Commit | Line | Data |
---|---|---|
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 | ||
7d17e84b DDG |
317 | err = gnttab_unmap_refs(map->unmap_ops + offset, map->pages + offset, |
318 | pages, true); | |
ab31523c GH |
319 | if (err) |
320 | return err; | |
321 | ||
322 | for (i = 0; i < pages; i++) { | |
323 | if (map->unmap_ops[offset+i].status) | |
324 | err = -EINVAL; | |
77c35acb DDG |
325 | pr_debug("unmap handle=%d st=%d\n", |
326 | map->unmap_ops[offset+i].handle, | |
327 | map->unmap_ops[offset+i].status); | |
328 | map->unmap_ops[offset+i].handle = -1; | |
ab31523c GH |
329 | } |
330 | return err; | |
331 | } | |
332 | ||
b57c1869 DDG |
333 | static int unmap_grant_pages(struct grant_map *map, int offset, int pages) |
334 | { | |
335 | int range, err = 0; | |
336 | ||
337 | pr_debug("unmap %d+%d [%d+%d]\n", map->index, map->count, offset, pages); | |
338 | ||
339 | /* It is possible the requested range will have a "hole" where we | |
340 | * already unmapped some of the grants. Only unmap valid ranges. | |
341 | */ | |
342 | while (pages && !err) { | |
77c35acb | 343 | while (pages && map->unmap_ops[offset].handle == -1) { |
b57c1869 DDG |
344 | offset++; |
345 | pages--; | |
346 | } | |
347 | range = 0; | |
348 | while (range < pages) { | |
77c35acb | 349 | if (map->unmap_ops[offset+range].handle == -1) { |
b57c1869 DDG |
350 | range--; |
351 | break; | |
352 | } | |
353 | range++; | |
354 | } | |
355 | err = __unmap_grant_pages(map, offset, range); | |
356 | offset += range; | |
357 | pages -= range; | |
358 | } | |
359 | ||
360 | return err; | |
361 | } | |
362 | ||
ab31523c GH |
363 | /* ------------------------------------------------------------------ */ |
364 | ||
d79647ae DDG |
365 | static void gntdev_vma_open(struct vm_area_struct *vma) |
366 | { | |
367 | struct grant_map *map = vma->vm_private_data; | |
368 | ||
369 | pr_debug("gntdev_vma_open %p\n", vma); | |
370 | atomic_inc(&map->users); | |
371 | } | |
372 | ||
ab31523c GH |
373 | static void gntdev_vma_close(struct vm_area_struct *vma) |
374 | { | |
375 | struct grant_map *map = vma->vm_private_data; | |
376 | ||
d79647ae | 377 | pr_debug("gntdev_vma_close %p\n", vma); |
ab31523c GH |
378 | map->vma = NULL; |
379 | vma->vm_private_data = NULL; | |
68b025c8 | 380 | gntdev_put_map(map); |
ab31523c GH |
381 | } |
382 | ||
ab31523c | 383 | static struct vm_operations_struct gntdev_vmops = { |
d79647ae | 384 | .open = gntdev_vma_open, |
ab31523c | 385 | .close = gntdev_vma_close, |
ab31523c GH |
386 | }; |
387 | ||
388 | /* ------------------------------------------------------------------ */ | |
389 | ||
390 | static void mn_invl_range_start(struct mmu_notifier *mn, | |
391 | struct mm_struct *mm, | |
392 | unsigned long start, unsigned long end) | |
393 | { | |
394 | struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn); | |
395 | struct grant_map *map; | |
396 | unsigned long mstart, mend; | |
397 | int err; | |
398 | ||
399 | spin_lock(&priv->lock); | |
400 | list_for_each_entry(map, &priv->maps, next) { | |
401 | if (!map->vma) | |
402 | continue; | |
ab31523c GH |
403 | if (map->vma->vm_start >= end) |
404 | continue; | |
405 | if (map->vma->vm_end <= start) | |
406 | continue; | |
407 | mstart = max(start, map->vma->vm_start); | |
408 | mend = min(end, map->vma->vm_end); | |
409 | pr_debug("map %d+%d (%lx %lx), range %lx %lx, mrange %lx %lx\n", | |
410 | map->index, map->count, | |
411 | map->vma->vm_start, map->vma->vm_end, | |
412 | start, end, mstart, mend); | |
413 | err = unmap_grant_pages(map, | |
414 | (mstart - map->vma->vm_start) >> PAGE_SHIFT, | |
415 | (mend - mstart) >> PAGE_SHIFT); | |
416 | WARN_ON(err); | |
417 | } | |
418 | spin_unlock(&priv->lock); | |
419 | } | |
420 | ||
421 | static void mn_invl_page(struct mmu_notifier *mn, | |
422 | struct mm_struct *mm, | |
423 | unsigned long address) | |
424 | { | |
425 | mn_invl_range_start(mn, mm, address, address + PAGE_SIZE); | |
426 | } | |
427 | ||
428 | static void mn_release(struct mmu_notifier *mn, | |
429 | struct mm_struct *mm) | |
430 | { | |
431 | struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn); | |
432 | struct grant_map *map; | |
433 | int err; | |
434 | ||
435 | spin_lock(&priv->lock); | |
436 | list_for_each_entry(map, &priv->maps, next) { | |
437 | if (!map->vma) | |
438 | continue; | |
439 | pr_debug("map %d+%d (%lx %lx)\n", | |
440 | map->index, map->count, | |
441 | map->vma->vm_start, map->vma->vm_end); | |
442 | err = unmap_grant_pages(map, /* offset */ 0, map->count); | |
443 | WARN_ON(err); | |
444 | } | |
445 | spin_unlock(&priv->lock); | |
446 | } | |
447 | ||
448 | struct mmu_notifier_ops gntdev_mmu_ops = { | |
449 | .release = mn_release, | |
450 | .invalidate_page = mn_invl_page, | |
451 | .invalidate_range_start = mn_invl_range_start, | |
452 | }; | |
453 | ||
454 | /* ------------------------------------------------------------------ */ | |
455 | ||
456 | static int gntdev_open(struct inode *inode, struct file *flip) | |
457 | { | |
458 | struct gntdev_priv *priv; | |
459 | int ret = 0; | |
460 | ||
461 | priv = kzalloc(sizeof(*priv), GFP_KERNEL); | |
462 | if (!priv) | |
463 | return -ENOMEM; | |
464 | ||
465 | INIT_LIST_HEAD(&priv->maps); | |
466 | spin_lock_init(&priv->lock); | |
ab31523c | 467 | |
aab8f11a DDG |
468 | if (use_ptemod) { |
469 | priv->mm = get_task_mm(current); | |
470 | if (!priv->mm) { | |
471 | kfree(priv); | |
472 | return -ENOMEM; | |
473 | } | |
474 | priv->mn.ops = &gntdev_mmu_ops; | |
475 | ret = mmu_notifier_register(&priv->mn, priv->mm); | |
476 | mmput(priv->mm); | |
ab31523c | 477 | } |
ab31523c GH |
478 | |
479 | if (ret) { | |
480 | kfree(priv); | |
481 | return ret; | |
482 | } | |
483 | ||
484 | flip->private_data = priv; | |
485 | pr_debug("priv %p\n", priv); | |
486 | ||
487 | return 0; | |
488 | } | |
489 | ||
490 | static int gntdev_release(struct inode *inode, struct file *flip) | |
491 | { | |
492 | struct gntdev_priv *priv = flip->private_data; | |
493 | struct grant_map *map; | |
ab31523c GH |
494 | |
495 | pr_debug("priv %p\n", priv); | |
496 | ||
ab31523c GH |
497 | while (!list_empty(&priv->maps)) { |
498 | map = list_entry(priv->maps.next, struct grant_map, next); | |
68b025c8 DDG |
499 | list_del(&map->next); |
500 | gntdev_put_map(map); | |
ab31523c | 501 | } |
ab31523c | 502 | |
aab8f11a DDG |
503 | if (use_ptemod) |
504 | mmu_notifier_unregister(&priv->mn, priv->mm); | |
ab31523c GH |
505 | kfree(priv); |
506 | return 0; | |
507 | } | |
508 | ||
509 | static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv, | |
510 | struct ioctl_gntdev_map_grant_ref __user *u) | |
511 | { | |
512 | struct ioctl_gntdev_map_grant_ref op; | |
513 | struct grant_map *map; | |
514 | int err; | |
515 | ||
516 | if (copy_from_user(&op, u, sizeof(op)) != 0) | |
517 | return -EFAULT; | |
518 | pr_debug("priv %p, add %d\n", priv, op.count); | |
519 | if (unlikely(op.count <= 0)) | |
520 | return -EINVAL; | |
ab31523c GH |
521 | |
522 | err = -ENOMEM; | |
523 | map = gntdev_alloc_map(priv, op.count); | |
524 | if (!map) | |
525 | return err; | |
ef91082e | 526 | |
68b025c8 DDG |
527 | if (unlikely(atomic_add_return(op.count, &pages_mapped) > limit)) { |
528 | pr_debug("can't map: over limit\n"); | |
529 | gntdev_put_map(map); | |
ab31523c GH |
530 | return err; |
531 | } | |
532 | ||
68b025c8 DDG |
533 | if (copy_from_user(map->grants, &u->refs, |
534 | sizeof(map->grants[0]) * op.count) != 0) { | |
535 | gntdev_put_map(map); | |
ef91082e DDG |
536 | return err; |
537 | } | |
538 | ||
ab31523c GH |
539 | spin_lock(&priv->lock); |
540 | gntdev_add_map(priv, map); | |
541 | op.index = map->index << PAGE_SHIFT; | |
542 | spin_unlock(&priv->lock); | |
543 | ||
68b025c8 DDG |
544 | if (copy_to_user(u, &op, sizeof(op)) != 0) |
545 | return -EFAULT; | |
546 | ||
ab31523c GH |
547 | return 0; |
548 | } | |
549 | ||
550 | static long gntdev_ioctl_unmap_grant_ref(struct gntdev_priv *priv, | |
551 | struct ioctl_gntdev_unmap_grant_ref __user *u) | |
552 | { | |
553 | struct ioctl_gntdev_unmap_grant_ref op; | |
554 | struct grant_map *map; | |
555 | int err = -ENOENT; | |
556 | ||
557 | if (copy_from_user(&op, u, sizeof(op)) != 0) | |
558 | return -EFAULT; | |
559 | pr_debug("priv %p, del %d+%d\n", priv, (int)op.index, (int)op.count); | |
560 | ||
561 | spin_lock(&priv->lock); | |
562 | map = gntdev_find_map_index(priv, op.index >> PAGE_SHIFT, op.count); | |
68b025c8 DDG |
563 | if (map) { |
564 | list_del(&map->next); | |
68b025c8 DDG |
565 | err = 0; |
566 | } | |
ab31523c | 567 | spin_unlock(&priv->lock); |
1f1503ba DDG |
568 | if (map) |
569 | gntdev_put_map(map); | |
ab31523c GH |
570 | return err; |
571 | } | |
572 | ||
573 | static long gntdev_ioctl_get_offset_for_vaddr(struct gntdev_priv *priv, | |
574 | struct ioctl_gntdev_get_offset_for_vaddr __user *u) | |
575 | { | |
576 | struct ioctl_gntdev_get_offset_for_vaddr op; | |
a879211b | 577 | struct vm_area_struct *vma; |
ab31523c GH |
578 | struct grant_map *map; |
579 | ||
580 | if (copy_from_user(&op, u, sizeof(op)) != 0) | |
581 | return -EFAULT; | |
582 | pr_debug("priv %p, offset for vaddr %lx\n", priv, (unsigned long)op.vaddr); | |
583 | ||
a879211b DDG |
584 | vma = find_vma(current->mm, op.vaddr); |
585 | if (!vma || vma->vm_ops != &gntdev_vmops) | |
ab31523c | 586 | return -EINVAL; |
a879211b DDG |
587 | |
588 | map = vma->vm_private_data; | |
589 | if (!map) | |
590 | return -EINVAL; | |
591 | ||
ab31523c GH |
592 | op.offset = map->index << PAGE_SHIFT; |
593 | op.count = map->count; | |
ab31523c GH |
594 | |
595 | if (copy_to_user(u, &op, sizeof(op)) != 0) | |
596 | return -EFAULT; | |
597 | return 0; | |
598 | } | |
599 | ||
bdc612dc DDG |
600 | static long gntdev_ioctl_notify(struct gntdev_priv *priv, void __user *u) |
601 | { | |
602 | struct ioctl_gntdev_unmap_notify op; | |
603 | struct grant_map *map; | |
604 | int rc; | |
0cc678f8 DDG |
605 | int out_flags; |
606 | unsigned int out_event; | |
bdc612dc DDG |
607 | |
608 | if (copy_from_user(&op, u, sizeof(op))) | |
609 | return -EFAULT; | |
610 | ||
611 | if (op.action & ~(UNMAP_NOTIFY_CLEAR_BYTE|UNMAP_NOTIFY_SEND_EVENT)) | |
612 | return -EINVAL; | |
613 | ||
0cc678f8 DDG |
614 | /* We need to grab a reference to the event channel we are going to use |
615 | * to send the notify before releasing the reference we may already have | |
616 | * (if someone has called this ioctl twice). This is required so that | |
617 | * it is possible to change the clear_byte part of the notification | |
618 | * without disturbing the event channel part, which may now be the last | |
619 | * reference to that event channel. | |
620 | */ | |
621 | if (op.action & UNMAP_NOTIFY_SEND_EVENT) { | |
622 | if (evtchn_get(op.event_channel_port)) | |
623 | return -EINVAL; | |
624 | } | |
625 | ||
626 | out_flags = op.action; | |
627 | out_event = op.event_channel_port; | |
628 | ||
bdc612dc DDG |
629 | spin_lock(&priv->lock); |
630 | ||
631 | list_for_each_entry(map, &priv->maps, next) { | |
632 | uint64_t begin = map->index << PAGE_SHIFT; | |
633 | uint64_t end = (map->index + map->count) << PAGE_SHIFT; | |
634 | if (op.index >= begin && op.index < end) | |
635 | goto found; | |
636 | } | |
637 | rc = -ENOENT; | |
638 | goto unlock_out; | |
639 | ||
640 | found: | |
9960be97 DDG |
641 | if ((op.action & UNMAP_NOTIFY_CLEAR_BYTE) && |
642 | (map->flags & GNTMAP_readonly)) { | |
643 | rc = -EINVAL; | |
644 | goto unlock_out; | |
645 | } | |
646 | ||
0cc678f8 DDG |
647 | out_flags = map->notify.flags; |
648 | out_event = map->notify.event; | |
649 | ||
bdc612dc DDG |
650 | map->notify.flags = op.action; |
651 | map->notify.addr = op.index - (map->index << PAGE_SHIFT); | |
652 | map->notify.event = op.event_channel_port; | |
0cc678f8 | 653 | |
bdc612dc | 654 | rc = 0; |
0cc678f8 | 655 | |
bdc612dc DDG |
656 | unlock_out: |
657 | spin_unlock(&priv->lock); | |
0cc678f8 DDG |
658 | |
659 | /* Drop the reference to the event channel we did not save in the map */ | |
660 | if (out_flags & UNMAP_NOTIFY_SEND_EVENT) | |
661 | evtchn_put(out_event); | |
662 | ||
bdc612dc DDG |
663 | return rc; |
664 | } | |
665 | ||
ab31523c GH |
666 | static long gntdev_ioctl(struct file *flip, |
667 | unsigned int cmd, unsigned long arg) | |
668 | { | |
669 | struct gntdev_priv *priv = flip->private_data; | |
670 | void __user *ptr = (void __user *)arg; | |
671 | ||
672 | switch (cmd) { | |
673 | case IOCTL_GNTDEV_MAP_GRANT_REF: | |
674 | return gntdev_ioctl_map_grant_ref(priv, ptr); | |
675 | ||
676 | case IOCTL_GNTDEV_UNMAP_GRANT_REF: | |
677 | return gntdev_ioctl_unmap_grant_ref(priv, ptr); | |
678 | ||
679 | case IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR: | |
680 | return gntdev_ioctl_get_offset_for_vaddr(priv, ptr); | |
681 | ||
bdc612dc DDG |
682 | case IOCTL_GNTDEV_SET_UNMAP_NOTIFY: |
683 | return gntdev_ioctl_notify(priv, ptr); | |
684 | ||
ab31523c GH |
685 | default: |
686 | pr_debug("priv %p, unknown cmd %x\n", priv, cmd); | |
687 | return -ENOIOCTLCMD; | |
688 | } | |
689 | ||
690 | return 0; | |
691 | } | |
692 | ||
693 | static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) | |
694 | { | |
695 | struct gntdev_priv *priv = flip->private_data; | |
696 | int index = vma->vm_pgoff; | |
697 | int count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; | |
698 | struct grant_map *map; | |
aab8f11a | 699 | int i, err = -EINVAL; |
ab31523c GH |
700 | |
701 | if ((vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_SHARED)) | |
702 | return -EINVAL; | |
703 | ||
704 | pr_debug("map %d+%d at %lx (pgoff %lx)\n", | |
705 | index, count, vma->vm_start, vma->vm_pgoff); | |
706 | ||
707 | spin_lock(&priv->lock); | |
708 | map = gntdev_find_map_index(priv, index, count); | |
709 | if (!map) | |
710 | goto unlock_out; | |
aab8f11a | 711 | if (use_ptemod && map->vma) |
ab31523c | 712 | goto unlock_out; |
aab8f11a | 713 | if (use_ptemod && priv->mm != vma->vm_mm) { |
ab31523c GH |
714 | printk(KERN_WARNING "Huh? Other mm?\n"); |
715 | goto unlock_out; | |
716 | } | |
717 | ||
68b025c8 DDG |
718 | atomic_inc(&map->users); |
719 | ||
ab31523c GH |
720 | vma->vm_ops = &gntdev_vmops; |
721 | ||
d79647ae DDG |
722 | vma->vm_flags |= VM_RESERVED|VM_DONTEXPAND; |
723 | ||
724 | if (use_ptemod) | |
e8e937be | 725 | vma->vm_flags |= VM_DONTCOPY; |
ab31523c GH |
726 | |
727 | vma->vm_private_data = map; | |
ab31523c | 728 | |
aab8f11a DDG |
729 | if (use_ptemod) |
730 | map->vma = vma; | |
731 | ||
12996fc3 DDG |
732 | if (map->flags) { |
733 | if ((vma->vm_flags & VM_WRITE) && | |
734 | (map->flags & GNTMAP_readonly)) | |
a93e20a8 | 735 | goto out_unlock_put; |
12996fc3 DDG |
736 | } else { |
737 | map->flags = GNTMAP_host_map; | |
738 | if (!(vma->vm_flags & VM_WRITE)) | |
739 | map->flags |= GNTMAP_readonly; | |
740 | } | |
ab31523c | 741 | |
f0a70c88 DDG |
742 | spin_unlock(&priv->lock); |
743 | ||
aab8f11a DDG |
744 | if (use_ptemod) { |
745 | err = apply_to_page_range(vma->vm_mm, vma->vm_start, | |
746 | vma->vm_end - vma->vm_start, | |
747 | find_grant_ptes, map); | |
748 | if (err) { | |
749 | printk(KERN_WARNING "find_grant_ptes() failure.\n"); | |
90b6f305 | 750 | goto out_put_map; |
aab8f11a | 751 | } |
ab31523c GH |
752 | } |
753 | ||
754 | err = map_grant_pages(map); | |
90b6f305 DDG |
755 | if (err) |
756 | goto out_put_map; | |
f0a70c88 | 757 | |
aab8f11a DDG |
758 | if (!use_ptemod) { |
759 | for (i = 0; i < count; i++) { | |
760 | err = vm_insert_page(vma, vma->vm_start + i*PAGE_SIZE, | |
761 | map->pages[i]); | |
762 | if (err) | |
90b6f305 | 763 | goto out_put_map; |
aab8f11a DDG |
764 | } |
765 | } | |
766 | ||
f0a70c88 DDG |
767 | return 0; |
768 | ||
ab31523c GH |
769 | unlock_out: |
770 | spin_unlock(&priv->lock); | |
771 | return err; | |
90b6f305 | 772 | |
a93e20a8 DC |
773 | out_unlock_put: |
774 | spin_unlock(&priv->lock); | |
90b6f305 | 775 | out_put_map: |
84e4075d DDG |
776 | if (use_ptemod) |
777 | map->vma = NULL; | |
90b6f305 DDG |
778 | gntdev_put_map(map); |
779 | return err; | |
ab31523c GH |
780 | } |
781 | ||
782 | static const struct file_operations gntdev_fops = { | |
783 | .owner = THIS_MODULE, | |
784 | .open = gntdev_open, | |
785 | .release = gntdev_release, | |
786 | .mmap = gntdev_mmap, | |
787 | .unlocked_ioctl = gntdev_ioctl | |
788 | }; | |
789 | ||
790 | static struct miscdevice gntdev_miscdev = { | |
791 | .minor = MISC_DYNAMIC_MINOR, | |
792 | .name = "xen/gntdev", | |
793 | .fops = &gntdev_fops, | |
794 | }; | |
795 | ||
796 | /* ------------------------------------------------------------------ */ | |
797 | ||
798 | static int __init gntdev_init(void) | |
799 | { | |
800 | int err; | |
801 | ||
802 | if (!xen_domain()) | |
803 | return -ENODEV; | |
804 | ||
aab8f11a DDG |
805 | use_ptemod = xen_pv_domain(); |
806 | ||
ab31523c GH |
807 | err = misc_register(&gntdev_miscdev); |
808 | if (err != 0) { | |
809 | printk(KERN_ERR "Could not register gntdev device\n"); | |
810 | return err; | |
811 | } | |
812 | return 0; | |
813 | } | |
814 | ||
815 | static void __exit gntdev_exit(void) | |
816 | { | |
817 | misc_deregister(&gntdev_miscdev); | |
818 | } | |
819 | ||
820 | module_init(gntdev_init); | |
821 | module_exit(gntdev_exit); | |
822 | ||
823 | /* ------------------------------------------------------------------ */ |