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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 | 58 | static int use_ptemod; |
16a1d022 | 59 | #define populate_freeable_maps use_ptemod |
aab8f11a | 60 | |
ab31523c | 61 | struct gntdev_priv { |
16a1d022 | 62 | /* maps with visible offsets in the file descriptor */ |
ab31523c | 63 | struct list_head maps; |
16a1d022 DDG |
64 | /* maps that are not visible; will be freed on munmap. |
65 | * Only populated if populate_freeable_maps == 1 */ | |
66 | struct list_head freeable_maps; | |
67 | /* lock protects maps and freeable_maps */ | |
ab31523c GH |
68 | spinlock_t lock; |
69 | struct mm_struct *mm; | |
70 | struct mmu_notifier mn; | |
71 | }; | |
72 | ||
bdc612dc DDG |
73 | struct unmap_notify { |
74 | int flags; | |
75 | /* Address relative to the start of the grant_map */ | |
76 | int addr; | |
77 | int event; | |
78 | }; | |
79 | ||
ab31523c GH |
80 | struct grant_map { |
81 | struct list_head next; | |
ab31523c GH |
82 | struct vm_area_struct *vma; |
83 | int index; | |
84 | int count; | |
85 | int flags; | |
68b025c8 | 86 | atomic_t users; |
bdc612dc | 87 | struct unmap_notify notify; |
ab31523c GH |
88 | struct ioctl_gntdev_grant_ref *grants; |
89 | struct gnttab_map_grant_ref *map_ops; | |
90 | struct gnttab_unmap_grant_ref *unmap_ops; | |
0930bba6 | 91 | struct gnttab_map_grant_ref *kmap_ops; |
a12b4eb3 | 92 | struct page **pages; |
ab31523c GH |
93 | }; |
94 | ||
aab8f11a DDG |
95 | static int unmap_grant_pages(struct grant_map *map, int offset, int pages); |
96 | ||
ab31523c GH |
97 | /* ------------------------------------------------------------------ */ |
98 | ||
99 | static void gntdev_print_maps(struct gntdev_priv *priv, | |
100 | char *text, int text_index) | |
101 | { | |
102 | #ifdef DEBUG | |
103 | struct grant_map *map; | |
104 | ||
ef91082e | 105 | pr_debug("%s: maps list (priv %p)\n", __func__, priv); |
ab31523c GH |
106 | list_for_each_entry(map, &priv->maps, next) |
107 | pr_debug(" index %2d, count %2d %s\n", | |
108 | map->index, map->count, | |
109 | map->index == text_index && text ? text : ""); | |
110 | #endif | |
111 | } | |
112 | ||
a67baeb7 DV |
113 | static void gntdev_free_map(struct grant_map *map) |
114 | { | |
115 | if (map == NULL) | |
116 | return; | |
117 | ||
118 | if (map->pages) | |
119 | free_xenballooned_pages(map->count, map->pages); | |
120 | kfree(map->pages); | |
121 | kfree(map->grants); | |
122 | kfree(map->map_ops); | |
123 | kfree(map->unmap_ops); | |
124 | kfree(map->kmap_ops); | |
125 | kfree(map); | |
126 | } | |
127 | ||
ab31523c GH |
128 | static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count) |
129 | { | |
130 | struct grant_map *add; | |
a12b4eb3 | 131 | int i; |
ab31523c GH |
132 | |
133 | add = kzalloc(sizeof(struct grant_map), GFP_KERNEL); | |
134 | if (NULL == add) | |
135 | return NULL; | |
136 | ||
fc6e0c3b DC |
137 | add->grants = kcalloc(count, sizeof(add->grants[0]), GFP_KERNEL); |
138 | add->map_ops = kcalloc(count, sizeof(add->map_ops[0]), GFP_KERNEL); | |
139 | add->unmap_ops = kcalloc(count, sizeof(add->unmap_ops[0]), GFP_KERNEL); | |
140 | add->kmap_ops = kcalloc(count, sizeof(add->kmap_ops[0]), GFP_KERNEL); | |
141 | add->pages = kcalloc(count, sizeof(add->pages[0]), GFP_KERNEL); | |
a12b4eb3 SS |
142 | if (NULL == add->grants || |
143 | NULL == add->map_ops || | |
144 | NULL == add->unmap_ops || | |
0930bba6 | 145 | NULL == add->kmap_ops || |
a12b4eb3 | 146 | NULL == add->pages) |
ab31523c GH |
147 | goto err; |
148 | ||
693394b8 | 149 | if (alloc_xenballooned_pages(count, add->pages, false /* lowmem */)) |
ca47ceaa DDG |
150 | goto err; |
151 | ||
a12b4eb3 | 152 | for (i = 0; i < count; i++) { |
77c35acb DDG |
153 | add->map_ops[i].handle = -1; |
154 | add->unmap_ops[i].handle = -1; | |
0930bba6 | 155 | add->kmap_ops[i].handle = -1; |
a12b4eb3 SS |
156 | } |
157 | ||
ab31523c GH |
158 | add->index = 0; |
159 | add->count = count; | |
68b025c8 | 160 | atomic_set(&add->users, 1); |
ab31523c | 161 | |
ab31523c GH |
162 | return add; |
163 | ||
164 | err: | |
a67baeb7 | 165 | gntdev_free_map(add); |
ab31523c GH |
166 | return NULL; |
167 | } | |
168 | ||
169 | static void gntdev_add_map(struct gntdev_priv *priv, struct grant_map *add) | |
170 | { | |
171 | struct grant_map *map; | |
172 | ||
173 | list_for_each_entry(map, &priv->maps, next) { | |
174 | if (add->index + add->count < map->index) { | |
175 | list_add_tail(&add->next, &map->next); | |
176 | goto done; | |
177 | } | |
178 | add->index = map->index + map->count; | |
179 | } | |
180 | list_add_tail(&add->next, &priv->maps); | |
181 | ||
182 | done: | |
ab31523c GH |
183 | gntdev_print_maps(priv, "[new]", add->index); |
184 | } | |
185 | ||
186 | static struct grant_map *gntdev_find_map_index(struct gntdev_priv *priv, | |
187 | int index, int count) | |
188 | { | |
189 | struct grant_map *map; | |
190 | ||
191 | list_for_each_entry(map, &priv->maps, next) { | |
192 | if (map->index != index) | |
193 | continue; | |
bdc612dc | 194 | if (count && map->count != count) |
ab31523c GH |
195 | continue; |
196 | return map; | |
197 | } | |
198 | return NULL; | |
199 | } | |
200 | ||
16a1d022 | 201 | static void gntdev_put_map(struct gntdev_priv *priv, struct grant_map *map) |
ab31523c GH |
202 | { |
203 | if (!map) | |
204 | return; | |
a12b4eb3 | 205 | |
68b025c8 DDG |
206 | if (!atomic_dec_and_test(&map->users)) |
207 | return; | |
208 | ||
209 | atomic_sub(map->count, &pages_mapped); | |
210 | ||
0cc678f8 | 211 | if (map->notify.flags & UNMAP_NOTIFY_SEND_EVENT) { |
bdc612dc | 212 | notify_remote_via_evtchn(map->notify.event); |
0cc678f8 DDG |
213 | evtchn_put(map->notify.event); |
214 | } | |
bdc612dc | 215 | |
16a1d022 DDG |
216 | if (populate_freeable_maps && priv) { |
217 | spin_lock(&priv->lock); | |
218 | list_del(&map->next); | |
219 | spin_unlock(&priv->lock); | |
220 | } | |
221 | ||
a67baeb7 DV |
222 | if (map->pages && !use_ptemod) |
223 | unmap_grant_pages(map, 0, map->count); | |
224 | gntdev_free_map(map); | |
ab31523c GH |
225 | } |
226 | ||
227 | /* ------------------------------------------------------------------ */ | |
228 | ||
229 | static int find_grant_ptes(pte_t *pte, pgtable_t token, | |
230 | unsigned long addr, void *data) | |
231 | { | |
232 | struct grant_map *map = data; | |
233 | unsigned int pgnr = (addr - map->vma->vm_start) >> PAGE_SHIFT; | |
aab8f11a | 234 | int flags = map->flags | GNTMAP_application_map | GNTMAP_contains_pte; |
ab31523c GH |
235 | u64 pte_maddr; |
236 | ||
237 | BUG_ON(pgnr >= map->count); | |
ba5d1012 JF |
238 | pte_maddr = arbitrary_virt_to_machine(pte).maddr; |
239 | ||
aab8f11a | 240 | gnttab_set_map_op(&map->map_ops[pgnr], pte_maddr, flags, |
ab31523c GH |
241 | map->grants[pgnr].ref, |
242 | map->grants[pgnr].domid); | |
aab8f11a | 243 | gnttab_set_unmap_op(&map->unmap_ops[pgnr], pte_maddr, flags, |
77c35acb | 244 | -1 /* handle */); |
ab31523c GH |
245 | return 0; |
246 | } | |
247 | ||
248 | static int map_grant_pages(struct grant_map *map) | |
249 | { | |
250 | int i, err = 0; | |
aab8f11a DDG |
251 | |
252 | if (!use_ptemod) { | |
12996fc3 | 253 | /* Note: it could already be mapped */ |
77c35acb | 254 | if (map->map_ops[0].handle != -1) |
12996fc3 | 255 | return 0; |
aab8f11a | 256 | for (i = 0; i < map->count; i++) { |
38eaeb0f | 257 | unsigned long addr = (unsigned long) |
aab8f11a DDG |
258 | pfn_to_kaddr(page_to_pfn(map->pages[i])); |
259 | gnttab_set_map_op(&map->map_ops[i], addr, map->flags, | |
260 | map->grants[i].ref, | |
261 | map->grants[i].domid); | |
262 | gnttab_set_unmap_op(&map->unmap_ops[i], addr, | |
77c35acb | 263 | map->flags, -1 /* handle */); |
aab8f11a | 264 | } |
0930bba6 SS |
265 | } else { |
266 | /* | |
267 | * Setup the map_ops corresponding to the pte entries pointing | |
268 | * to the kernel linear addresses of the struct pages. | |
269 | * These ptes are completely different from the user ptes dealt | |
270 | * with find_grant_ptes. | |
271 | */ | |
272 | for (i = 0; i < map->count; i++) { | |
273 | unsigned level; | |
274 | unsigned long address = (unsigned long) | |
275 | pfn_to_kaddr(page_to_pfn(map->pages[i])); | |
276 | pte_t *ptep; | |
277 | u64 pte_maddr = 0; | |
278 | BUG_ON(PageHighMem(map->pages[i])); | |
279 | ||
280 | ptep = lookup_address(address, &level); | |
281 | pte_maddr = arbitrary_virt_to_machine(ptep).maddr; | |
282 | gnttab_set_map_op(&map->kmap_ops[i], pte_maddr, | |
283 | map->flags | | |
284 | GNTMAP_host_map | | |
285 | GNTMAP_contains_pte, | |
286 | map->grants[i].ref, | |
287 | map->grants[i].domid); | |
288 | } | |
aab8f11a | 289 | } |
ab31523c GH |
290 | |
291 | pr_debug("map %d+%d\n", map->index, map->count); | |
0930bba6 SS |
292 | err = gnttab_map_refs(map->map_ops, use_ptemod ? map->kmap_ops : NULL, |
293 | map->pages, map->count); | |
ab31523c GH |
294 | if (err) |
295 | return err; | |
296 | ||
297 | for (i = 0; i < map->count; i++) { | |
298 | if (map->map_ops[i].status) | |
299 | err = -EINVAL; | |
77c35acb DDG |
300 | else { |
301 | BUG_ON(map->map_ops[i].handle == -1); | |
302 | map->unmap_ops[i].handle = map->map_ops[i].handle; | |
303 | pr_debug("map handle=%d\n", map->map_ops[i].handle); | |
304 | } | |
ab31523c GH |
305 | } |
306 | return err; | |
307 | } | |
308 | ||
b57c1869 | 309 | static int __unmap_grant_pages(struct grant_map *map, int offset, int pages) |
ab31523c GH |
310 | { |
311 | int i, err = 0; | |
312 | ||
bdc612dc DDG |
313 | if (map->notify.flags & UNMAP_NOTIFY_CLEAR_BYTE) { |
314 | int pgno = (map->notify.addr >> PAGE_SHIFT); | |
0ea22f07 | 315 | if (pgno >= offset && pgno < offset + pages && use_ptemod) { |
f4ee4af4 DDG |
316 | void __user *tmp = (void __user *) |
317 | map->vma->vm_start + map->notify.addr; | |
9960be97 DDG |
318 | err = copy_to_user(tmp, &err, 1); |
319 | if (err) | |
12f0258d | 320 | return -EFAULT; |
0ea22f07 DDG |
321 | map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE; |
322 | } else if (pgno >= offset && pgno < offset + pages) { | |
bdc612dc DDG |
323 | uint8_t *tmp = kmap(map->pages[pgno]); |
324 | tmp[map->notify.addr & (PAGE_SIZE-1)] = 0; | |
325 | kunmap(map->pages[pgno]); | |
326 | map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE; | |
327 | } | |
328 | } | |
329 | ||
2fc136ee SS |
330 | err = gnttab_unmap_refs(map->unmap_ops + offset, |
331 | use_ptemod ? map->kmap_ops + offset : NULL, map->pages + offset, | |
332 | pages); | |
ab31523c GH |
333 | if (err) |
334 | return err; | |
335 | ||
336 | for (i = 0; i < pages; i++) { | |
337 | if (map->unmap_ops[offset+i].status) | |
338 | err = -EINVAL; | |
77c35acb DDG |
339 | pr_debug("unmap handle=%d st=%d\n", |
340 | map->unmap_ops[offset+i].handle, | |
341 | map->unmap_ops[offset+i].status); | |
342 | map->unmap_ops[offset+i].handle = -1; | |
ab31523c GH |
343 | } |
344 | return err; | |
345 | } | |
346 | ||
b57c1869 DDG |
347 | static int unmap_grant_pages(struct grant_map *map, int offset, int pages) |
348 | { | |
349 | int range, err = 0; | |
350 | ||
351 | pr_debug("unmap %d+%d [%d+%d]\n", map->index, map->count, offset, pages); | |
352 | ||
353 | /* It is possible the requested range will have a "hole" where we | |
354 | * already unmapped some of the grants. Only unmap valid ranges. | |
355 | */ | |
356 | while (pages && !err) { | |
77c35acb | 357 | while (pages && map->unmap_ops[offset].handle == -1) { |
b57c1869 DDG |
358 | offset++; |
359 | pages--; | |
360 | } | |
361 | range = 0; | |
362 | while (range < pages) { | |
77c35acb | 363 | if (map->unmap_ops[offset+range].handle == -1) { |
b57c1869 DDG |
364 | range--; |
365 | break; | |
366 | } | |
367 | range++; | |
368 | } | |
369 | err = __unmap_grant_pages(map, offset, range); | |
370 | offset += range; | |
371 | pages -= range; | |
372 | } | |
373 | ||
374 | return err; | |
375 | } | |
376 | ||
ab31523c GH |
377 | /* ------------------------------------------------------------------ */ |
378 | ||
d79647ae DDG |
379 | static void gntdev_vma_open(struct vm_area_struct *vma) |
380 | { | |
381 | struct grant_map *map = vma->vm_private_data; | |
382 | ||
383 | pr_debug("gntdev_vma_open %p\n", vma); | |
384 | atomic_inc(&map->users); | |
385 | } | |
386 | ||
ab31523c GH |
387 | static void gntdev_vma_close(struct vm_area_struct *vma) |
388 | { | |
389 | struct grant_map *map = vma->vm_private_data; | |
16a1d022 DDG |
390 | struct file *file = vma->vm_file; |
391 | struct gntdev_priv *priv = file->private_data; | |
ab31523c | 392 | |
d79647ae | 393 | pr_debug("gntdev_vma_close %p\n", vma); |
2512f298 | 394 | if (use_ptemod) { |
2512f298 DDG |
395 | /* It is possible that an mmu notifier could be running |
396 | * concurrently, so take priv->lock to ensure that the vma won't | |
397 | * vanishing during the unmap_grant_pages call, since we will | |
398 | * spin here until that completes. Such a concurrent call will | |
399 | * not do any unmapping, since that has been done prior to | |
400 | * closing the vma, but it may still iterate the unmap_ops list. | |
401 | */ | |
402 | spin_lock(&priv->lock); | |
403 | map->vma = NULL; | |
404 | spin_unlock(&priv->lock); | |
405 | } | |
ab31523c | 406 | vma->vm_private_data = NULL; |
16a1d022 | 407 | gntdev_put_map(priv, map); |
ab31523c GH |
408 | } |
409 | ||
ab31523c | 410 | static struct vm_operations_struct gntdev_vmops = { |
d79647ae | 411 | .open = gntdev_vma_open, |
ab31523c | 412 | .close = gntdev_vma_close, |
ab31523c GH |
413 | }; |
414 | ||
415 | /* ------------------------------------------------------------------ */ | |
416 | ||
16a1d022 DDG |
417 | static void unmap_if_in_range(struct grant_map *map, |
418 | unsigned long start, unsigned long end) | |
419 | { | |
420 | unsigned long mstart, mend; | |
421 | int err; | |
422 | ||
423 | if (!map->vma) | |
424 | return; | |
425 | if (map->vma->vm_start >= end) | |
426 | return; | |
427 | if (map->vma->vm_end <= start) | |
428 | return; | |
429 | mstart = max(start, map->vma->vm_start); | |
430 | mend = min(end, map->vma->vm_end); | |
431 | pr_debug("map %d+%d (%lx %lx), range %lx %lx, mrange %lx %lx\n", | |
432 | map->index, map->count, | |
433 | map->vma->vm_start, map->vma->vm_end, | |
434 | start, end, mstart, mend); | |
435 | err = unmap_grant_pages(map, | |
436 | (mstart - map->vma->vm_start) >> PAGE_SHIFT, | |
437 | (mend - mstart) >> PAGE_SHIFT); | |
438 | WARN_ON(err); | |
439 | } | |
440 | ||
ab31523c GH |
441 | static void mn_invl_range_start(struct mmu_notifier *mn, |
442 | struct mm_struct *mm, | |
443 | unsigned long start, unsigned long end) | |
444 | { | |
445 | struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn); | |
446 | struct grant_map *map; | |
ab31523c GH |
447 | |
448 | spin_lock(&priv->lock); | |
449 | list_for_each_entry(map, &priv->maps, next) { | |
16a1d022 DDG |
450 | unmap_if_in_range(map, start, end); |
451 | } | |
452 | list_for_each_entry(map, &priv->freeable_maps, next) { | |
453 | unmap_if_in_range(map, start, end); | |
ab31523c GH |
454 | } |
455 | spin_unlock(&priv->lock); | |
456 | } | |
457 | ||
458 | static void mn_invl_page(struct mmu_notifier *mn, | |
459 | struct mm_struct *mm, | |
460 | unsigned long address) | |
461 | { | |
462 | mn_invl_range_start(mn, mm, address, address + PAGE_SIZE); | |
463 | } | |
464 | ||
465 | static void mn_release(struct mmu_notifier *mn, | |
466 | struct mm_struct *mm) | |
467 | { | |
468 | struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn); | |
469 | struct grant_map *map; | |
470 | int err; | |
471 | ||
472 | spin_lock(&priv->lock); | |
473 | list_for_each_entry(map, &priv->maps, next) { | |
474 | if (!map->vma) | |
475 | continue; | |
476 | pr_debug("map %d+%d (%lx %lx)\n", | |
477 | map->index, map->count, | |
478 | map->vma->vm_start, map->vma->vm_end); | |
479 | err = unmap_grant_pages(map, /* offset */ 0, map->count); | |
480 | WARN_ON(err); | |
481 | } | |
16a1d022 DDG |
482 | list_for_each_entry(map, &priv->freeable_maps, next) { |
483 | if (!map->vma) | |
484 | continue; | |
485 | pr_debug("map %d+%d (%lx %lx)\n", | |
486 | map->index, map->count, | |
487 | map->vma->vm_start, map->vma->vm_end); | |
488 | err = unmap_grant_pages(map, /* offset */ 0, map->count); | |
489 | WARN_ON(err); | |
490 | } | |
ab31523c GH |
491 | spin_unlock(&priv->lock); |
492 | } | |
493 | ||
b8b0f559 | 494 | static struct mmu_notifier_ops gntdev_mmu_ops = { |
ab31523c GH |
495 | .release = mn_release, |
496 | .invalidate_page = mn_invl_page, | |
497 | .invalidate_range_start = mn_invl_range_start, | |
498 | }; | |
499 | ||
500 | /* ------------------------------------------------------------------ */ | |
501 | ||
502 | static int gntdev_open(struct inode *inode, struct file *flip) | |
503 | { | |
504 | struct gntdev_priv *priv; | |
505 | int ret = 0; | |
506 | ||
507 | priv = kzalloc(sizeof(*priv), GFP_KERNEL); | |
508 | if (!priv) | |
509 | return -ENOMEM; | |
510 | ||
511 | INIT_LIST_HEAD(&priv->maps); | |
16a1d022 | 512 | INIT_LIST_HEAD(&priv->freeable_maps); |
ab31523c | 513 | spin_lock_init(&priv->lock); |
ab31523c | 514 | |
aab8f11a DDG |
515 | if (use_ptemod) { |
516 | priv->mm = get_task_mm(current); | |
517 | if (!priv->mm) { | |
518 | kfree(priv); | |
519 | return -ENOMEM; | |
520 | } | |
521 | priv->mn.ops = &gntdev_mmu_ops; | |
522 | ret = mmu_notifier_register(&priv->mn, priv->mm); | |
523 | mmput(priv->mm); | |
ab31523c | 524 | } |
ab31523c GH |
525 | |
526 | if (ret) { | |
527 | kfree(priv); | |
528 | return ret; | |
529 | } | |
530 | ||
531 | flip->private_data = priv; | |
532 | pr_debug("priv %p\n", priv); | |
533 | ||
534 | return 0; | |
535 | } | |
536 | ||
537 | static int gntdev_release(struct inode *inode, struct file *flip) | |
538 | { | |
539 | struct gntdev_priv *priv = flip->private_data; | |
540 | struct grant_map *map; | |
ab31523c GH |
541 | |
542 | pr_debug("priv %p\n", priv); | |
543 | ||
ab31523c GH |
544 | while (!list_empty(&priv->maps)) { |
545 | map = list_entry(priv->maps.next, struct grant_map, next); | |
68b025c8 | 546 | list_del(&map->next); |
16a1d022 | 547 | gntdev_put_map(NULL /* already removed */, map); |
ab31523c | 548 | } |
16a1d022 | 549 | WARN_ON(!list_empty(&priv->freeable_maps)); |
ab31523c | 550 | |
aab8f11a DDG |
551 | if (use_ptemod) |
552 | mmu_notifier_unregister(&priv->mn, priv->mm); | |
ab31523c GH |
553 | kfree(priv); |
554 | return 0; | |
555 | } | |
556 | ||
557 | static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv, | |
558 | struct ioctl_gntdev_map_grant_ref __user *u) | |
559 | { | |
560 | struct ioctl_gntdev_map_grant_ref op; | |
561 | struct grant_map *map; | |
562 | int err; | |
563 | ||
564 | if (copy_from_user(&op, u, sizeof(op)) != 0) | |
565 | return -EFAULT; | |
566 | pr_debug("priv %p, add %d\n", priv, op.count); | |
567 | if (unlikely(op.count <= 0)) | |
568 | return -EINVAL; | |
ab31523c GH |
569 | |
570 | err = -ENOMEM; | |
571 | map = gntdev_alloc_map(priv, op.count); | |
572 | if (!map) | |
573 | return err; | |
ef91082e | 574 | |
68b025c8 DDG |
575 | if (unlikely(atomic_add_return(op.count, &pages_mapped) > limit)) { |
576 | pr_debug("can't map: over limit\n"); | |
16a1d022 | 577 | gntdev_put_map(NULL, map); |
ab31523c GH |
578 | return err; |
579 | } | |
580 | ||
68b025c8 DDG |
581 | if (copy_from_user(map->grants, &u->refs, |
582 | sizeof(map->grants[0]) * op.count) != 0) { | |
16a1d022 DDG |
583 | gntdev_put_map(NULL, map); |
584 | return -EFAULT; | |
ef91082e DDG |
585 | } |
586 | ||
ab31523c GH |
587 | spin_lock(&priv->lock); |
588 | gntdev_add_map(priv, map); | |
589 | op.index = map->index << PAGE_SHIFT; | |
590 | spin_unlock(&priv->lock); | |
591 | ||
68b025c8 DDG |
592 | if (copy_to_user(u, &op, sizeof(op)) != 0) |
593 | return -EFAULT; | |
594 | ||
ab31523c GH |
595 | return 0; |
596 | } | |
597 | ||
598 | static long gntdev_ioctl_unmap_grant_ref(struct gntdev_priv *priv, | |
599 | struct ioctl_gntdev_unmap_grant_ref __user *u) | |
600 | { | |
601 | struct ioctl_gntdev_unmap_grant_ref op; | |
602 | struct grant_map *map; | |
603 | int err = -ENOENT; | |
604 | ||
605 | if (copy_from_user(&op, u, sizeof(op)) != 0) | |
606 | return -EFAULT; | |
607 | pr_debug("priv %p, del %d+%d\n", priv, (int)op.index, (int)op.count); | |
608 | ||
609 | spin_lock(&priv->lock); | |
610 | map = gntdev_find_map_index(priv, op.index >> PAGE_SHIFT, op.count); | |
68b025c8 DDG |
611 | if (map) { |
612 | list_del(&map->next); | |
16a1d022 DDG |
613 | if (populate_freeable_maps) |
614 | list_add_tail(&map->next, &priv->freeable_maps); | |
68b025c8 DDG |
615 | err = 0; |
616 | } | |
ab31523c | 617 | spin_unlock(&priv->lock); |
1f1503ba | 618 | if (map) |
16a1d022 | 619 | gntdev_put_map(priv, map); |
ab31523c GH |
620 | return err; |
621 | } | |
622 | ||
623 | static long gntdev_ioctl_get_offset_for_vaddr(struct gntdev_priv *priv, | |
624 | struct ioctl_gntdev_get_offset_for_vaddr __user *u) | |
625 | { | |
626 | struct ioctl_gntdev_get_offset_for_vaddr op; | |
a879211b | 627 | struct vm_area_struct *vma; |
ab31523c | 628 | struct grant_map *map; |
2512f298 | 629 | int rv = -EINVAL; |
ab31523c GH |
630 | |
631 | if (copy_from_user(&op, u, sizeof(op)) != 0) | |
632 | return -EFAULT; | |
633 | pr_debug("priv %p, offset for vaddr %lx\n", priv, (unsigned long)op.vaddr); | |
634 | ||
2512f298 | 635 | down_read(¤t->mm->mmap_sem); |
a879211b DDG |
636 | vma = find_vma(current->mm, op.vaddr); |
637 | if (!vma || vma->vm_ops != &gntdev_vmops) | |
2512f298 | 638 | goto out_unlock; |
a879211b DDG |
639 | |
640 | map = vma->vm_private_data; | |
641 | if (!map) | |
2512f298 | 642 | goto out_unlock; |
a879211b | 643 | |
ab31523c GH |
644 | op.offset = map->index << PAGE_SHIFT; |
645 | op.count = map->count; | |
2512f298 | 646 | rv = 0; |
ab31523c | 647 | |
2512f298 DDG |
648 | out_unlock: |
649 | up_read(¤t->mm->mmap_sem); | |
650 | ||
651 | if (rv == 0 && copy_to_user(u, &op, sizeof(op)) != 0) | |
ab31523c | 652 | return -EFAULT; |
2512f298 | 653 | return rv; |
ab31523c GH |
654 | } |
655 | ||
bdc612dc DDG |
656 | static long gntdev_ioctl_notify(struct gntdev_priv *priv, void __user *u) |
657 | { | |
658 | struct ioctl_gntdev_unmap_notify op; | |
659 | struct grant_map *map; | |
660 | int rc; | |
0cc678f8 DDG |
661 | int out_flags; |
662 | unsigned int out_event; | |
bdc612dc DDG |
663 | |
664 | if (copy_from_user(&op, u, sizeof(op))) | |
665 | return -EFAULT; | |
666 | ||
667 | if (op.action & ~(UNMAP_NOTIFY_CLEAR_BYTE|UNMAP_NOTIFY_SEND_EVENT)) | |
668 | return -EINVAL; | |
669 | ||
0cc678f8 DDG |
670 | /* We need to grab a reference to the event channel we are going to use |
671 | * to send the notify before releasing the reference we may already have | |
672 | * (if someone has called this ioctl twice). This is required so that | |
673 | * it is possible to change the clear_byte part of the notification | |
674 | * without disturbing the event channel part, which may now be the last | |
675 | * reference to that event channel. | |
676 | */ | |
677 | if (op.action & UNMAP_NOTIFY_SEND_EVENT) { | |
678 | if (evtchn_get(op.event_channel_port)) | |
679 | return -EINVAL; | |
680 | } | |
681 | ||
682 | out_flags = op.action; | |
683 | out_event = op.event_channel_port; | |
684 | ||
bdc612dc DDG |
685 | spin_lock(&priv->lock); |
686 | ||
687 | list_for_each_entry(map, &priv->maps, next) { | |
688 | uint64_t begin = map->index << PAGE_SHIFT; | |
689 | uint64_t end = (map->index + map->count) << PAGE_SHIFT; | |
690 | if (op.index >= begin && op.index < end) | |
691 | goto found; | |
692 | } | |
693 | rc = -ENOENT; | |
694 | goto unlock_out; | |
695 | ||
696 | found: | |
9960be97 DDG |
697 | if ((op.action & UNMAP_NOTIFY_CLEAR_BYTE) && |
698 | (map->flags & GNTMAP_readonly)) { | |
699 | rc = -EINVAL; | |
700 | goto unlock_out; | |
701 | } | |
702 | ||
0cc678f8 DDG |
703 | out_flags = map->notify.flags; |
704 | out_event = map->notify.event; | |
705 | ||
bdc612dc DDG |
706 | map->notify.flags = op.action; |
707 | map->notify.addr = op.index - (map->index << PAGE_SHIFT); | |
708 | map->notify.event = op.event_channel_port; | |
0cc678f8 | 709 | |
bdc612dc | 710 | rc = 0; |
0cc678f8 | 711 | |
bdc612dc DDG |
712 | unlock_out: |
713 | spin_unlock(&priv->lock); | |
0cc678f8 DDG |
714 | |
715 | /* Drop the reference to the event channel we did not save in the map */ | |
716 | if (out_flags & UNMAP_NOTIFY_SEND_EVENT) | |
717 | evtchn_put(out_event); | |
718 | ||
bdc612dc DDG |
719 | return rc; |
720 | } | |
721 | ||
ab31523c GH |
722 | static long gntdev_ioctl(struct file *flip, |
723 | unsigned int cmd, unsigned long arg) | |
724 | { | |
725 | struct gntdev_priv *priv = flip->private_data; | |
726 | void __user *ptr = (void __user *)arg; | |
727 | ||
728 | switch (cmd) { | |
729 | case IOCTL_GNTDEV_MAP_GRANT_REF: | |
730 | return gntdev_ioctl_map_grant_ref(priv, ptr); | |
731 | ||
732 | case IOCTL_GNTDEV_UNMAP_GRANT_REF: | |
733 | return gntdev_ioctl_unmap_grant_ref(priv, ptr); | |
734 | ||
735 | case IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR: | |
736 | return gntdev_ioctl_get_offset_for_vaddr(priv, ptr); | |
737 | ||
bdc612dc DDG |
738 | case IOCTL_GNTDEV_SET_UNMAP_NOTIFY: |
739 | return gntdev_ioctl_notify(priv, ptr); | |
740 | ||
ab31523c GH |
741 | default: |
742 | pr_debug("priv %p, unknown cmd %x\n", priv, cmd); | |
743 | return -ENOIOCTLCMD; | |
744 | } | |
745 | ||
746 | return 0; | |
747 | } | |
748 | ||
749 | static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) | |
750 | { | |
751 | struct gntdev_priv *priv = flip->private_data; | |
752 | int index = vma->vm_pgoff; | |
753 | int count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; | |
754 | struct grant_map *map; | |
aab8f11a | 755 | int i, err = -EINVAL; |
ab31523c GH |
756 | |
757 | if ((vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_SHARED)) | |
758 | return -EINVAL; | |
759 | ||
760 | pr_debug("map %d+%d at %lx (pgoff %lx)\n", | |
761 | index, count, vma->vm_start, vma->vm_pgoff); | |
762 | ||
763 | spin_lock(&priv->lock); | |
764 | map = gntdev_find_map_index(priv, index, count); | |
765 | if (!map) | |
766 | goto unlock_out; | |
aab8f11a | 767 | if (use_ptemod && map->vma) |
ab31523c | 768 | goto unlock_out; |
aab8f11a | 769 | if (use_ptemod && priv->mm != vma->vm_mm) { |
ab31523c GH |
770 | printk(KERN_WARNING "Huh? Other mm?\n"); |
771 | goto unlock_out; | |
772 | } | |
773 | ||
68b025c8 DDG |
774 | atomic_inc(&map->users); |
775 | ||
ab31523c GH |
776 | vma->vm_ops = &gntdev_vmops; |
777 | ||
314e51b9 | 778 | vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; |
d79647ae DDG |
779 | |
780 | if (use_ptemod) | |
e8e937be | 781 | vma->vm_flags |= VM_DONTCOPY; |
ab31523c GH |
782 | |
783 | vma->vm_private_data = map; | |
ab31523c | 784 | |
aab8f11a DDG |
785 | if (use_ptemod) |
786 | map->vma = vma; | |
787 | ||
12996fc3 DDG |
788 | if (map->flags) { |
789 | if ((vma->vm_flags & VM_WRITE) && | |
790 | (map->flags & GNTMAP_readonly)) | |
a93e20a8 | 791 | goto out_unlock_put; |
12996fc3 DDG |
792 | } else { |
793 | map->flags = GNTMAP_host_map; | |
794 | if (!(vma->vm_flags & VM_WRITE)) | |
795 | map->flags |= GNTMAP_readonly; | |
796 | } | |
ab31523c | 797 | |
f0a70c88 DDG |
798 | spin_unlock(&priv->lock); |
799 | ||
aab8f11a DDG |
800 | if (use_ptemod) { |
801 | err = apply_to_page_range(vma->vm_mm, vma->vm_start, | |
802 | vma->vm_end - vma->vm_start, | |
803 | find_grant_ptes, map); | |
804 | if (err) { | |
805 | printk(KERN_WARNING "find_grant_ptes() failure.\n"); | |
90b6f305 | 806 | goto out_put_map; |
aab8f11a | 807 | } |
ab31523c GH |
808 | } |
809 | ||
810 | err = map_grant_pages(map); | |
90b6f305 DDG |
811 | if (err) |
812 | goto out_put_map; | |
f0a70c88 | 813 | |
aab8f11a DDG |
814 | if (!use_ptemod) { |
815 | for (i = 0; i < count; i++) { | |
816 | err = vm_insert_page(vma, vma->vm_start + i*PAGE_SIZE, | |
817 | map->pages[i]); | |
818 | if (err) | |
90b6f305 | 819 | goto out_put_map; |
aab8f11a DDG |
820 | } |
821 | } | |
822 | ||
f0a70c88 DDG |
823 | return 0; |
824 | ||
ab31523c GH |
825 | unlock_out: |
826 | spin_unlock(&priv->lock); | |
827 | return err; | |
90b6f305 | 828 | |
a93e20a8 DC |
829 | out_unlock_put: |
830 | spin_unlock(&priv->lock); | |
90b6f305 | 831 | out_put_map: |
84e4075d DDG |
832 | if (use_ptemod) |
833 | map->vma = NULL; | |
16a1d022 | 834 | gntdev_put_map(priv, map); |
90b6f305 | 835 | return err; |
ab31523c GH |
836 | } |
837 | ||
838 | static const struct file_operations gntdev_fops = { | |
839 | .owner = THIS_MODULE, | |
840 | .open = gntdev_open, | |
841 | .release = gntdev_release, | |
842 | .mmap = gntdev_mmap, | |
843 | .unlocked_ioctl = gntdev_ioctl | |
844 | }; | |
845 | ||
846 | static struct miscdevice gntdev_miscdev = { | |
847 | .minor = MISC_DYNAMIC_MINOR, | |
848 | .name = "xen/gntdev", | |
849 | .fops = &gntdev_fops, | |
850 | }; | |
851 | ||
852 | /* ------------------------------------------------------------------ */ | |
853 | ||
854 | static int __init gntdev_init(void) | |
855 | { | |
856 | int err; | |
857 | ||
858 | if (!xen_domain()) | |
859 | return -ENODEV; | |
860 | ||
aab8f11a DDG |
861 | use_ptemod = xen_pv_domain(); |
862 | ||
ab31523c GH |
863 | err = misc_register(&gntdev_miscdev); |
864 | if (err != 0) { | |
865 | printk(KERN_ERR "Could not register gntdev device\n"); | |
866 | return err; | |
867 | } | |
868 | return 0; | |
869 | } | |
870 | ||
871 | static void __exit gntdev_exit(void) | |
872 | { | |
873 | misc_deregister(&gntdev_miscdev); | |
874 | } | |
875 | ||
876 | module_init(gntdev_init); | |
877 | module_exit(gntdev_exit); | |
878 | ||
879 | /* ------------------------------------------------------------------ */ |