1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2011 NetApp, Inc.
5 * All rights reserved.
6 * Copyright 2020-2021 Joyent, Inc.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30 #include <sys/param.h>
31 #include <sys/linker_set.h>
32 #include <sys/stat.h>
33 #include <sys/uio.h>
34 #include <sys/ioctl.h>
35 #include <sys/disk.h>
36
37 #include <machine/vmm_snapshot.h>
38
39 #include <errno.h>
40 #include <fcntl.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <stdint.h>
44 #include <string.h>
45 #include <strings.h>
46 #include <unistd.h>
47 #include <assert.h>
48 #include <pthread.h>
49 #include <md5.h>
50
51 #include "bhyverun.h"
52 #include "config.h"
53 #include "debug.h"
54 #include "pci_emul.h"
55 #include "virtio.h"
56 #include "block_if.h"
57
58 #define VTBLK_BSIZE 512
59 #define VTBLK_RINGSZ 128
60
61 _Static_assert(VTBLK_RINGSZ <= BLOCKIF_RING_MAX, "Each ring entry must be able to queue a request");
62
63 #define VTBLK_S_OK 0
64 #define VTBLK_S_IOERR 1
65 #define VTBLK_S_UNSUPP 2
66
67 #define VTBLK_BLK_ID_BYTES 20 + 1
68
69 /* Capability bits */
70 #define VTBLK_F_BARRIER (1 << 0) /* Does host support barriers? */
71 #define VTBLK_F_SIZE_MAX (1 << 1) /* Indicates maximum segment size */
72 #define VTBLK_F_SEG_MAX (1 << 2) /* Indicates maximum # of segments */
73 #define VTBLK_F_GEOMETRY (1 << 4) /* Legacy geometry available */
74 #define VTBLK_F_RO (1 << 5) /* Disk is read-only */
75 #define VTBLK_F_BLK_SIZE (1 << 6) /* Block size of disk is available*/
76 #define VTBLK_F_SCSI (1 << 7) /* Supports scsi command passthru */
77 #define VTBLK_F_FLUSH (1 << 9) /* Writeback mode enabled after reset */
78 #define VTBLK_F_WCE (1 << 9) /* Legacy alias for FLUSH */
79 #define VTBLK_F_TOPOLOGY (1 << 10) /* Topology information is available */
80 #define VTBLK_F_CONFIG_WCE (1 << 11) /* Writeback mode available in config */
81 #define VTBLK_F_MQ (1 << 12) /* Multi-Queue */
82 #define VTBLK_F_DISCARD (1 << 13) /* Trim blocks */
83 #define VTBLK_F_WRITE_ZEROES (1 << 14) /* Write zeros */
84
85 /*
86 * Host capabilities
87 */
88 #define VTBLK_S_HOSTCAPS \
89 ( VTBLK_F_SEG_MAX | \
90 VTBLK_F_BLK_SIZE | \
91 VTBLK_F_FLUSH | \
92 VTBLK_F_TOPOLOGY | \
93 VIRTIO_RING_F_INDIRECT_DESC ) /* indirect descriptors */
94
95 /*
96 * The current blockif_delete() interface only allows a single delete
97 * request at a time.
98 */
99 #define VTBLK_MAX_DISCARD_SEG 1
100
101 /*
102 * An arbitrary limit to prevent excessive latency due to large
103 * delete requests.
104 */
105 #define VTBLK_MAX_DISCARD_SECT ((16 << 20) / VTBLK_BSIZE) /* 16 MiB */
106
107 /*
108 * Config space "registers"
109 */
110 struct vtblk_config {
111 uint64_t vbc_capacity;
112 uint32_t vbc_size_max;
113 uint32_t vbc_seg_max;
114 struct {
115 uint16_t cylinders;
116 uint8_t heads;
117 uint8_t sectors;
118 } vbc_geometry;
119 uint32_t vbc_blk_size;
120 struct {
121 uint8_t physical_block_exp;
122 uint8_t alignment_offset;
123 uint16_t min_io_size;
124 uint32_t opt_io_size;
125 } vbc_topology;
126 uint8_t vbc_writeback;
127 uint8_t unused0[1];
128 uint16_t num_queues;
129 uint32_t max_discard_sectors;
130 uint32_t max_discard_seg;
131 uint32_t discard_sector_alignment;
132 uint32_t max_write_zeroes_sectors;
133 uint32_t max_write_zeroes_seg;
134 uint8_t write_zeroes_may_unmap;
135 uint8_t unused1[3];
136 } __packed;
137
138 /*
139 * Fixed-size block header
140 */
141 struct virtio_blk_hdr {
142 #define VBH_OP_READ 0
143 #define VBH_OP_WRITE 1
144 #define VBH_OP_SCSI_CMD 2
145 #define VBH_OP_SCSI_CMD_OUT 3
146 #define VBH_OP_FLUSH 4
147 #define VBH_OP_FLUSH_OUT 5
148 #define VBH_OP_IDENT 8
149 #define VBH_OP_DISCARD 11
150 #define VBH_OP_WRITE_ZEROES 13
151
152 #define VBH_FLAG_BARRIER 0x80000000 /* OR'ed into vbh_type */
153 uint32_t vbh_type;
154 uint32_t vbh_ioprio;
155 uint64_t vbh_sector;
156 } __packed;
157
158 /*
159 * Debug printf
160 */
161 static int pci_vtblk_debug;
162 #define DPRINTF(params) if (pci_vtblk_debug) PRINTLN params
163 #define WPRINTF(params) PRINTLN params
164
165 struct pci_vtblk_ioreq {
166 struct blockif_req io_req;
167 struct pci_vtblk_softc *io_sc;
168 uint8_t *io_status;
169 uint16_t io_idx;
170 };
171
172 struct virtio_blk_discard_write_zeroes {
173 uint64_t sector;
174 uint32_t num_sectors;
175 struct {
176 uint32_t unmap:1;
177 uint32_t reserved:31;
178 } flags;
179 };
180
181 /*
182 * Per-device softc
183 */
184 struct pci_vtblk_softc {
185 struct virtio_softc vbsc_vs;
186 pthread_mutex_t vsc_mtx;
187 struct vqueue_info vbsc_vq;
188 struct vtblk_config vbsc_cfg;
189 struct virtio_consts vbsc_consts;
190 struct blockif_ctxt *bc;
191 char vbsc_ident[VTBLK_BLK_ID_BYTES];
192 struct pci_vtblk_ioreq vbsc_ios[VTBLK_RINGSZ];
193 };
194
195 static void pci_vtblk_reset(void *);
196 static void pci_vtblk_notify(void *, struct vqueue_info *);
197 static int pci_vtblk_cfgread(void *, int, int, uint32_t *);
198 static int pci_vtblk_cfgwrite(void *, int, int, uint32_t);
199 #ifdef BHYVE_SNAPSHOT
200 static void pci_vtblk_pause(void *);
201 static void pci_vtblk_resume(void *);
202 static int pci_vtblk_snapshot(void *, struct vm_snapshot_meta *);
203 #endif
204
205 static struct virtio_consts vtblk_vi_consts = {
206 .vc_name = "vtblk",
207 .vc_nvq = 1,
208 .vc_cfgsize = sizeof(struct vtblk_config),
209 .vc_reset = pci_vtblk_reset,
210 .vc_qnotify = pci_vtblk_notify,
211 .vc_cfgread = pci_vtblk_cfgread,
212 .vc_cfgwrite = pci_vtblk_cfgwrite,
213 .vc_apply_features = NULL,
214 .vc_hv_caps = VTBLK_S_HOSTCAPS,
215 #ifdef BHYVE_SNAPSHOT
216 .vc_pause = pci_vtblk_pause,
217 .vc_resume = pci_vtblk_resume,
218 .vc_snapshot = pci_vtblk_snapshot,
219 #endif
220 };
221
222 static void
pci_vtblk_reset(void * vsc)223 pci_vtblk_reset(void *vsc)
224 {
225 struct pci_vtblk_softc *sc = vsc;
226
227 DPRINTF(("vtblk: device reset requested !"));
228 vi_reset_dev(&sc->vbsc_vs);
229 }
230
231 static void
pci_vtblk_done_locked(struct pci_vtblk_ioreq * io,int err)232 pci_vtblk_done_locked(struct pci_vtblk_ioreq *io, int err)
233 {
234 struct pci_vtblk_softc *sc = io->io_sc;
235
236 /* convert errno into a virtio block error return */
237 if (err == EOPNOTSUPP || err == ENOSYS)
238 *io->io_status = VTBLK_S_UNSUPP;
239 else if (err != 0)
240 *io->io_status = VTBLK_S_IOERR;
241 else
242 *io->io_status = VTBLK_S_OK;
243
244 /*
245 * Return the descriptor back to the host.
246 * We wrote 1 byte (our status) to host.
247 */
248 vq_relchain(&sc->vbsc_vq, io->io_idx, 1);
249 vq_endchains(&sc->vbsc_vq, 0);
250 }
251
252 #ifdef BHYVE_SNAPSHOT
253 static void
pci_vtblk_pause(void * vsc)254 pci_vtblk_pause(void *vsc)
255 {
256 struct pci_vtblk_softc *sc = vsc;
257
258 DPRINTF(("vtblk: device pause requested !\n"));
259 blockif_pause(sc->bc);
260 }
261
262 static void
pci_vtblk_resume(void * vsc)263 pci_vtblk_resume(void *vsc)
264 {
265 struct pci_vtblk_softc *sc = vsc;
266
267 DPRINTF(("vtblk: device resume requested !\n"));
268 blockif_resume(sc->bc);
269 }
270
271 static int
pci_vtblk_snapshot(void * vsc,struct vm_snapshot_meta * meta)272 pci_vtblk_snapshot(void *vsc, struct vm_snapshot_meta *meta)
273 {
274 int ret;
275 struct pci_vtblk_softc *sc = vsc;
276
277 SNAPSHOT_VAR_OR_LEAVE(sc->vbsc_cfg, meta, ret, done);
278 SNAPSHOT_BUF_OR_LEAVE(sc->vbsc_ident, sizeof(sc->vbsc_ident),
279 meta, ret, done);
280
281 done:
282 return (ret);
283 }
284 #endif
285
286 static void
pci_vtblk_done(struct blockif_req * br,int err)287 pci_vtblk_done(struct blockif_req *br, int err)
288 {
289 struct pci_vtblk_ioreq *io = br->br_param;
290 struct pci_vtblk_softc *sc = io->io_sc;
291
292 pthread_mutex_lock(&sc->vsc_mtx);
293 pci_vtblk_done_locked(io, err);
294 pthread_mutex_unlock(&sc->vsc_mtx);
295 }
296
297 static void
pci_vtblk_proc(struct pci_vtblk_softc * sc,struct vqueue_info * vq)298 pci_vtblk_proc(struct pci_vtblk_softc *sc, struct vqueue_info *vq)
299 {
300 struct virtio_blk_hdr *vbh;
301 struct pci_vtblk_ioreq *io;
302 int i, n;
303 int err;
304 ssize_t iolen;
305 int writeop, type;
306 struct vi_req req;
307 struct iovec iov[BLOCKIF_IOV_MAX + 2];
308 struct virtio_blk_discard_write_zeroes *discard;
309
310 n = vq_getchain(vq, iov, BLOCKIF_IOV_MAX + 2, &req);
311
312 /*
313 * The first descriptor will be the read-only fixed header,
314 * and the last is for status (hence +2 above and below).
315 * The remaining iov's are the actual data I/O vectors.
316 *
317 * XXX - note - this fails on crash dump, which does a
318 * VIRTIO_BLK_T_FLUSH with a zero transfer length
319 */
320 assert(n >= 2 && n <= BLOCKIF_IOV_MAX + 2);
321
322 io = &sc->vbsc_ios[req.idx];
323 assert(req.readable != 0);
324 assert(iov[0].iov_len == sizeof(struct virtio_blk_hdr));
325 vbh = (struct virtio_blk_hdr *)iov[0].iov_base;
326 memcpy(&io->io_req.br_iov, &iov[1], sizeof(struct iovec) * (n - 2));
327 io->io_req.br_iovcnt = n - 2;
328 io->io_req.br_offset = vbh->vbh_sector * VTBLK_BSIZE;
329 io->io_status = (uint8_t *)iov[--n].iov_base;
330 assert(req.writable != 0);
331 assert(iov[n].iov_len == 1);
332
333 /*
334 * XXX
335 * The guest should not be setting the BARRIER flag because
336 * we don't advertise the capability.
337 */
338 type = vbh->vbh_type & ~VBH_FLAG_BARRIER;
339 writeop = (type == VBH_OP_WRITE || type == VBH_OP_DISCARD);
340 /*
341 * - Write op implies read-only descriptor
342 * - Read/ident op implies write-only descriptor
343 *
344 * By taking away either the read-only fixed header or the write-only
345 * status iovec, the following condition should hold true.
346 */
347 assert(n == (writeop ? req.readable : req.writable));
348
349 iolen = 0;
350 for (i = 1; i < n; i++) {
351 iolen += iov[i].iov_len;
352 }
353 io->io_req.br_resid = iolen;
354
355 DPRINTF(("virtio-block: %s op, %zd bytes, %d segs, offset %ld",
356 writeop ? "write/discard" : "read/ident", iolen, i - 1,
357 io->io_req.br_offset));
358
359 switch (type) {
360 case VBH_OP_READ:
361 err = blockif_read(sc->bc, &io->io_req);
362 break;
363 case VBH_OP_WRITE:
364 err = blockif_write(sc->bc, &io->io_req);
365 break;
366 case VBH_OP_DISCARD:
367 /*
368 * We currently only support a single request, if the guest
369 * has submitted a request that doesn't conform to the
370 * requirements, we return a error.
371 */
372 if (iov[1].iov_len != sizeof (*discard)) {
373 pci_vtblk_done_locked(io, EINVAL);
374 return;
375 }
376
377 /* The segments to discard are provided rather than data */
378 discard = (struct virtio_blk_discard_write_zeroes *)
379 iov[1].iov_base;
380
381 /*
382 * virtio v1.1 5.2.6.2:
383 * The device MUST set the status byte to VIRTIO_BLK_S_UNSUPP
384 * for discard and write zeroes commands if any unknown flag is
385 * set. Furthermore, the device MUST set the status byte to
386 * VIRTIO_BLK_S_UNSUPP for discard commands if the unmap flag
387 * is set.
388 *
389 * Currently there are no known flags for a DISCARD request.
390 */
391 if (discard->flags.unmap != 0 || discard->flags.reserved != 0) {
392 pci_vtblk_done_locked(io, ENOTSUP);
393 return;
394 }
395
396 /* Make sure the request doesn't exceed our size limit */
397 if (discard->num_sectors > VTBLK_MAX_DISCARD_SECT) {
398 pci_vtblk_done_locked(io, EINVAL);
399 return;
400 }
401
402 io->io_req.br_offset = discard->sector * VTBLK_BSIZE;
403 io->io_req.br_resid = discard->num_sectors * VTBLK_BSIZE;
404 err = blockif_delete(sc->bc, &io->io_req);
405 break;
406 case VBH_OP_FLUSH:
407 case VBH_OP_FLUSH_OUT:
408 err = blockif_flush(sc->bc, &io->io_req);
409 break;
410 case VBH_OP_IDENT:
411 /* Assume a single buffer */
412 /* S/n equal to buffer is not zero-terminated. */
413 memset(iov[1].iov_base, 0, iov[1].iov_len);
414 strncpy(iov[1].iov_base, sc->vbsc_ident,
415 MIN(iov[1].iov_len, sizeof(sc->vbsc_ident)));
416 pci_vtblk_done_locked(io, 0);
417 return;
418 default:
419 pci_vtblk_done_locked(io, EOPNOTSUPP);
420 return;
421 }
422 assert(err == 0);
423 }
424
425 static void
pci_vtblk_notify(void * vsc,struct vqueue_info * vq)426 pci_vtblk_notify(void *vsc, struct vqueue_info *vq)
427 {
428 struct pci_vtblk_softc *sc = vsc;
429
430 while (vq_has_descs(vq))
431 pci_vtblk_proc(sc, vq);
432 }
433
434 static void
pci_vtblk_resized(struct blockif_ctxt * bctxt __unused,void * arg,size_t new_size)435 pci_vtblk_resized(struct blockif_ctxt *bctxt __unused, void *arg,
436 size_t new_size)
437 {
438 struct pci_vtblk_softc *sc;
439
440 sc = arg;
441
442 sc->vbsc_cfg.vbc_capacity = new_size / VTBLK_BSIZE; /* 512-byte units */
443 vi_interrupt(&sc->vbsc_vs, VIRTIO_PCI_ISR_CONFIG,
444 sc->vbsc_vs.vs_msix_cfg_idx);
445 }
446
447 static int
pci_vtblk_init(struct pci_devinst * pi,nvlist_t * nvl)448 pci_vtblk_init(struct pci_devinst *pi, nvlist_t *nvl)
449 {
450 char bident[sizeof("XXX:XXX")];
451 struct blockif_ctxt *bctxt;
452 const char *path, *serial;
453 MD5_CTX mdctx;
454 u_char digest[16];
455 struct pci_vtblk_softc *sc;
456 off_t size;
457 int i, sectsz, sts, sto;
458
459 /*
460 * The supplied backing file has to exist
461 */
462 snprintf(bident, sizeof(bident), "%u:%u", pi->pi_slot, pi->pi_func);
463 bctxt = blockif_open(nvl, bident);
464 if (bctxt == NULL) {
465 perror("Could not open backing file");
466 return (1);
467 }
468
469 if (blockif_add_boot_device(pi, bctxt)) {
470 perror("Invalid boot device");
471 return (1);
472 }
473
474 size = blockif_size(bctxt);
475 sectsz = blockif_sectsz(bctxt);
476 blockif_psectsz(bctxt, &sts, &sto);
477
478 sc = calloc(1, sizeof(struct pci_vtblk_softc));
479 sc->bc = bctxt;
480 for (i = 0; i < VTBLK_RINGSZ; i++) {
481 struct pci_vtblk_ioreq *io = &sc->vbsc_ios[i];
482 io->io_req.br_callback = pci_vtblk_done;
483 io->io_req.br_param = io;
484 io->io_sc = sc;
485 io->io_idx = i;
486 }
487
488 bcopy(&vtblk_vi_consts, &sc->vbsc_consts, sizeof (vtblk_vi_consts));
489 if (blockif_candelete(sc->bc))
490 sc->vbsc_consts.vc_hv_caps |= VTBLK_F_DISCARD;
491
492 pthread_mutex_init(&sc->vsc_mtx, NULL);
493
494 /* init virtio softc and virtqueues */
495 vi_softc_linkup(&sc->vbsc_vs, &sc->vbsc_consts, sc, pi, &sc->vbsc_vq);
496 sc->vbsc_vs.vs_mtx = &sc->vsc_mtx;
497
498 sc->vbsc_vq.vq_qsize = VTBLK_RINGSZ;
499 /* sc->vbsc_vq.vq_notify = we have no per-queue notify */
500
501 /*
502 * If an explicit identifier is not given, create an
503 * identifier using parts of the md5 sum of the filename.
504 */
505 bzero(sc->vbsc_ident, VTBLK_BLK_ID_BYTES);
506 if ((serial = get_config_value_node(nvl, "serial")) != NULL ||
507 (serial = get_config_value_node(nvl, "ser")) != NULL) {
508 strlcpy(sc->vbsc_ident, serial, VTBLK_BLK_ID_BYTES);
509 } else {
510 path = get_config_value_node(nvl, "path");
511 MD5Init(&mdctx);
512 MD5Update(&mdctx, path, strlen(path));
513 MD5Final(digest, &mdctx);
514 snprintf(sc->vbsc_ident, VTBLK_BLK_ID_BYTES,
515 "BHYVE-%02X%02X-%02X%02X-%02X%02X",
516 digest[0], digest[1], digest[2], digest[3], digest[4],
517 digest[5]);
518 }
519
520 /* setup virtio block config space */
521 sc->vbsc_cfg.vbc_capacity = size / VTBLK_BSIZE; /* 512-byte units */
522 sc->vbsc_cfg.vbc_size_max = 0; /* not negotiated */
523
524 /*
525 * If Linux is presented with a seg_max greater than the virtio queue
526 * size, it can stumble into situations where it violates its own
527 * invariants and panics. For safety, we keep seg_max clamped, paying
528 * heed to the two extra descriptors needed for the header and status
529 * of a request.
530 */
531 sc->vbsc_cfg.vbc_seg_max = MIN(VTBLK_RINGSZ - 2, BLOCKIF_IOV_MAX);
532 sc->vbsc_cfg.vbc_geometry.cylinders = 0; /* no geometry */
533 sc->vbsc_cfg.vbc_geometry.heads = 0;
534 sc->vbsc_cfg.vbc_geometry.sectors = 0;
535 sc->vbsc_cfg.vbc_blk_size = sectsz;
536 sc->vbsc_cfg.vbc_topology.physical_block_exp =
537 (sts > sectsz) ? (ffsll(sts / sectsz) - 1) : 0;
538 sc->vbsc_cfg.vbc_topology.alignment_offset =
539 (sto != 0) ? ((sts - sto) / sectsz) : 0;
540 sc->vbsc_cfg.vbc_topology.min_io_size = 0;
541 sc->vbsc_cfg.vbc_topology.opt_io_size = 0;
542 sc->vbsc_cfg.vbc_writeback = 0;
543 sc->vbsc_cfg.max_discard_sectors = VTBLK_MAX_DISCARD_SECT;
544 sc->vbsc_cfg.max_discard_seg = VTBLK_MAX_DISCARD_SEG;
545 sc->vbsc_cfg.discard_sector_alignment = MAX(sectsz, sts) / VTBLK_BSIZE;
546
547 /*
548 * Should we move some of this into virtio.c? Could
549 * have the device, class, and subdev_0 as fields in
550 * the virtio constants structure.
551 */
552 pci_set_cfgdata16(pi, PCIR_DEVICE, VIRTIO_DEV_BLOCK);
553 pci_set_cfgdata16(pi, PCIR_VENDOR, VIRTIO_VENDOR);
554 pci_set_cfgdata8(pi, PCIR_CLASS, PCIC_STORAGE);
555 pci_set_cfgdata16(pi, PCIR_SUBDEV_0, VIRTIO_ID_BLOCK);
556 pci_set_cfgdata16(pi, PCIR_SUBVEND_0, VIRTIO_VENDOR);
557
558 if (vi_intr_init(&sc->vbsc_vs, 1, fbsdrun_virtio_msix())) {
559 blockif_close(sc->bc);
560 free(sc);
561 return (1);
562 }
563 vi_set_io_bar(&sc->vbsc_vs, 0);
564 blockif_register_resize_callback(sc->bc, pci_vtblk_resized, sc);
565 return (0);
566 }
567
568 static int
pci_vtblk_cfgwrite(void * vsc __unused,int offset,int size __unused,uint32_t value __unused)569 pci_vtblk_cfgwrite(void *vsc __unused, int offset, int size __unused,
570 uint32_t value __unused)
571 {
572
573 DPRINTF(("vtblk: write to readonly reg %d", offset));
574 return (1);
575 }
576
577 static int
pci_vtblk_cfgread(void * vsc,int offset,int size,uint32_t * retval)578 pci_vtblk_cfgread(void *vsc, int offset, int size, uint32_t *retval)
579 {
580 struct pci_vtblk_softc *sc = vsc;
581 void *ptr;
582
583 /* our caller has already verified offset and size */
584 ptr = (uint8_t *)&sc->vbsc_cfg + offset;
585 memcpy(retval, ptr, size);
586 return (0);
587 }
588
589 static const struct pci_devemu pci_de_vblk = {
590 .pe_emu = "virtio-blk",
591 .pe_init = pci_vtblk_init,
592 .pe_legacy_config = blockif_legacy_config,
593 .pe_barwrite = vi_pci_write,
594 .pe_barread = vi_pci_read,
595 #ifdef BHYVE_SNAPSHOT
596 .pe_snapshot = vi_pci_snapshot,
597 .pe_pause = vi_pci_pause,
598 .pe_resume = vi_pci_resume,
599 #endif
600 };
601 PCI_EMUL_SET(pci_de_vblk);
602