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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 | ||
283c0972 JP |
22 | #define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt |
23 | ||
ab31523c GH |
24 | #include <linux/module.h> |
25 | #include <linux/kernel.h> | |
26 | #include <linux/init.h> | |
27 | #include <linux/miscdevice.h> | |
28 | #include <linux/fs.h> | |
29 | #include <linux/mm.h> | |
30 | #include <linux/mman.h> | |
31 | #include <linux/mmu_notifier.h> | |
32 | #include <linux/types.h> | |
33 | #include <linux/uaccess.h> | |
34 | #include <linux/sched.h> | |
6e84f315 | 35 | #include <linux/sched/mm.h> |
ab31523c GH |
36 | #include <linux/spinlock.h> |
37 | #include <linux/slab.h> | |
aab8f11a | 38 | #include <linux/highmem.h> |
c5f7c5a9 | 39 | #include <linux/refcount.h> |
ab31523c GH |
40 | |
41 | #include <xen/xen.h> | |
42 | #include <xen/grant_table.h> | |
ca47ceaa | 43 | #include <xen/balloon.h> |
ab31523c | 44 | #include <xen/gntdev.h> |
bdc612dc | 45 | #include <xen/events.h> |
a9fd60e2 | 46 | #include <xen/page.h> |
ab31523c GH |
47 | #include <asm/xen/hypervisor.h> |
48 | #include <asm/xen/hypercall.h> | |
ab31523c GH |
49 | |
50 | MODULE_LICENSE("GPL"); | |
51 | MODULE_AUTHOR("Derek G. Murray <Derek.Murray@cl.cam.ac.uk>, " | |
52 | "Gerd Hoffmann <kraxel@redhat.com>"); | |
53 | MODULE_DESCRIPTION("User-space granted page access driver"); | |
54 | ||
ef91082e | 55 | static int limit = 1024*1024; |
ab31523c | 56 | module_param(limit, int, 0644); |
ef91082e DDG |
57 | MODULE_PARM_DESC(limit, "Maximum number of grants that may be mapped by " |
58 | "the gntdev device"); | |
59 | ||
60 | static atomic_t pages_mapped = ATOMIC_INIT(0); | |
ab31523c | 61 | |
aab8f11a | 62 | static int use_ptemod; |
16a1d022 | 63 | #define populate_freeable_maps use_ptemod |
aab8f11a | 64 | |
ab31523c | 65 | struct gntdev_priv { |
16a1d022 | 66 | /* maps with visible offsets in the file descriptor */ |
ab31523c | 67 | struct list_head maps; |
16a1d022 DDG |
68 | /* maps that are not visible; will be freed on munmap. |
69 | * Only populated if populate_freeable_maps == 1 */ | |
70 | struct list_head freeable_maps; | |
71 | /* lock protects maps and freeable_maps */ | |
1401c00e | 72 | struct mutex lock; |
ab31523c GH |
73 | struct mm_struct *mm; |
74 | struct mmu_notifier mn; | |
75 | }; | |
76 | ||
bdc612dc DDG |
77 | struct unmap_notify { |
78 | int flags; | |
79 | /* Address relative to the start of the grant_map */ | |
80 | int addr; | |
81 | int event; | |
82 | }; | |
83 | ||
ab31523c GH |
84 | struct grant_map { |
85 | struct list_head next; | |
ab31523c GH |
86 | struct vm_area_struct *vma; |
87 | int index; | |
88 | int count; | |
89 | int flags; | |
c5f7c5a9 | 90 | refcount_t users; |
bdc612dc | 91 | struct unmap_notify notify; |
ab31523c GH |
92 | struct ioctl_gntdev_grant_ref *grants; |
93 | struct gnttab_map_grant_ref *map_ops; | |
94 | struct gnttab_unmap_grant_ref *unmap_ops; | |
0930bba6 | 95 | struct gnttab_map_grant_ref *kmap_ops; |
853d0289 | 96 | struct gnttab_unmap_grant_ref *kunmap_ops; |
a12b4eb3 | 97 | struct page **pages; |
dab069c6 | 98 | unsigned long pages_vm_start; |
ab31523c GH |
99 | }; |
100 | ||
aab8f11a DDG |
101 | static int unmap_grant_pages(struct grant_map *map, int offset, int pages); |
102 | ||
ab31523c GH |
103 | /* ------------------------------------------------------------------ */ |
104 | ||
105 | static void gntdev_print_maps(struct gntdev_priv *priv, | |
106 | char *text, int text_index) | |
107 | { | |
108 | #ifdef DEBUG | |
109 | struct grant_map *map; | |
110 | ||
ef91082e | 111 | pr_debug("%s: maps list (priv %p)\n", __func__, priv); |
ab31523c GH |
112 | list_for_each_entry(map, &priv->maps, next) |
113 | pr_debug(" index %2d, count %2d %s\n", | |
114 | map->index, map->count, | |
115 | map->index == text_index && text ? text : ""); | |
116 | #endif | |
117 | } | |
118 | ||
a67baeb7 DV |
119 | static void gntdev_free_map(struct grant_map *map) |
120 | { | |
121 | if (map == NULL) | |
122 | return; | |
123 | ||
124 | if (map->pages) | |
ff4b156f | 125 | gnttab_free_pages(map->count, map->pages); |
a67baeb7 DV |
126 | kfree(map->pages); |
127 | kfree(map->grants); | |
128 | kfree(map->map_ops); | |
129 | kfree(map->unmap_ops); | |
130 | kfree(map->kmap_ops); | |
853d0289 | 131 | kfree(map->kunmap_ops); |
a67baeb7 DV |
132 | kfree(map); |
133 | } | |
134 | ||
ab31523c GH |
135 | static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count) |
136 | { | |
137 | struct grant_map *add; | |
a12b4eb3 | 138 | int i; |
ab31523c GH |
139 | |
140 | add = kzalloc(sizeof(struct grant_map), GFP_KERNEL); | |
141 | if (NULL == add) | |
142 | return NULL; | |
143 | ||
fc6e0c3b DC |
144 | add->grants = kcalloc(count, sizeof(add->grants[0]), GFP_KERNEL); |
145 | add->map_ops = kcalloc(count, sizeof(add->map_ops[0]), GFP_KERNEL); | |
146 | add->unmap_ops = kcalloc(count, sizeof(add->unmap_ops[0]), GFP_KERNEL); | |
147 | add->kmap_ops = kcalloc(count, sizeof(add->kmap_ops[0]), GFP_KERNEL); | |
853d0289 | 148 | add->kunmap_ops = kcalloc(count, sizeof(add->kunmap_ops[0]), GFP_KERNEL); |
fc6e0c3b | 149 | add->pages = kcalloc(count, sizeof(add->pages[0]), GFP_KERNEL); |
a12b4eb3 SS |
150 | if (NULL == add->grants || |
151 | NULL == add->map_ops || | |
152 | NULL == add->unmap_ops || | |
0930bba6 | 153 | NULL == add->kmap_ops || |
853d0289 | 154 | NULL == add->kunmap_ops || |
a12b4eb3 | 155 | NULL == add->pages) |
ab31523c GH |
156 | goto err; |
157 | ||
ff4b156f | 158 | if (gnttab_alloc_pages(count, add->pages)) |
ca47ceaa DDG |
159 | goto err; |
160 | ||
a12b4eb3 | 161 | for (i = 0; i < count; i++) { |
77c35acb DDG |
162 | add->map_ops[i].handle = -1; |
163 | add->unmap_ops[i].handle = -1; | |
0930bba6 | 164 | add->kmap_ops[i].handle = -1; |
853d0289 | 165 | add->kunmap_ops[i].handle = -1; |
a12b4eb3 SS |
166 | } |
167 | ||
ab31523c GH |
168 | add->index = 0; |
169 | add->count = count; | |
c5f7c5a9 | 170 | refcount_set(&add->users, 1); |
ab31523c | 171 | |
ab31523c GH |
172 | return add; |
173 | ||
174 | err: | |
a67baeb7 | 175 | gntdev_free_map(add); |
ab31523c GH |
176 | return NULL; |
177 | } | |
178 | ||
179 | static void gntdev_add_map(struct gntdev_priv *priv, struct grant_map *add) | |
180 | { | |
181 | struct grant_map *map; | |
182 | ||
183 | list_for_each_entry(map, &priv->maps, next) { | |
184 | if (add->index + add->count < map->index) { | |
185 | list_add_tail(&add->next, &map->next); | |
186 | goto done; | |
187 | } | |
188 | add->index = map->index + map->count; | |
189 | } | |
190 | list_add_tail(&add->next, &priv->maps); | |
191 | ||
192 | done: | |
ab31523c GH |
193 | gntdev_print_maps(priv, "[new]", add->index); |
194 | } | |
195 | ||
196 | static struct grant_map *gntdev_find_map_index(struct gntdev_priv *priv, | |
197 | int index, int count) | |
198 | { | |
199 | struct grant_map *map; | |
200 | ||
201 | list_for_each_entry(map, &priv->maps, next) { | |
202 | if (map->index != index) | |
203 | continue; | |
bdc612dc | 204 | if (count && map->count != count) |
ab31523c GH |
205 | continue; |
206 | return map; | |
207 | } | |
208 | return NULL; | |
209 | } | |
210 | ||
16a1d022 | 211 | static void gntdev_put_map(struct gntdev_priv *priv, struct grant_map *map) |
ab31523c GH |
212 | { |
213 | if (!map) | |
214 | return; | |
a12b4eb3 | 215 | |
c5f7c5a9 | 216 | if (!refcount_dec_and_test(&map->users)) |
68b025c8 DDG |
217 | return; |
218 | ||
219 | atomic_sub(map->count, &pages_mapped); | |
220 | ||
0cc678f8 | 221 | if (map->notify.flags & UNMAP_NOTIFY_SEND_EVENT) { |
bdc612dc | 222 | notify_remote_via_evtchn(map->notify.event); |
0cc678f8 DDG |
223 | evtchn_put(map->notify.event); |
224 | } | |
bdc612dc | 225 | |
16a1d022 | 226 | if (populate_freeable_maps && priv) { |
1401c00e | 227 | mutex_lock(&priv->lock); |
16a1d022 | 228 | list_del(&map->next); |
1401c00e | 229 | mutex_unlock(&priv->lock); |
16a1d022 DDG |
230 | } |
231 | ||
a67baeb7 DV |
232 | if (map->pages && !use_ptemod) |
233 | unmap_grant_pages(map, 0, map->count); | |
234 | gntdev_free_map(map); | |
ab31523c GH |
235 | } |
236 | ||
237 | /* ------------------------------------------------------------------ */ | |
238 | ||
239 | static int find_grant_ptes(pte_t *pte, pgtable_t token, | |
240 | unsigned long addr, void *data) | |
241 | { | |
242 | struct grant_map *map = data; | |
243 | unsigned int pgnr = (addr - map->vma->vm_start) >> PAGE_SHIFT; | |
aab8f11a | 244 | int flags = map->flags | GNTMAP_application_map | GNTMAP_contains_pte; |
ab31523c GH |
245 | u64 pte_maddr; |
246 | ||
247 | BUG_ON(pgnr >= map->count); | |
ba5d1012 JF |
248 | pte_maddr = arbitrary_virt_to_machine(pte).maddr; |
249 | ||
923b2919 DV |
250 | /* |
251 | * Set the PTE as special to force get_user_pages_fast() fall | |
252 | * back to the slow path. If this is not supported as part of | |
253 | * the grant map, it will be done afterwards. | |
254 | */ | |
255 | if (xen_feature(XENFEAT_gnttab_map_avail_bits)) | |
256 | flags |= (1 << _GNTMAP_guest_avail0); | |
257 | ||
aab8f11a | 258 | gnttab_set_map_op(&map->map_ops[pgnr], pte_maddr, flags, |
ab31523c GH |
259 | map->grants[pgnr].ref, |
260 | map->grants[pgnr].domid); | |
aab8f11a | 261 | gnttab_set_unmap_op(&map->unmap_ops[pgnr], pte_maddr, flags, |
77c35acb | 262 | -1 /* handle */); |
ab31523c GH |
263 | return 0; |
264 | } | |
265 | ||
923b2919 DV |
266 | #ifdef CONFIG_X86 |
267 | static int set_grant_ptes_as_special(pte_t *pte, pgtable_t token, | |
268 | unsigned long addr, void *data) | |
269 | { | |
270 | set_pte_at(current->mm, addr, pte, pte_mkspecial(*pte)); | |
271 | return 0; | |
272 | } | |
273 | #endif | |
274 | ||
ab31523c GH |
275 | static int map_grant_pages(struct grant_map *map) |
276 | { | |
277 | int i, err = 0; | |
aab8f11a DDG |
278 | |
279 | if (!use_ptemod) { | |
12996fc3 | 280 | /* Note: it could already be mapped */ |
77c35acb | 281 | if (map->map_ops[0].handle != -1) |
12996fc3 | 282 | return 0; |
aab8f11a | 283 | for (i = 0; i < map->count; i++) { |
38eaeb0f | 284 | unsigned long addr = (unsigned long) |
aab8f11a DDG |
285 | pfn_to_kaddr(page_to_pfn(map->pages[i])); |
286 | gnttab_set_map_op(&map->map_ops[i], addr, map->flags, | |
287 | map->grants[i].ref, | |
288 | map->grants[i].domid); | |
289 | gnttab_set_unmap_op(&map->unmap_ops[i], addr, | |
77c35acb | 290 | map->flags, -1 /* handle */); |
aab8f11a | 291 | } |
0930bba6 SS |
292 | } else { |
293 | /* | |
294 | * Setup the map_ops corresponding to the pte entries pointing | |
295 | * to the kernel linear addresses of the struct pages. | |
296 | * These ptes are completely different from the user ptes dealt | |
297 | * with find_grant_ptes. | |
298 | */ | |
299 | for (i = 0; i < map->count; i++) { | |
0930bba6 SS |
300 | unsigned long address = (unsigned long) |
301 | pfn_to_kaddr(page_to_pfn(map->pages[i])); | |
0930bba6 SS |
302 | BUG_ON(PageHighMem(map->pages[i])); |
303 | ||
ee072640 SS |
304 | gnttab_set_map_op(&map->kmap_ops[i], address, |
305 | map->flags | GNTMAP_host_map, | |
0930bba6 SS |
306 | map->grants[i].ref, |
307 | map->grants[i].domid); | |
853d0289 DV |
308 | gnttab_set_unmap_op(&map->kunmap_ops[i], address, |
309 | map->flags | GNTMAP_host_map, -1); | |
0930bba6 | 310 | } |
aab8f11a | 311 | } |
ab31523c GH |
312 | |
313 | pr_debug("map %d+%d\n", map->index, map->count); | |
e85fc980 KRW |
314 | err = gnttab_map_refs(map->map_ops, use_ptemod ? map->kmap_ops : NULL, |
315 | map->pages, map->count); | |
ab31523c GH |
316 | if (err) |
317 | return err; | |
318 | ||
319 | for (i = 0; i < map->count; i++) { | |
853d0289 | 320 | if (map->map_ops[i].status) { |
ab31523c | 321 | err = -EINVAL; |
853d0289 | 322 | continue; |
77c35acb | 323 | } |
853d0289 DV |
324 | |
325 | map->unmap_ops[i].handle = map->map_ops[i].handle; | |
326 | if (use_ptemod) | |
327 | map->kunmap_ops[i].handle = map->kmap_ops[i].handle; | |
ab31523c GH |
328 | } |
329 | return err; | |
330 | } | |
331 | ||
b57c1869 | 332 | static int __unmap_grant_pages(struct grant_map *map, int offset, int pages) |
ab31523c GH |
333 | { |
334 | int i, err = 0; | |
74528225 | 335 | struct gntab_unmap_queue_data unmap_data; |
ab31523c | 336 | |
bdc612dc DDG |
337 | if (map->notify.flags & UNMAP_NOTIFY_CLEAR_BYTE) { |
338 | int pgno = (map->notify.addr >> PAGE_SHIFT); | |
1affa98d DDG |
339 | if (pgno >= offset && pgno < offset + pages) { |
340 | /* No need for kmap, pages are in lowmem */ | |
341 | uint8_t *tmp = pfn_to_kaddr(page_to_pfn(map->pages[pgno])); | |
bdc612dc | 342 | tmp[map->notify.addr & (PAGE_SIZE-1)] = 0; |
bdc612dc DDG |
343 | map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE; |
344 | } | |
345 | } | |
346 | ||
74528225 JH |
347 | unmap_data.unmap_ops = map->unmap_ops + offset; |
348 | unmap_data.kunmap_ops = use_ptemod ? map->kunmap_ops + offset : NULL; | |
349 | unmap_data.pages = map->pages + offset; | |
350 | unmap_data.count = pages; | |
351 | ||
b44166cd BL |
352 | err = gnttab_unmap_refs_sync(&unmap_data); |
353 | if (err) | |
354 | return err; | |
ab31523c GH |
355 | |
356 | for (i = 0; i < pages; i++) { | |
357 | if (map->unmap_ops[offset+i].status) | |
358 | err = -EINVAL; | |
77c35acb DDG |
359 | pr_debug("unmap handle=%d st=%d\n", |
360 | map->unmap_ops[offset+i].handle, | |
361 | map->unmap_ops[offset+i].status); | |
362 | map->unmap_ops[offset+i].handle = -1; | |
ab31523c GH |
363 | } |
364 | return err; | |
365 | } | |
366 | ||
b57c1869 DDG |
367 | static int unmap_grant_pages(struct grant_map *map, int offset, int pages) |
368 | { | |
369 | int range, err = 0; | |
370 | ||
371 | pr_debug("unmap %d+%d [%d+%d]\n", map->index, map->count, offset, pages); | |
372 | ||
373 | /* It is possible the requested range will have a "hole" where we | |
374 | * already unmapped some of the grants. Only unmap valid ranges. | |
375 | */ | |
376 | while (pages && !err) { | |
77c35acb | 377 | while (pages && map->unmap_ops[offset].handle == -1) { |
b57c1869 DDG |
378 | offset++; |
379 | pages--; | |
380 | } | |
381 | range = 0; | |
382 | while (range < pages) { | |
77c35acb | 383 | if (map->unmap_ops[offset+range].handle == -1) { |
b57c1869 DDG |
384 | range--; |
385 | break; | |
386 | } | |
387 | range++; | |
388 | } | |
389 | err = __unmap_grant_pages(map, offset, range); | |
390 | offset += range; | |
391 | pages -= range; | |
392 | } | |
393 | ||
394 | return err; | |
395 | } | |
396 | ||
ab31523c GH |
397 | /* ------------------------------------------------------------------ */ |
398 | ||
d79647ae DDG |
399 | static void gntdev_vma_open(struct vm_area_struct *vma) |
400 | { | |
401 | struct grant_map *map = vma->vm_private_data; | |
402 | ||
403 | pr_debug("gntdev_vma_open %p\n", vma); | |
c5f7c5a9 | 404 | refcount_inc(&map->users); |
d79647ae DDG |
405 | } |
406 | ||
ab31523c GH |
407 | static void gntdev_vma_close(struct vm_area_struct *vma) |
408 | { | |
409 | struct grant_map *map = vma->vm_private_data; | |
16a1d022 DDG |
410 | struct file *file = vma->vm_file; |
411 | struct gntdev_priv *priv = file->private_data; | |
ab31523c | 412 | |
d79647ae | 413 | pr_debug("gntdev_vma_close %p\n", vma); |
2512f298 | 414 | if (use_ptemod) { |
2512f298 DDG |
415 | /* It is possible that an mmu notifier could be running |
416 | * concurrently, so take priv->lock to ensure that the vma won't | |
417 | * vanishing during the unmap_grant_pages call, since we will | |
418 | * spin here until that completes. Such a concurrent call will | |
419 | * not do any unmapping, since that has been done prior to | |
420 | * closing the vma, but it may still iterate the unmap_ops list. | |
421 | */ | |
1401c00e | 422 | mutex_lock(&priv->lock); |
2512f298 | 423 | map->vma = NULL; |
1401c00e | 424 | mutex_unlock(&priv->lock); |
2512f298 | 425 | } |
ab31523c | 426 | vma->vm_private_data = NULL; |
16a1d022 | 427 | gntdev_put_map(priv, map); |
ab31523c GH |
428 | } |
429 | ||
dab069c6 DV |
430 | static struct page *gntdev_vma_find_special_page(struct vm_area_struct *vma, |
431 | unsigned long addr) | |
432 | { | |
433 | struct grant_map *map = vma->vm_private_data; | |
434 | ||
435 | return map->pages[(addr - map->pages_vm_start) >> PAGE_SHIFT]; | |
436 | } | |
437 | ||
7cbea8dc | 438 | static const struct vm_operations_struct gntdev_vmops = { |
d79647ae | 439 | .open = gntdev_vma_open, |
ab31523c | 440 | .close = gntdev_vma_close, |
dab069c6 | 441 | .find_special_page = gntdev_vma_find_special_page, |
ab31523c GH |
442 | }; |
443 | ||
444 | /* ------------------------------------------------------------------ */ | |
445 | ||
16a1d022 DDG |
446 | static void unmap_if_in_range(struct grant_map *map, |
447 | unsigned long start, unsigned long end) | |
448 | { | |
449 | unsigned long mstart, mend; | |
450 | int err; | |
451 | ||
452 | if (!map->vma) | |
453 | return; | |
454 | if (map->vma->vm_start >= end) | |
455 | return; | |
456 | if (map->vma->vm_end <= start) | |
457 | return; | |
458 | mstart = max(start, map->vma->vm_start); | |
459 | mend = min(end, map->vma->vm_end); | |
460 | pr_debug("map %d+%d (%lx %lx), range %lx %lx, mrange %lx %lx\n", | |
461 | map->index, map->count, | |
462 | map->vma->vm_start, map->vma->vm_end, | |
463 | start, end, mstart, mend); | |
464 | err = unmap_grant_pages(map, | |
465 | (mstart - map->vma->vm_start) >> PAGE_SHIFT, | |
466 | (mend - mstart) >> PAGE_SHIFT); | |
467 | WARN_ON(err); | |
468 | } | |
469 | ||
ab31523c GH |
470 | static void mn_invl_range_start(struct mmu_notifier *mn, |
471 | struct mm_struct *mm, | |
472 | unsigned long start, unsigned long end) | |
473 | { | |
474 | struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn); | |
475 | struct grant_map *map; | |
ab31523c | 476 | |
1401c00e | 477 | mutex_lock(&priv->lock); |
ab31523c | 478 | list_for_each_entry(map, &priv->maps, next) { |
16a1d022 DDG |
479 | unmap_if_in_range(map, start, end); |
480 | } | |
481 | list_for_each_entry(map, &priv->freeable_maps, next) { | |
482 | unmap_if_in_range(map, start, end); | |
ab31523c | 483 | } |
1401c00e | 484 | mutex_unlock(&priv->lock); |
ab31523c GH |
485 | } |
486 | ||
ab31523c GH |
487 | static void mn_release(struct mmu_notifier *mn, |
488 | struct mm_struct *mm) | |
489 | { | |
490 | struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn); | |
491 | struct grant_map *map; | |
492 | int err; | |
493 | ||
1401c00e | 494 | mutex_lock(&priv->lock); |
ab31523c GH |
495 | list_for_each_entry(map, &priv->maps, next) { |
496 | if (!map->vma) | |
497 | continue; | |
498 | pr_debug("map %d+%d (%lx %lx)\n", | |
499 | map->index, map->count, | |
500 | map->vma->vm_start, map->vma->vm_end); | |
501 | err = unmap_grant_pages(map, /* offset */ 0, map->count); | |
502 | WARN_ON(err); | |
503 | } | |
16a1d022 DDG |
504 | list_for_each_entry(map, &priv->freeable_maps, next) { |
505 | if (!map->vma) | |
506 | continue; | |
507 | pr_debug("map %d+%d (%lx %lx)\n", | |
508 | map->index, map->count, | |
509 | map->vma->vm_start, map->vma->vm_end); | |
510 | err = unmap_grant_pages(map, /* offset */ 0, map->count); | |
511 | WARN_ON(err); | |
512 | } | |
1401c00e | 513 | mutex_unlock(&priv->lock); |
ab31523c GH |
514 | } |
515 | ||
b9c0a92a | 516 | static const struct mmu_notifier_ops gntdev_mmu_ops = { |
ab31523c | 517 | .release = mn_release, |
ab31523c GH |
518 | .invalidate_range_start = mn_invl_range_start, |
519 | }; | |
520 | ||
521 | /* ------------------------------------------------------------------ */ | |
522 | ||
523 | static int gntdev_open(struct inode *inode, struct file *flip) | |
524 | { | |
525 | struct gntdev_priv *priv; | |
526 | int ret = 0; | |
527 | ||
528 | priv = kzalloc(sizeof(*priv), GFP_KERNEL); | |
529 | if (!priv) | |
530 | return -ENOMEM; | |
531 | ||
532 | INIT_LIST_HEAD(&priv->maps); | |
16a1d022 | 533 | INIT_LIST_HEAD(&priv->freeable_maps); |
1401c00e | 534 | mutex_init(&priv->lock); |
ab31523c | 535 | |
aab8f11a DDG |
536 | if (use_ptemod) { |
537 | priv->mm = get_task_mm(current); | |
538 | if (!priv->mm) { | |
539 | kfree(priv); | |
540 | return -ENOMEM; | |
541 | } | |
542 | priv->mn.ops = &gntdev_mmu_ops; | |
543 | ret = mmu_notifier_register(&priv->mn, priv->mm); | |
544 | mmput(priv->mm); | |
ab31523c | 545 | } |
ab31523c GH |
546 | |
547 | if (ret) { | |
548 | kfree(priv); | |
549 | return ret; | |
550 | } | |
551 | ||
552 | flip->private_data = priv; | |
553 | pr_debug("priv %p\n", priv); | |
554 | ||
555 | return 0; | |
556 | } | |
557 | ||
558 | static int gntdev_release(struct inode *inode, struct file *flip) | |
559 | { | |
560 | struct gntdev_priv *priv = flip->private_data; | |
561 | struct grant_map *map; | |
ab31523c GH |
562 | |
563 | pr_debug("priv %p\n", priv); | |
564 | ||
30b03d05 | 565 | mutex_lock(&priv->lock); |
ab31523c GH |
566 | while (!list_empty(&priv->maps)) { |
567 | map = list_entry(priv->maps.next, struct grant_map, next); | |
68b025c8 | 568 | list_del(&map->next); |
16a1d022 | 569 | gntdev_put_map(NULL /* already removed */, map); |
ab31523c | 570 | } |
16a1d022 | 571 | WARN_ON(!list_empty(&priv->freeable_maps)); |
30b03d05 | 572 | mutex_unlock(&priv->lock); |
ab31523c | 573 | |
aab8f11a DDG |
574 | if (use_ptemod) |
575 | mmu_notifier_unregister(&priv->mn, priv->mm); | |
ab31523c GH |
576 | kfree(priv); |
577 | return 0; | |
578 | } | |
579 | ||
580 | static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv, | |
581 | struct ioctl_gntdev_map_grant_ref __user *u) | |
582 | { | |
583 | struct ioctl_gntdev_map_grant_ref op; | |
584 | struct grant_map *map; | |
585 | int err; | |
586 | ||
587 | if (copy_from_user(&op, u, sizeof(op)) != 0) | |
588 | return -EFAULT; | |
589 | pr_debug("priv %p, add %d\n", priv, op.count); | |
590 | if (unlikely(op.count <= 0)) | |
591 | return -EINVAL; | |
ab31523c GH |
592 | |
593 | err = -ENOMEM; | |
594 | map = gntdev_alloc_map(priv, op.count); | |
595 | if (!map) | |
596 | return err; | |
ef91082e | 597 | |
68b025c8 DDG |
598 | if (unlikely(atomic_add_return(op.count, &pages_mapped) > limit)) { |
599 | pr_debug("can't map: over limit\n"); | |
16a1d022 | 600 | gntdev_put_map(NULL, map); |
ab31523c GH |
601 | return err; |
602 | } | |
603 | ||
68b025c8 DDG |
604 | if (copy_from_user(map->grants, &u->refs, |
605 | sizeof(map->grants[0]) * op.count) != 0) { | |
16a1d022 DDG |
606 | gntdev_put_map(NULL, map); |
607 | return -EFAULT; | |
ef91082e DDG |
608 | } |
609 | ||
1401c00e | 610 | mutex_lock(&priv->lock); |
ab31523c GH |
611 | gntdev_add_map(priv, map); |
612 | op.index = map->index << PAGE_SHIFT; | |
1401c00e | 613 | mutex_unlock(&priv->lock); |
ab31523c | 614 | |
68b025c8 DDG |
615 | if (copy_to_user(u, &op, sizeof(op)) != 0) |
616 | return -EFAULT; | |
617 | ||
ab31523c GH |
618 | return 0; |
619 | } | |
620 | ||
621 | static long gntdev_ioctl_unmap_grant_ref(struct gntdev_priv *priv, | |
622 | struct ioctl_gntdev_unmap_grant_ref __user *u) | |
623 | { | |
624 | struct ioctl_gntdev_unmap_grant_ref op; | |
625 | struct grant_map *map; | |
626 | int err = -ENOENT; | |
627 | ||
628 | if (copy_from_user(&op, u, sizeof(op)) != 0) | |
629 | return -EFAULT; | |
630 | pr_debug("priv %p, del %d+%d\n", priv, (int)op.index, (int)op.count); | |
631 | ||
1401c00e | 632 | mutex_lock(&priv->lock); |
ab31523c | 633 | map = gntdev_find_map_index(priv, op.index >> PAGE_SHIFT, op.count); |
68b025c8 DDG |
634 | if (map) { |
635 | list_del(&map->next); | |
16a1d022 DDG |
636 | if (populate_freeable_maps) |
637 | list_add_tail(&map->next, &priv->freeable_maps); | |
68b025c8 DDG |
638 | err = 0; |
639 | } | |
1401c00e | 640 | mutex_unlock(&priv->lock); |
1f1503ba | 641 | if (map) |
16a1d022 | 642 | gntdev_put_map(priv, map); |
ab31523c GH |
643 | return err; |
644 | } | |
645 | ||
646 | static long gntdev_ioctl_get_offset_for_vaddr(struct gntdev_priv *priv, | |
647 | struct ioctl_gntdev_get_offset_for_vaddr __user *u) | |
648 | { | |
649 | struct ioctl_gntdev_get_offset_for_vaddr op; | |
a879211b | 650 | struct vm_area_struct *vma; |
ab31523c | 651 | struct grant_map *map; |
2512f298 | 652 | int rv = -EINVAL; |
ab31523c GH |
653 | |
654 | if (copy_from_user(&op, u, sizeof(op)) != 0) | |
655 | return -EFAULT; | |
656 | pr_debug("priv %p, offset for vaddr %lx\n", priv, (unsigned long)op.vaddr); | |
657 | ||
2512f298 | 658 | down_read(¤t->mm->mmap_sem); |
a879211b DDG |
659 | vma = find_vma(current->mm, op.vaddr); |
660 | if (!vma || vma->vm_ops != &gntdev_vmops) | |
2512f298 | 661 | goto out_unlock; |
a879211b DDG |
662 | |
663 | map = vma->vm_private_data; | |
664 | if (!map) | |
2512f298 | 665 | goto out_unlock; |
a879211b | 666 | |
ab31523c GH |
667 | op.offset = map->index << PAGE_SHIFT; |
668 | op.count = map->count; | |
2512f298 | 669 | rv = 0; |
ab31523c | 670 | |
2512f298 DDG |
671 | out_unlock: |
672 | up_read(¤t->mm->mmap_sem); | |
673 | ||
674 | if (rv == 0 && copy_to_user(u, &op, sizeof(op)) != 0) | |
ab31523c | 675 | return -EFAULT; |
2512f298 | 676 | return rv; |
ab31523c GH |
677 | } |
678 | ||
bdc612dc DDG |
679 | static long gntdev_ioctl_notify(struct gntdev_priv *priv, void __user *u) |
680 | { | |
681 | struct ioctl_gntdev_unmap_notify op; | |
682 | struct grant_map *map; | |
683 | int rc; | |
0cc678f8 DDG |
684 | int out_flags; |
685 | unsigned int out_event; | |
bdc612dc DDG |
686 | |
687 | if (copy_from_user(&op, u, sizeof(op))) | |
688 | return -EFAULT; | |
689 | ||
690 | if (op.action & ~(UNMAP_NOTIFY_CLEAR_BYTE|UNMAP_NOTIFY_SEND_EVENT)) | |
691 | return -EINVAL; | |
692 | ||
0cc678f8 DDG |
693 | /* We need to grab a reference to the event channel we are going to use |
694 | * to send the notify before releasing the reference we may already have | |
695 | * (if someone has called this ioctl twice). This is required so that | |
696 | * it is possible to change the clear_byte part of the notification | |
697 | * without disturbing the event channel part, which may now be the last | |
698 | * reference to that event channel. | |
699 | */ | |
700 | if (op.action & UNMAP_NOTIFY_SEND_EVENT) { | |
701 | if (evtchn_get(op.event_channel_port)) | |
702 | return -EINVAL; | |
703 | } | |
704 | ||
705 | out_flags = op.action; | |
706 | out_event = op.event_channel_port; | |
707 | ||
1401c00e | 708 | mutex_lock(&priv->lock); |
bdc612dc DDG |
709 | |
710 | list_for_each_entry(map, &priv->maps, next) { | |
711 | uint64_t begin = map->index << PAGE_SHIFT; | |
712 | uint64_t end = (map->index + map->count) << PAGE_SHIFT; | |
713 | if (op.index >= begin && op.index < end) | |
714 | goto found; | |
715 | } | |
716 | rc = -ENOENT; | |
717 | goto unlock_out; | |
718 | ||
719 | found: | |
9960be97 DDG |
720 | if ((op.action & UNMAP_NOTIFY_CLEAR_BYTE) && |
721 | (map->flags & GNTMAP_readonly)) { | |
722 | rc = -EINVAL; | |
723 | goto unlock_out; | |
724 | } | |
725 | ||
0cc678f8 DDG |
726 | out_flags = map->notify.flags; |
727 | out_event = map->notify.event; | |
728 | ||
bdc612dc DDG |
729 | map->notify.flags = op.action; |
730 | map->notify.addr = op.index - (map->index << PAGE_SHIFT); | |
731 | map->notify.event = op.event_channel_port; | |
0cc678f8 | 732 | |
bdc612dc | 733 | rc = 0; |
0cc678f8 | 734 | |
bdc612dc | 735 | unlock_out: |
1401c00e | 736 | mutex_unlock(&priv->lock); |
0cc678f8 DDG |
737 | |
738 | /* Drop the reference to the event channel we did not save in the map */ | |
739 | if (out_flags & UNMAP_NOTIFY_SEND_EVENT) | |
740 | evtchn_put(out_event); | |
741 | ||
bdc612dc DDG |
742 | return rc; |
743 | } | |
744 | ||
36ae220a | 745 | #define GNTDEV_COPY_BATCH 16 |
a4cdb556 DV |
746 | |
747 | struct gntdev_copy_batch { | |
748 | struct gnttab_copy ops[GNTDEV_COPY_BATCH]; | |
749 | struct page *pages[GNTDEV_COPY_BATCH]; | |
750 | s16 __user *status[GNTDEV_COPY_BATCH]; | |
751 | unsigned int nr_ops; | |
752 | unsigned int nr_pages; | |
753 | }; | |
754 | ||
755 | static int gntdev_get_page(struct gntdev_copy_batch *batch, void __user *virt, | |
756 | bool writeable, unsigned long *gfn) | |
757 | { | |
758 | unsigned long addr = (unsigned long)virt; | |
759 | struct page *page; | |
760 | unsigned long xen_pfn; | |
761 | int ret; | |
762 | ||
763 | ret = get_user_pages_fast(addr, 1, writeable, &page); | |
764 | if (ret < 0) | |
765 | return ret; | |
766 | ||
767 | batch->pages[batch->nr_pages++] = page; | |
768 | ||
769 | xen_pfn = page_to_xen_pfn(page) + XEN_PFN_DOWN(addr & ~PAGE_MASK); | |
770 | *gfn = pfn_to_gfn(xen_pfn); | |
771 | ||
772 | return 0; | |
773 | } | |
774 | ||
775 | static void gntdev_put_pages(struct gntdev_copy_batch *batch) | |
776 | { | |
777 | unsigned int i; | |
778 | ||
779 | for (i = 0; i < batch->nr_pages; i++) | |
780 | put_page(batch->pages[i]); | |
781 | batch->nr_pages = 0; | |
782 | } | |
783 | ||
784 | static int gntdev_copy(struct gntdev_copy_batch *batch) | |
785 | { | |
786 | unsigned int i; | |
787 | ||
788 | gnttab_batch_copy(batch->ops, batch->nr_ops); | |
789 | gntdev_put_pages(batch); | |
790 | ||
791 | /* | |
792 | * For each completed op, update the status if the op failed | |
793 | * and all previous ops for the segment were successful. | |
794 | */ | |
795 | for (i = 0; i < batch->nr_ops; i++) { | |
796 | s16 status = batch->ops[i].status; | |
797 | s16 old_status; | |
798 | ||
799 | if (status == GNTST_okay) | |
800 | continue; | |
801 | ||
802 | if (__get_user(old_status, batch->status[i])) | |
803 | return -EFAULT; | |
804 | ||
805 | if (old_status != GNTST_okay) | |
806 | continue; | |
807 | ||
808 | if (__put_user(status, batch->status[i])) | |
809 | return -EFAULT; | |
810 | } | |
811 | ||
812 | batch->nr_ops = 0; | |
813 | return 0; | |
814 | } | |
815 | ||
816 | static int gntdev_grant_copy_seg(struct gntdev_copy_batch *batch, | |
817 | struct gntdev_grant_copy_segment *seg, | |
818 | s16 __user *status) | |
819 | { | |
820 | uint16_t copied = 0; | |
821 | ||
822 | /* | |
823 | * Disallow local -> local copies since there is only space in | |
824 | * batch->pages for one page per-op and this would be a very | |
825 | * expensive memcpy(). | |
826 | */ | |
827 | if (!(seg->flags & (GNTCOPY_source_gref | GNTCOPY_dest_gref))) | |
828 | return -EINVAL; | |
829 | ||
830 | /* Can't cross page if source/dest is a grant ref. */ | |
831 | if (seg->flags & GNTCOPY_source_gref) { | |
832 | if (seg->source.foreign.offset + seg->len > XEN_PAGE_SIZE) | |
833 | return -EINVAL; | |
834 | } | |
835 | if (seg->flags & GNTCOPY_dest_gref) { | |
836 | if (seg->dest.foreign.offset + seg->len > XEN_PAGE_SIZE) | |
837 | return -EINVAL; | |
838 | } | |
839 | ||
840 | if (put_user(GNTST_okay, status)) | |
841 | return -EFAULT; | |
842 | ||
843 | while (copied < seg->len) { | |
844 | struct gnttab_copy *op; | |
845 | void __user *virt; | |
846 | size_t len, off; | |
847 | unsigned long gfn; | |
848 | int ret; | |
849 | ||
850 | if (batch->nr_ops >= GNTDEV_COPY_BATCH) { | |
851 | ret = gntdev_copy(batch); | |
852 | if (ret < 0) | |
853 | return ret; | |
854 | } | |
855 | ||
856 | len = seg->len - copied; | |
857 | ||
858 | op = &batch->ops[batch->nr_ops]; | |
859 | op->flags = 0; | |
860 | ||
861 | if (seg->flags & GNTCOPY_source_gref) { | |
862 | op->source.u.ref = seg->source.foreign.ref; | |
863 | op->source.domid = seg->source.foreign.domid; | |
864 | op->source.offset = seg->source.foreign.offset + copied; | |
865 | op->flags |= GNTCOPY_source_gref; | |
866 | } else { | |
867 | virt = seg->source.virt + copied; | |
868 | off = (unsigned long)virt & ~XEN_PAGE_MASK; | |
869 | len = min(len, (size_t)XEN_PAGE_SIZE - off); | |
870 | ||
871 | ret = gntdev_get_page(batch, virt, false, &gfn); | |
872 | if (ret < 0) | |
873 | return ret; | |
874 | ||
875 | op->source.u.gmfn = gfn; | |
876 | op->source.domid = DOMID_SELF; | |
877 | op->source.offset = off; | |
878 | } | |
879 | ||
880 | if (seg->flags & GNTCOPY_dest_gref) { | |
881 | op->dest.u.ref = seg->dest.foreign.ref; | |
882 | op->dest.domid = seg->dest.foreign.domid; | |
883 | op->dest.offset = seg->dest.foreign.offset + copied; | |
884 | op->flags |= GNTCOPY_dest_gref; | |
885 | } else { | |
886 | virt = seg->dest.virt + copied; | |
887 | off = (unsigned long)virt & ~XEN_PAGE_MASK; | |
888 | len = min(len, (size_t)XEN_PAGE_SIZE - off); | |
889 | ||
890 | ret = gntdev_get_page(batch, virt, true, &gfn); | |
891 | if (ret < 0) | |
892 | return ret; | |
893 | ||
894 | op->dest.u.gmfn = gfn; | |
895 | op->dest.domid = DOMID_SELF; | |
896 | op->dest.offset = off; | |
897 | } | |
898 | ||
899 | op->len = len; | |
900 | copied += len; | |
901 | ||
902 | batch->status[batch->nr_ops] = status; | |
903 | batch->nr_ops++; | |
904 | } | |
905 | ||
906 | return 0; | |
907 | } | |
908 | ||
909 | static long gntdev_ioctl_grant_copy(struct gntdev_priv *priv, void __user *u) | |
910 | { | |
911 | struct ioctl_gntdev_grant_copy copy; | |
912 | struct gntdev_copy_batch batch; | |
913 | unsigned int i; | |
914 | int ret = 0; | |
915 | ||
916 | if (copy_from_user(©, u, sizeof(copy))) | |
917 | return -EFAULT; | |
918 | ||
919 | batch.nr_ops = 0; | |
920 | batch.nr_pages = 0; | |
921 | ||
922 | for (i = 0; i < copy.count; i++) { | |
923 | struct gntdev_grant_copy_segment seg; | |
924 | ||
925 | if (copy_from_user(&seg, ©.segments[i], sizeof(seg))) { | |
926 | ret = -EFAULT; | |
927 | goto out; | |
928 | } | |
929 | ||
930 | ret = gntdev_grant_copy_seg(&batch, &seg, ©.segments[i].status); | |
931 | if (ret < 0) | |
932 | goto out; | |
933 | ||
934 | cond_resched(); | |
935 | } | |
936 | if (batch.nr_ops) | |
937 | ret = gntdev_copy(&batch); | |
938 | return ret; | |
939 | ||
940 | out: | |
941 | gntdev_put_pages(&batch); | |
942 | return ret; | |
943 | } | |
944 | ||
ab31523c GH |
945 | static long gntdev_ioctl(struct file *flip, |
946 | unsigned int cmd, unsigned long arg) | |
947 | { | |
948 | struct gntdev_priv *priv = flip->private_data; | |
949 | void __user *ptr = (void __user *)arg; | |
950 | ||
951 | switch (cmd) { | |
952 | case IOCTL_GNTDEV_MAP_GRANT_REF: | |
953 | return gntdev_ioctl_map_grant_ref(priv, ptr); | |
954 | ||
955 | case IOCTL_GNTDEV_UNMAP_GRANT_REF: | |
956 | return gntdev_ioctl_unmap_grant_ref(priv, ptr); | |
957 | ||
958 | case IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR: | |
959 | return gntdev_ioctl_get_offset_for_vaddr(priv, ptr); | |
960 | ||
bdc612dc DDG |
961 | case IOCTL_GNTDEV_SET_UNMAP_NOTIFY: |
962 | return gntdev_ioctl_notify(priv, ptr); | |
963 | ||
a4cdb556 DV |
964 | case IOCTL_GNTDEV_GRANT_COPY: |
965 | return gntdev_ioctl_grant_copy(priv, ptr); | |
966 | ||
ab31523c GH |
967 | default: |
968 | pr_debug("priv %p, unknown cmd %x\n", priv, cmd); | |
969 | return -ENOIOCTLCMD; | |
970 | } | |
971 | ||
972 | return 0; | |
973 | } | |
974 | ||
975 | static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) | |
976 | { | |
977 | struct gntdev_priv *priv = flip->private_data; | |
978 | int index = vma->vm_pgoff; | |
c7ebf9d9 | 979 | int count = vma_pages(vma); |
ab31523c | 980 | struct grant_map *map; |
aab8f11a | 981 | int i, err = -EINVAL; |
ab31523c GH |
982 | |
983 | if ((vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_SHARED)) | |
984 | return -EINVAL; | |
985 | ||
986 | pr_debug("map %d+%d at %lx (pgoff %lx)\n", | |
987 | index, count, vma->vm_start, vma->vm_pgoff); | |
988 | ||
1401c00e | 989 | mutex_lock(&priv->lock); |
ab31523c GH |
990 | map = gntdev_find_map_index(priv, index, count); |
991 | if (!map) | |
992 | goto unlock_out; | |
aab8f11a | 993 | if (use_ptemod && map->vma) |
ab31523c | 994 | goto unlock_out; |
aab8f11a | 995 | if (use_ptemod && priv->mm != vma->vm_mm) { |
283c0972 | 996 | pr_warn("Huh? Other mm?\n"); |
ab31523c GH |
997 | goto unlock_out; |
998 | } | |
999 | ||
c5f7c5a9 | 1000 | refcount_inc(&map->users); |
68b025c8 | 1001 | |
ab31523c GH |
1002 | vma->vm_ops = &gntdev_vmops; |
1003 | ||
30faaafd | 1004 | vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP | VM_MIXEDMAP; |
d79647ae DDG |
1005 | |
1006 | if (use_ptemod) | |
e8e937be | 1007 | vma->vm_flags |= VM_DONTCOPY; |
ab31523c GH |
1008 | |
1009 | vma->vm_private_data = map; | |
ab31523c | 1010 | |
aab8f11a DDG |
1011 | if (use_ptemod) |
1012 | map->vma = vma; | |
1013 | ||
12996fc3 DDG |
1014 | if (map->flags) { |
1015 | if ((vma->vm_flags & VM_WRITE) && | |
1016 | (map->flags & GNTMAP_readonly)) | |
a93e20a8 | 1017 | goto out_unlock_put; |
12996fc3 DDG |
1018 | } else { |
1019 | map->flags = GNTMAP_host_map; | |
1020 | if (!(vma->vm_flags & VM_WRITE)) | |
1021 | map->flags |= GNTMAP_readonly; | |
1022 | } | |
ab31523c | 1023 | |
1401c00e | 1024 | mutex_unlock(&priv->lock); |
f0a70c88 | 1025 | |
aab8f11a | 1026 | if (use_ptemod) { |
4e5e7dad | 1027 | map->pages_vm_start = vma->vm_start; |
aab8f11a DDG |
1028 | err = apply_to_page_range(vma->vm_mm, vma->vm_start, |
1029 | vma->vm_end - vma->vm_start, | |
1030 | find_grant_ptes, map); | |
1031 | if (err) { | |
283c0972 | 1032 | pr_warn("find_grant_ptes() failure.\n"); |
90b6f305 | 1033 | goto out_put_map; |
aab8f11a | 1034 | } |
ab31523c GH |
1035 | } |
1036 | ||
1037 | err = map_grant_pages(map); | |
90b6f305 DDG |
1038 | if (err) |
1039 | goto out_put_map; | |
f0a70c88 | 1040 | |
aab8f11a DDG |
1041 | if (!use_ptemod) { |
1042 | for (i = 0; i < count; i++) { | |
1043 | err = vm_insert_page(vma, vma->vm_start + i*PAGE_SIZE, | |
1044 | map->pages[i]); | |
1045 | if (err) | |
90b6f305 | 1046 | goto out_put_map; |
aab8f11a | 1047 | } |
923b2919 DV |
1048 | } else { |
1049 | #ifdef CONFIG_X86 | |
1050 | /* | |
1051 | * If the PTEs were not made special by the grant map | |
1052 | * hypercall, do so here. | |
1053 | * | |
1054 | * This is racy since the mapping is already visible | |
1055 | * to userspace but userspace should be well-behaved | |
1056 | * enough to not touch it until the mmap() call | |
1057 | * returns. | |
1058 | */ | |
1059 | if (!xen_feature(XENFEAT_gnttab_map_avail_bits)) { | |
1060 | apply_to_page_range(vma->vm_mm, vma->vm_start, | |
1061 | vma->vm_end - vma->vm_start, | |
1062 | set_grant_ptes_as_special, NULL); | |
1063 | } | |
1064 | #endif | |
aab8f11a DDG |
1065 | } |
1066 | ||
f0a70c88 DDG |
1067 | return 0; |
1068 | ||
ab31523c | 1069 | unlock_out: |
1401c00e | 1070 | mutex_unlock(&priv->lock); |
ab31523c | 1071 | return err; |
90b6f305 | 1072 | |
a93e20a8 | 1073 | out_unlock_put: |
1401c00e | 1074 | mutex_unlock(&priv->lock); |
90b6f305 | 1075 | out_put_map: |
84e4075d DDG |
1076 | if (use_ptemod) |
1077 | map->vma = NULL; | |
16a1d022 | 1078 | gntdev_put_map(priv, map); |
90b6f305 | 1079 | return err; |
ab31523c GH |
1080 | } |
1081 | ||
1082 | static const struct file_operations gntdev_fops = { | |
1083 | .owner = THIS_MODULE, | |
1084 | .open = gntdev_open, | |
1085 | .release = gntdev_release, | |
1086 | .mmap = gntdev_mmap, | |
1087 | .unlocked_ioctl = gntdev_ioctl | |
1088 | }; | |
1089 | ||
1090 | static struct miscdevice gntdev_miscdev = { | |
1091 | .minor = MISC_DYNAMIC_MINOR, | |
1092 | .name = "xen/gntdev", | |
1093 | .fops = &gntdev_fops, | |
1094 | }; | |
1095 | ||
1096 | /* ------------------------------------------------------------------ */ | |
1097 | ||
1098 | static int __init gntdev_init(void) | |
1099 | { | |
1100 | int err; | |
1101 | ||
1102 | if (!xen_domain()) | |
1103 | return -ENODEV; | |
1104 | ||
6926f6d6 | 1105 | use_ptemod = !xen_feature(XENFEAT_auto_translated_physmap); |
aab8f11a | 1106 | |
ab31523c GH |
1107 | err = misc_register(&gntdev_miscdev); |
1108 | if (err != 0) { | |
283c0972 | 1109 | pr_err("Could not register gntdev device\n"); |
ab31523c GH |
1110 | return err; |
1111 | } | |
1112 | return 0; | |
1113 | } | |
1114 | ||
1115 | static void __exit gntdev_exit(void) | |
1116 | { | |
1117 | misc_deregister(&gntdev_miscdev); | |
1118 | } | |
1119 | ||
1120 | module_init(gntdev_init); | |
1121 | module_exit(gntdev_exit); | |
1122 | ||
1123 | /* ------------------------------------------------------------------ */ |