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ab31523c GH |
1 | /****************************************************************************** |
2 | * gntdev.c | |
3 | * | |
4 | * Device for accessing (in user-space) pages that have been granted by other | |
5 | * domains. | |
6 | * | |
7 | * Copyright (c) 2006-2007, D G Murray. | |
8 | * (c) 2009 Gerd Hoffmann <kraxel@redhat.com> | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write to the Free Software | |
17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
18 | */ | |
19 | ||
20 | #undef DEBUG | |
21 | ||
22 | #include <linux/module.h> | |
23 | #include <linux/kernel.h> | |
24 | #include <linux/init.h> | |
25 | #include <linux/miscdevice.h> | |
26 | #include <linux/fs.h> | |
27 | #include <linux/mm.h> | |
28 | #include <linux/mman.h> | |
29 | #include <linux/mmu_notifier.h> | |
30 | #include <linux/types.h> | |
31 | #include <linux/uaccess.h> | |
32 | #include <linux/sched.h> | |
33 | #include <linux/spinlock.h> | |
34 | #include <linux/slab.h> | |
aab8f11a | 35 | #include <linux/highmem.h> |
ab31523c GH |
36 | |
37 | #include <xen/xen.h> | |
38 | #include <xen/grant_table.h> | |
ca47ceaa | 39 | #include <xen/balloon.h> |
ab31523c | 40 | #include <xen/gntdev.h> |
bdc612dc | 41 | #include <xen/events.h> |
ab31523c GH |
42 | #include <asm/xen/hypervisor.h> |
43 | #include <asm/xen/hypercall.h> | |
44 | #include <asm/xen/page.h> | |
45 | ||
46 | MODULE_LICENSE("GPL"); | |
47 | MODULE_AUTHOR("Derek G. Murray <Derek.Murray@cl.cam.ac.uk>, " | |
48 | "Gerd Hoffmann <kraxel@redhat.com>"); | |
49 | MODULE_DESCRIPTION("User-space granted page access driver"); | |
50 | ||
ef91082e | 51 | static int limit = 1024*1024; |
ab31523c | 52 | module_param(limit, int, 0644); |
ef91082e DDG |
53 | MODULE_PARM_DESC(limit, "Maximum number of grants that may be mapped by " |
54 | "the gntdev device"); | |
55 | ||
56 | static atomic_t pages_mapped = ATOMIC_INIT(0); | |
ab31523c | 57 | |
aab8f11a DDG |
58 | static int use_ptemod; |
59 | ||
ab31523c GH |
60 | struct gntdev_priv { |
61 | struct list_head maps; | |
ab31523c GH |
62 | /* lock protects maps from concurrent changes */ |
63 | spinlock_t lock; | |
64 | struct mm_struct *mm; | |
65 | struct mmu_notifier mn; | |
66 | }; | |
67 | ||
bdc612dc DDG |
68 | struct unmap_notify { |
69 | int flags; | |
70 | /* Address relative to the start of the grant_map */ | |
71 | int addr; | |
72 | int event; | |
73 | }; | |
74 | ||
ab31523c GH |
75 | struct grant_map { |
76 | struct list_head next; | |
ab31523c GH |
77 | struct vm_area_struct *vma; |
78 | int index; | |
79 | int count; | |
80 | int flags; | |
68b025c8 | 81 | atomic_t users; |
bdc612dc | 82 | struct unmap_notify notify; |
ab31523c GH |
83 | struct ioctl_gntdev_grant_ref *grants; |
84 | struct gnttab_map_grant_ref *map_ops; | |
85 | struct gnttab_unmap_grant_ref *unmap_ops; | |
0930bba6 | 86 | struct gnttab_map_grant_ref *kmap_ops; |
a12b4eb3 | 87 | struct page **pages; |
ab31523c GH |
88 | }; |
89 | ||
aab8f11a DDG |
90 | static int unmap_grant_pages(struct grant_map *map, int offset, int pages); |
91 | ||
ab31523c GH |
92 | /* ------------------------------------------------------------------ */ |
93 | ||
94 | static void gntdev_print_maps(struct gntdev_priv *priv, | |
95 | char *text, int text_index) | |
96 | { | |
97 | #ifdef DEBUG | |
98 | struct grant_map *map; | |
99 | ||
ef91082e | 100 | pr_debug("%s: maps list (priv %p)\n", __func__, priv); |
ab31523c GH |
101 | list_for_each_entry(map, &priv->maps, next) |
102 | pr_debug(" index %2d, count %2d %s\n", | |
103 | map->index, map->count, | |
104 | map->index == text_index && text ? text : ""); | |
105 | #endif | |
106 | } | |
107 | ||
108 | static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count) | |
109 | { | |
110 | struct grant_map *add; | |
a12b4eb3 | 111 | int i; |
ab31523c GH |
112 | |
113 | add = kzalloc(sizeof(struct grant_map), GFP_KERNEL); | |
114 | if (NULL == add) | |
115 | return NULL; | |
116 | ||
fc6e0c3b DC |
117 | add->grants = kcalloc(count, sizeof(add->grants[0]), GFP_KERNEL); |
118 | add->map_ops = kcalloc(count, sizeof(add->map_ops[0]), GFP_KERNEL); | |
119 | add->unmap_ops = kcalloc(count, sizeof(add->unmap_ops[0]), GFP_KERNEL); | |
120 | add->kmap_ops = kcalloc(count, sizeof(add->kmap_ops[0]), GFP_KERNEL); | |
121 | add->pages = kcalloc(count, sizeof(add->pages[0]), GFP_KERNEL); | |
a12b4eb3 SS |
122 | if (NULL == add->grants || |
123 | NULL == add->map_ops || | |
124 | NULL == add->unmap_ops || | |
0930bba6 | 125 | NULL == add->kmap_ops || |
a12b4eb3 | 126 | NULL == add->pages) |
ab31523c GH |
127 | goto err; |
128 | ||
693394b8 | 129 | if (alloc_xenballooned_pages(count, add->pages, false /* lowmem */)) |
ca47ceaa DDG |
130 | goto err; |
131 | ||
a12b4eb3 | 132 | for (i = 0; i < count; i++) { |
77c35acb DDG |
133 | add->map_ops[i].handle = -1; |
134 | add->unmap_ops[i].handle = -1; | |
0930bba6 | 135 | add->kmap_ops[i].handle = -1; |
a12b4eb3 SS |
136 | } |
137 | ||
ab31523c GH |
138 | add->index = 0; |
139 | add->count = count; | |
68b025c8 | 140 | atomic_set(&add->users, 1); |
ab31523c | 141 | |
ab31523c GH |
142 | return add; |
143 | ||
144 | err: | |
a12b4eb3 | 145 | kfree(add->pages); |
ab31523c GH |
146 | kfree(add->grants); |
147 | kfree(add->map_ops); | |
148 | kfree(add->unmap_ops); | |
0930bba6 | 149 | kfree(add->kmap_ops); |
ab31523c GH |
150 | kfree(add); |
151 | return NULL; | |
152 | } | |
153 | ||
154 | static void gntdev_add_map(struct gntdev_priv *priv, struct grant_map *add) | |
155 | { | |
156 | struct grant_map *map; | |
157 | ||
158 | list_for_each_entry(map, &priv->maps, next) { | |
159 | if (add->index + add->count < map->index) { | |
160 | list_add_tail(&add->next, &map->next); | |
161 | goto done; | |
162 | } | |
163 | add->index = map->index + map->count; | |
164 | } | |
165 | list_add_tail(&add->next, &priv->maps); | |
166 | ||
167 | done: | |
ab31523c GH |
168 | gntdev_print_maps(priv, "[new]", add->index); |
169 | } | |
170 | ||
171 | static struct grant_map *gntdev_find_map_index(struct gntdev_priv *priv, | |
172 | int index, int count) | |
173 | { | |
174 | struct grant_map *map; | |
175 | ||
176 | list_for_each_entry(map, &priv->maps, next) { | |
177 | if (map->index != index) | |
178 | continue; | |
bdc612dc | 179 | if (count && map->count != count) |
ab31523c GH |
180 | continue; |
181 | return map; | |
182 | } | |
183 | return NULL; | |
184 | } | |
185 | ||
68b025c8 | 186 | static void gntdev_put_map(struct grant_map *map) |
ab31523c GH |
187 | { |
188 | if (!map) | |
189 | return; | |
a12b4eb3 | 190 | |
68b025c8 DDG |
191 | if (!atomic_dec_and_test(&map->users)) |
192 | return; | |
193 | ||
194 | atomic_sub(map->count, &pages_mapped); | |
195 | ||
0cc678f8 | 196 | if (map->notify.flags & UNMAP_NOTIFY_SEND_EVENT) { |
bdc612dc | 197 | notify_remote_via_evtchn(map->notify.event); |
0cc678f8 DDG |
198 | evtchn_put(map->notify.event); |
199 | } | |
bdc612dc | 200 | |
aab8f11a DDG |
201 | if (map->pages) { |
202 | if (!use_ptemod) | |
203 | unmap_grant_pages(map, 0, map->count); | |
204 | ||
ca47ceaa | 205 | free_xenballooned_pages(map->count, map->pages); |
aab8f11a | 206 | } |
a12b4eb3 | 207 | kfree(map->pages); |
ab31523c GH |
208 | kfree(map->grants); |
209 | kfree(map->map_ops); | |
210 | kfree(map->unmap_ops); | |
211 | kfree(map); | |
212 | } | |
213 | ||
214 | /* ------------------------------------------------------------------ */ | |
215 | ||
216 | static int find_grant_ptes(pte_t *pte, pgtable_t token, | |
217 | unsigned long addr, void *data) | |
218 | { | |
219 | struct grant_map *map = data; | |
220 | unsigned int pgnr = (addr - map->vma->vm_start) >> PAGE_SHIFT; | |
aab8f11a | 221 | int flags = map->flags | GNTMAP_application_map | GNTMAP_contains_pte; |
ab31523c GH |
222 | u64 pte_maddr; |
223 | ||
224 | BUG_ON(pgnr >= map->count); | |
ba5d1012 JF |
225 | pte_maddr = arbitrary_virt_to_machine(pte).maddr; |
226 | ||
aab8f11a | 227 | gnttab_set_map_op(&map->map_ops[pgnr], pte_maddr, flags, |
ab31523c GH |
228 | map->grants[pgnr].ref, |
229 | map->grants[pgnr].domid); | |
aab8f11a | 230 | gnttab_set_unmap_op(&map->unmap_ops[pgnr], pte_maddr, flags, |
77c35acb | 231 | -1 /* handle */); |
ab31523c GH |
232 | return 0; |
233 | } | |
234 | ||
235 | static int map_grant_pages(struct grant_map *map) | |
236 | { | |
237 | int i, err = 0; | |
aab8f11a DDG |
238 | |
239 | if (!use_ptemod) { | |
12996fc3 | 240 | /* Note: it could already be mapped */ |
77c35acb | 241 | if (map->map_ops[0].handle != -1) |
12996fc3 | 242 | return 0; |
aab8f11a | 243 | for (i = 0; i < map->count; i++) { |
38eaeb0f | 244 | unsigned long addr = (unsigned long) |
aab8f11a DDG |
245 | pfn_to_kaddr(page_to_pfn(map->pages[i])); |
246 | gnttab_set_map_op(&map->map_ops[i], addr, map->flags, | |
247 | map->grants[i].ref, | |
248 | map->grants[i].domid); | |
249 | gnttab_set_unmap_op(&map->unmap_ops[i], addr, | |
77c35acb | 250 | map->flags, -1 /* handle */); |
aab8f11a | 251 | } |
0930bba6 SS |
252 | } else { |
253 | /* | |
254 | * Setup the map_ops corresponding to the pte entries pointing | |
255 | * to the kernel linear addresses of the struct pages. | |
256 | * These ptes are completely different from the user ptes dealt | |
257 | * with find_grant_ptes. | |
258 | */ | |
259 | for (i = 0; i < map->count; i++) { | |
260 | unsigned level; | |
261 | unsigned long address = (unsigned long) | |
262 | pfn_to_kaddr(page_to_pfn(map->pages[i])); | |
263 | pte_t *ptep; | |
264 | u64 pte_maddr = 0; | |
265 | BUG_ON(PageHighMem(map->pages[i])); | |
266 | ||
267 | ptep = lookup_address(address, &level); | |
268 | pte_maddr = arbitrary_virt_to_machine(ptep).maddr; | |
269 | gnttab_set_map_op(&map->kmap_ops[i], pte_maddr, | |
270 | map->flags | | |
271 | GNTMAP_host_map | | |
272 | GNTMAP_contains_pte, | |
273 | map->grants[i].ref, | |
274 | map->grants[i].domid); | |
275 | } | |
aab8f11a | 276 | } |
ab31523c GH |
277 | |
278 | pr_debug("map %d+%d\n", map->index, map->count); | |
0930bba6 SS |
279 | err = gnttab_map_refs(map->map_ops, use_ptemod ? map->kmap_ops : NULL, |
280 | map->pages, map->count); | |
ab31523c GH |
281 | if (err) |
282 | return err; | |
283 | ||
284 | for (i = 0; i < map->count; i++) { | |
285 | if (map->map_ops[i].status) | |
286 | err = -EINVAL; | |
77c35acb DDG |
287 | else { |
288 | BUG_ON(map->map_ops[i].handle == -1); | |
289 | map->unmap_ops[i].handle = map->map_ops[i].handle; | |
290 | pr_debug("map handle=%d\n", map->map_ops[i].handle); | |
291 | } | |
ab31523c GH |
292 | } |
293 | return err; | |
294 | } | |
295 | ||
b57c1869 | 296 | static int __unmap_grant_pages(struct grant_map *map, int offset, int pages) |
ab31523c GH |
297 | { |
298 | int i, err = 0; | |
299 | ||
bdc612dc DDG |
300 | if (map->notify.flags & UNMAP_NOTIFY_CLEAR_BYTE) { |
301 | int pgno = (map->notify.addr >> PAGE_SHIFT); | |
0ea22f07 | 302 | if (pgno >= offset && pgno < offset + pages && use_ptemod) { |
f4ee4af4 DDG |
303 | void __user *tmp = (void __user *) |
304 | map->vma->vm_start + map->notify.addr; | |
9960be97 DDG |
305 | err = copy_to_user(tmp, &err, 1); |
306 | if (err) | |
12f0258d | 307 | return -EFAULT; |
0ea22f07 DDG |
308 | map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE; |
309 | } else if (pgno >= offset && pgno < offset + pages) { | |
bdc612dc DDG |
310 | uint8_t *tmp = kmap(map->pages[pgno]); |
311 | tmp[map->notify.addr & (PAGE_SIZE-1)] = 0; | |
312 | kunmap(map->pages[pgno]); | |
313 | map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE; | |
314 | } | |
315 | } | |
316 | ||
2fc136ee SS |
317 | err = gnttab_unmap_refs(map->unmap_ops + offset, |
318 | use_ptemod ? map->kmap_ops + offset : NULL, map->pages + offset, | |
319 | pages); | |
ab31523c GH |
320 | if (err) |
321 | return err; | |
322 | ||
323 | for (i = 0; i < pages; i++) { | |
324 | if (map->unmap_ops[offset+i].status) | |
325 | err = -EINVAL; | |
77c35acb DDG |
326 | pr_debug("unmap handle=%d st=%d\n", |
327 | map->unmap_ops[offset+i].handle, | |
328 | map->unmap_ops[offset+i].status); | |
329 | map->unmap_ops[offset+i].handle = -1; | |
ab31523c GH |
330 | } |
331 | return err; | |
332 | } | |
333 | ||
b57c1869 DDG |
334 | static int unmap_grant_pages(struct grant_map *map, int offset, int pages) |
335 | { | |
336 | int range, err = 0; | |
337 | ||
338 | pr_debug("unmap %d+%d [%d+%d]\n", map->index, map->count, offset, pages); | |
339 | ||
340 | /* It is possible the requested range will have a "hole" where we | |
341 | * already unmapped some of the grants. Only unmap valid ranges. | |
342 | */ | |
343 | while (pages && !err) { | |
77c35acb | 344 | while (pages && map->unmap_ops[offset].handle == -1) { |
b57c1869 DDG |
345 | offset++; |
346 | pages--; | |
347 | } | |
348 | range = 0; | |
349 | while (range < pages) { | |
77c35acb | 350 | if (map->unmap_ops[offset+range].handle == -1) { |
b57c1869 DDG |
351 | range--; |
352 | break; | |
353 | } | |
354 | range++; | |
355 | } | |
356 | err = __unmap_grant_pages(map, offset, range); | |
357 | offset += range; | |
358 | pages -= range; | |
359 | } | |
360 | ||
361 | return err; | |
362 | } | |
363 | ||
ab31523c GH |
364 | /* ------------------------------------------------------------------ */ |
365 | ||
d79647ae DDG |
366 | static void gntdev_vma_open(struct vm_area_struct *vma) |
367 | { | |
368 | struct grant_map *map = vma->vm_private_data; | |
369 | ||
370 | pr_debug("gntdev_vma_open %p\n", vma); | |
371 | atomic_inc(&map->users); | |
372 | } | |
373 | ||
ab31523c GH |
374 | static void gntdev_vma_close(struct vm_area_struct *vma) |
375 | { | |
376 | struct grant_map *map = vma->vm_private_data; | |
377 | ||
d79647ae | 378 | pr_debug("gntdev_vma_close %p\n", vma); |
ab31523c GH |
379 | map->vma = NULL; |
380 | vma->vm_private_data = NULL; | |
68b025c8 | 381 | gntdev_put_map(map); |
ab31523c GH |
382 | } |
383 | ||
ab31523c | 384 | static struct vm_operations_struct gntdev_vmops = { |
d79647ae | 385 | .open = gntdev_vma_open, |
ab31523c | 386 | .close = gntdev_vma_close, |
ab31523c GH |
387 | }; |
388 | ||
389 | /* ------------------------------------------------------------------ */ | |
390 | ||
391 | static void mn_invl_range_start(struct mmu_notifier *mn, | |
392 | struct mm_struct *mm, | |
393 | unsigned long start, unsigned long end) | |
394 | { | |
395 | struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn); | |
396 | struct grant_map *map; | |
397 | unsigned long mstart, mend; | |
398 | int err; | |
399 | ||
400 | spin_lock(&priv->lock); | |
401 | list_for_each_entry(map, &priv->maps, next) { | |
402 | if (!map->vma) | |
403 | continue; | |
ab31523c GH |
404 | if (map->vma->vm_start >= end) |
405 | continue; | |
406 | if (map->vma->vm_end <= start) | |
407 | continue; | |
408 | mstart = max(start, map->vma->vm_start); | |
409 | mend = min(end, map->vma->vm_end); | |
410 | pr_debug("map %d+%d (%lx %lx), range %lx %lx, mrange %lx %lx\n", | |
411 | map->index, map->count, | |
412 | map->vma->vm_start, map->vma->vm_end, | |
413 | start, end, mstart, mend); | |
414 | err = unmap_grant_pages(map, | |
415 | (mstart - map->vma->vm_start) >> PAGE_SHIFT, | |
416 | (mend - mstart) >> PAGE_SHIFT); | |
417 | WARN_ON(err); | |
418 | } | |
419 | spin_unlock(&priv->lock); | |
420 | } | |
421 | ||
422 | static void mn_invl_page(struct mmu_notifier *mn, | |
423 | struct mm_struct *mm, | |
424 | unsigned long address) | |
425 | { | |
426 | mn_invl_range_start(mn, mm, address, address + PAGE_SIZE); | |
427 | } | |
428 | ||
429 | static void mn_release(struct mmu_notifier *mn, | |
430 | struct mm_struct *mm) | |
431 | { | |
432 | struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn); | |
433 | struct grant_map *map; | |
434 | int err; | |
435 | ||
436 | spin_lock(&priv->lock); | |
437 | list_for_each_entry(map, &priv->maps, next) { | |
438 | if (!map->vma) | |
439 | continue; | |
440 | pr_debug("map %d+%d (%lx %lx)\n", | |
441 | map->index, map->count, | |
442 | map->vma->vm_start, map->vma->vm_end); | |
443 | err = unmap_grant_pages(map, /* offset */ 0, map->count); | |
444 | WARN_ON(err); | |
445 | } | |
446 | spin_unlock(&priv->lock); | |
447 | } | |
448 | ||
b8b0f559 | 449 | static struct mmu_notifier_ops gntdev_mmu_ops = { |
ab31523c GH |
450 | .release = mn_release, |
451 | .invalidate_page = mn_invl_page, | |
452 | .invalidate_range_start = mn_invl_range_start, | |
453 | }; | |
454 | ||
455 | /* ------------------------------------------------------------------ */ | |
456 | ||
457 | static int gntdev_open(struct inode *inode, struct file *flip) | |
458 | { | |
459 | struct gntdev_priv *priv; | |
460 | int ret = 0; | |
461 | ||
462 | priv = kzalloc(sizeof(*priv), GFP_KERNEL); | |
463 | if (!priv) | |
464 | return -ENOMEM; | |
465 | ||
466 | INIT_LIST_HEAD(&priv->maps); | |
467 | spin_lock_init(&priv->lock); | |
ab31523c | 468 | |
aab8f11a DDG |
469 | if (use_ptemod) { |
470 | priv->mm = get_task_mm(current); | |
471 | if (!priv->mm) { | |
472 | kfree(priv); | |
473 | return -ENOMEM; | |
474 | } | |
475 | priv->mn.ops = &gntdev_mmu_ops; | |
476 | ret = mmu_notifier_register(&priv->mn, priv->mm); | |
477 | mmput(priv->mm); | |
ab31523c | 478 | } |
ab31523c GH |
479 | |
480 | if (ret) { | |
481 | kfree(priv); | |
482 | return ret; | |
483 | } | |
484 | ||
485 | flip->private_data = priv; | |
486 | pr_debug("priv %p\n", priv); | |
487 | ||
488 | return 0; | |
489 | } | |
490 | ||
491 | static int gntdev_release(struct inode *inode, struct file *flip) | |
492 | { | |
493 | struct gntdev_priv *priv = flip->private_data; | |
494 | struct grant_map *map; | |
ab31523c GH |
495 | |
496 | pr_debug("priv %p\n", priv); | |
497 | ||
ab31523c GH |
498 | while (!list_empty(&priv->maps)) { |
499 | map = list_entry(priv->maps.next, struct grant_map, next); | |
68b025c8 DDG |
500 | list_del(&map->next); |
501 | gntdev_put_map(map); | |
ab31523c | 502 | } |
ab31523c | 503 | |
aab8f11a DDG |
504 | if (use_ptemod) |
505 | mmu_notifier_unregister(&priv->mn, priv->mm); | |
ab31523c GH |
506 | kfree(priv); |
507 | return 0; | |
508 | } | |
509 | ||
510 | static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv, | |
511 | struct ioctl_gntdev_map_grant_ref __user *u) | |
512 | { | |
513 | struct ioctl_gntdev_map_grant_ref op; | |
514 | struct grant_map *map; | |
515 | int err; | |
516 | ||
517 | if (copy_from_user(&op, u, sizeof(op)) != 0) | |
518 | return -EFAULT; | |
519 | pr_debug("priv %p, add %d\n", priv, op.count); | |
520 | if (unlikely(op.count <= 0)) | |
521 | return -EINVAL; | |
ab31523c GH |
522 | |
523 | err = -ENOMEM; | |
524 | map = gntdev_alloc_map(priv, op.count); | |
525 | if (!map) | |
526 | return err; | |
ef91082e | 527 | |
68b025c8 DDG |
528 | if (unlikely(atomic_add_return(op.count, &pages_mapped) > limit)) { |
529 | pr_debug("can't map: over limit\n"); | |
530 | gntdev_put_map(map); | |
ab31523c GH |
531 | return err; |
532 | } | |
533 | ||
68b025c8 DDG |
534 | if (copy_from_user(map->grants, &u->refs, |
535 | sizeof(map->grants[0]) * op.count) != 0) { | |
536 | gntdev_put_map(map); | |
ef91082e DDG |
537 | return err; |
538 | } | |
539 | ||
ab31523c GH |
540 | spin_lock(&priv->lock); |
541 | gntdev_add_map(priv, map); | |
542 | op.index = map->index << PAGE_SHIFT; | |
543 | spin_unlock(&priv->lock); | |
544 | ||
68b025c8 DDG |
545 | if (copy_to_user(u, &op, sizeof(op)) != 0) |
546 | return -EFAULT; | |
547 | ||
ab31523c GH |
548 | return 0; |
549 | } | |
550 | ||
551 | static long gntdev_ioctl_unmap_grant_ref(struct gntdev_priv *priv, | |
552 | struct ioctl_gntdev_unmap_grant_ref __user *u) | |
553 | { | |
554 | struct ioctl_gntdev_unmap_grant_ref op; | |
555 | struct grant_map *map; | |
556 | int err = -ENOENT; | |
557 | ||
558 | if (copy_from_user(&op, u, sizeof(op)) != 0) | |
559 | return -EFAULT; | |
560 | pr_debug("priv %p, del %d+%d\n", priv, (int)op.index, (int)op.count); | |
561 | ||
562 | spin_lock(&priv->lock); | |
563 | map = gntdev_find_map_index(priv, op.index >> PAGE_SHIFT, op.count); | |
68b025c8 DDG |
564 | if (map) { |
565 | list_del(&map->next); | |
68b025c8 DDG |
566 | err = 0; |
567 | } | |
ab31523c | 568 | spin_unlock(&priv->lock); |
1f1503ba DDG |
569 | if (map) |
570 | gntdev_put_map(map); | |
ab31523c GH |
571 | return err; |
572 | } | |
573 | ||
574 | static long gntdev_ioctl_get_offset_for_vaddr(struct gntdev_priv *priv, | |
575 | struct ioctl_gntdev_get_offset_for_vaddr __user *u) | |
576 | { | |
577 | struct ioctl_gntdev_get_offset_for_vaddr op; | |
a879211b | 578 | struct vm_area_struct *vma; |
ab31523c GH |
579 | struct grant_map *map; |
580 | ||
581 | if (copy_from_user(&op, u, sizeof(op)) != 0) | |
582 | return -EFAULT; | |
583 | pr_debug("priv %p, offset for vaddr %lx\n", priv, (unsigned long)op.vaddr); | |
584 | ||
a879211b DDG |
585 | vma = find_vma(current->mm, op.vaddr); |
586 | if (!vma || vma->vm_ops != &gntdev_vmops) | |
ab31523c | 587 | return -EINVAL; |
a879211b DDG |
588 | |
589 | map = vma->vm_private_data; | |
590 | if (!map) | |
591 | return -EINVAL; | |
592 | ||
ab31523c GH |
593 | op.offset = map->index << PAGE_SHIFT; |
594 | op.count = map->count; | |
ab31523c GH |
595 | |
596 | if (copy_to_user(u, &op, sizeof(op)) != 0) | |
597 | return -EFAULT; | |
598 | return 0; | |
599 | } | |
600 | ||
bdc612dc DDG |
601 | static long gntdev_ioctl_notify(struct gntdev_priv *priv, void __user *u) |
602 | { | |
603 | struct ioctl_gntdev_unmap_notify op; | |
604 | struct grant_map *map; | |
605 | int rc; | |
0cc678f8 DDG |
606 | int out_flags; |
607 | unsigned int out_event; | |
bdc612dc DDG |
608 | |
609 | if (copy_from_user(&op, u, sizeof(op))) | |
610 | return -EFAULT; | |
611 | ||
612 | if (op.action & ~(UNMAP_NOTIFY_CLEAR_BYTE|UNMAP_NOTIFY_SEND_EVENT)) | |
613 | return -EINVAL; | |
614 | ||
0cc678f8 DDG |
615 | /* We need to grab a reference to the event channel we are going to use |
616 | * to send the notify before releasing the reference we may already have | |
617 | * (if someone has called this ioctl twice). This is required so that | |
618 | * it is possible to change the clear_byte part of the notification | |
619 | * without disturbing the event channel part, which may now be the last | |
620 | * reference to that event channel. | |
621 | */ | |
622 | if (op.action & UNMAP_NOTIFY_SEND_EVENT) { | |
623 | if (evtchn_get(op.event_channel_port)) | |
624 | return -EINVAL; | |
625 | } | |
626 | ||
627 | out_flags = op.action; | |
628 | out_event = op.event_channel_port; | |
629 | ||
bdc612dc DDG |
630 | spin_lock(&priv->lock); |
631 | ||
632 | list_for_each_entry(map, &priv->maps, next) { | |
633 | uint64_t begin = map->index << PAGE_SHIFT; | |
634 | uint64_t end = (map->index + map->count) << PAGE_SHIFT; | |
635 | if (op.index >= begin && op.index < end) | |
636 | goto found; | |
637 | } | |
638 | rc = -ENOENT; | |
639 | goto unlock_out; | |
640 | ||
641 | found: | |
9960be97 DDG |
642 | if ((op.action & UNMAP_NOTIFY_CLEAR_BYTE) && |
643 | (map->flags & GNTMAP_readonly)) { | |
644 | rc = -EINVAL; | |
645 | goto unlock_out; | |
646 | } | |
647 | ||
0cc678f8 DDG |
648 | out_flags = map->notify.flags; |
649 | out_event = map->notify.event; | |
650 | ||
bdc612dc DDG |
651 | map->notify.flags = op.action; |
652 | map->notify.addr = op.index - (map->index << PAGE_SHIFT); | |
653 | map->notify.event = op.event_channel_port; | |
0cc678f8 | 654 | |
bdc612dc | 655 | rc = 0; |
0cc678f8 | 656 | |
bdc612dc DDG |
657 | unlock_out: |
658 | spin_unlock(&priv->lock); | |
0cc678f8 DDG |
659 | |
660 | /* Drop the reference to the event channel we did not save in the map */ | |
661 | if (out_flags & UNMAP_NOTIFY_SEND_EVENT) | |
662 | evtchn_put(out_event); | |
663 | ||
bdc612dc DDG |
664 | return rc; |
665 | } | |
666 | ||
ab31523c GH |
667 | static long gntdev_ioctl(struct file *flip, |
668 | unsigned int cmd, unsigned long arg) | |
669 | { | |
670 | struct gntdev_priv *priv = flip->private_data; | |
671 | void __user *ptr = (void __user *)arg; | |
672 | ||
673 | switch (cmd) { | |
674 | case IOCTL_GNTDEV_MAP_GRANT_REF: | |
675 | return gntdev_ioctl_map_grant_ref(priv, ptr); | |
676 | ||
677 | case IOCTL_GNTDEV_UNMAP_GRANT_REF: | |
678 | return gntdev_ioctl_unmap_grant_ref(priv, ptr); | |
679 | ||
680 | case IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR: | |
681 | return gntdev_ioctl_get_offset_for_vaddr(priv, ptr); | |
682 | ||
bdc612dc DDG |
683 | case IOCTL_GNTDEV_SET_UNMAP_NOTIFY: |
684 | return gntdev_ioctl_notify(priv, ptr); | |
685 | ||
ab31523c GH |
686 | default: |
687 | pr_debug("priv %p, unknown cmd %x\n", priv, cmd); | |
688 | return -ENOIOCTLCMD; | |
689 | } | |
690 | ||
691 | return 0; | |
692 | } | |
693 | ||
694 | static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) | |
695 | { | |
696 | struct gntdev_priv *priv = flip->private_data; | |
697 | int index = vma->vm_pgoff; | |
698 | int count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; | |
699 | struct grant_map *map; | |
aab8f11a | 700 | int i, err = -EINVAL; |
ab31523c GH |
701 | |
702 | if ((vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_SHARED)) | |
703 | return -EINVAL; | |
704 | ||
705 | pr_debug("map %d+%d at %lx (pgoff %lx)\n", | |
706 | index, count, vma->vm_start, vma->vm_pgoff); | |
707 | ||
708 | spin_lock(&priv->lock); | |
709 | map = gntdev_find_map_index(priv, index, count); | |
710 | if (!map) | |
711 | goto unlock_out; | |
aab8f11a | 712 | if (use_ptemod && map->vma) |
ab31523c | 713 | goto unlock_out; |
aab8f11a | 714 | if (use_ptemod && priv->mm != vma->vm_mm) { |
ab31523c GH |
715 | printk(KERN_WARNING "Huh? Other mm?\n"); |
716 | goto unlock_out; | |
717 | } | |
718 | ||
68b025c8 DDG |
719 | atomic_inc(&map->users); |
720 | ||
ab31523c GH |
721 | vma->vm_ops = &gntdev_vmops; |
722 | ||
314e51b9 | 723 | vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; |
d79647ae DDG |
724 | |
725 | if (use_ptemod) | |
e8e937be | 726 | vma->vm_flags |= VM_DONTCOPY; |
ab31523c GH |
727 | |
728 | vma->vm_private_data = map; | |
ab31523c | 729 | |
aab8f11a DDG |
730 | if (use_ptemod) |
731 | map->vma = vma; | |
732 | ||
12996fc3 DDG |
733 | if (map->flags) { |
734 | if ((vma->vm_flags & VM_WRITE) && | |
735 | (map->flags & GNTMAP_readonly)) | |
a93e20a8 | 736 | goto out_unlock_put; |
12996fc3 DDG |
737 | } else { |
738 | map->flags = GNTMAP_host_map; | |
739 | if (!(vma->vm_flags & VM_WRITE)) | |
740 | map->flags |= GNTMAP_readonly; | |
741 | } | |
ab31523c | 742 | |
f0a70c88 DDG |
743 | spin_unlock(&priv->lock); |
744 | ||
aab8f11a DDG |
745 | if (use_ptemod) { |
746 | err = apply_to_page_range(vma->vm_mm, vma->vm_start, | |
747 | vma->vm_end - vma->vm_start, | |
748 | find_grant_ptes, map); | |
749 | if (err) { | |
750 | printk(KERN_WARNING "find_grant_ptes() failure.\n"); | |
90b6f305 | 751 | goto out_put_map; |
aab8f11a | 752 | } |
ab31523c GH |
753 | } |
754 | ||
755 | err = map_grant_pages(map); | |
90b6f305 DDG |
756 | if (err) |
757 | goto out_put_map; | |
f0a70c88 | 758 | |
aab8f11a DDG |
759 | if (!use_ptemod) { |
760 | for (i = 0; i < count; i++) { | |
761 | err = vm_insert_page(vma, vma->vm_start + i*PAGE_SIZE, | |
762 | map->pages[i]); | |
763 | if (err) | |
90b6f305 | 764 | goto out_put_map; |
aab8f11a DDG |
765 | } |
766 | } | |
767 | ||
f0a70c88 DDG |
768 | return 0; |
769 | ||
ab31523c GH |
770 | unlock_out: |
771 | spin_unlock(&priv->lock); | |
772 | return err; | |
90b6f305 | 773 | |
a93e20a8 DC |
774 | out_unlock_put: |
775 | spin_unlock(&priv->lock); | |
90b6f305 | 776 | out_put_map: |
84e4075d DDG |
777 | if (use_ptemod) |
778 | map->vma = NULL; | |
90b6f305 DDG |
779 | gntdev_put_map(map); |
780 | return err; | |
ab31523c GH |
781 | } |
782 | ||
783 | static const struct file_operations gntdev_fops = { | |
784 | .owner = THIS_MODULE, | |
785 | .open = gntdev_open, | |
786 | .release = gntdev_release, | |
787 | .mmap = gntdev_mmap, | |
788 | .unlocked_ioctl = gntdev_ioctl | |
789 | }; | |
790 | ||
791 | static struct miscdevice gntdev_miscdev = { | |
792 | .minor = MISC_DYNAMIC_MINOR, | |
793 | .name = "xen/gntdev", | |
794 | .fops = &gntdev_fops, | |
795 | }; | |
796 | ||
797 | /* ------------------------------------------------------------------ */ | |
798 | ||
799 | static int __init gntdev_init(void) | |
800 | { | |
801 | int err; | |
802 | ||
803 | if (!xen_domain()) | |
804 | return -ENODEV; | |
805 | ||
aab8f11a DDG |
806 | use_ptemod = xen_pv_domain(); |
807 | ||
ab31523c GH |
808 | err = misc_register(&gntdev_miscdev); |
809 | if (err != 0) { | |
810 | printk(KERN_ERR "Could not register gntdev device\n"); | |
811 | return err; | |
812 | } | |
813 | return 0; | |
814 | } | |
815 | ||
816 | static void __exit gntdev_exit(void) | |
817 | { | |
818 | misc_deregister(&gntdev_miscdev); | |
819 | } | |
820 | ||
821 | module_init(gntdev_init); | |
822 | module_exit(gntdev_exit); | |
823 | ||
824 | /* ------------------------------------------------------------------ */ |