xref: /titanic_41/usr/src/uts/i86xpv/io/privcmd.c (revision f998c95e3b7029fe5f7542e115f7474ddb8024d7)
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 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 #include <sys/types.h>
30 #include <sys/file.h>
31 #include <sys/errno.h>
32 #include <sys/open.h>
33 #include <sys/cred.h>
34 #include <sys/conf.h>
35 #include <sys/stat.h>
36 #include <sys/modctl.h>
37 #include <sys/ddi.h>
38 #include <sys/sunddi.h>
39 #include <sys/vmsystm.h>
40 #include <sys/sdt.h>
41 #include <sys/hypervisor.h>
42 #include <sys/xen_errno.h>
43 
44 #include <vm/hat_i86.h>
45 #include <vm/hat_pte.h>
46 #include <vm/seg_mf.h>
47 
48 #include <xen/sys/privcmd.h>
49 #include <sys/privcmd_impl.h>
50 
51 static dev_info_t *privcmd_devi;
52 
53 /*ARGSUSED*/
54 static int
55 privcmd_getinfo(dev_info_t *devi, ddi_info_cmd_t cmd, void *arg, void **result)
56 {
57 	switch (cmd) {
58 	case DDI_INFO_DEVT2DEVINFO:
59 	case DDI_INFO_DEVT2INSTANCE:
60 		break;
61 	default:
62 		return (DDI_FAILURE);
63 	}
64 
65 	switch (getminor((dev_t)arg)) {
66 	case PRIVCMD_MINOR:
67 		break;
68 	default:
69 		return (DDI_FAILURE);
70 	}
71 
72 	if (cmd == DDI_INFO_DEVT2INSTANCE)
73 		*result = 0;
74 	else
75 		*result = privcmd_devi;
76 	return (DDI_SUCCESS);
77 }
78 
79 static int
80 privcmd_attach(dev_info_t *devi, ddi_attach_cmd_t cmd)
81 {
82 	if (cmd != DDI_ATTACH)
83 		return (DDI_FAILURE);
84 
85 	if (ddi_create_minor_node(devi, PRIVCMD_NODE,
86 	    S_IFCHR, PRIVCMD_MINOR, DDI_PSEUDO, 0) != DDI_SUCCESS)
87 		return (DDI_FAILURE);
88 
89 	privcmd_devi = devi;
90 	ddi_report_dev(devi);
91 	return (DDI_SUCCESS);
92 }
93 
94 static int
95 privcmd_detach(dev_info_t *devi, ddi_detach_cmd_t cmd)
96 {
97 	if (cmd != DDI_DETACH)
98 		return (DDI_FAILURE);
99 	ddi_remove_minor_node(devi, NULL);
100 	privcmd_devi = NULL;
101 	return (DDI_SUCCESS);
102 }
103 
104 /*ARGSUSED1*/
105 static int
106 privcmd_open(dev_t *dev, int flag, int otyp, cred_t *cr)
107 {
108 	return (getminor(*dev) == PRIVCMD_MINOR ? 0 : ENXIO);
109 }
110 
111 /*
112  * Map a contiguous set of machine frames in a foreign domain.
113  * Used in the following way:
114  *
115  *	privcmd_mmap_t p;
116  *	privcmd_mmap_entry_t e;
117  *
118  *	addr = mmap(NULL, size, prot, MAP_SHARED, fd, 0);
119  *	p.num = number of privcmd_mmap_entry_t's
120  *	p.dom = domid;
121  *	p.entry = &e;
122  *	e.va = addr;
123  *	e.mfn = mfn;
124  *	e.npages = btopr(size);
125  *	ioctl(fd, IOCTL_PRIVCMD_MMAP, &p);
126  */
127 /*ARGSUSED2*/
128 int
129 do_privcmd_mmap(void *uarg, int mode, cred_t *cr)
130 {
131 	privcmd_mmap_t __mmapcmd, *mmc = &__mmapcmd;
132 	privcmd_mmap_entry_t *umme;
133 	struct as *as = curproc->p_as;
134 	struct seg *seg;
135 	int i, error = 0;
136 
137 	if (ddi_copyin(uarg, mmc, sizeof (*mmc), mode))
138 		return (EFAULT);
139 
140 	DTRACE_XPV3(mmap__start, domid_t, mmc->dom, int, mmc->num,
141 	    privcmd_mmap_entry_t *, mmc->entry);
142 
143 	if (mmc->dom == DOMID_SELF) {
144 		error = ENOTSUP;	/* Too paranoid? */
145 		goto done;
146 	}
147 
148 	for (umme = mmc->entry, i = 0; i < mmc->num; i++, umme++) {
149 		privcmd_mmap_entry_t __mmapent, *mme = &__mmapent;
150 		caddr_t addr;
151 
152 		if (ddi_copyin(umme, mme, sizeof (*mme), mode)) {
153 			error = EFAULT;
154 			break;
155 		}
156 
157 		DTRACE_XPV3(mmap__entry, ulong_t, mme->va, ulong_t, mme->mfn,
158 		    ulong_t, mme->npages);
159 
160 		if (mme->mfn == MFN_INVALID) {
161 			error = EINVAL;
162 			break;
163 		}
164 
165 		addr = (caddr_t)mme->va;
166 
167 		/*
168 		 * Find the segment we want to mess with, then add
169 		 * the mfn range to the segment.
170 		 */
171 		AS_LOCK_ENTER(as, &as->a_lock, RW_READER);
172 		if ((seg = as_findseg(as, addr, 0)) == NULL ||
173 		    addr + mmu_ptob(mme->npages) > seg->s_base + seg->s_size)
174 			error = EINVAL;
175 		else
176 			error = segmf_add_mfns(seg, addr,
177 			    mme->mfn, mme->npages, mmc->dom);
178 		AS_LOCK_EXIT(as, &as->a_lock);
179 
180 		if (error != 0)
181 			break;
182 	}
183 
184 done:
185 	DTRACE_XPV1(mmap__end, int, error);
186 
187 	return (error);
188 }
189 
190 /*
191  * Set up the address range to map to an array of mfns in
192  * a foreign domain.  Used in the following way:
193  *
194  *	privcmd_mmap_batch_t p;
195  *
196  *	addr = mmap(NULL, size, prot, MAP_SHARED, fd, 0);
197  *	p.num = number of pages
198  *	p.dom = domid
199  *	p.addr = addr;
200  *	p.arr = array of mfns, indexed 0 .. p.num - 1
201  *	ioctl(fd, IOCTL_PRIVCMD_MMAPBATCH, &p);
202  */
203 /*ARGSUSED2*/
204 static int
205 do_privcmd_mmapbatch(void *uarg, int mode, cred_t *cr)
206 {
207 	privcmd_mmapbatch_t __mmapbatch, *mmb = &__mmapbatch;
208 	struct as *as = curproc->p_as;
209 	struct seg *seg;
210 	int i, error = 0;
211 	caddr_t addr;
212 	ulong_t *ulp;
213 
214 	if (ddi_copyin(uarg, mmb, sizeof (*mmb), mode))
215 		return (EFAULT);
216 
217 	DTRACE_XPV3(mmapbatch__start, domid_t, mmb->dom, int, mmb->num,
218 	    caddr_t, mmb->addr);
219 
220 	addr = (caddr_t)mmb->addr;
221 	AS_LOCK_ENTER(as, &as->a_lock, RW_READER);
222 	if ((seg = as_findseg(as, addr, 0)) == NULL ||
223 	    addr + ptob(mmb->num) > seg->s_base + seg->s_size) {
224 		error = EINVAL;
225 		goto done;
226 	}
227 
228 	for (i = 0, ulp = mmb->arr;
229 	    i < mmb->num; i++, addr += PAGESIZE, ulp++) {
230 		mfn_t mfn;
231 
232 		if (fulword(ulp, &mfn) != 0) {
233 			error = EFAULT;
234 			break;
235 		}
236 
237 		if (mfn == MFN_INVALID) {
238 			/*
239 			 * This mfn is invalid and should not be added to
240 			 * segmf, as we'd only cause an immediate EFAULT when
241 			 * we tried to fault it in.
242 			 */
243 			mfn |= XEN_DOMCTL_PFINFO_XTAB;
244 			continue;
245 		}
246 
247 		if (segmf_add_mfns(seg, addr, mfn, 1, mmb->dom) == 0)
248 			continue;
249 
250 		/*
251 		 * Tell the process that this MFN could not be mapped, so it
252 		 * won't later try to access it.
253 		 */
254 		mfn |= XEN_DOMCTL_PFINFO_XTAB;
255 		if (sulword(ulp, mfn) != 0) {
256 			error = EFAULT;
257 			break;
258 		}
259 	}
260 
261 done:
262 	AS_LOCK_EXIT(as, &as->a_lock);
263 
264 	DTRACE_XPV3(mmapbatch__end, int, error, struct seg *, seg, caddr_t,
265 	    mmb->addr);
266 
267 	return (error);
268 }
269 
270 /*ARGSUSED*/
271 static int
272 privcmd_ioctl(dev_t dev, int cmd, intptr_t arg, int mode, cred_t *cr, int *rval)
273 {
274 	if ((mode & FMODELS) != FNATIVE)
275 		return (EOVERFLOW);
276 
277 	/*
278 	 * Everything is a -native- data type.
279 	 */
280 
281 	switch (cmd) {
282 	case IOCTL_PRIVCMD_HYPERCALL:
283 		return (do_privcmd_hypercall((void *)arg, mode, cr, rval));
284 	case IOCTL_PRIVCMD_MMAP:
285 		if (DOMAIN_IS_PRIVILEGED(xen_info))
286 			return (do_privcmd_mmap((void *)arg, mode, cr));
287 		break;
288 	case IOCTL_PRIVCMD_MMAPBATCH:
289 		if (DOMAIN_IS_PRIVILEGED(xen_info))
290 			return (do_privcmd_mmapbatch((void *)arg, mode, cr));
291 		break;
292 	default:
293 		break;
294 	}
295 	return (EINVAL);
296 }
297 
298 /*
299  * The real magic happens in the segmf segment driver.
300  */
301 /*ARGSUSED8*/
302 static int
303 privcmd_segmap(dev_t dev, off_t off, struct as *as, caddr_t *addrp,
304     off_t len, uint_t prot, uint_t maxprot, uint_t flags, cred_t *cr)
305 {
306 	struct segmf_crargs a;
307 	int error;
308 
309 	as_rangelock(as);
310 	if ((flags & MAP_FIXED) == 0) {
311 		map_addr(addrp, len, (offset_t)off, 0, flags);
312 		if (*addrp == NULL) {
313 			error = ENOMEM;
314 			goto rangeunlock;
315 		}
316 	} else {
317 		/*
318 		 * User specified address
319 		 */
320 		(void) as_unmap(as, *addrp, len);
321 	}
322 
323 	/*
324 	 * The mapping *must* be MAP_SHARED at offset 0.
325 	 *
326 	 * (Foreign pages are treated like device memory; the
327 	 * ioctl interface allows the backing objects to be
328 	 * arbitrarily redefined to point at any machine frame.)
329 	 */
330 	if ((flags & MAP_TYPE) != MAP_SHARED || off != 0) {
331 		error = EINVAL;
332 		goto rangeunlock;
333 	}
334 
335 	a.dev = dev;
336 	a.prot = (uchar_t)prot;
337 	a.maxprot = (uchar_t)maxprot;
338 	error = as_map(as, *addrp, len, segmf_create, &a);
339 
340 rangeunlock:
341 	as_rangeunlock(as);
342 	return (error);
343 }
344 
345 static struct cb_ops privcmd_cb_ops = {
346 	privcmd_open,
347 	nulldev,	/* close */
348 	nodev,		/* strategy */
349 	nodev,		/* print */
350 	nodev,		/* dump */
351 	nodev,		/* read */
352 	nodev,		/* write */
353 	privcmd_ioctl,
354 	nodev,		/* devmap */
355 	nodev,		/* mmap */
356 	privcmd_segmap,
357 	nochpoll,	/* poll */
358 	ddi_prop_op,
359 	NULL,
360 	D_64BIT | D_NEW | D_MP
361 };
362 
363 static struct dev_ops privcmd_dv_ops = {
364 	DEVO_REV,
365 	0,
366 	privcmd_getinfo,
367 	nulldev,	/* identify */
368 	nulldev,	/* probe */
369 	privcmd_attach,
370 	privcmd_detach,
371 	nodev,		/* reset */
372 	&privcmd_cb_ops,
373 	0		/* struct bus_ops */
374 };
375 
376 static struct modldrv modldrv = {
377 	&mod_driverops,
378 	"privcmd driver %I%",
379 	&privcmd_dv_ops
380 };
381 
382 static struct modlinkage modl = {
383 	MODREV_1,
384 	&modldrv
385 };
386 
387 int
388 _init(void)
389 {
390 	return (mod_install(&modl));
391 }
392 
393 int
394 _fini(void)
395 {
396 	return (mod_remove(&modl));
397 }
398 
399 int
400 _info(struct modinfo *modinfo)
401 {
402 	return (mod_info(&modl, modinfo));
403 }
404