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ad9a8612 JF |
1 | /****************************************************************************** |
2 | * grant_table.c | |
3 | * | |
4 | * Granting foreign access to our memory reservation. | |
5 | * | |
6 | * Copyright (c) 2005-2006, Christopher Clark | |
7 | * Copyright (c) 2004-2005, K A Fraser | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU General Public License version 2 | |
11 | * as published by the Free Software Foundation; or, when distributed | |
12 | * separately from the Linux kernel or incorporated into other | |
13 | * software packages, subject to the following license: | |
14 | * | |
15 | * Permission is hereby granted, free of charge, to any person obtaining a copy | |
16 | * of this source file (the "Software"), to deal in the Software without | |
17 | * restriction, including without limitation the rights to use, copy, modify, | |
18 | * merge, publish, distribute, sublicense, and/or sell copies of the Software, | |
19 | * and to permit persons to whom the Software is furnished to do so, subject to | |
20 | * the following conditions: | |
21 | * | |
22 | * The above copyright notice and this permission notice shall be included in | |
23 | * all copies or substantial portions of the Software. | |
24 | * | |
25 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
26 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
27 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE | |
28 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
29 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING | |
30 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS | |
31 | * IN THE SOFTWARE. | |
32 | */ | |
33 | ||
34 | #include <linux/module.h> | |
35 | #include <linux/sched.h> | |
36 | #include <linux/mm.h> | |
5a0e3ad6 | 37 | #include <linux/slab.h> |
ad9a8612 JF |
38 | #include <linux/vmalloc.h> |
39 | #include <linux/uaccess.h> | |
183d03cc | 40 | #include <linux/io.h> |
f62805f1 | 41 | #include <linux/hardirq.h> |
ad9a8612 | 42 | |
1ccbf534 | 43 | #include <xen/xen.h> |
ad9a8612 JF |
44 | #include <xen/interface/xen.h> |
45 | #include <xen/page.h> | |
46 | #include <xen/grant_table.h> | |
183d03cc | 47 | #include <xen/interface/memory.h> |
85ff6acb | 48 | #include <xen/hvc-console.h> |
ecbf29cd | 49 | #include <asm/xen/hypercall.h> |
4d9310e3 | 50 | #include <asm/xen/interface.h> |
ad9a8612 JF |
51 | |
52 | #include <asm/pgtable.h> | |
53 | #include <asm/sync_bitops.h> | |
54 | ||
ad9a8612 JF |
55 | /* External tools reserve first few grant table entries. */ |
56 | #define NR_RESERVED_ENTRIES 8 | |
57 | #define GNTTAB_LIST_END 0xffffffff | |
85ff6acb AL |
58 | #define GREFS_PER_GRANT_FRAME \ |
59 | (grant_table_version == 1 ? \ | |
60 | (PAGE_SIZE / sizeof(struct grant_entry_v1)) : \ | |
61 | (PAGE_SIZE / sizeof(union grant_entry_v2))) | |
ad9a8612 JF |
62 | |
63 | static grant_ref_t **gnttab_list; | |
64 | static unsigned int nr_grant_frames; | |
65 | static unsigned int boot_max_nr_grant_frames; | |
66 | static int gnttab_free_count; | |
67 | static grant_ref_t gnttab_free_head; | |
68 | static DEFINE_SPINLOCK(gnttab_list_lock); | |
183d03cc SS |
69 | unsigned long xen_hvm_resume_frames; |
70 | EXPORT_SYMBOL_GPL(xen_hvm_resume_frames); | |
ad9a8612 | 71 | |
0f9f5a95 AL |
72 | static union { |
73 | struct grant_entry_v1 *v1; | |
85ff6acb | 74 | union grant_entry_v2 *v2; |
0f9f5a95 AL |
75 | void *addr; |
76 | } gnttab_shared; | |
77 | ||
78 | /*This is a structure of function pointers for grant table*/ | |
79 | struct gnttab_ops { | |
80 | /* | |
9dbc71d5 AL |
81 | * Mapping a list of frames for storing grant entries. Frames parameter |
82 | * is used to store grant table address when grant table being setup, | |
83 | * nr_gframes is the number of frames to map grant table. Returning | |
84 | * GNTST_okay means success and negative value means failure. | |
0f9f5a95 | 85 | */ |
9dbc71d5 | 86 | int (*map_frames)(unsigned long *frames, unsigned int nr_gframes); |
0f9f5a95 AL |
87 | /* |
88 | * Release a list of frames which are mapped in map_frames for grant | |
89 | * entry status. | |
90 | */ | |
91 | void (*unmap_frames)(void); | |
92 | /* | |
9dbc71d5 AL |
93 | * Introducing a valid entry into the grant table, granting the frame of |
94 | * this grant entry to domain for accessing or transfering. Ref | |
95 | * parameter is reference of this introduced grant entry, domid is id of | |
96 | * granted domain, frame is the page frame to be granted, and flags is | |
97 | * status of the grant entry to be updated. | |
0f9f5a95 | 98 | */ |
9dbc71d5 AL |
99 | void (*update_entry)(grant_ref_t ref, domid_t domid, |
100 | unsigned long frame, unsigned flags); | |
0f9f5a95 | 101 | /* |
9dbc71d5 AL |
102 | * Stop granting a grant entry to domain for accessing. Ref parameter is |
103 | * reference of a grant entry whose grant access will be stopped, | |
104 | * readonly is not in use in this function. If the grant entry is | |
0f9f5a95 AL |
105 | * currently mapped for reading or writing, just return failure(==0) |
106 | * directly and don't tear down the grant access. Otherwise, stop grant | |
107 | * access for this entry and return success(==1). | |
108 | */ | |
9dbc71d5 | 109 | int (*end_foreign_access_ref)(grant_ref_t ref, int readonly); |
0f9f5a95 | 110 | /* |
9dbc71d5 AL |
111 | * Stop granting a grant entry to domain for transfer. Ref parameter is |
112 | * reference of a grant entry whose grant transfer will be stopped. If | |
113 | * tranfer has not started, just reclaim the grant entry and return | |
114 | * failure(==0). Otherwise, wait for the transfer to complete and then | |
115 | * return the frame. | |
0f9f5a95 | 116 | */ |
9dbc71d5 | 117 | unsigned long (*end_foreign_transfer_ref)(grant_ref_t ref); |
0f9f5a95 | 118 | /* |
9dbc71d5 | 119 | * Query the status of a grant entry. Ref parameter is reference of |
0f9f5a95 AL |
120 | * queried grant entry, return value is the status of queried entry. |
121 | * Detailed status(writing/reading) can be gotten from the return value | |
122 | * by bit operations. | |
123 | */ | |
9dbc71d5 | 124 | int (*query_foreign_access)(grant_ref_t ref); |
6666754b AL |
125 | /* |
126 | * Grant a domain to access a range of bytes within the page referred by | |
127 | * an available grant entry. Ref parameter is reference of a grant entry | |
128 | * which will be sub-page accessed, domid is id of grantee domain, frame | |
129 | * is frame address of subpage grant, flags is grant type and flag | |
130 | * information, page_off is offset of the range of bytes, and length is | |
131 | * length of bytes to be accessed. | |
132 | */ | |
133 | void (*update_subpage_entry)(grant_ref_t ref, domid_t domid, | |
134 | unsigned long frame, int flags, | |
135 | unsigned page_off, unsigned length); | |
9438ce9d AL |
136 | /* |
137 | * Redirect an available grant entry on domain A to another grant | |
138 | * reference of domain B, then allow domain C to use grant reference | |
139 | * of domain B transitively. Ref parameter is an available grant entry | |
140 | * reference on domain A, domid is id of domain C which accesses grant | |
141 | * entry transitively, flags is grant type and flag information, | |
142 | * trans_domid is id of domain B whose grant entry is finally accessed | |
143 | * transitively, trans_gref is grant entry transitive reference of | |
144 | * domain B. | |
145 | */ | |
146 | void (*update_trans_entry)(grant_ref_t ref, domid_t domid, int flags, | |
147 | domid_t trans_domid, grant_ref_t trans_gref); | |
0f9f5a95 AL |
148 | }; |
149 | ||
150 | static struct gnttab_ops *gnttab_interface; | |
151 | ||
85ff6acb AL |
152 | /*This reflects status of grant entries, so act as a global value*/ |
153 | static grant_status_t *grstatus; | |
154 | ||
0f9f5a95 | 155 | static int grant_table_version; |
ad9a8612 JF |
156 | |
157 | static struct gnttab_free_callback *gnttab_free_callback_list; | |
158 | ||
159 | static int gnttab_expand(unsigned int req_entries); | |
160 | ||
161 | #define RPP (PAGE_SIZE / sizeof(grant_ref_t)) | |
85ff6acb | 162 | #define SPP (PAGE_SIZE / sizeof(grant_status_t)) |
ad9a8612 JF |
163 | |
164 | static inline grant_ref_t *__gnttab_entry(grant_ref_t entry) | |
165 | { | |
166 | return &gnttab_list[(entry) / RPP][(entry) % RPP]; | |
167 | } | |
168 | /* This can be used as an l-value */ | |
169 | #define gnttab_entry(entry) (*__gnttab_entry(entry)) | |
170 | ||
171 | static int get_free_entries(unsigned count) | |
172 | { | |
173 | unsigned long flags; | |
272800dc | 174 | int ref, rc = 0; |
ad9a8612 JF |
175 | grant_ref_t head; |
176 | ||
177 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
178 | ||
179 | if ((gnttab_free_count < count) && | |
180 | ((rc = gnttab_expand(count - gnttab_free_count)) < 0)) { | |
181 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
182 | return rc; | |
183 | } | |
184 | ||
185 | ref = head = gnttab_free_head; | |
186 | gnttab_free_count -= count; | |
187 | while (count-- > 1) | |
188 | head = gnttab_entry(head); | |
189 | gnttab_free_head = gnttab_entry(head); | |
190 | gnttab_entry(head) = GNTTAB_LIST_END; | |
191 | ||
192 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
193 | ||
194 | return ref; | |
195 | } | |
196 | ||
197 | static void do_free_callbacks(void) | |
198 | { | |
199 | struct gnttab_free_callback *callback, *next; | |
200 | ||
201 | callback = gnttab_free_callback_list; | |
202 | gnttab_free_callback_list = NULL; | |
203 | ||
204 | while (callback != NULL) { | |
205 | next = callback->next; | |
206 | if (gnttab_free_count >= callback->count) { | |
207 | callback->next = NULL; | |
208 | callback->fn(callback->arg); | |
209 | } else { | |
210 | callback->next = gnttab_free_callback_list; | |
211 | gnttab_free_callback_list = callback; | |
212 | } | |
213 | callback = next; | |
214 | } | |
215 | } | |
216 | ||
217 | static inline void check_free_callbacks(void) | |
218 | { | |
219 | if (unlikely(gnttab_free_callback_list)) | |
220 | do_free_callbacks(); | |
221 | } | |
222 | ||
223 | static void put_free_entry(grant_ref_t ref) | |
224 | { | |
225 | unsigned long flags; | |
226 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
227 | gnttab_entry(ref) = gnttab_free_head; | |
228 | gnttab_free_head = ref; | |
229 | gnttab_free_count++; | |
230 | check_free_callbacks(); | |
231 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
232 | } | |
233 | ||
0f9f5a95 | 234 | /* |
85ff6acb | 235 | * Following applies to gnttab_update_entry_v1 and gnttab_update_entry_v2. |
0f9f5a95 AL |
236 | * Introducing a valid entry into the grant table: |
237 | * 1. Write ent->domid. | |
238 | * 2. Write ent->frame: | |
239 | * GTF_permit_access: Frame to which access is permitted. | |
240 | * GTF_accept_transfer: Pseudo-phys frame slot being filled by new | |
241 | * frame, or zero if none. | |
242 | * 3. Write memory barrier (WMB). | |
243 | * 4. Write ent->flags, inc. valid type. | |
244 | */ | |
245 | static void gnttab_update_entry_v1(grant_ref_t ref, domid_t domid, | |
246 | unsigned long frame, unsigned flags) | |
ad9a8612 | 247 | { |
0f9f5a95 AL |
248 | gnttab_shared.v1[ref].domid = domid; |
249 | gnttab_shared.v1[ref].frame = frame; | |
ad9a8612 | 250 | wmb(); |
0f9f5a95 | 251 | gnttab_shared.v1[ref].flags = flags; |
ad9a8612 JF |
252 | } |
253 | ||
85ff6acb AL |
254 | static void gnttab_update_entry_v2(grant_ref_t ref, domid_t domid, |
255 | unsigned long frame, unsigned flags) | |
256 | { | |
257 | gnttab_shared.v2[ref].hdr.domid = domid; | |
258 | gnttab_shared.v2[ref].full_page.frame = frame; | |
259 | wmb(); | |
260 | gnttab_shared.v2[ref].hdr.flags = GTF_permit_access | flags; | |
261 | } | |
262 | ||
ad9a8612 JF |
263 | /* |
264 | * Public grant-issuing interface functions | |
265 | */ | |
266 | void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid, | |
267 | unsigned long frame, int readonly) | |
268 | { | |
0f9f5a95 | 269 | gnttab_interface->update_entry(ref, domid, frame, |
ad9a8612 JF |
270 | GTF_permit_access | (readonly ? GTF_readonly : 0)); |
271 | } | |
272 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_ref); | |
273 | ||
274 | int gnttab_grant_foreign_access(domid_t domid, unsigned long frame, | |
275 | int readonly) | |
276 | { | |
277 | int ref; | |
278 | ||
279 | ref = get_free_entries(1); | |
280 | if (unlikely(ref < 0)) | |
281 | return -ENOSPC; | |
282 | ||
283 | gnttab_grant_foreign_access_ref(ref, domid, frame, readonly); | |
284 | ||
285 | return ref; | |
286 | } | |
287 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access); | |
288 | ||
6666754b AL |
289 | void gnttab_update_subpage_entry_v2(grant_ref_t ref, domid_t domid, |
290 | unsigned long frame, int flags, | |
291 | unsigned page_off, | |
292 | unsigned length) | |
293 | { | |
294 | gnttab_shared.v2[ref].sub_page.frame = frame; | |
295 | gnttab_shared.v2[ref].sub_page.page_off = page_off; | |
296 | gnttab_shared.v2[ref].sub_page.length = length; | |
297 | gnttab_shared.v2[ref].hdr.domid = domid; | |
298 | wmb(); | |
299 | gnttab_shared.v2[ref].hdr.flags = | |
300 | GTF_permit_access | GTF_sub_page | flags; | |
301 | } | |
302 | ||
303 | int gnttab_grant_foreign_access_subpage_ref(grant_ref_t ref, domid_t domid, | |
304 | unsigned long frame, int flags, | |
305 | unsigned page_off, | |
306 | unsigned length) | |
307 | { | |
308 | if (flags & (GTF_accept_transfer | GTF_reading | | |
309 | GTF_writing | GTF_transitive)) | |
310 | return -EPERM; | |
311 | ||
312 | if (gnttab_interface->update_subpage_entry == NULL) | |
313 | return -ENOSYS; | |
314 | ||
315 | gnttab_interface->update_subpage_entry(ref, domid, frame, flags, | |
316 | page_off, length); | |
317 | ||
318 | return 0; | |
319 | } | |
320 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_subpage_ref); | |
321 | ||
322 | int gnttab_grant_foreign_access_subpage(domid_t domid, unsigned long frame, | |
323 | int flags, unsigned page_off, | |
324 | unsigned length) | |
325 | { | |
326 | int ref, rc; | |
327 | ||
328 | ref = get_free_entries(1); | |
329 | if (unlikely(ref < 0)) | |
330 | return -ENOSPC; | |
331 | ||
332 | rc = gnttab_grant_foreign_access_subpage_ref(ref, domid, frame, flags, | |
333 | page_off, length); | |
334 | if (rc < 0) { | |
335 | put_free_entry(ref); | |
336 | return rc; | |
337 | } | |
338 | ||
339 | return ref; | |
340 | } | |
341 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_subpage); | |
342 | ||
343 | bool gnttab_subpage_grants_available(void) | |
344 | { | |
345 | return gnttab_interface->update_subpage_entry != NULL; | |
346 | } | |
347 | EXPORT_SYMBOL_GPL(gnttab_subpage_grants_available); | |
348 | ||
9438ce9d AL |
349 | void gnttab_update_trans_entry_v2(grant_ref_t ref, domid_t domid, |
350 | int flags, domid_t trans_domid, | |
351 | grant_ref_t trans_gref) | |
352 | { | |
353 | gnttab_shared.v2[ref].transitive.trans_domid = trans_domid; | |
354 | gnttab_shared.v2[ref].transitive.gref = trans_gref; | |
355 | gnttab_shared.v2[ref].hdr.domid = domid; | |
356 | wmb(); | |
357 | gnttab_shared.v2[ref].hdr.flags = | |
358 | GTF_permit_access | GTF_transitive | flags; | |
359 | } | |
360 | ||
361 | int gnttab_grant_foreign_access_trans_ref(grant_ref_t ref, domid_t domid, | |
362 | int flags, domid_t trans_domid, | |
363 | grant_ref_t trans_gref) | |
364 | { | |
365 | if (flags & (GTF_accept_transfer | GTF_reading | | |
366 | GTF_writing | GTF_sub_page)) | |
367 | return -EPERM; | |
368 | ||
369 | if (gnttab_interface->update_trans_entry == NULL) | |
370 | return -ENOSYS; | |
371 | ||
372 | gnttab_interface->update_trans_entry(ref, domid, flags, trans_domid, | |
373 | trans_gref); | |
374 | ||
375 | return 0; | |
376 | } | |
377 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_trans_ref); | |
378 | ||
379 | int gnttab_grant_foreign_access_trans(domid_t domid, int flags, | |
380 | domid_t trans_domid, | |
381 | grant_ref_t trans_gref) | |
382 | { | |
383 | int ref, rc; | |
384 | ||
385 | ref = get_free_entries(1); | |
386 | if (unlikely(ref < 0)) | |
387 | return -ENOSPC; | |
388 | ||
389 | rc = gnttab_grant_foreign_access_trans_ref(ref, domid, flags, | |
390 | trans_domid, trans_gref); | |
391 | if (rc < 0) { | |
392 | put_free_entry(ref); | |
393 | return rc; | |
394 | } | |
395 | ||
396 | return ref; | |
397 | } | |
398 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_trans); | |
399 | ||
400 | bool gnttab_trans_grants_available(void) | |
401 | { | |
402 | return gnttab_interface->update_trans_entry != NULL; | |
403 | } | |
404 | EXPORT_SYMBOL_GPL(gnttab_trans_grants_available); | |
405 | ||
0f9f5a95 | 406 | static int gnttab_query_foreign_access_v1(grant_ref_t ref) |
ad9a8612 | 407 | { |
0f9f5a95 AL |
408 | return gnttab_shared.v1[ref].flags & (GTF_reading|GTF_writing); |
409 | } | |
ad9a8612 | 410 | |
85ff6acb AL |
411 | static int gnttab_query_foreign_access_v2(grant_ref_t ref) |
412 | { | |
413 | return grstatus[ref] & (GTF_reading|GTF_writing); | |
414 | } | |
415 | ||
0f9f5a95 AL |
416 | int gnttab_query_foreign_access(grant_ref_t ref) |
417 | { | |
418 | return gnttab_interface->query_foreign_access(ref); | |
ad9a8612 JF |
419 | } |
420 | EXPORT_SYMBOL_GPL(gnttab_query_foreign_access); | |
421 | ||
0f9f5a95 | 422 | static int gnttab_end_foreign_access_ref_v1(grant_ref_t ref, int readonly) |
ad9a8612 JF |
423 | { |
424 | u16 flags, nflags; | |
b1e495b2 | 425 | u16 *pflags; |
ad9a8612 | 426 | |
b1e495b2 AL |
427 | pflags = &gnttab_shared.v1[ref].flags; |
428 | nflags = *pflags; | |
ad9a8612 JF |
429 | do { |
430 | flags = nflags; | |
569ca5b3 | 431 | if (flags & (GTF_reading|GTF_writing)) |
ad9a8612 | 432 | return 0; |
b1e495b2 | 433 | } while ((nflags = sync_cmpxchg(pflags, flags, 0)) != flags); |
ad9a8612 JF |
434 | |
435 | return 1; | |
436 | } | |
0f9f5a95 | 437 | |
85ff6acb AL |
438 | static int gnttab_end_foreign_access_ref_v2(grant_ref_t ref, int readonly) |
439 | { | |
440 | gnttab_shared.v2[ref].hdr.flags = 0; | |
441 | mb(); | |
442 | if (grstatus[ref] & (GTF_reading|GTF_writing)) { | |
443 | return 0; | |
444 | } else { | |
445 | /* The read of grstatus needs to have acquire | |
446 | semantics. On x86, reads already have | |
447 | that, and we just need to protect against | |
448 | compiler reorderings. On other | |
449 | architectures we may need a full | |
450 | barrier. */ | |
451 | #ifdef CONFIG_X86 | |
452 | barrier(); | |
453 | #else | |
454 | mb(); | |
455 | #endif | |
456 | } | |
457 | ||
458 | return 1; | |
459 | } | |
460 | ||
569ca5b3 | 461 | static inline int _gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly) |
0f9f5a95 AL |
462 | { |
463 | return gnttab_interface->end_foreign_access_ref(ref, readonly); | |
464 | } | |
569ca5b3 JB |
465 | |
466 | int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly) | |
467 | { | |
468 | if (_gnttab_end_foreign_access_ref(ref, readonly)) | |
469 | return 1; | |
470 | pr_warn("WARNING: g.e. %#x still in use!\n", ref); | |
471 | return 0; | |
472 | } | |
ad9a8612 JF |
473 | EXPORT_SYMBOL_GPL(gnttab_end_foreign_access_ref); |
474 | ||
569ca5b3 JB |
475 | struct deferred_entry { |
476 | struct list_head list; | |
477 | grant_ref_t ref; | |
478 | bool ro; | |
479 | uint16_t warn_delay; | |
480 | struct page *page; | |
481 | }; | |
482 | static LIST_HEAD(deferred_list); | |
483 | static void gnttab_handle_deferred(unsigned long); | |
484 | static DEFINE_TIMER(deferred_timer, gnttab_handle_deferred, 0, 0); | |
485 | ||
486 | static void gnttab_handle_deferred(unsigned long unused) | |
487 | { | |
488 | unsigned int nr = 10; | |
489 | struct deferred_entry *first = NULL; | |
490 | unsigned long flags; | |
491 | ||
492 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
493 | while (nr--) { | |
494 | struct deferred_entry *entry | |
495 | = list_first_entry(&deferred_list, | |
496 | struct deferred_entry, list); | |
497 | ||
498 | if (entry == first) | |
499 | break; | |
500 | list_del(&entry->list); | |
501 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
502 | if (_gnttab_end_foreign_access_ref(entry->ref, entry->ro)) { | |
503 | put_free_entry(entry->ref); | |
504 | if (entry->page) { | |
505 | pr_debug("freeing g.e. %#x (pfn %#lx)\n", | |
506 | entry->ref, page_to_pfn(entry->page)); | |
507 | __free_page(entry->page); | |
508 | } else | |
509 | pr_info("freeing g.e. %#x\n", entry->ref); | |
510 | kfree(entry); | |
511 | entry = NULL; | |
512 | } else { | |
513 | if (!--entry->warn_delay) | |
514 | pr_info("g.e. %#x still pending\n", | |
515 | entry->ref); | |
516 | if (!first) | |
517 | first = entry; | |
518 | } | |
519 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
520 | if (entry) | |
521 | list_add_tail(&entry->list, &deferred_list); | |
522 | else if (list_empty(&deferred_list)) | |
523 | break; | |
524 | } | |
525 | if (!list_empty(&deferred_list) && !timer_pending(&deferred_timer)) { | |
526 | deferred_timer.expires = jiffies + HZ; | |
527 | add_timer(&deferred_timer); | |
528 | } | |
529 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
530 | } | |
531 | ||
532 | static void gnttab_add_deferred(grant_ref_t ref, bool readonly, | |
533 | struct page *page) | |
534 | { | |
535 | struct deferred_entry *entry = kmalloc(sizeof(*entry), GFP_ATOMIC); | |
536 | const char *what = KERN_WARNING "leaking"; | |
537 | ||
538 | if (entry) { | |
539 | unsigned long flags; | |
540 | ||
541 | entry->ref = ref; | |
542 | entry->ro = readonly; | |
543 | entry->page = page; | |
544 | entry->warn_delay = 60; | |
545 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
546 | list_add_tail(&entry->list, &deferred_list); | |
547 | if (!timer_pending(&deferred_timer)) { | |
548 | deferred_timer.expires = jiffies + HZ; | |
549 | add_timer(&deferred_timer); | |
550 | } | |
551 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
552 | what = KERN_DEBUG "deferring"; | |
553 | } | |
554 | printk("%s g.e. %#x (pfn %#lx)\n", | |
555 | what, ref, page ? page_to_pfn(page) : -1); | |
556 | } | |
557 | ||
ad9a8612 JF |
558 | void gnttab_end_foreign_access(grant_ref_t ref, int readonly, |
559 | unsigned long page) | |
560 | { | |
561 | if (gnttab_end_foreign_access_ref(ref, readonly)) { | |
562 | put_free_entry(ref); | |
563 | if (page != 0) | |
564 | free_page(page); | |
569ca5b3 JB |
565 | } else |
566 | gnttab_add_deferred(ref, readonly, | |
567 | page ? virt_to_page(page) : NULL); | |
ad9a8612 JF |
568 | } |
569 | EXPORT_SYMBOL_GPL(gnttab_end_foreign_access); | |
570 | ||
571 | int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn) | |
572 | { | |
573 | int ref; | |
574 | ||
575 | ref = get_free_entries(1); | |
576 | if (unlikely(ref < 0)) | |
577 | return -ENOSPC; | |
578 | gnttab_grant_foreign_transfer_ref(ref, domid, pfn); | |
579 | ||
580 | return ref; | |
581 | } | |
582 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_transfer); | |
583 | ||
584 | void gnttab_grant_foreign_transfer_ref(grant_ref_t ref, domid_t domid, | |
585 | unsigned long pfn) | |
586 | { | |
0f9f5a95 | 587 | gnttab_interface->update_entry(ref, domid, pfn, GTF_accept_transfer); |
ad9a8612 JF |
588 | } |
589 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_transfer_ref); | |
590 | ||
0f9f5a95 | 591 | static unsigned long gnttab_end_foreign_transfer_ref_v1(grant_ref_t ref) |
ad9a8612 JF |
592 | { |
593 | unsigned long frame; | |
594 | u16 flags; | |
b1e495b2 AL |
595 | u16 *pflags; |
596 | ||
597 | pflags = &gnttab_shared.v1[ref].flags; | |
ad9a8612 JF |
598 | |
599 | /* | |
600 | * If a transfer is not even yet started, try to reclaim the grant | |
601 | * reference and return failure (== 0). | |
602 | */ | |
b1e495b2 AL |
603 | while (!((flags = *pflags) & GTF_transfer_committed)) { |
604 | if (sync_cmpxchg(pflags, flags, 0) == flags) | |
ad9a8612 JF |
605 | return 0; |
606 | cpu_relax(); | |
607 | } | |
608 | ||
609 | /* If a transfer is in progress then wait until it is completed. */ | |
610 | while (!(flags & GTF_transfer_completed)) { | |
b1e495b2 | 611 | flags = *pflags; |
ad9a8612 JF |
612 | cpu_relax(); |
613 | } | |
614 | ||
615 | rmb(); /* Read the frame number /after/ reading completion status. */ | |
0f9f5a95 | 616 | frame = gnttab_shared.v1[ref].frame; |
ad9a8612 JF |
617 | BUG_ON(frame == 0); |
618 | ||
619 | return frame; | |
620 | } | |
0f9f5a95 | 621 | |
85ff6acb AL |
622 | static unsigned long gnttab_end_foreign_transfer_ref_v2(grant_ref_t ref) |
623 | { | |
624 | unsigned long frame; | |
625 | u16 flags; | |
626 | u16 *pflags; | |
627 | ||
628 | pflags = &gnttab_shared.v2[ref].hdr.flags; | |
629 | ||
630 | /* | |
631 | * If a transfer is not even yet started, try to reclaim the grant | |
632 | * reference and return failure (== 0). | |
633 | */ | |
634 | while (!((flags = *pflags) & GTF_transfer_committed)) { | |
635 | if (sync_cmpxchg(pflags, flags, 0) == flags) | |
636 | return 0; | |
637 | cpu_relax(); | |
638 | } | |
639 | ||
640 | /* If a transfer is in progress then wait until it is completed. */ | |
641 | while (!(flags & GTF_transfer_completed)) { | |
642 | flags = *pflags; | |
643 | cpu_relax(); | |
644 | } | |
645 | ||
646 | rmb(); /* Read the frame number /after/ reading completion status. */ | |
647 | frame = gnttab_shared.v2[ref].full_page.frame; | |
648 | BUG_ON(frame == 0); | |
649 | ||
650 | return frame; | |
651 | } | |
652 | ||
0f9f5a95 AL |
653 | unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref) |
654 | { | |
655 | return gnttab_interface->end_foreign_transfer_ref(ref); | |
656 | } | |
ad9a8612 JF |
657 | EXPORT_SYMBOL_GPL(gnttab_end_foreign_transfer_ref); |
658 | ||
659 | unsigned long gnttab_end_foreign_transfer(grant_ref_t ref) | |
660 | { | |
661 | unsigned long frame = gnttab_end_foreign_transfer_ref(ref); | |
662 | put_free_entry(ref); | |
663 | return frame; | |
664 | } | |
665 | EXPORT_SYMBOL_GPL(gnttab_end_foreign_transfer); | |
666 | ||
667 | void gnttab_free_grant_reference(grant_ref_t ref) | |
668 | { | |
669 | put_free_entry(ref); | |
670 | } | |
671 | EXPORT_SYMBOL_GPL(gnttab_free_grant_reference); | |
672 | ||
673 | void gnttab_free_grant_references(grant_ref_t head) | |
674 | { | |
675 | grant_ref_t ref; | |
676 | unsigned long flags; | |
677 | int count = 1; | |
678 | if (head == GNTTAB_LIST_END) | |
679 | return; | |
680 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
681 | ref = head; | |
682 | while (gnttab_entry(ref) != GNTTAB_LIST_END) { | |
683 | ref = gnttab_entry(ref); | |
684 | count++; | |
685 | } | |
686 | gnttab_entry(ref) = gnttab_free_head; | |
687 | gnttab_free_head = head; | |
688 | gnttab_free_count += count; | |
689 | check_free_callbacks(); | |
690 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
691 | } | |
692 | EXPORT_SYMBOL_GPL(gnttab_free_grant_references); | |
693 | ||
694 | int gnttab_alloc_grant_references(u16 count, grant_ref_t *head) | |
695 | { | |
696 | int h = get_free_entries(count); | |
697 | ||
698 | if (h < 0) | |
699 | return -ENOSPC; | |
700 | ||
701 | *head = h; | |
702 | ||
703 | return 0; | |
704 | } | |
705 | EXPORT_SYMBOL_GPL(gnttab_alloc_grant_references); | |
706 | ||
707 | int gnttab_empty_grant_references(const grant_ref_t *private_head) | |
708 | { | |
709 | return (*private_head == GNTTAB_LIST_END); | |
710 | } | |
711 | EXPORT_SYMBOL_GPL(gnttab_empty_grant_references); | |
712 | ||
713 | int gnttab_claim_grant_reference(grant_ref_t *private_head) | |
714 | { | |
715 | grant_ref_t g = *private_head; | |
716 | if (unlikely(g == GNTTAB_LIST_END)) | |
717 | return -ENOSPC; | |
718 | *private_head = gnttab_entry(g); | |
719 | return g; | |
720 | } | |
721 | EXPORT_SYMBOL_GPL(gnttab_claim_grant_reference); | |
722 | ||
723 | void gnttab_release_grant_reference(grant_ref_t *private_head, | |
724 | grant_ref_t release) | |
725 | { | |
726 | gnttab_entry(release) = *private_head; | |
727 | *private_head = release; | |
728 | } | |
729 | EXPORT_SYMBOL_GPL(gnttab_release_grant_reference); | |
730 | ||
731 | void gnttab_request_free_callback(struct gnttab_free_callback *callback, | |
732 | void (*fn)(void *), void *arg, u16 count) | |
733 | { | |
734 | unsigned long flags; | |
735 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
736 | if (callback->next) | |
737 | goto out; | |
738 | callback->fn = fn; | |
739 | callback->arg = arg; | |
740 | callback->count = count; | |
741 | callback->next = gnttab_free_callback_list; | |
742 | gnttab_free_callback_list = callback; | |
743 | check_free_callbacks(); | |
744 | out: | |
745 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
746 | } | |
747 | EXPORT_SYMBOL_GPL(gnttab_request_free_callback); | |
748 | ||
749 | void gnttab_cancel_free_callback(struct gnttab_free_callback *callback) | |
750 | { | |
751 | struct gnttab_free_callback **pcb; | |
752 | unsigned long flags; | |
753 | ||
754 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
755 | for (pcb = &gnttab_free_callback_list; *pcb; pcb = &(*pcb)->next) { | |
756 | if (*pcb == callback) { | |
757 | *pcb = callback->next; | |
758 | break; | |
759 | } | |
760 | } | |
761 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
762 | } | |
763 | EXPORT_SYMBOL_GPL(gnttab_cancel_free_callback); | |
764 | ||
765 | static int grow_gnttab_list(unsigned int more_frames) | |
766 | { | |
767 | unsigned int new_nr_grant_frames, extra_entries, i; | |
bbc60c18 | 768 | unsigned int nr_glist_frames, new_nr_glist_frames; |
ad9a8612 JF |
769 | |
770 | new_nr_grant_frames = nr_grant_frames + more_frames; | |
771 | extra_entries = more_frames * GREFS_PER_GRANT_FRAME; | |
772 | ||
bbc60c18 MAEM |
773 | nr_glist_frames = (nr_grant_frames * GREFS_PER_GRANT_FRAME + RPP - 1) / RPP; |
774 | new_nr_glist_frames = | |
775 | (new_nr_grant_frames * GREFS_PER_GRANT_FRAME + RPP - 1) / RPP; | |
776 | for (i = nr_glist_frames; i < new_nr_glist_frames; i++) { | |
ad9a8612 JF |
777 | gnttab_list[i] = (grant_ref_t *)__get_free_page(GFP_ATOMIC); |
778 | if (!gnttab_list[i]) | |
779 | goto grow_nomem; | |
780 | } | |
781 | ||
782 | ||
783 | for (i = GREFS_PER_GRANT_FRAME * nr_grant_frames; | |
784 | i < GREFS_PER_GRANT_FRAME * new_nr_grant_frames - 1; i++) | |
785 | gnttab_entry(i) = i + 1; | |
786 | ||
787 | gnttab_entry(i) = gnttab_free_head; | |
788 | gnttab_free_head = GREFS_PER_GRANT_FRAME * nr_grant_frames; | |
789 | gnttab_free_count += extra_entries; | |
790 | ||
791 | nr_grant_frames = new_nr_grant_frames; | |
792 | ||
793 | check_free_callbacks(); | |
794 | ||
795 | return 0; | |
796 | ||
797 | grow_nomem: | |
bbc60c18 | 798 | for ( ; i >= nr_glist_frames; i--) |
ad9a8612 JF |
799 | free_page((unsigned long) gnttab_list[i]); |
800 | return -ENOMEM; | |
801 | } | |
802 | ||
803 | static unsigned int __max_nr_grant_frames(void) | |
804 | { | |
805 | struct gnttab_query_size query; | |
806 | int rc; | |
807 | ||
808 | query.dom = DOMID_SELF; | |
809 | ||
810 | rc = HYPERVISOR_grant_table_op(GNTTABOP_query_size, &query, 1); | |
811 | if ((rc < 0) || (query.status != GNTST_okay)) | |
812 | return 4; /* Legacy max supported number of frames */ | |
813 | ||
814 | return query.max_nr_frames; | |
815 | } | |
816 | ||
183d03cc | 817 | unsigned int gnttab_max_grant_frames(void) |
ad9a8612 JF |
818 | { |
819 | unsigned int xen_max = __max_nr_grant_frames(); | |
820 | ||
821 | if (xen_max > boot_max_nr_grant_frames) | |
822 | return boot_max_nr_grant_frames; | |
823 | return xen_max; | |
824 | } | |
183d03cc | 825 | EXPORT_SYMBOL_GPL(gnttab_max_grant_frames); |
ad9a8612 | 826 | |
289b777e | 827 | int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, |
c123799a AL |
828 | struct gnttab_map_grant_ref *kmap_ops, |
829 | struct page **pages, unsigned int count) | |
289b777e SS |
830 | { |
831 | int i, ret; | |
f62805f1 | 832 | bool lazy = false; |
289b777e SS |
833 | pte_t *pte; |
834 | unsigned long mfn; | |
835 | ||
836 | ret = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, map_ops, count); | |
87f1d40a JF |
837 | if (ret) |
838 | return ret; | |
289b777e | 839 | |
aab8f11a DDG |
840 | if (xen_feature(XENFEAT_auto_translated_physmap)) |
841 | return ret; | |
842 | ||
f62805f1 SS |
843 | if (!in_interrupt() && paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) { |
844 | arch_enter_lazy_mmu_mode(); | |
845 | lazy = true; | |
846 | } | |
847 | ||
289b777e | 848 | for (i = 0; i < count; i++) { |
dc4972a4 IC |
849 | /* Do not add to override if the map failed. */ |
850 | if (map_ops[i].status) | |
851 | continue; | |
852 | ||
cf8d9163 KRW |
853 | if (map_ops[i].flags & GNTMAP_contains_pte) { |
854 | pte = (pte_t *) (mfn_to_virt(PFN_DOWN(map_ops[i].host_addr)) + | |
289b777e | 855 | (map_ops[i].host_addr & ~PAGE_MASK)); |
cf8d9163 KRW |
856 | mfn = pte_mfn(*pte); |
857 | } else { | |
7d17e84b | 858 | mfn = PFN_DOWN(map_ops[i].dev_bus_addr); |
cf8d9163 | 859 | } |
7d17e84b DDG |
860 | ret = m2p_add_override(mfn, pages[i], kmap_ops ? |
861 | &kmap_ops[i] : NULL); | |
87f1d40a JF |
862 | if (ret) |
863 | return ret; | |
289b777e SS |
864 | } |
865 | ||
f62805f1 SS |
866 | if (lazy) |
867 | arch_leave_lazy_mmu_mode(); | |
868 | ||
289b777e SS |
869 | return ret; |
870 | } | |
871 | EXPORT_SYMBOL_GPL(gnttab_map_refs); | |
872 | ||
873 | int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, | |
7d17e84b | 874 | struct page **pages, unsigned int count, bool clear_pte) |
289b777e SS |
875 | { |
876 | int i, ret; | |
f62805f1 | 877 | bool lazy = false; |
289b777e SS |
878 | |
879 | ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap_ops, count); | |
87f1d40a JF |
880 | if (ret) |
881 | return ret; | |
882 | ||
aab8f11a DDG |
883 | if (xen_feature(XENFEAT_auto_translated_physmap)) |
884 | return ret; | |
885 | ||
f62805f1 SS |
886 | if (!in_interrupt() && paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) { |
887 | arch_enter_lazy_mmu_mode(); | |
888 | lazy = true; | |
889 | } | |
890 | ||
87f1d40a | 891 | for (i = 0; i < count; i++) { |
7d17e84b | 892 | ret = m2p_remove_override(pages[i], clear_pte); |
87f1d40a JF |
893 | if (ret) |
894 | return ret; | |
895 | } | |
289b777e | 896 | |
f62805f1 SS |
897 | if (lazy) |
898 | arch_leave_lazy_mmu_mode(); | |
899 | ||
289b777e SS |
900 | return ret; |
901 | } | |
902 | EXPORT_SYMBOL_GPL(gnttab_unmap_refs); | |
903 | ||
85ff6acb AL |
904 | static unsigned nr_status_frames(unsigned nr_grant_frames) |
905 | { | |
906 | return (nr_grant_frames * GREFS_PER_GRANT_FRAME + SPP - 1) / SPP; | |
907 | } | |
908 | ||
0f9f5a95 AL |
909 | static int gnttab_map_frames_v1(unsigned long *frames, unsigned int nr_gframes) |
910 | { | |
911 | int rc; | |
912 | ||
913 | rc = arch_gnttab_map_shared(frames, nr_gframes, | |
914 | gnttab_max_grant_frames(), | |
915 | &gnttab_shared.addr); | |
916 | BUG_ON(rc); | |
917 | ||
918 | return 0; | |
919 | } | |
920 | ||
921 | static void gnttab_unmap_frames_v1(void) | |
922 | { | |
85ff6acb AL |
923 | arch_gnttab_unmap(gnttab_shared.addr, nr_grant_frames); |
924 | } | |
925 | ||
926 | static int gnttab_map_frames_v2(unsigned long *frames, unsigned int nr_gframes) | |
927 | { | |
928 | uint64_t *sframes; | |
929 | unsigned int nr_sframes; | |
930 | struct gnttab_get_status_frames getframes; | |
931 | int rc; | |
932 | ||
933 | nr_sframes = nr_status_frames(nr_gframes); | |
934 | ||
935 | /* No need for kzalloc as it is initialized in following hypercall | |
936 | * GNTTABOP_get_status_frames. | |
937 | */ | |
938 | sframes = kmalloc(nr_sframes * sizeof(uint64_t), GFP_ATOMIC); | |
939 | if (!sframes) | |
940 | return -ENOMEM; | |
941 | ||
942 | getframes.dom = DOMID_SELF; | |
943 | getframes.nr_frames = nr_sframes; | |
944 | set_xen_guest_handle(getframes.frame_list, sframes); | |
945 | ||
946 | rc = HYPERVISOR_grant_table_op(GNTTABOP_get_status_frames, | |
947 | &getframes, 1); | |
948 | if (rc == -ENOSYS) { | |
949 | kfree(sframes); | |
950 | return -ENOSYS; | |
951 | } | |
952 | ||
953 | BUG_ON(rc || getframes.status); | |
954 | ||
955 | rc = arch_gnttab_map_status(sframes, nr_sframes, | |
956 | nr_status_frames(gnttab_max_grant_frames()), | |
957 | &grstatus); | |
958 | BUG_ON(rc); | |
959 | kfree(sframes); | |
960 | ||
961 | rc = arch_gnttab_map_shared(frames, nr_gframes, | |
962 | gnttab_max_grant_frames(), | |
963 | &gnttab_shared.addr); | |
964 | BUG_ON(rc); | |
965 | ||
966 | return 0; | |
967 | } | |
968 | ||
969 | static void gnttab_unmap_frames_v2(void) | |
970 | { | |
971 | arch_gnttab_unmap(gnttab_shared.addr, nr_grant_frames); | |
972 | arch_gnttab_unmap(grstatus, nr_status_frames(nr_grant_frames)); | |
0f9f5a95 AL |
973 | } |
974 | ||
ad9a8612 JF |
975 | static int gnttab_map(unsigned int start_idx, unsigned int end_idx) |
976 | { | |
977 | struct gnttab_setup_table setup; | |
978 | unsigned long *frames; | |
979 | unsigned int nr_gframes = end_idx + 1; | |
980 | int rc; | |
981 | ||
183d03cc SS |
982 | if (xen_hvm_domain()) { |
983 | struct xen_add_to_physmap xatp; | |
984 | unsigned int i = end_idx; | |
985 | rc = 0; | |
986 | /* | |
987 | * Loop backwards, so that the first hypercall has the largest | |
988 | * index, ensuring that the table will grow only once. | |
989 | */ | |
990 | do { | |
991 | xatp.domid = DOMID_SELF; | |
992 | xatp.idx = i; | |
993 | xatp.space = XENMAPSPACE_grant_table; | |
994 | xatp.gpfn = (xen_hvm_resume_frames >> PAGE_SHIFT) + i; | |
995 | rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp); | |
996 | if (rc != 0) { | |
997 | printk(KERN_WARNING | |
998 | "grant table add_to_physmap failed, err=%d\n", rc); | |
999 | break; | |
1000 | } | |
1001 | } while (i-- > start_idx); | |
1002 | ||
1003 | return rc; | |
1004 | } | |
1005 | ||
85ff6acb AL |
1006 | /* No need for kzalloc as it is initialized in following hypercall |
1007 | * GNTTABOP_setup_table. | |
1008 | */ | |
ad9a8612 JF |
1009 | frames = kmalloc(nr_gframes * sizeof(unsigned long), GFP_ATOMIC); |
1010 | if (!frames) | |
1011 | return -ENOMEM; | |
1012 | ||
1013 | setup.dom = DOMID_SELF; | |
1014 | setup.nr_frames = nr_gframes; | |
87e27cf6 | 1015 | set_xen_guest_handle(setup.frame_list, frames); |
ad9a8612 JF |
1016 | |
1017 | rc = HYPERVISOR_grant_table_op(GNTTABOP_setup_table, &setup, 1); | |
1018 | if (rc == -ENOSYS) { | |
1019 | kfree(frames); | |
1020 | return -ENOSYS; | |
1021 | } | |
1022 | ||
1023 | BUG_ON(rc || setup.status); | |
1024 | ||
0f9f5a95 | 1025 | rc = gnttab_interface->map_frames(frames, nr_gframes); |
ad9a8612 JF |
1026 | |
1027 | kfree(frames); | |
1028 | ||
0f9f5a95 AL |
1029 | return rc; |
1030 | } | |
1031 | ||
1032 | static struct gnttab_ops gnttab_v1_ops = { | |
1033 | .map_frames = gnttab_map_frames_v1, | |
1034 | .unmap_frames = gnttab_unmap_frames_v1, | |
1035 | .update_entry = gnttab_update_entry_v1, | |
1036 | .end_foreign_access_ref = gnttab_end_foreign_access_ref_v1, | |
1037 | .end_foreign_transfer_ref = gnttab_end_foreign_transfer_ref_v1, | |
1038 | .query_foreign_access = gnttab_query_foreign_access_v1, | |
1039 | }; | |
1040 | ||
85ff6acb AL |
1041 | static struct gnttab_ops gnttab_v2_ops = { |
1042 | .map_frames = gnttab_map_frames_v2, | |
1043 | .unmap_frames = gnttab_unmap_frames_v2, | |
1044 | .update_entry = gnttab_update_entry_v2, | |
1045 | .end_foreign_access_ref = gnttab_end_foreign_access_ref_v2, | |
1046 | .end_foreign_transfer_ref = gnttab_end_foreign_transfer_ref_v2, | |
1047 | .query_foreign_access = gnttab_query_foreign_access_v2, | |
6666754b | 1048 | .update_subpage_entry = gnttab_update_subpage_entry_v2, |
9438ce9d | 1049 | .update_trans_entry = gnttab_update_trans_entry_v2, |
85ff6acb AL |
1050 | }; |
1051 | ||
0f9f5a95 AL |
1052 | static void gnttab_request_version(void) |
1053 | { | |
85ff6acb AL |
1054 | int rc; |
1055 | struct gnttab_set_version gsv; | |
1056 | ||
69e8f430 KRW |
1057 | if (xen_hvm_domain()) |
1058 | gsv.version = 1; | |
1059 | else | |
1060 | gsv.version = 2; | |
85ff6acb | 1061 | rc = HYPERVISOR_grant_table_op(GNTTABOP_set_version, &gsv, 1); |
69e8f430 | 1062 | if (rc == 0 && gsv.version == 2) { |
85ff6acb AL |
1063 | grant_table_version = 2; |
1064 | gnttab_interface = &gnttab_v2_ops; | |
1065 | } else if (grant_table_version == 2) { | |
1066 | /* | |
1067 | * If we've already used version 2 features, | |
1068 | * but then suddenly discover that they're not | |
1069 | * available (e.g. migrating to an older | |
1070 | * version of Xen), almost unbounded badness | |
1071 | * can happen. | |
1072 | */ | |
1073 | panic("we need grant tables version 2, but only version 1 is available"); | |
1074 | } else { | |
1075 | grant_table_version = 1; | |
1076 | gnttab_interface = &gnttab_v1_ops; | |
1077 | } | |
0f9f5a95 AL |
1078 | printk(KERN_INFO "Grant tables using version %d layout.\n", |
1079 | grant_table_version); | |
ad9a8612 JF |
1080 | } |
1081 | ||
0e91398f | 1082 | int gnttab_resume(void) |
ad9a8612 | 1083 | { |
183d03cc SS |
1084 | unsigned int max_nr_gframes; |
1085 | ||
0f9f5a95 | 1086 | gnttab_request_version(); |
183d03cc SS |
1087 | max_nr_gframes = gnttab_max_grant_frames(); |
1088 | if (max_nr_gframes < nr_grant_frames) | |
ad9a8612 | 1089 | return -ENOSYS; |
183d03cc SS |
1090 | |
1091 | if (xen_pv_domain()) | |
1092 | return gnttab_map(0, nr_grant_frames - 1); | |
1093 | ||
0f9f5a95 AL |
1094 | if (gnttab_shared.addr == NULL) { |
1095 | gnttab_shared.addr = ioremap(xen_hvm_resume_frames, | |
1096 | PAGE_SIZE * max_nr_gframes); | |
1097 | if (gnttab_shared.addr == NULL) { | |
183d03cc SS |
1098 | printk(KERN_WARNING |
1099 | "Failed to ioremap gnttab share frames!"); | |
1100 | return -ENOMEM; | |
1101 | } | |
1102 | } | |
1103 | ||
1104 | gnttab_map(0, nr_grant_frames - 1); | |
1105 | ||
1106 | return 0; | |
ad9a8612 JF |
1107 | } |
1108 | ||
0e91398f | 1109 | int gnttab_suspend(void) |
ad9a8612 | 1110 | { |
0f9f5a95 | 1111 | gnttab_interface->unmap_frames(); |
ad9a8612 JF |
1112 | return 0; |
1113 | } | |
1114 | ||
1115 | static int gnttab_expand(unsigned int req_entries) | |
1116 | { | |
1117 | int rc; | |
1118 | unsigned int cur, extra; | |
1119 | ||
1120 | cur = nr_grant_frames; | |
1121 | extra = ((req_entries + (GREFS_PER_GRANT_FRAME-1)) / | |
1122 | GREFS_PER_GRANT_FRAME); | |
183d03cc | 1123 | if (cur + extra > gnttab_max_grant_frames()) |
ad9a8612 JF |
1124 | return -ENOSPC; |
1125 | ||
1126 | rc = gnttab_map(cur, cur + extra - 1); | |
1127 | if (rc == 0) | |
1128 | rc = grow_gnttab_list(extra); | |
1129 | ||
1130 | return rc; | |
1131 | } | |
1132 | ||
183d03cc | 1133 | int gnttab_init(void) |
ad9a8612 JF |
1134 | { |
1135 | int i; | |
bbc60c18 | 1136 | unsigned int max_nr_glist_frames, nr_glist_frames; |
ad9a8612 | 1137 | unsigned int nr_init_grefs; |
6b5e7d9e | 1138 | int ret; |
ad9a8612 | 1139 | |
ad9a8612 JF |
1140 | nr_grant_frames = 1; |
1141 | boot_max_nr_grant_frames = __max_nr_grant_frames(); | |
1142 | ||
1143 | /* Determine the maximum number of frames required for the | |
1144 | * grant reference free list on the current hypervisor. | |
1145 | */ | |
1146 | max_nr_glist_frames = (boot_max_nr_grant_frames * | |
bbc60c18 | 1147 | GREFS_PER_GRANT_FRAME / RPP); |
ad9a8612 JF |
1148 | |
1149 | gnttab_list = kmalloc(max_nr_glist_frames * sizeof(grant_ref_t *), | |
1150 | GFP_KERNEL); | |
1151 | if (gnttab_list == NULL) | |
1152 | return -ENOMEM; | |
1153 | ||
bbc60c18 MAEM |
1154 | nr_glist_frames = (nr_grant_frames * GREFS_PER_GRANT_FRAME + RPP - 1) / RPP; |
1155 | for (i = 0; i < nr_glist_frames; i++) { | |
ad9a8612 | 1156 | gnttab_list[i] = (grant_ref_t *)__get_free_page(GFP_KERNEL); |
6b5e7d9e JL |
1157 | if (gnttab_list[i] == NULL) { |
1158 | ret = -ENOMEM; | |
ad9a8612 | 1159 | goto ini_nomem; |
6b5e7d9e | 1160 | } |
ad9a8612 JF |
1161 | } |
1162 | ||
6b5e7d9e JL |
1163 | if (gnttab_resume() < 0) { |
1164 | ret = -ENODEV; | |
1165 | goto ini_nomem; | |
1166 | } | |
ad9a8612 JF |
1167 | |
1168 | nr_init_grefs = nr_grant_frames * GREFS_PER_GRANT_FRAME; | |
1169 | ||
1170 | for (i = NR_RESERVED_ENTRIES; i < nr_init_grefs - 1; i++) | |
1171 | gnttab_entry(i) = i + 1; | |
1172 | ||
1173 | gnttab_entry(nr_init_grefs - 1) = GNTTAB_LIST_END; | |
1174 | gnttab_free_count = nr_init_grefs - NR_RESERVED_ENTRIES; | |
1175 | gnttab_free_head = NR_RESERVED_ENTRIES; | |
1176 | ||
1177 | printk("Grant table initialized\n"); | |
1178 | return 0; | |
1179 | ||
1180 | ini_nomem: | |
1181 | for (i--; i >= 0; i--) | |
1182 | free_page((unsigned long)gnttab_list[i]); | |
1183 | kfree(gnttab_list); | |
6b5e7d9e | 1184 | return ret; |
ad9a8612 | 1185 | } |
183d03cc SS |
1186 | EXPORT_SYMBOL_GPL(gnttab_init); |
1187 | ||
1188 | static int __devinit __gnttab_init(void) | |
1189 | { | |
1190 | /* Delay grant-table initialization in the PV on HVM case */ | |
1191 | if (xen_hvm_domain()) | |
1192 | return 0; | |
1193 | ||
1194 | if (!xen_pv_domain()) | |
1195 | return -ENODEV; | |
1196 | ||
1197 | return gnttab_init(); | |
1198 | } | |
ad9a8612 | 1199 | |
183d03cc | 1200 | core_initcall(__gnttab_init); |