blob: dc495383ad7335b2022f65df051700ca180de7d3 [file] [log] [blame]
Gerd Hoffmannab315232010-12-14 18:40:46 +00001/******************************************************************************
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
Joe Perches283c0972013-06-28 03:21:41 -070022#define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt
23
Gerd Hoffmannab315232010-12-14 18:40:46 +000024#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>
35#include <linux/spinlock.h>
36#include <linux/slab.h>
Daniel De Graafaab8f112011-02-03 12:19:02 -050037#include <linux/highmem.h>
Gerd Hoffmannab315232010-12-14 18:40:46 +000038
39#include <xen/xen.h>
40#include <xen/grant_table.h>
Daniel De Graafca47cea2011-03-09 18:07:34 -050041#include <xen/balloon.h>
Gerd Hoffmannab315232010-12-14 18:40:46 +000042#include <xen/gntdev.h>
Daniel De Graafbdc612d2011-02-03 12:19:04 -050043#include <xen/events.h>
Julien Gralla9fd60e2015-06-17 15:28:02 +010044#include <xen/page.h>
Gerd Hoffmannab315232010-12-14 18:40:46 +000045#include <asm/xen/hypervisor.h>
46#include <asm/xen/hypercall.h>
Gerd Hoffmannab315232010-12-14 18:40:46 +000047
48MODULE_LICENSE("GPL");
49MODULE_AUTHOR("Derek G. Murray <Derek.Murray@cl.cam.ac.uk>, "
50 "Gerd Hoffmann <kraxel@redhat.com>");
51MODULE_DESCRIPTION("User-space granted page access driver");
52
Daniel De Graafef910822011-02-03 12:18:59 -050053static int limit = 1024*1024;
Gerd Hoffmannab315232010-12-14 18:40:46 +000054module_param(limit, int, 0644);
Daniel De Graafef910822011-02-03 12:18:59 -050055MODULE_PARM_DESC(limit, "Maximum number of grants that may be mapped by "
56 "the gntdev device");
57
58static atomic_t pages_mapped = ATOMIC_INIT(0);
Gerd Hoffmannab315232010-12-14 18:40:46 +000059
Daniel De Graafaab8f112011-02-03 12:19:02 -050060static int use_ptemod;
Daniel De Graaf16a1d022013-01-02 22:57:12 +000061#define populate_freeable_maps use_ptemod
Daniel De Graafaab8f112011-02-03 12:19:02 -050062
Gerd Hoffmannab315232010-12-14 18:40:46 +000063struct gntdev_priv {
Daniel De Graaf16a1d022013-01-02 22:57:12 +000064 /* maps with visible offsets in the file descriptor */
Gerd Hoffmannab315232010-12-14 18:40:46 +000065 struct list_head maps;
Daniel De Graaf16a1d022013-01-02 22:57:12 +000066 /* maps that are not visible; will be freed on munmap.
67 * Only populated if populate_freeable_maps == 1 */
68 struct list_head freeable_maps;
69 /* lock protects maps and freeable_maps */
David Vrabel1401c002015-01-09 18:06:12 +000070 struct mutex lock;
Gerd Hoffmannab315232010-12-14 18:40:46 +000071 struct mm_struct *mm;
72 struct mmu_notifier mn;
73};
74
Daniel De Graafbdc612d2011-02-03 12:19:04 -050075struct unmap_notify {
76 int flags;
77 /* Address relative to the start of the grant_map */
78 int addr;
79 int event;
80};
81
Gerd Hoffmannab315232010-12-14 18:40:46 +000082struct grant_map {
83 struct list_head next;
Gerd Hoffmannab315232010-12-14 18:40:46 +000084 struct vm_area_struct *vma;
85 int index;
86 int count;
87 int flags;
Daniel De Graaf68b025c2011-02-03 12:19:01 -050088 atomic_t users;
Daniel De Graafbdc612d2011-02-03 12:19:04 -050089 struct unmap_notify notify;
Gerd Hoffmannab315232010-12-14 18:40:46 +000090 struct ioctl_gntdev_grant_ref *grants;
91 struct gnttab_map_grant_ref *map_ops;
92 struct gnttab_unmap_grant_ref *unmap_ops;
Stefano Stabellini0930bba2011-09-29 11:57:56 +010093 struct gnttab_map_grant_ref *kmap_ops;
David Vrabel853d0282015-01-05 14:13:41 +000094 struct gnttab_unmap_grant_ref *kunmap_ops;
Stefano Stabellinia12b4eb2010-12-10 14:56:42 +000095 struct page **pages;
David Vrabeldab069c2014-12-18 14:59:07 +000096 unsigned long pages_vm_start;
Gerd Hoffmannab315232010-12-14 18:40:46 +000097};
98
Daniel De Graafaab8f112011-02-03 12:19:02 -050099static int unmap_grant_pages(struct grant_map *map, int offset, int pages);
100
Gerd Hoffmannab315232010-12-14 18:40:46 +0000101/* ------------------------------------------------------------------ */
102
103static void gntdev_print_maps(struct gntdev_priv *priv,
104 char *text, int text_index)
105{
106#ifdef DEBUG
107 struct grant_map *map;
108
Daniel De Graafef910822011-02-03 12:18:59 -0500109 pr_debug("%s: maps list (priv %p)\n", __func__, priv);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000110 list_for_each_entry(map, &priv->maps, next)
111 pr_debug(" index %2d, count %2d %s\n",
112 map->index, map->count,
113 map->index == text_index && text ? text : "");
114#endif
115}
116
David Vrabela67baeb2012-10-24 12:39:02 +0100117static void gntdev_free_map(struct grant_map *map)
118{
119 if (map == NULL)
120 return;
121
122 if (map->pages)
David Vrabelff4b1562015-01-08 18:06:01 +0000123 gnttab_free_pages(map->count, map->pages);
David Vrabela67baeb2012-10-24 12:39:02 +0100124 kfree(map->pages);
125 kfree(map->grants);
126 kfree(map->map_ops);
127 kfree(map->unmap_ops);
128 kfree(map->kmap_ops);
David Vrabel853d0282015-01-05 14:13:41 +0000129 kfree(map->kunmap_ops);
David Vrabela67baeb2012-10-24 12:39:02 +0100130 kfree(map);
131}
132
Gerd Hoffmannab315232010-12-14 18:40:46 +0000133static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count)
134{
135 struct grant_map *add;
Stefano Stabellinia12b4eb2010-12-10 14:56:42 +0000136 int i;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000137
138 add = kzalloc(sizeof(struct grant_map), GFP_KERNEL);
139 if (NULL == add)
140 return NULL;
141
Dan Carpenterfc6e0c32011-11-04 21:23:32 +0300142 add->grants = kcalloc(count, sizeof(add->grants[0]), GFP_KERNEL);
143 add->map_ops = kcalloc(count, sizeof(add->map_ops[0]), GFP_KERNEL);
144 add->unmap_ops = kcalloc(count, sizeof(add->unmap_ops[0]), GFP_KERNEL);
145 add->kmap_ops = kcalloc(count, sizeof(add->kmap_ops[0]), GFP_KERNEL);
David Vrabel853d0282015-01-05 14:13:41 +0000146 add->kunmap_ops = kcalloc(count, sizeof(add->kunmap_ops[0]), GFP_KERNEL);
Dan Carpenterfc6e0c32011-11-04 21:23:32 +0300147 add->pages = kcalloc(count, sizeof(add->pages[0]), GFP_KERNEL);
Stefano Stabellinia12b4eb2010-12-10 14:56:42 +0000148 if (NULL == add->grants ||
149 NULL == add->map_ops ||
150 NULL == add->unmap_ops ||
Stefano Stabellini0930bba2011-09-29 11:57:56 +0100151 NULL == add->kmap_ops ||
David Vrabel853d0282015-01-05 14:13:41 +0000152 NULL == add->kunmap_ops ||
Stefano Stabellinia12b4eb2010-12-10 14:56:42 +0000153 NULL == add->pages)
Gerd Hoffmannab315232010-12-14 18:40:46 +0000154 goto err;
155
David Vrabelff4b1562015-01-08 18:06:01 +0000156 if (gnttab_alloc_pages(count, add->pages))
Daniel De Graafca47cea2011-03-09 18:07:34 -0500157 goto err;
158
Stefano Stabellinia12b4eb2010-12-10 14:56:42 +0000159 for (i = 0; i < count; i++) {
Daniel De Graaf77c35ac2011-02-23 08:11:35 -0500160 add->map_ops[i].handle = -1;
161 add->unmap_ops[i].handle = -1;
Stefano Stabellini0930bba2011-09-29 11:57:56 +0100162 add->kmap_ops[i].handle = -1;
David Vrabel853d0282015-01-05 14:13:41 +0000163 add->kunmap_ops[i].handle = -1;
Stefano Stabellinia12b4eb2010-12-10 14:56:42 +0000164 }
165
Gerd Hoffmannab315232010-12-14 18:40:46 +0000166 add->index = 0;
167 add->count = count;
Daniel De Graaf68b025c2011-02-03 12:19:01 -0500168 atomic_set(&add->users, 1);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000169
Gerd Hoffmannab315232010-12-14 18:40:46 +0000170 return add;
171
172err:
David Vrabela67baeb2012-10-24 12:39:02 +0100173 gntdev_free_map(add);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000174 return NULL;
175}
176
177static void gntdev_add_map(struct gntdev_priv *priv, struct grant_map *add)
178{
179 struct grant_map *map;
180
181 list_for_each_entry(map, &priv->maps, next) {
182 if (add->index + add->count < map->index) {
183 list_add_tail(&add->next, &map->next);
184 goto done;
185 }
186 add->index = map->index + map->count;
187 }
188 list_add_tail(&add->next, &priv->maps);
189
190done:
Gerd Hoffmannab315232010-12-14 18:40:46 +0000191 gntdev_print_maps(priv, "[new]", add->index);
192}
193
194static struct grant_map *gntdev_find_map_index(struct gntdev_priv *priv,
195 int index, int count)
196{
197 struct grant_map *map;
198
199 list_for_each_entry(map, &priv->maps, next) {
200 if (map->index != index)
201 continue;
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500202 if (count && map->count != count)
Gerd Hoffmannab315232010-12-14 18:40:46 +0000203 continue;
204 return map;
205 }
206 return NULL;
207}
208
Daniel De Graaf16a1d022013-01-02 22:57:12 +0000209static void gntdev_put_map(struct gntdev_priv *priv, struct grant_map *map)
Gerd Hoffmannab315232010-12-14 18:40:46 +0000210{
211 if (!map)
212 return;
Stefano Stabellinia12b4eb2010-12-10 14:56:42 +0000213
Daniel De Graaf68b025c2011-02-03 12:19:01 -0500214 if (!atomic_dec_and_test(&map->users))
215 return;
216
217 atomic_sub(map->count, &pages_mapped);
218
Daniel De Graaf0cc678f2011-10-27 17:58:49 -0400219 if (map->notify.flags & UNMAP_NOTIFY_SEND_EVENT) {
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500220 notify_remote_via_evtchn(map->notify.event);
Daniel De Graaf0cc678f2011-10-27 17:58:49 -0400221 evtchn_put(map->notify.event);
222 }
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500223
Daniel De Graaf16a1d022013-01-02 22:57:12 +0000224 if (populate_freeable_maps && priv) {
David Vrabel1401c002015-01-09 18:06:12 +0000225 mutex_lock(&priv->lock);
Daniel De Graaf16a1d022013-01-02 22:57:12 +0000226 list_del(&map->next);
David Vrabel1401c002015-01-09 18:06:12 +0000227 mutex_unlock(&priv->lock);
Daniel De Graaf16a1d022013-01-02 22:57:12 +0000228 }
229
David Vrabela67baeb2012-10-24 12:39:02 +0100230 if (map->pages && !use_ptemod)
231 unmap_grant_pages(map, 0, map->count);
232 gntdev_free_map(map);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000233}
234
235/* ------------------------------------------------------------------ */
236
237static int find_grant_ptes(pte_t *pte, pgtable_t token,
238 unsigned long addr, void *data)
239{
240 struct grant_map *map = data;
241 unsigned int pgnr = (addr - map->vma->vm_start) >> PAGE_SHIFT;
Daniel De Graafaab8f112011-02-03 12:19:02 -0500242 int flags = map->flags | GNTMAP_application_map | GNTMAP_contains_pte;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000243 u64 pte_maddr;
244
245 BUG_ON(pgnr >= map->count);
Jeremy Fitzhardingeba5d1012010-12-08 10:54:32 -0800246 pte_maddr = arbitrary_virt_to_machine(pte).maddr;
247
David Vrabel923b2912014-12-18 14:56:54 +0000248 /*
249 * Set the PTE as special to force get_user_pages_fast() fall
250 * back to the slow path. If this is not supported as part of
251 * the grant map, it will be done afterwards.
252 */
253 if (xen_feature(XENFEAT_gnttab_map_avail_bits))
254 flags |= (1 << _GNTMAP_guest_avail0);
255
Daniel De Graafaab8f112011-02-03 12:19:02 -0500256 gnttab_set_map_op(&map->map_ops[pgnr], pte_maddr, flags,
Gerd Hoffmannab315232010-12-14 18:40:46 +0000257 map->grants[pgnr].ref,
258 map->grants[pgnr].domid);
Daniel De Graafaab8f112011-02-03 12:19:02 -0500259 gnttab_set_unmap_op(&map->unmap_ops[pgnr], pte_maddr, flags,
Daniel De Graaf77c35ac2011-02-23 08:11:35 -0500260 -1 /* handle */);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000261 return 0;
262}
263
David Vrabel923b2912014-12-18 14:56:54 +0000264#ifdef CONFIG_X86
265static int set_grant_ptes_as_special(pte_t *pte, pgtable_t token,
266 unsigned long addr, void *data)
267{
268 set_pte_at(current->mm, addr, pte, pte_mkspecial(*pte));
269 return 0;
270}
271#endif
272
Gerd Hoffmannab315232010-12-14 18:40:46 +0000273static int map_grant_pages(struct grant_map *map)
274{
275 int i, err = 0;
Daniel De Graafaab8f112011-02-03 12:19:02 -0500276
277 if (!use_ptemod) {
Daniel De Graaf12996fc2011-02-09 16:11:32 -0500278 /* Note: it could already be mapped */
Daniel De Graaf77c35ac2011-02-23 08:11:35 -0500279 if (map->map_ops[0].handle != -1)
Daniel De Graaf12996fc2011-02-09 16:11:32 -0500280 return 0;
Daniel De Graafaab8f112011-02-03 12:19:02 -0500281 for (i = 0; i < map->count; i++) {
Ian Campbell38eaeb02011-03-08 16:56:43 +0000282 unsigned long addr = (unsigned long)
Daniel De Graafaab8f112011-02-03 12:19:02 -0500283 pfn_to_kaddr(page_to_pfn(map->pages[i]));
284 gnttab_set_map_op(&map->map_ops[i], addr, map->flags,
285 map->grants[i].ref,
286 map->grants[i].domid);
287 gnttab_set_unmap_op(&map->unmap_ops[i], addr,
Daniel De Graaf77c35ac2011-02-23 08:11:35 -0500288 map->flags, -1 /* handle */);
Daniel De Graafaab8f112011-02-03 12:19:02 -0500289 }
Stefano Stabellini0930bba2011-09-29 11:57:56 +0100290 } else {
291 /*
292 * Setup the map_ops corresponding to the pte entries pointing
293 * to the kernel linear addresses of the struct pages.
294 * These ptes are completely different from the user ptes dealt
295 * with find_grant_ptes.
296 */
297 for (i = 0; i < map->count; i++) {
Stefano Stabellini0930bba2011-09-29 11:57:56 +0100298 unsigned long address = (unsigned long)
299 pfn_to_kaddr(page_to_pfn(map->pages[i]));
Stefano Stabellini0930bba2011-09-29 11:57:56 +0100300 BUG_ON(PageHighMem(map->pages[i]));
301
Stefano Stabelliniee072642013-07-23 17:23:54 +0000302 gnttab_set_map_op(&map->kmap_ops[i], address,
303 map->flags | GNTMAP_host_map,
Stefano Stabellini0930bba2011-09-29 11:57:56 +0100304 map->grants[i].ref,
305 map->grants[i].domid);
David Vrabel853d0282015-01-05 14:13:41 +0000306 gnttab_set_unmap_op(&map->kunmap_ops[i], address,
307 map->flags | GNTMAP_host_map, -1);
Stefano Stabellini0930bba2011-09-29 11:57:56 +0100308 }
Daniel De Graafaab8f112011-02-03 12:19:02 -0500309 }
Gerd Hoffmannab315232010-12-14 18:40:46 +0000310
311 pr_debug("map %d+%d\n", map->index, map->count);
Konrad Rzeszutek Wilke85fc982014-02-03 06:43:59 -0500312 err = gnttab_map_refs(map->map_ops, use_ptemod ? map->kmap_ops : NULL,
313 map->pages, map->count);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000314 if (err)
315 return err;
316
317 for (i = 0; i < map->count; i++) {
David Vrabel853d0282015-01-05 14:13:41 +0000318 if (map->map_ops[i].status) {
Gerd Hoffmannab315232010-12-14 18:40:46 +0000319 err = -EINVAL;
David Vrabel853d0282015-01-05 14:13:41 +0000320 continue;
Daniel De Graaf77c35ac2011-02-23 08:11:35 -0500321 }
David Vrabel853d0282015-01-05 14:13:41 +0000322
323 map->unmap_ops[i].handle = map->map_ops[i].handle;
324 if (use_ptemod)
325 map->kunmap_ops[i].handle = map->kmap_ops[i].handle;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000326 }
327 return err;
328}
329
Daniel De Graafb57c1862011-02-09 15:12:00 -0500330static int __unmap_grant_pages(struct grant_map *map, int offset, int pages)
Gerd Hoffmannab315232010-12-14 18:40:46 +0000331{
332 int i, err = 0;
Jennifer Herbert74528222015-01-05 15:07:46 +0000333 struct gntab_unmap_queue_data unmap_data;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000334
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500335 if (map->notify.flags & UNMAP_NOTIFY_CLEAR_BYTE) {
336 int pgno = (map->notify.addr >> PAGE_SHIFT);
Daniel De Graaf1affa982013-01-02 17:57:13 -0500337 if (pgno >= offset && pgno < offset + pages) {
338 /* No need for kmap, pages are in lowmem */
339 uint8_t *tmp = pfn_to_kaddr(page_to_pfn(map->pages[pgno]));
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500340 tmp[map->notify.addr & (PAGE_SIZE-1)] = 0;
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500341 map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE;
342 }
343 }
344
Jennifer Herbert74528222015-01-05 15:07:46 +0000345 unmap_data.unmap_ops = map->unmap_ops + offset;
346 unmap_data.kunmap_ops = use_ptemod ? map->kunmap_ops + offset : NULL;
347 unmap_data.pages = map->pages + offset;
348 unmap_data.count = pages;
349
Bob Liub44166c2015-04-03 14:42:59 +0800350 err = gnttab_unmap_refs_sync(&unmap_data);
351 if (err)
352 return err;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000353
354 for (i = 0; i < pages; i++) {
355 if (map->unmap_ops[offset+i].status)
356 err = -EINVAL;
Daniel De Graaf77c35ac2011-02-23 08:11:35 -0500357 pr_debug("unmap handle=%d st=%d\n",
358 map->unmap_ops[offset+i].handle,
359 map->unmap_ops[offset+i].status);
360 map->unmap_ops[offset+i].handle = -1;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000361 }
362 return err;
363}
364
Daniel De Graafb57c1862011-02-09 15:12:00 -0500365static int unmap_grant_pages(struct grant_map *map, int offset, int pages)
366{
367 int range, err = 0;
368
369 pr_debug("unmap %d+%d [%d+%d]\n", map->index, map->count, offset, pages);
370
371 /* It is possible the requested range will have a "hole" where we
372 * already unmapped some of the grants. Only unmap valid ranges.
373 */
374 while (pages && !err) {
Daniel De Graaf77c35ac2011-02-23 08:11:35 -0500375 while (pages && map->unmap_ops[offset].handle == -1) {
Daniel De Graafb57c1862011-02-09 15:12:00 -0500376 offset++;
377 pages--;
378 }
379 range = 0;
380 while (range < pages) {
Daniel De Graaf77c35ac2011-02-23 08:11:35 -0500381 if (map->unmap_ops[offset+range].handle == -1) {
Daniel De Graafb57c1862011-02-09 15:12:00 -0500382 range--;
383 break;
384 }
385 range++;
386 }
387 err = __unmap_grant_pages(map, offset, range);
388 offset += range;
389 pages -= range;
390 }
391
392 return err;
393}
394
Gerd Hoffmannab315232010-12-14 18:40:46 +0000395/* ------------------------------------------------------------------ */
396
Daniel De Graafd79647a2011-03-07 15:18:57 -0500397static void gntdev_vma_open(struct vm_area_struct *vma)
398{
399 struct grant_map *map = vma->vm_private_data;
400
401 pr_debug("gntdev_vma_open %p\n", vma);
402 atomic_inc(&map->users);
403}
404
Gerd Hoffmannab315232010-12-14 18:40:46 +0000405static void gntdev_vma_close(struct vm_area_struct *vma)
406{
407 struct grant_map *map = vma->vm_private_data;
Daniel De Graaf16a1d022013-01-02 22:57:12 +0000408 struct file *file = vma->vm_file;
409 struct gntdev_priv *priv = file->private_data;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000410
Daniel De Graafd79647a2011-03-07 15:18:57 -0500411 pr_debug("gntdev_vma_close %p\n", vma);
Daniel De Graaf2512f292013-01-02 22:57:11 +0000412 if (use_ptemod) {
Daniel De Graaf2512f292013-01-02 22:57:11 +0000413 /* It is possible that an mmu notifier could be running
414 * concurrently, so take priv->lock to ensure that the vma won't
415 * vanishing during the unmap_grant_pages call, since we will
416 * spin here until that completes. Such a concurrent call will
417 * not do any unmapping, since that has been done prior to
418 * closing the vma, but it may still iterate the unmap_ops list.
419 */
David Vrabel1401c002015-01-09 18:06:12 +0000420 mutex_lock(&priv->lock);
Daniel De Graaf2512f292013-01-02 22:57:11 +0000421 map->vma = NULL;
David Vrabel1401c002015-01-09 18:06:12 +0000422 mutex_unlock(&priv->lock);
Daniel De Graaf2512f292013-01-02 22:57:11 +0000423 }
Gerd Hoffmannab315232010-12-14 18:40:46 +0000424 vma->vm_private_data = NULL;
Daniel De Graaf16a1d022013-01-02 22:57:12 +0000425 gntdev_put_map(priv, map);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000426}
427
David Vrabeldab069c2014-12-18 14:59:07 +0000428static struct page *gntdev_vma_find_special_page(struct vm_area_struct *vma,
429 unsigned long addr)
430{
431 struct grant_map *map = vma->vm_private_data;
432
433 return map->pages[(addr - map->pages_vm_start) >> PAGE_SHIFT];
434}
435
Kirill A. Shutemov7cbea8d2015-09-09 15:39:26 -0700436static const struct vm_operations_struct gntdev_vmops = {
Daniel De Graafd79647a2011-03-07 15:18:57 -0500437 .open = gntdev_vma_open,
Gerd Hoffmannab315232010-12-14 18:40:46 +0000438 .close = gntdev_vma_close,
David Vrabeldab069c2014-12-18 14:59:07 +0000439 .find_special_page = gntdev_vma_find_special_page,
Gerd Hoffmannab315232010-12-14 18:40:46 +0000440};
441
442/* ------------------------------------------------------------------ */
443
Daniel De Graaf16a1d022013-01-02 22:57:12 +0000444static void unmap_if_in_range(struct grant_map *map,
445 unsigned long start, unsigned long end)
446{
447 unsigned long mstart, mend;
448 int err;
449
450 if (!map->vma)
451 return;
452 if (map->vma->vm_start >= end)
453 return;
454 if (map->vma->vm_end <= start)
455 return;
456 mstart = max(start, map->vma->vm_start);
457 mend = min(end, map->vma->vm_end);
458 pr_debug("map %d+%d (%lx %lx), range %lx %lx, mrange %lx %lx\n",
459 map->index, map->count,
460 map->vma->vm_start, map->vma->vm_end,
461 start, end, mstart, mend);
462 err = unmap_grant_pages(map,
463 (mstart - map->vma->vm_start) >> PAGE_SHIFT,
464 (mend - mstart) >> PAGE_SHIFT);
465 WARN_ON(err);
466}
467
Gerd Hoffmannab315232010-12-14 18:40:46 +0000468static void mn_invl_range_start(struct mmu_notifier *mn,
469 struct mm_struct *mm,
470 unsigned long start, unsigned long end)
471{
472 struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn);
473 struct grant_map *map;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000474
David Vrabel1401c002015-01-09 18:06:12 +0000475 mutex_lock(&priv->lock);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000476 list_for_each_entry(map, &priv->maps, next) {
Daniel De Graaf16a1d022013-01-02 22:57:12 +0000477 unmap_if_in_range(map, start, end);
478 }
479 list_for_each_entry(map, &priv->freeable_maps, next) {
480 unmap_if_in_range(map, start, end);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000481 }
David Vrabel1401c002015-01-09 18:06:12 +0000482 mutex_unlock(&priv->lock);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000483}
484
485static void mn_invl_page(struct mmu_notifier *mn,
486 struct mm_struct *mm,
487 unsigned long address)
488{
489 mn_invl_range_start(mn, mm, address, address + PAGE_SIZE);
490}
491
492static void mn_release(struct mmu_notifier *mn,
493 struct mm_struct *mm)
494{
495 struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn);
496 struct grant_map *map;
497 int err;
498
David Vrabel1401c002015-01-09 18:06:12 +0000499 mutex_lock(&priv->lock);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000500 list_for_each_entry(map, &priv->maps, next) {
501 if (!map->vma)
502 continue;
503 pr_debug("map %d+%d (%lx %lx)\n",
504 map->index, map->count,
505 map->vma->vm_start, map->vma->vm_end);
506 err = unmap_grant_pages(map, /* offset */ 0, map->count);
507 WARN_ON(err);
508 }
Daniel De Graaf16a1d022013-01-02 22:57:12 +0000509 list_for_each_entry(map, &priv->freeable_maps, next) {
510 if (!map->vma)
511 continue;
512 pr_debug("map %d+%d (%lx %lx)\n",
513 map->index, map->count,
514 map->vma->vm_start, map->vma->vm_end);
515 err = unmap_grant_pages(map, /* offset */ 0, map->count);
516 WARN_ON(err);
517 }
David Vrabel1401c002015-01-09 18:06:12 +0000518 mutex_unlock(&priv->lock);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000519}
520
Julia Lawallb9c0a922015-11-29 23:02:49 +0100521static const struct mmu_notifier_ops gntdev_mmu_ops = {
Gerd Hoffmannab315232010-12-14 18:40:46 +0000522 .release = mn_release,
523 .invalidate_page = mn_invl_page,
524 .invalidate_range_start = mn_invl_range_start,
525};
526
527/* ------------------------------------------------------------------ */
528
529static int gntdev_open(struct inode *inode, struct file *flip)
530{
531 struct gntdev_priv *priv;
532 int ret = 0;
533
534 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
535 if (!priv)
536 return -ENOMEM;
537
538 INIT_LIST_HEAD(&priv->maps);
Daniel De Graaf16a1d022013-01-02 22:57:12 +0000539 INIT_LIST_HEAD(&priv->freeable_maps);
David Vrabel1401c002015-01-09 18:06:12 +0000540 mutex_init(&priv->lock);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000541
Daniel De Graafaab8f112011-02-03 12:19:02 -0500542 if (use_ptemod) {
543 priv->mm = get_task_mm(current);
544 if (!priv->mm) {
545 kfree(priv);
546 return -ENOMEM;
547 }
548 priv->mn.ops = &gntdev_mmu_ops;
549 ret = mmu_notifier_register(&priv->mn, priv->mm);
550 mmput(priv->mm);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000551 }
Gerd Hoffmannab315232010-12-14 18:40:46 +0000552
553 if (ret) {
554 kfree(priv);
555 return ret;
556 }
557
558 flip->private_data = priv;
559 pr_debug("priv %p\n", priv);
560
561 return 0;
562}
563
564static int gntdev_release(struct inode *inode, struct file *flip)
565{
566 struct gntdev_priv *priv = flip->private_data;
567 struct grant_map *map;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000568
569 pr_debug("priv %p\n", priv);
570
Marek Marczykowski-Górecki30b03d02015-06-26 03:28:24 +0200571 mutex_lock(&priv->lock);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000572 while (!list_empty(&priv->maps)) {
573 map = list_entry(priv->maps.next, struct grant_map, next);
Daniel De Graaf68b025c2011-02-03 12:19:01 -0500574 list_del(&map->next);
Daniel De Graaf16a1d022013-01-02 22:57:12 +0000575 gntdev_put_map(NULL /* already removed */, map);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000576 }
Daniel De Graaf16a1d022013-01-02 22:57:12 +0000577 WARN_ON(!list_empty(&priv->freeable_maps));
Marek Marczykowski-Górecki30b03d02015-06-26 03:28:24 +0200578 mutex_unlock(&priv->lock);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000579
Daniel De Graafaab8f112011-02-03 12:19:02 -0500580 if (use_ptemod)
581 mmu_notifier_unregister(&priv->mn, priv->mm);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000582 kfree(priv);
583 return 0;
584}
585
586static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv,
587 struct ioctl_gntdev_map_grant_ref __user *u)
588{
589 struct ioctl_gntdev_map_grant_ref op;
590 struct grant_map *map;
591 int err;
592
593 if (copy_from_user(&op, u, sizeof(op)) != 0)
594 return -EFAULT;
595 pr_debug("priv %p, add %d\n", priv, op.count);
596 if (unlikely(op.count <= 0))
597 return -EINVAL;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000598
599 err = -ENOMEM;
600 map = gntdev_alloc_map(priv, op.count);
601 if (!map)
602 return err;
Daniel De Graafef910822011-02-03 12:18:59 -0500603
Daniel De Graaf68b025c2011-02-03 12:19:01 -0500604 if (unlikely(atomic_add_return(op.count, &pages_mapped) > limit)) {
605 pr_debug("can't map: over limit\n");
Daniel De Graaf16a1d022013-01-02 22:57:12 +0000606 gntdev_put_map(NULL, map);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000607 return err;
608 }
609
Daniel De Graaf68b025c2011-02-03 12:19:01 -0500610 if (copy_from_user(map->grants, &u->refs,
611 sizeof(map->grants[0]) * op.count) != 0) {
Daniel De Graaf16a1d022013-01-02 22:57:12 +0000612 gntdev_put_map(NULL, map);
613 return -EFAULT;
Daniel De Graafef910822011-02-03 12:18:59 -0500614 }
615
David Vrabel1401c002015-01-09 18:06:12 +0000616 mutex_lock(&priv->lock);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000617 gntdev_add_map(priv, map);
618 op.index = map->index << PAGE_SHIFT;
David Vrabel1401c002015-01-09 18:06:12 +0000619 mutex_unlock(&priv->lock);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000620
Daniel De Graaf68b025c2011-02-03 12:19:01 -0500621 if (copy_to_user(u, &op, sizeof(op)) != 0)
622 return -EFAULT;
623
Gerd Hoffmannab315232010-12-14 18:40:46 +0000624 return 0;
625}
626
627static long gntdev_ioctl_unmap_grant_ref(struct gntdev_priv *priv,
628 struct ioctl_gntdev_unmap_grant_ref __user *u)
629{
630 struct ioctl_gntdev_unmap_grant_ref op;
631 struct grant_map *map;
632 int err = -ENOENT;
633
634 if (copy_from_user(&op, u, sizeof(op)) != 0)
635 return -EFAULT;
636 pr_debug("priv %p, del %d+%d\n", priv, (int)op.index, (int)op.count);
637
David Vrabel1401c002015-01-09 18:06:12 +0000638 mutex_lock(&priv->lock);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000639 map = gntdev_find_map_index(priv, op.index >> PAGE_SHIFT, op.count);
Daniel De Graaf68b025c2011-02-03 12:19:01 -0500640 if (map) {
641 list_del(&map->next);
Daniel De Graaf16a1d022013-01-02 22:57:12 +0000642 if (populate_freeable_maps)
643 list_add_tail(&map->next, &priv->freeable_maps);
Daniel De Graaf68b025c2011-02-03 12:19:01 -0500644 err = 0;
645 }
David Vrabel1401c002015-01-09 18:06:12 +0000646 mutex_unlock(&priv->lock);
Daniel De Graaf1f1503b2011-10-11 15:16:06 -0400647 if (map)
Daniel De Graaf16a1d022013-01-02 22:57:12 +0000648 gntdev_put_map(priv, map);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000649 return err;
650}
651
652static long gntdev_ioctl_get_offset_for_vaddr(struct gntdev_priv *priv,
653 struct ioctl_gntdev_get_offset_for_vaddr __user *u)
654{
655 struct ioctl_gntdev_get_offset_for_vaddr op;
Daniel De Graafa8792112011-02-03 12:19:00 -0500656 struct vm_area_struct *vma;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000657 struct grant_map *map;
Daniel De Graaf2512f292013-01-02 22:57:11 +0000658 int rv = -EINVAL;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000659
660 if (copy_from_user(&op, u, sizeof(op)) != 0)
661 return -EFAULT;
662 pr_debug("priv %p, offset for vaddr %lx\n", priv, (unsigned long)op.vaddr);
663
Daniel De Graaf2512f292013-01-02 22:57:11 +0000664 down_read(&current->mm->mmap_sem);
Daniel De Graafa8792112011-02-03 12:19:00 -0500665 vma = find_vma(current->mm, op.vaddr);
666 if (!vma || vma->vm_ops != &gntdev_vmops)
Daniel De Graaf2512f292013-01-02 22:57:11 +0000667 goto out_unlock;
Daniel De Graafa8792112011-02-03 12:19:00 -0500668
669 map = vma->vm_private_data;
670 if (!map)
Daniel De Graaf2512f292013-01-02 22:57:11 +0000671 goto out_unlock;
Daniel De Graafa8792112011-02-03 12:19:00 -0500672
Gerd Hoffmannab315232010-12-14 18:40:46 +0000673 op.offset = map->index << PAGE_SHIFT;
674 op.count = map->count;
Daniel De Graaf2512f292013-01-02 22:57:11 +0000675 rv = 0;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000676
Daniel De Graaf2512f292013-01-02 22:57:11 +0000677 out_unlock:
678 up_read(&current->mm->mmap_sem);
679
680 if (rv == 0 && copy_to_user(u, &op, sizeof(op)) != 0)
Gerd Hoffmannab315232010-12-14 18:40:46 +0000681 return -EFAULT;
Daniel De Graaf2512f292013-01-02 22:57:11 +0000682 return rv;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000683}
684
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500685static long gntdev_ioctl_notify(struct gntdev_priv *priv, void __user *u)
686{
687 struct ioctl_gntdev_unmap_notify op;
688 struct grant_map *map;
689 int rc;
Daniel De Graaf0cc678f2011-10-27 17:58:49 -0400690 int out_flags;
691 unsigned int out_event;
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500692
693 if (copy_from_user(&op, u, sizeof(op)))
694 return -EFAULT;
695
696 if (op.action & ~(UNMAP_NOTIFY_CLEAR_BYTE|UNMAP_NOTIFY_SEND_EVENT))
697 return -EINVAL;
698
Daniel De Graaf0cc678f2011-10-27 17:58:49 -0400699 /* We need to grab a reference to the event channel we are going to use
700 * to send the notify before releasing the reference we may already have
701 * (if someone has called this ioctl twice). This is required so that
702 * it is possible to change the clear_byte part of the notification
703 * without disturbing the event channel part, which may now be the last
704 * reference to that event channel.
705 */
706 if (op.action & UNMAP_NOTIFY_SEND_EVENT) {
707 if (evtchn_get(op.event_channel_port))
708 return -EINVAL;
709 }
710
711 out_flags = op.action;
712 out_event = op.event_channel_port;
713
David Vrabel1401c002015-01-09 18:06:12 +0000714 mutex_lock(&priv->lock);
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500715
716 list_for_each_entry(map, &priv->maps, next) {
717 uint64_t begin = map->index << PAGE_SHIFT;
718 uint64_t end = (map->index + map->count) << PAGE_SHIFT;
719 if (op.index >= begin && op.index < end)
720 goto found;
721 }
722 rc = -ENOENT;
723 goto unlock_out;
724
725 found:
Daniel De Graaf9960be92011-02-09 18:15:50 -0500726 if ((op.action & UNMAP_NOTIFY_CLEAR_BYTE) &&
727 (map->flags & GNTMAP_readonly)) {
728 rc = -EINVAL;
729 goto unlock_out;
730 }
731
Daniel De Graaf0cc678f2011-10-27 17:58:49 -0400732 out_flags = map->notify.flags;
733 out_event = map->notify.event;
734
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500735 map->notify.flags = op.action;
736 map->notify.addr = op.index - (map->index << PAGE_SHIFT);
737 map->notify.event = op.event_channel_port;
Daniel De Graaf0cc678f2011-10-27 17:58:49 -0400738
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500739 rc = 0;
Daniel De Graaf0cc678f2011-10-27 17:58:49 -0400740
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500741 unlock_out:
David Vrabel1401c002015-01-09 18:06:12 +0000742 mutex_unlock(&priv->lock);
Daniel De Graaf0cc678f2011-10-27 17:58:49 -0400743
744 /* Drop the reference to the event channel we did not save in the map */
745 if (out_flags & UNMAP_NOTIFY_SEND_EVENT)
746 evtchn_put(out_event);
747
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500748 return rc;
749}
750
David Vrabela4cdb552014-12-02 16:13:26 +0000751#define GNTDEV_COPY_BATCH 24
752
753struct gntdev_copy_batch {
754 struct gnttab_copy ops[GNTDEV_COPY_BATCH];
755 struct page *pages[GNTDEV_COPY_BATCH];
756 s16 __user *status[GNTDEV_COPY_BATCH];
757 unsigned int nr_ops;
758 unsigned int nr_pages;
759};
760
761static int gntdev_get_page(struct gntdev_copy_batch *batch, void __user *virt,
762 bool writeable, unsigned long *gfn)
763{
764 unsigned long addr = (unsigned long)virt;
765 struct page *page;
766 unsigned long xen_pfn;
767 int ret;
768
769 ret = get_user_pages_fast(addr, 1, writeable, &page);
770 if (ret < 0)
771 return ret;
772
773 batch->pages[batch->nr_pages++] = page;
774
775 xen_pfn = page_to_xen_pfn(page) + XEN_PFN_DOWN(addr & ~PAGE_MASK);
776 *gfn = pfn_to_gfn(xen_pfn);
777
778 return 0;
779}
780
781static void gntdev_put_pages(struct gntdev_copy_batch *batch)
782{
783 unsigned int i;
784
785 for (i = 0; i < batch->nr_pages; i++)
786 put_page(batch->pages[i]);
787 batch->nr_pages = 0;
788}
789
790static int gntdev_copy(struct gntdev_copy_batch *batch)
791{
792 unsigned int i;
793
794 gnttab_batch_copy(batch->ops, batch->nr_ops);
795 gntdev_put_pages(batch);
796
797 /*
798 * For each completed op, update the status if the op failed
799 * and all previous ops for the segment were successful.
800 */
801 for (i = 0; i < batch->nr_ops; i++) {
802 s16 status = batch->ops[i].status;
803 s16 old_status;
804
805 if (status == GNTST_okay)
806 continue;
807
808 if (__get_user(old_status, batch->status[i]))
809 return -EFAULT;
810
811 if (old_status != GNTST_okay)
812 continue;
813
814 if (__put_user(status, batch->status[i]))
815 return -EFAULT;
816 }
817
818 batch->nr_ops = 0;
819 return 0;
820}
821
822static int gntdev_grant_copy_seg(struct gntdev_copy_batch *batch,
823 struct gntdev_grant_copy_segment *seg,
824 s16 __user *status)
825{
826 uint16_t copied = 0;
827
828 /*
829 * Disallow local -> local copies since there is only space in
830 * batch->pages for one page per-op and this would be a very
831 * expensive memcpy().
832 */
833 if (!(seg->flags & (GNTCOPY_source_gref | GNTCOPY_dest_gref)))
834 return -EINVAL;
835
836 /* Can't cross page if source/dest is a grant ref. */
837 if (seg->flags & GNTCOPY_source_gref) {
838 if (seg->source.foreign.offset + seg->len > XEN_PAGE_SIZE)
839 return -EINVAL;
840 }
841 if (seg->flags & GNTCOPY_dest_gref) {
842 if (seg->dest.foreign.offset + seg->len > XEN_PAGE_SIZE)
843 return -EINVAL;
844 }
845
846 if (put_user(GNTST_okay, status))
847 return -EFAULT;
848
849 while (copied < seg->len) {
850 struct gnttab_copy *op;
851 void __user *virt;
852 size_t len, off;
853 unsigned long gfn;
854 int ret;
855
856 if (batch->nr_ops >= GNTDEV_COPY_BATCH) {
857 ret = gntdev_copy(batch);
858 if (ret < 0)
859 return ret;
860 }
861
862 len = seg->len - copied;
863
864 op = &batch->ops[batch->nr_ops];
865 op->flags = 0;
866
867 if (seg->flags & GNTCOPY_source_gref) {
868 op->source.u.ref = seg->source.foreign.ref;
869 op->source.domid = seg->source.foreign.domid;
870 op->source.offset = seg->source.foreign.offset + copied;
871 op->flags |= GNTCOPY_source_gref;
872 } else {
873 virt = seg->source.virt + copied;
874 off = (unsigned long)virt & ~XEN_PAGE_MASK;
875 len = min(len, (size_t)XEN_PAGE_SIZE - off);
876
877 ret = gntdev_get_page(batch, virt, false, &gfn);
878 if (ret < 0)
879 return ret;
880
881 op->source.u.gmfn = gfn;
882 op->source.domid = DOMID_SELF;
883 op->source.offset = off;
884 }
885
886 if (seg->flags & GNTCOPY_dest_gref) {
887 op->dest.u.ref = seg->dest.foreign.ref;
888 op->dest.domid = seg->dest.foreign.domid;
889 op->dest.offset = seg->dest.foreign.offset + copied;
890 op->flags |= GNTCOPY_dest_gref;
891 } else {
892 virt = seg->dest.virt + copied;
893 off = (unsigned long)virt & ~XEN_PAGE_MASK;
894 len = min(len, (size_t)XEN_PAGE_SIZE - off);
895
896 ret = gntdev_get_page(batch, virt, true, &gfn);
897 if (ret < 0)
898 return ret;
899
900 op->dest.u.gmfn = gfn;
901 op->dest.domid = DOMID_SELF;
902 op->dest.offset = off;
903 }
904
905 op->len = len;
906 copied += len;
907
908 batch->status[batch->nr_ops] = status;
909 batch->nr_ops++;
910 }
911
912 return 0;
913}
914
915static long gntdev_ioctl_grant_copy(struct gntdev_priv *priv, void __user *u)
916{
917 struct ioctl_gntdev_grant_copy copy;
918 struct gntdev_copy_batch batch;
919 unsigned int i;
920 int ret = 0;
921
922 if (copy_from_user(&copy, u, sizeof(copy)))
923 return -EFAULT;
924
925 batch.nr_ops = 0;
926 batch.nr_pages = 0;
927
928 for (i = 0; i < copy.count; i++) {
929 struct gntdev_grant_copy_segment seg;
930
931 if (copy_from_user(&seg, &copy.segments[i], sizeof(seg))) {
932 ret = -EFAULT;
933 goto out;
934 }
935
936 ret = gntdev_grant_copy_seg(&batch, &seg, &copy.segments[i].status);
937 if (ret < 0)
938 goto out;
939
940 cond_resched();
941 }
942 if (batch.nr_ops)
943 ret = gntdev_copy(&batch);
944 return ret;
945
946 out:
947 gntdev_put_pages(&batch);
948 return ret;
949}
950
Gerd Hoffmannab315232010-12-14 18:40:46 +0000951static long gntdev_ioctl(struct file *flip,
952 unsigned int cmd, unsigned long arg)
953{
954 struct gntdev_priv *priv = flip->private_data;
955 void __user *ptr = (void __user *)arg;
956
957 switch (cmd) {
958 case IOCTL_GNTDEV_MAP_GRANT_REF:
959 return gntdev_ioctl_map_grant_ref(priv, ptr);
960
961 case IOCTL_GNTDEV_UNMAP_GRANT_REF:
962 return gntdev_ioctl_unmap_grant_ref(priv, ptr);
963
964 case IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR:
965 return gntdev_ioctl_get_offset_for_vaddr(priv, ptr);
966
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500967 case IOCTL_GNTDEV_SET_UNMAP_NOTIFY:
968 return gntdev_ioctl_notify(priv, ptr);
969
David Vrabela4cdb552014-12-02 16:13:26 +0000970 case IOCTL_GNTDEV_GRANT_COPY:
971 return gntdev_ioctl_grant_copy(priv, ptr);
972
Gerd Hoffmannab315232010-12-14 18:40:46 +0000973 default:
974 pr_debug("priv %p, unknown cmd %x\n", priv, cmd);
975 return -ENOIOCTLCMD;
976 }
977
978 return 0;
979}
980
981static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
982{
983 struct gntdev_priv *priv = flip->private_data;
984 int index = vma->vm_pgoff;
985 int count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
986 struct grant_map *map;
Daniel De Graafaab8f112011-02-03 12:19:02 -0500987 int i, err = -EINVAL;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000988
989 if ((vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_SHARED))
990 return -EINVAL;
991
992 pr_debug("map %d+%d at %lx (pgoff %lx)\n",
993 index, count, vma->vm_start, vma->vm_pgoff);
994
David Vrabel1401c002015-01-09 18:06:12 +0000995 mutex_lock(&priv->lock);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000996 map = gntdev_find_map_index(priv, index, count);
997 if (!map)
998 goto unlock_out;
Daniel De Graafaab8f112011-02-03 12:19:02 -0500999 if (use_ptemod && map->vma)
Gerd Hoffmannab315232010-12-14 18:40:46 +00001000 goto unlock_out;
Daniel De Graafaab8f112011-02-03 12:19:02 -05001001 if (use_ptemod && priv->mm != vma->vm_mm) {
Joe Perches283c0972013-06-28 03:21:41 -07001002 pr_warn("Huh? Other mm?\n");
Gerd Hoffmannab315232010-12-14 18:40:46 +00001003 goto unlock_out;
1004 }
1005
Daniel De Graaf68b025c2011-02-03 12:19:01 -05001006 atomic_inc(&map->users);
1007
Gerd Hoffmannab315232010-12-14 18:40:46 +00001008 vma->vm_ops = &gntdev_vmops;
1009
Boris Ostrovsky9c17d962015-11-10 15:10:33 -05001010 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP | VM_IO;
Daniel De Graafd79647a2011-03-07 15:18:57 -05001011
1012 if (use_ptemod)
Stefano Stabellinie8e937b2012-04-03 18:05:47 +01001013 vma->vm_flags |= VM_DONTCOPY;
Gerd Hoffmannab315232010-12-14 18:40:46 +00001014
1015 vma->vm_private_data = map;
Gerd Hoffmannab315232010-12-14 18:40:46 +00001016
Daniel De Graafaab8f112011-02-03 12:19:02 -05001017 if (use_ptemod)
1018 map->vma = vma;
1019
Daniel De Graaf12996fc2011-02-09 16:11:32 -05001020 if (map->flags) {
1021 if ((vma->vm_flags & VM_WRITE) &&
1022 (map->flags & GNTMAP_readonly))
Dan Carpentera93e20a2011-03-19 08:45:43 +03001023 goto out_unlock_put;
Daniel De Graaf12996fc2011-02-09 16:11:32 -05001024 } else {
1025 map->flags = GNTMAP_host_map;
1026 if (!(vma->vm_flags & VM_WRITE))
1027 map->flags |= GNTMAP_readonly;
1028 }
Gerd Hoffmannab315232010-12-14 18:40:46 +00001029
David Vrabel1401c002015-01-09 18:06:12 +00001030 mutex_unlock(&priv->lock);
Daniel De Graaff0a70c82011-01-07 11:51:47 +00001031
Daniel De Graafaab8f112011-02-03 12:19:02 -05001032 if (use_ptemod) {
1033 err = apply_to_page_range(vma->vm_mm, vma->vm_start,
1034 vma->vm_end - vma->vm_start,
1035 find_grant_ptes, map);
1036 if (err) {
Joe Perches283c0972013-06-28 03:21:41 -07001037 pr_warn("find_grant_ptes() failure.\n");
Daniel De Graaf90b6f302011-02-03 14:16:54 -05001038 goto out_put_map;
Daniel De Graafaab8f112011-02-03 12:19:02 -05001039 }
Gerd Hoffmannab315232010-12-14 18:40:46 +00001040 }
1041
1042 err = map_grant_pages(map);
Daniel De Graaf90b6f302011-02-03 14:16:54 -05001043 if (err)
1044 goto out_put_map;
Daniel De Graaff0a70c82011-01-07 11:51:47 +00001045
Daniel De Graafaab8f112011-02-03 12:19:02 -05001046 if (!use_ptemod) {
1047 for (i = 0; i < count; i++) {
1048 err = vm_insert_page(vma, vma->vm_start + i*PAGE_SIZE,
1049 map->pages[i]);
1050 if (err)
Daniel De Graaf90b6f302011-02-03 14:16:54 -05001051 goto out_put_map;
Daniel De Graafaab8f112011-02-03 12:19:02 -05001052 }
David Vrabel923b2912014-12-18 14:56:54 +00001053 } else {
1054#ifdef CONFIG_X86
1055 /*
1056 * If the PTEs were not made special by the grant map
1057 * hypercall, do so here.
1058 *
1059 * This is racy since the mapping is already visible
1060 * to userspace but userspace should be well-behaved
1061 * enough to not touch it until the mmap() call
1062 * returns.
1063 */
1064 if (!xen_feature(XENFEAT_gnttab_map_avail_bits)) {
1065 apply_to_page_range(vma->vm_mm, vma->vm_start,
1066 vma->vm_end - vma->vm_start,
1067 set_grant_ptes_as_special, NULL);
1068 }
1069#endif
David Vrabeldab069c2014-12-18 14:59:07 +00001070 map->pages_vm_start = vma->vm_start;
Daniel De Graafaab8f112011-02-03 12:19:02 -05001071 }
1072
Daniel De Graaff0a70c82011-01-07 11:51:47 +00001073 return 0;
1074
Gerd Hoffmannab315232010-12-14 18:40:46 +00001075unlock_out:
David Vrabel1401c002015-01-09 18:06:12 +00001076 mutex_unlock(&priv->lock);
Gerd Hoffmannab315232010-12-14 18:40:46 +00001077 return err;
Daniel De Graaf90b6f302011-02-03 14:16:54 -05001078
Dan Carpentera93e20a2011-03-19 08:45:43 +03001079out_unlock_put:
David Vrabel1401c002015-01-09 18:06:12 +00001080 mutex_unlock(&priv->lock);
Daniel De Graaf90b6f302011-02-03 14:16:54 -05001081out_put_map:
Daniel De Graaf84e40752011-02-09 15:11:59 -05001082 if (use_ptemod)
1083 map->vma = NULL;
Daniel De Graaf16a1d022013-01-02 22:57:12 +00001084 gntdev_put_map(priv, map);
Daniel De Graaf90b6f302011-02-03 14:16:54 -05001085 return err;
Gerd Hoffmannab315232010-12-14 18:40:46 +00001086}
1087
1088static const struct file_operations gntdev_fops = {
1089 .owner = THIS_MODULE,
1090 .open = gntdev_open,
1091 .release = gntdev_release,
1092 .mmap = gntdev_mmap,
1093 .unlocked_ioctl = gntdev_ioctl
1094};
1095
1096static struct miscdevice gntdev_miscdev = {
1097 .minor = MISC_DYNAMIC_MINOR,
1098 .name = "xen/gntdev",
1099 .fops = &gntdev_fops,
1100};
1101
1102/* ------------------------------------------------------------------ */
1103
1104static int __init gntdev_init(void)
1105{
1106 int err;
1107
1108 if (!xen_domain())
1109 return -ENODEV;
1110
Konrad Rzeszutek Wilk6926f6d2014-01-03 10:20:18 -05001111 use_ptemod = !xen_feature(XENFEAT_auto_translated_physmap);
Daniel De Graafaab8f112011-02-03 12:19:02 -05001112
Gerd Hoffmannab315232010-12-14 18:40:46 +00001113 err = misc_register(&gntdev_miscdev);
1114 if (err != 0) {
Joe Perches283c0972013-06-28 03:21:41 -07001115 pr_err("Could not register gntdev device\n");
Gerd Hoffmannab315232010-12-14 18:40:46 +00001116 return err;
1117 }
1118 return 0;
1119}
1120
1121static void __exit gntdev_exit(void)
1122{
1123 misc_deregister(&gntdev_miscdev);
1124}
1125
1126module_init(gntdev_init);
1127module_exit(gntdev_exit);
1128
1129/* ------------------------------------------------------------------ */