 vdc_get_vtoc_convert(vdc_t *vdc, void *from, void *to, int mode, int dir)
7516 {
7517 	int		i;
7518 	struct vtoc	vtoc;
7519 	struct vtoc32	vtoc32;
7520 	struct extvtoc	evtoc;
7521 	int		rv;
7522 
7523 	if (dir != VD_COPYOUT)
7524 		return (0);	/* nothing to do */
7525 
7526 	if ((from == NULL) || (to == NULL))
7527 		return (ENXIO);
7528 
7529 	if (vdc->vdisk_size > VD_OLDVTOC_LIMIT)
7530 		return (EOVERFLOW);
7531 
7532 	VD_VTOC2VTOC((vd_vtoc_t *)from, &evtoc);
7533 
7534 	/* fake the VTOC timestamp field */
7535 	for (i = 0; i < V_NUMPAR; i++) {
7536 		evtoc.timestamp[i] = vdc->vtoc->timestamp[i];
7537 	}
7538 
7539 	if (ddi_model_convert_from(mode & FMODELS) == DDI_MODEL_ILP32) {
7540 		/* LINTED E_ASSIGN_NARROW_CONV */
7541 		extvtoctovtoc32(evtoc, vtoc32);
7542 		rv = ddi_copyout(&vtoc32, to, sizeof (vtoc32), mode);
7543 		if (rv != 0)
7544 			rv = EFAULT;
7545 	} else {
7546 		extvtoctovtoc(evtoc, vtoc);
7547 		rv = ddi_copyout(&vtoc, to, sizeof (vtoc), mode);
7548 		if (rv != 0)
7549 			rv = EFAULT;
7550 	}
7551 
7552 	return (rv);
7553 }
7554 
7555 /*
7556  * Function:
7557  *	vdc_set_vtoc_convert()
7558  *
7559  * Description:
7560  *	This routine performs the necessary convertions from the DKIOCSVTOC
7561  *	Solaris structure to the format defined in FWARC 2006/195.
7562  *
7563  * Arguments:
7564  *	vdc	- the vDisk client
7565  *	from	- Buffer with data
7566  *	to	- Buffer where data is to be copied to
7567  *	mode	- flags passed to ioctl
7568  *	dir	- direction of copy (in or out)
7569  *
7570  * Return Code:
7571  *	0	- Success
7572  *	ENXIO	- Invalid buffer passed in
7573  *	EFAULT	- ddi_copyin of data failed
7574  */
7575 static int
7576 vdc_set_vtoc_convert(vdc_t *vdc, void *from, void *to, int mode, int dir)
7577 {
7578 	void		*uvtoc;
7579 	struct vtoc	vtoc;
7580 	struct vtoc32	vtoc32;
7581 	struct extvtoc	evtoc;
7582 	int		i, rv;
7583 
7584 	if ((from == NULL) || (to == NULL))
7585 		return (ENXIO);
7586 
7587 	if (vdc->vdisk_size > VD_OLDVTOC_LIMIT)
7588 		return (EOVERFLOW);
7589 
7590 	uvtoc = (dir == VD_COPYIN)? from : to;
7591 
7592 	if (ddi_model_convert_from(mode & FMODELS) == DDI_MODEL_ILP32) {
7593 		rv = ddi_copyin(uvtoc, &vtoc32, sizeof (vtoc32), mode);
7594 		if (rv != 0)
7595 			return (EFAULT);
7596 		vtoc32toextvtoc(vtoc32, evtoc);
7597 	} else {
7598 		rv = ddi_copyin(uvtoc, &vtoc, sizeof (vtoc), mode);
7599 		if (rv != 0)
7600 			return (EFAULT);
7601 		vtoctoextvtoc(vtoc, evtoc);
7602 	}
7603 
7604 	if (dir == VD_COPYOUT) {
7605 		/*
7606 		 * The disk label may have changed. Revalidate the disk
7607 		 * geometry. This will also update the device nodes.
7608 		 */
7609 		vdc_validate(vdc);
7610 
7611 		/*
7612 		 * We also need to keep track of the timestamp fields.
7613 		 */
7614 		for (i = 0; i < V_NUMPAR; i++) {
7615 			vdc->vtoc->timestamp[i] = evtoc.timestamp[i];
7616 		}
7617 
7618 	} else {
7619 		VTOC2VD_VTOC(&evtoc, (vd_vtoc_t *)to);
7620 	}
7621 
7622 	return (0);
7623 }
7624 
7625 static int
7626 vdc_get_extvtoc_convert(vdc_t *vdc, void *from, void *to, int mode, int dir)
7627 {
7628 	int		i, rv;
7629 	struct extvtoc	evtoc;
7630 
7631 	if (dir != VD_COPYOUT)
7632 		return (0);	/* nothing to do */
7633 
7634 	if ((from == NULL) || (to == NULL))
7635 		return (ENXIO);
7636 
7637 	VD_VTOC2VTOC((vd_vtoc_t *)from, &evtoc);
7638 
7639 	/* fake the VTOC timestamp field */
7640 	for (i = 0; i < V_NUMPAR; i++) {
7641 		evtoc.timestamp[i] = vdc->vtoc->timestamp[i];
7642 	}
7643 
7644 	rv = ddi_copyout(&evtoc, to, sizeof (struct extvtoc), mode);
7645 	if (rv != 0)
7646 		rv = EFAULT;
7647 
7648 	return (rv);
7649 }
7650 
7651 static int
7652 vdc_set_extvtoc_convert(vdc_t *vdc, void *from, void *to, int mode, int dir)
7653 {
7654 	void		*uvtoc;
7655 	struct extvtoc	evtoc;
7656 	int		i, rv;
7657 
7658 	if ((from == NULL) || (to == NULL))
7659 		return (ENXIO);
7660 
7661 	uvtoc = (dir == VD_COPYIN)? from : to;
7662 
7663 	rv = ddi_copyin(uvtoc, &evtoc, sizeof (struct extvtoc), mode);
7664 	if (rv != 0)
7665 		return (EFAULT);
7666 
7667 	if (dir == VD_COPYOUT) {
7668 		/*
7669 		 * The disk label may have changed. Revalidate the disk
7670 		 * geometry. This will also update the device nodes.
7671 		 */
7672 		vdc_validate(vdc);
7673 
7674 		/*
7675 		 * We also need to keep track of the timestamp fields.
7676 		 */
7677 		for (i = 0; i < V_NUMPAR; i++) {
7678 			vdc->vtoc->timestamp[i] = evtoc.timestamp[i];
7679 		}
7680 
7681 	} else {
7682 		VTOC2VD_VTOC(&evtoc, (vd_vtoc_t *)to);
7683 	}
7684 
7685 	return (0);
7686 }
7687 
7688 /*
7689  * Function:
7690  *	vdc_get_geom_convert()
7691  *
7692  * Description:
7693  *	This routine performs the necessary convertions from the DKIOCGGEOM,
7694  *	DKIOCG_PHYSGEOM and DKIOG_VIRTGEOM Solaris structures to the format
7695  *	defined in FWARC 2006/195
7696  *
7697  * Arguments:
7698  *	vdc	- the vDisk client
7699  *	from	- Buffer with data
7700  *	to	- Buffer where data is to be copied to
7701  *	mode	- flags passed to ioctl
7702  *	dir	- direction of copy (in or out)
7703  *
7704  * Return Code:
7705  *	0	- Success
7706  *	ENXIO	- Invalid buffer passed in
7707  *	EFAULT	- ddi_copyout of data failed
7708  */
7709 static int
7710 vdc_get_geom_convert(vdc_t *vdc, void *from, void *to, int mode, int dir)
7711 {
7712 	_NOTE(ARGUNUSED(vdc))
7713 
7714 	struct dk_geom	geom;
7715 	int	copy_len = sizeof (struct dk_geom);
7716 	int	rv = 0;
7717 
7718 	if (dir != VD_COPYOUT)
7719 		return (0);	/* nothing to do */
7720 
7721 	if ((from == NULL) || (to == NULL))
7722 		return (ENXIO);
7723 
7724 	VD_GEOM2DK_GEOM((vd_geom_t *)from, &geom);
7725 	rv = ddi_copyout(&geom, to, copy_len, mode);
7726 	if (rv != 0)
7727 		rv = EFAULT;
7728 
7729 	return (rv);
7730 }
7731 
7732 /*
7733  * Function:
7734  *	vdc_set_geom_convert()
7735  *
7736  * Description:
7737  *	This routine performs the necessary convertions from the DKIOCSGEOM
7738  *	Solaris structure to the format defined in FWARC 2006/195.
7739  *
7740  * Arguments:
7741  *	vdc	- the vDisk client
7742  *	from	- Buffer with data
7743  *	to	- Buffer where data is to be copied to
7744  *	mode	- flags passed to ioctl
7745  *	dir	- direction of copy (in or out)
7746  *
7747  * Return Code:
7748  *	0	- Success
7749  *	ENXIO	- Invalid buffer passed in
7750  *	EFAULT	- ddi_copyin of data failed
7751  */
7752 static int
7753 vdc_set_geom_convert(vdc_t *vdc, void *from, void *to, int mode, int dir)
7754 {
7755 	_NOTE(ARGUNUSED(vdc))
7756 
7757 	vd_geom_t	vdgeom;
7758 	void		*tmp_mem = NULL;
7759 	int		copy_len = sizeof (struct dk_geom);
7760 	int		rv = 0;
7761 
7762 	if (dir != VD_COPYIN)
7763 		return (0);	/* nothing to do */
7764 
7765 	if ((from == NULL) || (to == NULL))
7766 		return (ENXIO);
7767 
7768 	tmp_mem = kmem_alloc(copy_len, KM_SLEEP);
7769 
7770 	rv = ddi_copyin(from, tmp_mem, copy_len, mode);
7771 	if (rv != 0) {
7772 		kmem_free(tmp_mem, copy_len);
7773 		return (EFAULT);
7774 	}
7775 	DK_GEOM2VD_GEOM((struct dk_geom *)tmp_mem, &vdgeom);
7776 	bcopy(&vdgeom, to, sizeof (vdgeom));
7777 	kmem_free(tmp_mem, copy_len);
7778 
7779 	return (0);
7780 }
7781 
7782 static int
7783 vdc_get_efi_convert(vdc_t *vdc, void *from, void *to, int mode, int dir)
7784 {
7785 	_NOTE(ARGUNUSED(vdc))
7786 
7787 	vd_efi_t	*vd_efi;
7788 	dk_efi_t	dk_efi;
7789 	int		rv = 0;
7790 	void		*uaddr;
7791 
7792 	if ((from == NULL) || (to == NULL))
7793 		return (ENXIO);
7794 
7795 	if (dir == VD_COPYIN) {
7796 
7797 		vd_efi = (vd_efi_t *)to;
7798 
7799 		rv = ddi_copyin(from, &dk_efi, sizeof (dk_efi_t), mode);
7800 		if (rv != 0)
7801 			return (EFAULT);
7802 
7803 		vd_efi->lba = dk_efi.dki_lba;
7804 		vd_efi->length = dk_efi.dki_length;
7805 		bzero(vd_efi->data, vd_efi->length);
7806 
7807 	} else {
7808 
7809 		rv = ddi_copyin(to, &dk_efi, sizeof (dk_efi_t), mode);
7810 		if (rv != 0)
7811 			return (EFAULT);
7812 
7813 		uaddr = dk_efi.dki_data;
7814 
7815 		dk_efi.dki_data = kmem_alloc(dk_efi.dki_length, KM_SLEEP);
7816 
7817 		VD_EFI2DK_EFI((vd_efi_t *)from, &dk_efi);
7818 
7819 		rv = ddi_copyout(dk_efi.dki_data, uaddr, dk_efi.dki_length,
7820 		    mode);
7821 		if (rv != 0)
7822 			return (EFAULT);
7823 
7824 		kmem_free(dk_efi.dki_data, dk_efi.dki_length);
7825 	}
7826 
7827 	return (0);
7828 }
7829 
7830 static int
7831 vdc_set_efi_convert(vdc_t *vdc, void *from, void *to, int mode, int dir)
7832 {
7833 	_NOTE(ARGUNUSED(vdc))
7834 
7835 	dk_efi_t	dk_efi;
7836 	void		*uaddr;
7837 
7838 	if (dir == VD_COPYOUT) {
7839 		/*
7840 		 * The disk label may have changed. Revalidate the disk
7841 		 * geometry. This will also update the device nodes.
7842 		 */
7843 		vdc_validate(vdc);
7844 		return (0);
7845 	}
7846 
7847 	if ((from == NULL) || (to == NULL))
7848 		return (ENXIO);
7849 
7850 	if (ddi_copyin(from, &dk_efi, sizeof (dk_efi_t), mode) != 0)
7851 		return (EFAULT);
7852 
7853 	uaddr = dk_efi.dki_data;
7854 
7855 	dk_efi.dki_data = kmem_alloc(dk_efi.dki_length, KM_SLEEP);
7856 
7857 	if (ddi_copyin(uaddr, dk_efi.dki_data, dk_efi.dki_length, mode) != 0)
7858 		return (EFAULT);
7859 
7860 	DK_EFI2VD_EFI(&dk_efi, (vd_efi_t *)to);
7861 
7862 	kmem_free(dk_efi.dki_data, dk_efi.dki_length);
7863 
7864 	return (0);
7865 }
7866 
7867 
7868 /* -------------------------------------------------------------------------- */
7869 
7870 /*
7871  * Function:
7872  *	vdc_create_fake_geometry()
7873  *
7874  * Description:
7875  *	This routine fakes up the disk info needed for some DKIO ioctls such
7876  *	as DKIOCINFO and DKIOCGMEDIAINFO [just like lofi(7D) and ramdisk(7D) do]
7877  *
7878  *	Note: This function must not be called until the vDisk attributes have
7879  *	been exchanged as part of the handshake with the vDisk server.
7880  *
7881  * Arguments:
7882  *	vdc	- soft state pointer for this instance of the device driver.
7883  *
7884  * Return Code:
7885  *	none.
7886  */
7887 static void
7888 vdc_create_fake_geometry(vdc_t *vdc)
7889 {
7890 	ASSERT(vdc != NULL);
7891 	ASSERT(vdc->max_xfer_sz != 0);
7892 
7893 	/*
7894 	 * DKIOCINFO support
7895 	 */
7896 	if (vdc->cinfo == NULL)
7897 		vdc->cinfo = kmem_zalloc(sizeof (struct dk_cinfo), KM_SLEEP);
7898 
7899 	(void) strcpy(vdc->cinfo->dki_cname, VDC_DRIVER_NAME);
7900 	(void) strcpy(vdc->cinfo->dki_dname, VDC_DRIVER_NAME);
7901 	/* max_xfer_sz is #blocks so we don't need to divide by vdisk_bsize */
7902 	vdc->cinfo->dki_maxtransfer = vdc->max_xfer_sz;
7903 
7904 	/*
7905 	 * We set the controller type to DKC_SCSI_CCS only if the VD_OP_SCSICMD
7906 	 * operation is supported, otherwise the controller type is DKC_DIRECT.
7907 	 * Version 1.0 does not support the VD_OP_SCSICMD operation, so the
7908 	 * controller type is always DKC_DIRECT in that case.
7909 	 *
7910 	 * If the virtual disk is backed by a physical CD/DVD device or
7911 	 * an ISO image, modify the controller type to indicate this
7912 	 */
7913 	switch (vdc->vdisk_media) {
7914 	case VD_MEDIA_CD:
7915 	case VD_MEDIA_DVD:
7916 		vdc->cinfo->dki_ctype = DKC_CDROM;
7917 		break;
7918 	case VD_MEDIA_FIXED:
7919 		if (VD_OP_SUPPORTED(vdc->operations, VD_OP_SCSICMD))
7920 			vdc->cinfo->dki_ctype = DKC_SCSI_CCS;
7921 		else
7922 			vdc->cinfo->dki_ctype = DKC_DIRECT;
7923 		break;
7924 	default:
7925 		/* in the case of v1.0 we default to a fixed disk */
7926 		vdc->cinfo->dki_ctype = DKC_DIRECT;
7927 		break;
7928 	}
7929 	vdc->cinfo->dki_flags = DKI_FMTVOL;
7930 	vdc->cinfo->dki_cnum = 0;
7931 	vdc->cinfo->dki_addr = 0;
7932 	vdc->cinfo->dki_space = 0;
7933 	vdc->cinfo->dki_prio = 0;
7934 	vdc->cinfo->dki_vec = 0;
7935 	vdc->cinfo->dki_unit = vdc->instance;
7936 	vdc->cinfo->dki_slave = 0;
7937 	/*
7938 	 * The partition number will be created on the fly depending on the
7939 	 * actual slice (i.e. minor node) that is used to request the data.
7940 	 */
7941 	vdc->cinfo->dki_partition = 0;
7942 
7943 	/*
7944 	 * DKIOCGMEDIAINFO support
7945 	 */
7946 	if (vdc->minfo == NULL)
7947 		vdc->minfo = kmem_zalloc(sizeof (struct dk_minfo), KM_SLEEP);
7948 
7949 	if (vio_ver_is_supported(vdc->ver, 1, 1)) {
7950 		vdc->minfo->dki_media_type =
7951 		    VD_MEDIATYPE2DK_MEDIATYPE(vdc->vdisk_media);
7952 	} else {
7953 		vdc->minfo->dki_media_type = DK_FIXED_DISK;
7954 	}
7955 
7956 	vdc->minfo->dki_capacity = vdc->vdisk_size;
7957 	vdc->minfo->dki_lbsize = vdc->vdisk_bsize;
7958 }
7959 
7960 static ushort_t
7961 vdc_lbl2cksum(struct dk_label *label)
7962 {
7963 	int	count;
7964 	ushort_t sum, *sp;
7965 
7966 	count =	(sizeof (struct dk_label)) / (sizeof (short)) - 1;
7967 	sp = (ushort_t *)label;
7968 	sum = 0;
7969 	while (count--) {
7970 		sum ^= *sp++;
7971 	}
7972 
7973 	return (sum);
7974 }
7975 
7976 static void
7977 vdc_update_size(vdc_t *vdc, size_t dsk_size, size_t blk_size, size_t xfr_size)
7978 {
7979 	vd_err_stats_t  *stp;
7980 
7981 	ASSERT(MUTEX_HELD(&vdc->lock));
7982 	ASSERT(xfr_size != 0);
7983 
7984 	/*
7985 	 * If the disk size is unknown or sizes are unchanged then don't
7986 	 * update anything.
7987 	 */
7988 	if (dsk_size == VD_SIZE_UNKNOWN || dsk_size == 0 ||
7989 	    (blk_size == vdc->vdisk_bsize && dsk_size == vdc->vdisk_size &&
7990 	    xfr_size == vdc->max_xfer_sz))
7991 		return;
7992 
7993 	/*
7994 	 * We don't know at compile time what the vDisk server will think
7995 	 * are good values but we apply a large (arbitrary) upper bound to
7996 	 * prevent memory exhaustion in vdc if it was allocating a DRing
7997 	 * based of huge values sent by the server. We probably will never
7998 	 * exceed this except if the message was garbage.
7999 	 */
8000 	if ((xfr_size * blk_size) > (PAGESIZE * DEV_BSIZE)) {
8001 		DMSG(vdc, 0, "[%d] vds block transfer size too big;"
8002 		    " using max supported by vdc", vdc->instance);
8003 		xfr_size = maxphys / blk_size;
8004 	}
8005 
8006 	vdc->max_xfer_sz = xfr_size;
8007 	vdc->vdisk_bsize = blk_size;
8008 	vdc->vdisk_size = dsk_size;
8009 
8010 	stp = (vd_err_stats_t *)vdc->err_stats->ks_data;
8011 	stp->vd_capacity.value.ui64 = dsk_size * blk_size;
8012 
8013 	vdc->minfo->dki_capacity = dsk_size;
8014 	vdc->minfo->dki_lbsize = (uint_t)blk_size;
8015 }
8016 
8017 /*
8018  * Update information about the VIO block size. The VIO block size is the
8019  * same as the vdisk block size which is stored in vdc->vdisk_bsize so we
8020  * do not store that information again.
8021  *
8022  * However, buf structures will always use a logical block size of 512 bytes
8023  * (DEV_BSIZE) and we will need to convert logical block numbers to VIO block
8024  * numbers for each read or write operation using vdc_strategy(). To speed up
8025  * this conversion, we expect the VIO block size to be a power of 2 and a
8026  * multiple 512 bytes (DEV_BSIZE), and we cache some useful information.
8027  *
8028  * The function return EINVAL if the new VIO block size (blk_size) is not a
8029  * power of 2 or not a multiple of 512 bytes, otherwise it returns 0.
8030  */
8031 static int
8032 vdc_update_vio_bsize(vdc_t *vdc, uint32_t blk_size)
8033 {
8034 	uint32_t ratio, n;
8035 	int nshift = 0;
8036 
8037 	vdc->vio_bmask = 0;
8038 	vdc->vio_bshift = 0;
8039 
8040 	ASSERT(blk_size > 0);
8041 
8042 	if ((blk_size % DEV_BSIZE) != 0)
8043 		return (EINVAL);
8044 
8045 	ratio = blk_size / DEV_BSIZE;
8046 
8047 	for (n = ratio; n > 1; n >>= 1) {
8048 		if ((n & 0x1) != 0) {
8049 			/* blk_size is not a power of 2 */
8050 			return (EINVAL);
8051 		}
8052 		nshift++;
8053 	}
8054 
8055 	vdc->vio_bshift = nshift;
8056 	vdc->vio_bmask = ratio - 1;
8057 
8058 	return (0);
8059 }
8060 
8061 /*
8062  * Function:
8063  *	vdc_validate_geometry
8064  *
8065  * Description:
8066  *	This routine discovers the label and geometry of the disk. It stores
8067  *	the disk label and related information in the vdc structure. If it
8068  *	fails to validate the geometry or to discover the disk label then
8069  *	the label is marked as unknown (VD_DISK_LABEL_UNK).
8070  *
8071  * Arguments:
8072  *	vdc	- soft state pointer for this instance of the device driver.
8073  *
8074  * Return Code:
8075  *	0	- success.
8076  *	EINVAL	- unknown disk label.
8077  *	ENOTSUP	- geometry not applicable (EFI label).
8078  *	EIO	- error accessing the disk.
8079  */
8080 static int
8081 vdc_validate_geometry(vdc_t *vdc)
8082 {
8083 	dev_t	dev;
8084 	int	rv, rval;
8085 	struct dk_label *label;
8086 	struct dk_geom geom;
8087 	struct extvtoc vtoc;
8088 	efi_gpt_t *gpt;
8089 	efi_gpe_t *gpe;
8090 	vd_efi_dev_t edev;
8091 
8092 	ASSERT(vdc != NULL);
8093 	ASSERT(vdc->vtoc != NULL && vdc->geom != NULL);
8094 	ASSERT(MUTEX_HELD(&vdc->lock));
8095 
8096 	mutex_exit(&vdc->lock);
8097 	/*
8098 	 * Check the disk capacity in case it has changed. If that fails then
8099 	 * we proceed and we will be using the disk size we currently have.
8100 	 */
8101 	(void) vdc_check_capacity(vdc);
8102 	dev = makedevice(ddi_driver_major(vdc->dip),
8103 	    VD_MAKE_DEV(vdc->instance, 0));
8104 
8105 	rv = vd_process_ioctl(dev, DKIOCGGEOM, (caddr_t)&geom, FKIOCTL, &rval);
8106 	if (rv == 0)
8107 		rv = vd_process_ioctl(dev, DKIOCGEXTVTOC, (caddr_t)&vtoc,
8108 		    FKIOCTL, &rval);
8109 
8110 	if (rv == ENOTSUP) {
8111 		/*
8112 		 * If the device does not support VTOC then we try
8113 		 * to read an EFI label.
8114 		 *
8115 		 * We need to know the block size and the disk size to
8116 		 * be able to read an EFI label.
8117 		 */
8118 		if (vdc->vdisk_size == 0) {
8119 			mutex_enter(&vdc->lock);
8120 			vdc_store_label_unk(vdc);
8121 			return (EIO);
8122 		}
8123 
8124 		VDC_EFI_DEV_SET(edev, vdc, vd_process_efi_ioctl);
8125 
8126 		rv = vd_efi_alloc_and_read(&edev, &gpt, &gpe);
8127 
8128 		if (rv) {
8129 			DMSG(vdc, 0, "[%d] Failed to get EFI (err=%d)",
8130 			    vdc->instance, rv);
8131 			mutex_enter(&vdc->lock);
8132 			vdc_store_label_unk(vdc);
8133 			return (EIO);
8134 		}
8135 
8136 		mutex_enter(&vdc->lock);
8137 		vdc_store_label_efi(vdc, gpt, gpe);
8138 		vd_efi_free(&edev, gpt, gpe);
8139 		return (ENOTSUP);
8140 	}
8141 
8142 	if (rv != 0) {
8143 		DMSG(vdc, 0, "[%d] Failed to get VTOC (err=%d)",
8144 		    vdc->instance, rv);
8145 		mutex_enter(&vdc->lock);
8146 		vdc_store_label_unk(vdc);
8147 		if (rv != EINVAL)
8148 			rv = EIO;
8149 		return (rv);
8150 	}
8151 
8152 	/* check that geometry and vtoc are valid */
8153 	if (geom.dkg_nhead == 0 || geom.dkg_nsect == 0 ||
8154 	    vtoc.v_sanity != VTOC_SANE) {
8155 		mutex_enter(&vdc->lock);
8156 		vdc_store_label_unk(vdc);
8157 		return (EINVAL);
8158 	}
8159 
8160 	/*
8161 	 * We have a disk and a valid VTOC. However this does not mean
8162 	 * that the disk currently have a VTOC label. The returned VTOC may
8163 	 * be a default VTOC to be used for configuring the disk (this is
8164 	 * what is done for disk image). So we read the label from the
8165 	 * beginning of the disk to ensure we really have a VTOC label.
8166 	 *
8167 	 * FUTURE: This could be the default way for reading the VTOC
8168 	 * from the disk as opposed to sending the VD_OP_GET_VTOC
8169 	 * to the server. This will be the default if vdc is implemented
8170 	 * ontop of cmlb.
8171 	 */
8172 
8173 	/*
8174 	 * Single slice disk does not support read using an absolute disk
8175 	 * offset so we just rely on the DKIOCGVTOC ioctl in that case.
8176 	 */
8177 	if (vdc->vdisk_type == VD_DISK_TYPE_SLICE) {
8178 		mutex_enter(&vdc->lock);
8179 		if (vtoc.v_nparts != 1) {
8180 			vdc_store_label_unk(vdc);
8181 			return (EINVAL);
8182 		}
8183 		vdc_store_label_vtoc(vdc, &geom, &vtoc);
8184 		return (0);
8185 	}
8186 
8187 	if (vtoc.v_nparts != V_NUMPAR) {
8188 		mutex_enter(&vdc->lock);
8189 		vdc_store_label_unk(vdc);
8190 		return (EINVAL);
8191 	}
8192 
8193 	/*
8194 	 * Most CD/DVDs do not have a disk label and the label is
8195 	 * generated by the disk driver.  So the on-disk label check
8196 	 * below may fail and we return now to avoid this problem.
8197 	 */
8198 	if (vdc->vdisk_media == VD_MEDIA_CD ||
8199 	    vdc->vdisk_media == VD_MEDIA_DVD) {
8200 		mutex_enter(&vdc->lock);
8201 		vdc_store_label_vtoc(vdc, &geom, &vtoc);
8202 		return (0);
8203 	}
8204 
8205 	/*
8206 	 * Read disk label from start of disk
8207 	 */
8208 	label = kmem_alloc(vdc->vdisk_bsize, KM_SLEEP);
8209 
8210 	rv = vdc_do_op(vdc, VD_OP_BREAD, (caddr_t)label, vdc->vdisk_bsize,
8211 	    VD_SLICE_NONE, 0, NULL, VIO_read_dir, VDC_OP_NORMAL);
8212 
8213 	if (rv != 0 || label->dkl_magic != DKL_MAGIC ||
8214 	    label->dkl_cksum != vdc_lbl2cksum(label)) {
8215 		DMSG(vdc, 1, "[%d] Got VTOC with invalid label\n",
8216 		    vdc->instance);
8217 		kmem_free(label, vdc->vdisk_bsize);
8218 		mutex_enter(&vdc->lock);
8219 		vdc_store_label_unk(vdc);
8220 		return (EINVAL);
8221 	}
8222 
8223 	kmem_free(label, vdc->vdisk_bsize);
8224 	mutex_enter(&vdc->lock);
8225 	vdc_store_label_vtoc(vdc, &geom, &vtoc);
8226 	return (0);
8227 }
8228 
8229 /*
8230  * Function:
8231  *	vdc_validate
8232  *
8233  * Description:
8234  *	This routine discovers the label of the disk and create the
8235  *	appropriate device nodes if the label has changed.
8236  *
8237  * Arguments:
8238  *	vdc	- soft state pointer for this instance of the device driver.
8239  *
8240  * Return Code:
8241  *	none.
8242  */
8243 static void
8244 vdc_validate(vdc_t *vdc)
8245 {
8246 	vd_disk_label_t old_label;
8247 	vd_slice_t old_slice[V_NUMPAR];
8248 	int rv;
8249 
8250 	ASSERT(!MUTEX_HELD(&vdc->lock));
8251 
8252 	mutex_enter(&vdc->lock);
8253 
8254 	/* save the current label and vtoc */
8255 	old_label = vdc->vdisk_label;
8256 	bcopy(vdc->slice, &old_slice, sizeof (vd_slice_t) * V_NUMPAR);
8257 
8258 	/* check the geometry */
8259 	(void) vdc_validate_geometry(vdc);
8260 
8261 	/* if the disk label has changed, update device nodes */
8262 	if (vdc->vdisk_type == VD_DISK_TYPE_DISK &&
8263 	    vdc->vdisk_label != old_label) {
8264 
8265 		if (vdc->vdisk_label == VD_DISK_LABEL_EFI)
8266 			rv = vdc_create_device_nodes_efi(vdc);
8267 		else
8268 			rv = vdc_create_device_nodes_vtoc(vdc);
8269 
8270 		if (rv != 0) {
8271 			DMSG(vdc, 0, "![%d] Failed to update device nodes",
8272 			    vdc->instance);
8273 		}
8274 	}
8275 
8276 	mutex_exit(&vdc->lock);
8277 }
8278 
8279 static void
8280 vdc_validate_task(void *arg)
8281 {
8282 	vdc_t *vdc = (vdc_t *)arg;
8283 
8284 	vdc_validate(vdc);
8285 
8286 	mutex_enter(&vdc->lock);
8287 	ASSERT(vdc->validate_pending > 0);
8288 	vdc->validate_pending--;
8289 	mutex_exit(&vdc->lock);
8290 }
8291 
8292 /*
8293  * Function:
8294  *	vdc_setup_devid()
8295  *
8296  * Description:
8297  *	This routine discovers the devid of a vDisk. It requests the devid of
8298  *	the underlying device from the vDisk server, builds an encapsulated
8299  *	devid based on the retrieved devid and registers that new devid to
8300  *	the vDisk.
8301  *
8302  * Arguments:
8303  *	vdc	- soft state pointer for this instance of the device driver.
8304  *
8305  * Return Code:
8306  *	0	- A devid was succesfully registered for the vDisk
8307  */
8308 static int
8309 vdc_setup_devid(vdc_t *vdc)
8310 {
8311 	int rv;
8312 	vd_devid_t *vd_devid;
8313 	size_t bufsize, bufid_len;
8314 	ddi_devid_t vdisk_devid;
8315 	char *devid_str;
8316 
8317 	/*
8318 	 * At first sight, we don't know the size of the devid that the
8319 	 * server will return but this size will be encoded into the
8320 	 * reply. So we do a first request using a default size then we
8321 	 * check if this size was large enough. If not then we do a second
8322 	 * request with the correct size returned by the server. Note that
8323 	 * ldc requires size to be 8-byte aligned.
8324 	 */
8325 	bufsize = P2ROUNDUP(VD_DEVID_SIZE(VD_DEVID_DEFAULT_LEN),
8326 	    sizeof (uint64_t));
8327 	vd_devid = kmem_zalloc(bufsize, KM_SLEEP);
8328 	bufid_len = bufsize - sizeof (vd_efi_t) - 1;
8329 
8330 	rv = vdc_do_op(vdc, VD_OP_GET_DEVID, (caddr_t)vd_devid,
8331 	    bufsize, 0, 0, NULL, VIO_both_dir, 0);
8332 
8333 	DMSG(vdc, 2, "do_op returned %d\n", rv);
8334 
8335 	if (rv) {
8336 		kmem_free(vd_devid, bufsize);
8337 		return (rv);
8338 	}
8339 
8340 	if (vd_devid->length > bufid_len) {
8341 		/*
8342 		 * The returned devid is larger than the buffer used. Try again
8343 		 * with a buffer with the right size.
8344 		 */
8345 		kmem_free(vd_devid, bufsize);
8346 		bufsize = P2ROUNDUP(VD_DEVID_SIZE(vd_devid->length),
8347 		    sizeof (uint64_t));
8348 		vd_devid = kmem_zalloc(bufsize, KM_SLEEP);
8349 		bufid_len = bufsize - sizeof (vd_efi_t) - 1;
8350 
8351 		rv = vdc_do_sync_op(vdc, VD_OP_GET_DEVID, (caddr_t)vd_devid,
8352 		    bufsize, 0, 0, VIO_both_dir, B_TRUE);
8353 
8354 		if (rv) {
8355 			kmem_free(vd_devid, bufsize);
8356 			return (rv);
8357 		}
8358 	}
8359 
8360 	/*
8361 	 * The virtual disk should have the same device id as the one associated
8362 	 * with the physical disk it is mapped on, otherwise sharing a disk
8363 	 * between a LDom and a non-LDom may not work (for example for a shared
8364 	 * SVM disk set).
8365 	 *
8366 	 * The DDI framework does not allow creating a device id with any
8367 	 * type so we first create a device id of type DEVID_ENCAP and then
8368 	 * we restore the orignal type of the physical device.
8369 	 */
8370 
8371 	DMSG(vdc, 2, ": devid length = %d\n", vd_devid->length);
8372 
8373 	/* build an encapsulated devid based on the returned devid */
8374 	if (ddi_devid_init(vdc->dip, DEVID_ENCAP, vd_devid->length,
8375 	    vd_devid->id, &vdisk_devid) != DDI_SUCCESS) {
8376 		DMSG(vdc, 1, "[%d] Fail to created devid\n", vdc->instance);
8377 		kmem_free(vd_devid, bufsize);
8378 		return (1);
8379 	}
8380 
8381 	DEVID_FORMTYPE((impl_devid_t *)vdisk_devid, vd_devid->type);
8382 
8383 	ASSERT(ddi_devid_valid(vdisk_devid) == DDI_SUCCESS);
8384 
8385 	kmem_free(vd_devid, bufsize);
8386 
8387 	if (vdc->devid != NULL) {
8388 		/* check that the devid hasn't changed */
8389 		if (ddi_devid_compare(vdisk_devid, vdc->devid) == 0) {
8390 			ddi_devid_free(vdisk_devid);
8391 			return (0);
8392 		}
8393 
8394 		cmn_err(CE_WARN, "vdisk@%d backend devid has changed",
8395 		    vdc->instance);
8396 
8397 		devid_str = ddi_devid_str_encode(vdc->devid, NULL);
8398 
8399 		cmn_err(CE_CONT, "vdisk@%d backend initial devid: %s",
8400 		    vdc->instance,
8401 		    (devid_str)? devid_str : "<encoding error>");
8402 
8403 		if (devid_str)
8404 			ddi_devid_str_free(devid_str);
8405 
8406 		devid_str = ddi_devid_str_encode(vdisk_devid, NULL);
8407 
8408 		cmn_err(CE_CONT, "vdisk@%d backend current devid: %s",
8409 		    vdc->instance,
8410 		    (devid_str)? devid_str : "<encoding error>");
8411 
8412 		if (devid_str)
8413 			ddi_devid_str_free(devid_str);
8414 
8415 		ddi_devid_free(vdisk_devid);
8416 		return (1);
8417 	}
8418 
8419 	if (ddi_devid_register(vdc->dip, vdisk_devid) != DDI_SUCCESS) {
8420 		DMSG(vdc, 1, "[%d] Fail to register devid\n", vdc->instance);
8421 		ddi_devid_free(vdisk_devid);
8422 		return (1);
8423 	}
8424 
8425 	vdc->devid = vdisk_devid;
8426 
8427 	return (0);
8428 }
8429 
8430 static void
8431 vdc_store_label_efi(vdc_t *vdc, efi_gpt_t *gpt, efi_gpe_t *gpe)
8432 {
8433 	int i, nparts;
8434 
8435 	ASSERT(MUTEX_HELD(&vdc->lock));
8436 
8437 	vdc->vdisk_label = VD_DISK_LABEL_EFI;
8438 	bzero(vdc->vtoc, sizeof (struct extvtoc));
8439 	bzero(vdc->geom, sizeof (struct dk_geom));
8440 	bzero(vdc->slice, sizeof (vd_slice_t) * V_NUMPAR);
8441 
8442 	nparts = gpt->efi_gpt_NumberOfPartitionEntries;
8443 
8444 	for (i = 0; i < nparts && i < VD_EFI_WD_SLICE; i++) {
8445 
8446 		if (gpe[i].efi_gpe_StartingLBA == 0 &&
8447 		    gpe[i].efi_gpe_EndingLBA == 0) {
8448 			continue;
8449 		}
8450 
8451 		vdc->slice[i].start = gpe[i].efi_gpe_StartingLBA;
8452 		vdc->slice[i].nblocks = gpe[i].efi_gpe_EndingLBA -
8453 		    gpe[i].efi_gpe_StartingLBA + 1;
8454 	}
8455 
8456 	ASSERT(vdc->vdisk_size != 0);
8457 	vdc->slice[VD_EFI_WD_SLICE].start = 0;
8458 	vdc->slice[VD_EFI_WD_SLICE].nblocks = vdc->vdisk_size;
8459 
8460 }
8461 
8462 static void
8463 vdc_store_label_vtoc(vdc_t *vdc, struct dk_geom *geom, struct extvtoc *vtoc)
8464 {
8465 	int i;
8466 
8467 	ASSERT(MUTEX_HELD(&vdc->lock));
8468 	ASSERT(vdc->vdisk_bsize == vtoc->v_sectorsz);
8469 
8470 	vdc->vdisk_label = VD_DISK_LABEL_VTOC;
8471 	bcopy(vtoc, vdc->vtoc, sizeof (struct extvtoc));
8472 	bcopy(geom, vdc->geom, sizeof (struct dk_geom));
8473 	bzero(vdc->slice, sizeof (vd_slice_t) * V_NUMPAR);
8474 
8475 	for (i = 0; i < vtoc->v_nparts; i++) {
8476 		vdc->slice[i].start = vtoc->v_part[i].p_start;
8477 		vdc->slice[i].nblocks = vtoc->v_part[i].p_size;
8478 	}
8479 }
8480 
8481 static void
8482 vdc_store_label_unk(vdc_t *vdc)
8483 {
8484 	ASSERT(MUTEX_HELD(&vdc->lock));
8485 
8486 	vdc->vdisk_label = VD_DISK_LABEL_UNK;
8487 	bzero(vdc->vtoc, sizeof (struct extvtoc));
8488 	bzero(vdc->geom, sizeof (struct dk_geom));
8489 	bzero(vdc->slice, sizeof (vd_slice_t) * V_NUMPAR);
8490 }
8491