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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> |
c571898f | 41 | #include <linux/delay.h> |
f62805f1 | 42 | #include <linux/hardirq.h> |
ad9a8612 | 43 | |
1ccbf534 | 44 | #include <xen/xen.h> |
ad9a8612 JF |
45 | #include <xen/interface/xen.h> |
46 | #include <xen/page.h> | |
47 | #include <xen/grant_table.h> | |
183d03cc | 48 | #include <xen/interface/memory.h> |
85ff6acb | 49 | #include <xen/hvc-console.h> |
ecbf29cd | 50 | #include <asm/xen/hypercall.h> |
4d9310e3 | 51 | #include <asm/xen/interface.h> |
ad9a8612 JF |
52 | |
53 | #include <asm/pgtable.h> | |
54 | #include <asm/sync_bitops.h> | |
55 | ||
ad9a8612 JF |
56 | /* External tools reserve first few grant table entries. */ |
57 | #define NR_RESERVED_ENTRIES 8 | |
58 | #define GNTTAB_LIST_END 0xffffffff | |
ad9a8612 JF |
59 | |
60 | static grant_ref_t **gnttab_list; | |
61 | static unsigned int nr_grant_frames; | |
62 | static unsigned int boot_max_nr_grant_frames; | |
63 | static int gnttab_free_count; | |
64 | static grant_ref_t gnttab_free_head; | |
65 | static DEFINE_SPINLOCK(gnttab_list_lock); | |
183d03cc SS |
66 | unsigned long xen_hvm_resume_frames; |
67 | EXPORT_SYMBOL_GPL(xen_hvm_resume_frames); | |
ad9a8612 | 68 | |
0f9f5a95 AL |
69 | static union { |
70 | struct grant_entry_v1 *v1; | |
85ff6acb | 71 | union grant_entry_v2 *v2; |
0f9f5a95 AL |
72 | void *addr; |
73 | } gnttab_shared; | |
74 | ||
75 | /*This is a structure of function pointers for grant table*/ | |
76 | struct gnttab_ops { | |
77 | /* | |
9dbc71d5 AL |
78 | * Mapping a list of frames for storing grant entries. Frames parameter |
79 | * is used to store grant table address when grant table being setup, | |
80 | * nr_gframes is the number of frames to map grant table. Returning | |
81 | * GNTST_okay means success and negative value means failure. | |
0f9f5a95 | 82 | */ |
ef32f892 | 83 | int (*map_frames)(xen_pfn_t *frames, unsigned int nr_gframes); |
0f9f5a95 AL |
84 | /* |
85 | * Release a list of frames which are mapped in map_frames for grant | |
86 | * entry status. | |
87 | */ | |
88 | void (*unmap_frames)(void); | |
89 | /* | |
9dbc71d5 AL |
90 | * Introducing a valid entry into the grant table, granting the frame of |
91 | * this grant entry to domain for accessing or transfering. Ref | |
92 | * parameter is reference of this introduced grant entry, domid is id of | |
93 | * granted domain, frame is the page frame to be granted, and flags is | |
94 | * status of the grant entry to be updated. | |
0f9f5a95 | 95 | */ |
9dbc71d5 AL |
96 | void (*update_entry)(grant_ref_t ref, domid_t domid, |
97 | unsigned long frame, unsigned flags); | |
0f9f5a95 | 98 | /* |
9dbc71d5 AL |
99 | * Stop granting a grant entry to domain for accessing. Ref parameter is |
100 | * reference of a grant entry whose grant access will be stopped, | |
101 | * readonly is not in use in this function. If the grant entry is | |
0f9f5a95 AL |
102 | * currently mapped for reading or writing, just return failure(==0) |
103 | * directly and don't tear down the grant access. Otherwise, stop grant | |
104 | * access for this entry and return success(==1). | |
105 | */ | |
9dbc71d5 | 106 | int (*end_foreign_access_ref)(grant_ref_t ref, int readonly); |
0f9f5a95 | 107 | /* |
9dbc71d5 AL |
108 | * Stop granting a grant entry to domain for transfer. Ref parameter is |
109 | * reference of a grant entry whose grant transfer will be stopped. If | |
110 | * tranfer has not started, just reclaim the grant entry and return | |
111 | * failure(==0). Otherwise, wait for the transfer to complete and then | |
112 | * return the frame. | |
0f9f5a95 | 113 | */ |
9dbc71d5 | 114 | unsigned long (*end_foreign_transfer_ref)(grant_ref_t ref); |
0f9f5a95 | 115 | /* |
9dbc71d5 | 116 | * Query the status of a grant entry. Ref parameter is reference of |
0f9f5a95 AL |
117 | * queried grant entry, return value is the status of queried entry. |
118 | * Detailed status(writing/reading) can be gotten from the return value | |
119 | * by bit operations. | |
120 | */ | |
9dbc71d5 | 121 | int (*query_foreign_access)(grant_ref_t ref); |
6666754b AL |
122 | /* |
123 | * Grant a domain to access a range of bytes within the page referred by | |
124 | * an available grant entry. Ref parameter is reference of a grant entry | |
125 | * which will be sub-page accessed, domid is id of grantee domain, frame | |
126 | * is frame address of subpage grant, flags is grant type and flag | |
127 | * information, page_off is offset of the range of bytes, and length is | |
128 | * length of bytes to be accessed. | |
129 | */ | |
130 | void (*update_subpage_entry)(grant_ref_t ref, domid_t domid, | |
131 | unsigned long frame, int flags, | |
132 | unsigned page_off, unsigned length); | |
9438ce9d AL |
133 | /* |
134 | * Redirect an available grant entry on domain A to another grant | |
135 | * reference of domain B, then allow domain C to use grant reference | |
136 | * of domain B transitively. Ref parameter is an available grant entry | |
137 | * reference on domain A, domid is id of domain C which accesses grant | |
138 | * entry transitively, flags is grant type and flag information, | |
139 | * trans_domid is id of domain B whose grant entry is finally accessed | |
140 | * transitively, trans_gref is grant entry transitive reference of | |
141 | * domain B. | |
142 | */ | |
143 | void (*update_trans_entry)(grant_ref_t ref, domid_t domid, int flags, | |
144 | domid_t trans_domid, grant_ref_t trans_gref); | |
0f9f5a95 AL |
145 | }; |
146 | ||
147 | static struct gnttab_ops *gnttab_interface; | |
148 | ||
85ff6acb AL |
149 | /*This reflects status of grant entries, so act as a global value*/ |
150 | static grant_status_t *grstatus; | |
151 | ||
0f9f5a95 | 152 | static int grant_table_version; |
d0b4d64a | 153 | static int grefs_per_grant_frame; |
ad9a8612 JF |
154 | |
155 | static struct gnttab_free_callback *gnttab_free_callback_list; | |
156 | ||
157 | static int gnttab_expand(unsigned int req_entries); | |
158 | ||
159 | #define RPP (PAGE_SIZE / sizeof(grant_ref_t)) | |
85ff6acb | 160 | #define SPP (PAGE_SIZE / sizeof(grant_status_t)) |
ad9a8612 JF |
161 | |
162 | static inline grant_ref_t *__gnttab_entry(grant_ref_t entry) | |
163 | { | |
164 | return &gnttab_list[(entry) / RPP][(entry) % RPP]; | |
165 | } | |
166 | /* This can be used as an l-value */ | |
167 | #define gnttab_entry(entry) (*__gnttab_entry(entry)) | |
168 | ||
169 | static int get_free_entries(unsigned count) | |
170 | { | |
171 | unsigned long flags; | |
272800dc | 172 | int ref, rc = 0; |
ad9a8612 JF |
173 | grant_ref_t head; |
174 | ||
175 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
176 | ||
177 | if ((gnttab_free_count < count) && | |
178 | ((rc = gnttab_expand(count - gnttab_free_count)) < 0)) { | |
179 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
180 | return rc; | |
181 | } | |
182 | ||
183 | ref = head = gnttab_free_head; | |
184 | gnttab_free_count -= count; | |
185 | while (count-- > 1) | |
186 | head = gnttab_entry(head); | |
187 | gnttab_free_head = gnttab_entry(head); | |
188 | gnttab_entry(head) = GNTTAB_LIST_END; | |
189 | ||
190 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
191 | ||
192 | return ref; | |
193 | } | |
194 | ||
195 | static void do_free_callbacks(void) | |
196 | { | |
197 | struct gnttab_free_callback *callback, *next; | |
198 | ||
199 | callback = gnttab_free_callback_list; | |
200 | gnttab_free_callback_list = NULL; | |
201 | ||
202 | while (callback != NULL) { | |
203 | next = callback->next; | |
204 | if (gnttab_free_count >= callback->count) { | |
205 | callback->next = NULL; | |
206 | callback->fn(callback->arg); | |
207 | } else { | |
208 | callback->next = gnttab_free_callback_list; | |
209 | gnttab_free_callback_list = callback; | |
210 | } | |
211 | callback = next; | |
212 | } | |
213 | } | |
214 | ||
215 | static inline void check_free_callbacks(void) | |
216 | { | |
217 | if (unlikely(gnttab_free_callback_list)) | |
218 | do_free_callbacks(); | |
219 | } | |
220 | ||
221 | static void put_free_entry(grant_ref_t ref) | |
222 | { | |
223 | unsigned long flags; | |
224 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
225 | gnttab_entry(ref) = gnttab_free_head; | |
226 | gnttab_free_head = ref; | |
227 | gnttab_free_count++; | |
228 | check_free_callbacks(); | |
229 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
230 | } | |
231 | ||
0f9f5a95 | 232 | /* |
85ff6acb | 233 | * Following applies to gnttab_update_entry_v1 and gnttab_update_entry_v2. |
0f9f5a95 AL |
234 | * Introducing a valid entry into the grant table: |
235 | * 1. Write ent->domid. | |
236 | * 2. Write ent->frame: | |
237 | * GTF_permit_access: Frame to which access is permitted. | |
238 | * GTF_accept_transfer: Pseudo-phys frame slot being filled by new | |
239 | * frame, or zero if none. | |
240 | * 3. Write memory barrier (WMB). | |
241 | * 4. Write ent->flags, inc. valid type. | |
242 | */ | |
243 | static void gnttab_update_entry_v1(grant_ref_t ref, domid_t domid, | |
244 | unsigned long frame, unsigned flags) | |
ad9a8612 | 245 | { |
0f9f5a95 AL |
246 | gnttab_shared.v1[ref].domid = domid; |
247 | gnttab_shared.v1[ref].frame = frame; | |
ad9a8612 | 248 | wmb(); |
0f9f5a95 | 249 | gnttab_shared.v1[ref].flags = flags; |
ad9a8612 JF |
250 | } |
251 | ||
85ff6acb AL |
252 | static void gnttab_update_entry_v2(grant_ref_t ref, domid_t domid, |
253 | unsigned long frame, unsigned flags) | |
254 | { | |
255 | gnttab_shared.v2[ref].hdr.domid = domid; | |
256 | gnttab_shared.v2[ref].full_page.frame = frame; | |
257 | wmb(); | |
258 | gnttab_shared.v2[ref].hdr.flags = GTF_permit_access | flags; | |
259 | } | |
260 | ||
ad9a8612 JF |
261 | /* |
262 | * Public grant-issuing interface functions | |
263 | */ | |
264 | void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid, | |
265 | unsigned long frame, int readonly) | |
266 | { | |
0f9f5a95 | 267 | gnttab_interface->update_entry(ref, domid, frame, |
ad9a8612 JF |
268 | GTF_permit_access | (readonly ? GTF_readonly : 0)); |
269 | } | |
270 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_ref); | |
271 | ||
272 | int gnttab_grant_foreign_access(domid_t domid, unsigned long frame, | |
273 | int readonly) | |
274 | { | |
275 | int ref; | |
276 | ||
277 | ref = get_free_entries(1); | |
278 | if (unlikely(ref < 0)) | |
279 | return -ENOSPC; | |
280 | ||
281 | gnttab_grant_foreign_access_ref(ref, domid, frame, readonly); | |
282 | ||
283 | return ref; | |
284 | } | |
285 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access); | |
286 | ||
b8b0f559 KRW |
287 | static void gnttab_update_subpage_entry_v2(grant_ref_t ref, domid_t domid, |
288 | unsigned long frame, int flags, | |
289 | unsigned page_off, unsigned length) | |
6666754b AL |
290 | { |
291 | gnttab_shared.v2[ref].sub_page.frame = frame; | |
292 | gnttab_shared.v2[ref].sub_page.page_off = page_off; | |
293 | gnttab_shared.v2[ref].sub_page.length = length; | |
294 | gnttab_shared.v2[ref].hdr.domid = domid; | |
295 | wmb(); | |
296 | gnttab_shared.v2[ref].hdr.flags = | |
297 | GTF_permit_access | GTF_sub_page | flags; | |
298 | } | |
299 | ||
300 | int gnttab_grant_foreign_access_subpage_ref(grant_ref_t ref, domid_t domid, | |
301 | unsigned long frame, int flags, | |
302 | unsigned page_off, | |
303 | unsigned length) | |
304 | { | |
305 | if (flags & (GTF_accept_transfer | GTF_reading | | |
306 | GTF_writing | GTF_transitive)) | |
307 | return -EPERM; | |
308 | ||
309 | if (gnttab_interface->update_subpage_entry == NULL) | |
310 | return -ENOSYS; | |
311 | ||
312 | gnttab_interface->update_subpage_entry(ref, domid, frame, flags, | |
313 | page_off, length); | |
314 | ||
315 | return 0; | |
316 | } | |
317 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_subpage_ref); | |
318 | ||
319 | int gnttab_grant_foreign_access_subpage(domid_t domid, unsigned long frame, | |
320 | int flags, unsigned page_off, | |
321 | unsigned length) | |
322 | { | |
323 | int ref, rc; | |
324 | ||
325 | ref = get_free_entries(1); | |
326 | if (unlikely(ref < 0)) | |
327 | return -ENOSPC; | |
328 | ||
329 | rc = gnttab_grant_foreign_access_subpage_ref(ref, domid, frame, flags, | |
330 | page_off, length); | |
331 | if (rc < 0) { | |
332 | put_free_entry(ref); | |
333 | return rc; | |
334 | } | |
335 | ||
336 | return ref; | |
337 | } | |
338 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_subpage); | |
339 | ||
340 | bool gnttab_subpage_grants_available(void) | |
341 | { | |
342 | return gnttab_interface->update_subpage_entry != NULL; | |
343 | } | |
344 | EXPORT_SYMBOL_GPL(gnttab_subpage_grants_available); | |
345 | ||
b8b0f559 KRW |
346 | static void gnttab_update_trans_entry_v2(grant_ref_t ref, domid_t domid, |
347 | int flags, domid_t trans_domid, | |
348 | grant_ref_t trans_gref) | |
9438ce9d AL |
349 | { |
350 | gnttab_shared.v2[ref].transitive.trans_domid = trans_domid; | |
351 | gnttab_shared.v2[ref].transitive.gref = trans_gref; | |
352 | gnttab_shared.v2[ref].hdr.domid = domid; | |
353 | wmb(); | |
354 | gnttab_shared.v2[ref].hdr.flags = | |
355 | GTF_permit_access | GTF_transitive | flags; | |
356 | } | |
357 | ||
358 | int gnttab_grant_foreign_access_trans_ref(grant_ref_t ref, domid_t domid, | |
359 | int flags, domid_t trans_domid, | |
360 | grant_ref_t trans_gref) | |
361 | { | |
362 | if (flags & (GTF_accept_transfer | GTF_reading | | |
363 | GTF_writing | GTF_sub_page)) | |
364 | return -EPERM; | |
365 | ||
366 | if (gnttab_interface->update_trans_entry == NULL) | |
367 | return -ENOSYS; | |
368 | ||
369 | gnttab_interface->update_trans_entry(ref, domid, flags, trans_domid, | |
370 | trans_gref); | |
371 | ||
372 | return 0; | |
373 | } | |
374 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_trans_ref); | |
375 | ||
376 | int gnttab_grant_foreign_access_trans(domid_t domid, int flags, | |
377 | domid_t trans_domid, | |
378 | grant_ref_t trans_gref) | |
379 | { | |
380 | int ref, rc; | |
381 | ||
382 | ref = get_free_entries(1); | |
383 | if (unlikely(ref < 0)) | |
384 | return -ENOSPC; | |
385 | ||
386 | rc = gnttab_grant_foreign_access_trans_ref(ref, domid, flags, | |
387 | trans_domid, trans_gref); | |
388 | if (rc < 0) { | |
389 | put_free_entry(ref); | |
390 | return rc; | |
391 | } | |
392 | ||
393 | return ref; | |
394 | } | |
395 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_trans); | |
396 | ||
397 | bool gnttab_trans_grants_available(void) | |
398 | { | |
399 | return gnttab_interface->update_trans_entry != NULL; | |
400 | } | |
401 | EXPORT_SYMBOL_GPL(gnttab_trans_grants_available); | |
402 | ||
0f9f5a95 | 403 | static int gnttab_query_foreign_access_v1(grant_ref_t ref) |
ad9a8612 | 404 | { |
0f9f5a95 AL |
405 | return gnttab_shared.v1[ref].flags & (GTF_reading|GTF_writing); |
406 | } | |
ad9a8612 | 407 | |
85ff6acb AL |
408 | static int gnttab_query_foreign_access_v2(grant_ref_t ref) |
409 | { | |
410 | return grstatus[ref] & (GTF_reading|GTF_writing); | |
411 | } | |
412 | ||
0f9f5a95 AL |
413 | int gnttab_query_foreign_access(grant_ref_t ref) |
414 | { | |
415 | return gnttab_interface->query_foreign_access(ref); | |
ad9a8612 JF |
416 | } |
417 | EXPORT_SYMBOL_GPL(gnttab_query_foreign_access); | |
418 | ||
0f9f5a95 | 419 | static int gnttab_end_foreign_access_ref_v1(grant_ref_t ref, int readonly) |
ad9a8612 JF |
420 | { |
421 | u16 flags, nflags; | |
b1e495b2 | 422 | u16 *pflags; |
ad9a8612 | 423 | |
b1e495b2 AL |
424 | pflags = &gnttab_shared.v1[ref].flags; |
425 | nflags = *pflags; | |
ad9a8612 JF |
426 | do { |
427 | flags = nflags; | |
569ca5b3 | 428 | if (flags & (GTF_reading|GTF_writing)) |
ad9a8612 | 429 | return 0; |
b1e495b2 | 430 | } while ((nflags = sync_cmpxchg(pflags, flags, 0)) != flags); |
ad9a8612 JF |
431 | |
432 | return 1; | |
433 | } | |
0f9f5a95 | 434 | |
85ff6acb AL |
435 | static int gnttab_end_foreign_access_ref_v2(grant_ref_t ref, int readonly) |
436 | { | |
437 | gnttab_shared.v2[ref].hdr.flags = 0; | |
438 | mb(); | |
439 | if (grstatus[ref] & (GTF_reading|GTF_writing)) { | |
440 | return 0; | |
441 | } else { | |
442 | /* The read of grstatus needs to have acquire | |
443 | semantics. On x86, reads already have | |
444 | that, and we just need to protect against | |
445 | compiler reorderings. On other | |
446 | architectures we may need a full | |
447 | barrier. */ | |
448 | #ifdef CONFIG_X86 | |
449 | barrier(); | |
450 | #else | |
451 | mb(); | |
452 | #endif | |
453 | } | |
454 | ||
455 | return 1; | |
456 | } | |
457 | ||
569ca5b3 | 458 | static inline int _gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly) |
0f9f5a95 AL |
459 | { |
460 | return gnttab_interface->end_foreign_access_ref(ref, readonly); | |
461 | } | |
569ca5b3 JB |
462 | |
463 | int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly) | |
464 | { | |
465 | if (_gnttab_end_foreign_access_ref(ref, readonly)) | |
466 | return 1; | |
467 | pr_warn("WARNING: g.e. %#x still in use!\n", ref); | |
468 | return 0; | |
469 | } | |
ad9a8612 JF |
470 | EXPORT_SYMBOL_GPL(gnttab_end_foreign_access_ref); |
471 | ||
569ca5b3 JB |
472 | struct deferred_entry { |
473 | struct list_head list; | |
474 | grant_ref_t ref; | |
475 | bool ro; | |
476 | uint16_t warn_delay; | |
477 | struct page *page; | |
478 | }; | |
479 | static LIST_HEAD(deferred_list); | |
480 | static void gnttab_handle_deferred(unsigned long); | |
481 | static DEFINE_TIMER(deferred_timer, gnttab_handle_deferred, 0, 0); | |
482 | ||
483 | static void gnttab_handle_deferred(unsigned long unused) | |
484 | { | |
485 | unsigned int nr = 10; | |
486 | struct deferred_entry *first = NULL; | |
487 | unsigned long flags; | |
488 | ||
489 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
490 | while (nr--) { | |
491 | struct deferred_entry *entry | |
492 | = list_first_entry(&deferred_list, | |
493 | struct deferred_entry, list); | |
494 | ||
495 | if (entry == first) | |
496 | break; | |
497 | list_del(&entry->list); | |
498 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
499 | if (_gnttab_end_foreign_access_ref(entry->ref, entry->ro)) { | |
500 | put_free_entry(entry->ref); | |
501 | if (entry->page) { | |
502 | pr_debug("freeing g.e. %#x (pfn %#lx)\n", | |
503 | entry->ref, page_to_pfn(entry->page)); | |
504 | __free_page(entry->page); | |
505 | } else | |
506 | pr_info("freeing g.e. %#x\n", entry->ref); | |
507 | kfree(entry); | |
508 | entry = NULL; | |
509 | } else { | |
510 | if (!--entry->warn_delay) | |
511 | pr_info("g.e. %#x still pending\n", | |
512 | entry->ref); | |
513 | if (!first) | |
514 | first = entry; | |
515 | } | |
516 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
517 | if (entry) | |
518 | list_add_tail(&entry->list, &deferred_list); | |
519 | else if (list_empty(&deferred_list)) | |
520 | break; | |
521 | } | |
522 | if (!list_empty(&deferred_list) && !timer_pending(&deferred_timer)) { | |
523 | deferred_timer.expires = jiffies + HZ; | |
524 | add_timer(&deferred_timer); | |
525 | } | |
526 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
527 | } | |
528 | ||
529 | static void gnttab_add_deferred(grant_ref_t ref, bool readonly, | |
530 | struct page *page) | |
531 | { | |
532 | struct deferred_entry *entry = kmalloc(sizeof(*entry), GFP_ATOMIC); | |
533 | const char *what = KERN_WARNING "leaking"; | |
534 | ||
535 | if (entry) { | |
536 | unsigned long flags; | |
537 | ||
538 | entry->ref = ref; | |
539 | entry->ro = readonly; | |
540 | entry->page = page; | |
541 | entry->warn_delay = 60; | |
542 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
543 | list_add_tail(&entry->list, &deferred_list); | |
544 | if (!timer_pending(&deferred_timer)) { | |
545 | deferred_timer.expires = jiffies + HZ; | |
546 | add_timer(&deferred_timer); | |
547 | } | |
548 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
549 | what = KERN_DEBUG "deferring"; | |
550 | } | |
551 | printk("%s g.e. %#x (pfn %#lx)\n", | |
552 | what, ref, page ? page_to_pfn(page) : -1); | |
553 | } | |
554 | ||
ad9a8612 JF |
555 | void gnttab_end_foreign_access(grant_ref_t ref, int readonly, |
556 | unsigned long page) | |
557 | { | |
558 | if (gnttab_end_foreign_access_ref(ref, readonly)) { | |
559 | put_free_entry(ref); | |
560 | if (page != 0) | |
561 | free_page(page); | |
569ca5b3 JB |
562 | } else |
563 | gnttab_add_deferred(ref, readonly, | |
564 | page ? virt_to_page(page) : NULL); | |
ad9a8612 JF |
565 | } |
566 | EXPORT_SYMBOL_GPL(gnttab_end_foreign_access); | |
567 | ||
568 | int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn) | |
569 | { | |
570 | int ref; | |
571 | ||
572 | ref = get_free_entries(1); | |
573 | if (unlikely(ref < 0)) | |
574 | return -ENOSPC; | |
575 | gnttab_grant_foreign_transfer_ref(ref, domid, pfn); | |
576 | ||
577 | return ref; | |
578 | } | |
579 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_transfer); | |
580 | ||
581 | void gnttab_grant_foreign_transfer_ref(grant_ref_t ref, domid_t domid, | |
582 | unsigned long pfn) | |
583 | { | |
0f9f5a95 | 584 | gnttab_interface->update_entry(ref, domid, pfn, GTF_accept_transfer); |
ad9a8612 JF |
585 | } |
586 | EXPORT_SYMBOL_GPL(gnttab_grant_foreign_transfer_ref); | |
587 | ||
0f9f5a95 | 588 | static unsigned long gnttab_end_foreign_transfer_ref_v1(grant_ref_t ref) |
ad9a8612 JF |
589 | { |
590 | unsigned long frame; | |
591 | u16 flags; | |
b1e495b2 AL |
592 | u16 *pflags; |
593 | ||
594 | pflags = &gnttab_shared.v1[ref].flags; | |
ad9a8612 JF |
595 | |
596 | /* | |
597 | * If a transfer is not even yet started, try to reclaim the grant | |
598 | * reference and return failure (== 0). | |
599 | */ | |
b1e495b2 AL |
600 | while (!((flags = *pflags) & GTF_transfer_committed)) { |
601 | if (sync_cmpxchg(pflags, flags, 0) == flags) | |
ad9a8612 JF |
602 | return 0; |
603 | cpu_relax(); | |
604 | } | |
605 | ||
606 | /* If a transfer is in progress then wait until it is completed. */ | |
607 | while (!(flags & GTF_transfer_completed)) { | |
b1e495b2 | 608 | flags = *pflags; |
ad9a8612 JF |
609 | cpu_relax(); |
610 | } | |
611 | ||
612 | rmb(); /* Read the frame number /after/ reading completion status. */ | |
0f9f5a95 | 613 | frame = gnttab_shared.v1[ref].frame; |
ad9a8612 JF |
614 | BUG_ON(frame == 0); |
615 | ||
616 | return frame; | |
617 | } | |
0f9f5a95 | 618 | |
85ff6acb AL |
619 | static unsigned long gnttab_end_foreign_transfer_ref_v2(grant_ref_t ref) |
620 | { | |
621 | unsigned long frame; | |
622 | u16 flags; | |
623 | u16 *pflags; | |
624 | ||
625 | pflags = &gnttab_shared.v2[ref].hdr.flags; | |
626 | ||
627 | /* | |
628 | * If a transfer is not even yet started, try to reclaim the grant | |
629 | * reference and return failure (== 0). | |
630 | */ | |
631 | while (!((flags = *pflags) & GTF_transfer_committed)) { | |
632 | if (sync_cmpxchg(pflags, flags, 0) == flags) | |
633 | return 0; | |
634 | cpu_relax(); | |
635 | } | |
636 | ||
637 | /* If a transfer is in progress then wait until it is completed. */ | |
638 | while (!(flags & GTF_transfer_completed)) { | |
639 | flags = *pflags; | |
640 | cpu_relax(); | |
641 | } | |
642 | ||
643 | rmb(); /* Read the frame number /after/ reading completion status. */ | |
644 | frame = gnttab_shared.v2[ref].full_page.frame; | |
645 | BUG_ON(frame == 0); | |
646 | ||
647 | return frame; | |
648 | } | |
649 | ||
0f9f5a95 AL |
650 | unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref) |
651 | { | |
652 | return gnttab_interface->end_foreign_transfer_ref(ref); | |
653 | } | |
ad9a8612 JF |
654 | EXPORT_SYMBOL_GPL(gnttab_end_foreign_transfer_ref); |
655 | ||
656 | unsigned long gnttab_end_foreign_transfer(grant_ref_t ref) | |
657 | { | |
658 | unsigned long frame = gnttab_end_foreign_transfer_ref(ref); | |
659 | put_free_entry(ref); | |
660 | return frame; | |
661 | } | |
662 | EXPORT_SYMBOL_GPL(gnttab_end_foreign_transfer); | |
663 | ||
664 | void gnttab_free_grant_reference(grant_ref_t ref) | |
665 | { | |
666 | put_free_entry(ref); | |
667 | } | |
668 | EXPORT_SYMBOL_GPL(gnttab_free_grant_reference); | |
669 | ||
670 | void gnttab_free_grant_references(grant_ref_t head) | |
671 | { | |
672 | grant_ref_t ref; | |
673 | unsigned long flags; | |
674 | int count = 1; | |
675 | if (head == GNTTAB_LIST_END) | |
676 | return; | |
677 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
678 | ref = head; | |
679 | while (gnttab_entry(ref) != GNTTAB_LIST_END) { | |
680 | ref = gnttab_entry(ref); | |
681 | count++; | |
682 | } | |
683 | gnttab_entry(ref) = gnttab_free_head; | |
684 | gnttab_free_head = head; | |
685 | gnttab_free_count += count; | |
686 | check_free_callbacks(); | |
687 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
688 | } | |
689 | EXPORT_SYMBOL_GPL(gnttab_free_grant_references); | |
690 | ||
691 | int gnttab_alloc_grant_references(u16 count, grant_ref_t *head) | |
692 | { | |
693 | int h = get_free_entries(count); | |
694 | ||
695 | if (h < 0) | |
696 | return -ENOSPC; | |
697 | ||
698 | *head = h; | |
699 | ||
700 | return 0; | |
701 | } | |
702 | EXPORT_SYMBOL_GPL(gnttab_alloc_grant_references); | |
703 | ||
704 | int gnttab_empty_grant_references(const grant_ref_t *private_head) | |
705 | { | |
706 | return (*private_head == GNTTAB_LIST_END); | |
707 | } | |
708 | EXPORT_SYMBOL_GPL(gnttab_empty_grant_references); | |
709 | ||
710 | int gnttab_claim_grant_reference(grant_ref_t *private_head) | |
711 | { | |
712 | grant_ref_t g = *private_head; | |
713 | if (unlikely(g == GNTTAB_LIST_END)) | |
714 | return -ENOSPC; | |
715 | *private_head = gnttab_entry(g); | |
716 | return g; | |
717 | } | |
718 | EXPORT_SYMBOL_GPL(gnttab_claim_grant_reference); | |
719 | ||
720 | void gnttab_release_grant_reference(grant_ref_t *private_head, | |
721 | grant_ref_t release) | |
722 | { | |
723 | gnttab_entry(release) = *private_head; | |
724 | *private_head = release; | |
725 | } | |
726 | EXPORT_SYMBOL_GPL(gnttab_release_grant_reference); | |
727 | ||
728 | void gnttab_request_free_callback(struct gnttab_free_callback *callback, | |
729 | void (*fn)(void *), void *arg, u16 count) | |
730 | { | |
731 | unsigned long flags; | |
93326685 RPM |
732 | struct gnttab_free_callback *cb; |
733 | ||
ad9a8612 | 734 | spin_lock_irqsave(&gnttab_list_lock, flags); |
93326685 RPM |
735 | |
736 | /* Check if the callback is already on the list */ | |
737 | cb = gnttab_free_callback_list; | |
738 | while (cb) { | |
739 | if (cb == callback) | |
740 | goto out; | |
741 | cb = cb->next; | |
742 | } | |
743 | ||
ad9a8612 JF |
744 | callback->fn = fn; |
745 | callback->arg = arg; | |
746 | callback->count = count; | |
747 | callback->next = gnttab_free_callback_list; | |
748 | gnttab_free_callback_list = callback; | |
749 | check_free_callbacks(); | |
750 | out: | |
751 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
752 | } | |
753 | EXPORT_SYMBOL_GPL(gnttab_request_free_callback); | |
754 | ||
755 | void gnttab_cancel_free_callback(struct gnttab_free_callback *callback) | |
756 | { | |
757 | struct gnttab_free_callback **pcb; | |
758 | unsigned long flags; | |
759 | ||
760 | spin_lock_irqsave(&gnttab_list_lock, flags); | |
761 | for (pcb = &gnttab_free_callback_list; *pcb; pcb = &(*pcb)->next) { | |
762 | if (*pcb == callback) { | |
763 | *pcb = callback->next; | |
764 | break; | |
765 | } | |
766 | } | |
767 | spin_unlock_irqrestore(&gnttab_list_lock, flags); | |
768 | } | |
769 | EXPORT_SYMBOL_GPL(gnttab_cancel_free_callback); | |
770 | ||
771 | static int grow_gnttab_list(unsigned int more_frames) | |
772 | { | |
773 | unsigned int new_nr_grant_frames, extra_entries, i; | |
bbc60c18 | 774 | unsigned int nr_glist_frames, new_nr_glist_frames; |
ad9a8612 | 775 | |
d0b4d64a MW |
776 | BUG_ON(grefs_per_grant_frame == 0); |
777 | ||
ad9a8612 | 778 | new_nr_grant_frames = nr_grant_frames + more_frames; |
d0b4d64a | 779 | extra_entries = more_frames * grefs_per_grant_frame; |
ad9a8612 | 780 | |
d0b4d64a | 781 | nr_glist_frames = (nr_grant_frames * grefs_per_grant_frame + RPP - 1) / RPP; |
bbc60c18 | 782 | new_nr_glist_frames = |
d0b4d64a | 783 | (new_nr_grant_frames * grefs_per_grant_frame + RPP - 1) / RPP; |
bbc60c18 | 784 | for (i = nr_glist_frames; i < new_nr_glist_frames; i++) { |
ad9a8612 JF |
785 | gnttab_list[i] = (grant_ref_t *)__get_free_page(GFP_ATOMIC); |
786 | if (!gnttab_list[i]) | |
787 | goto grow_nomem; | |
788 | } | |
789 | ||
790 | ||
d0b4d64a MW |
791 | for (i = grefs_per_grant_frame * nr_grant_frames; |
792 | i < grefs_per_grant_frame * new_nr_grant_frames - 1; i++) | |
ad9a8612 JF |
793 | gnttab_entry(i) = i + 1; |
794 | ||
795 | gnttab_entry(i) = gnttab_free_head; | |
d0b4d64a | 796 | gnttab_free_head = grefs_per_grant_frame * nr_grant_frames; |
ad9a8612 JF |
797 | gnttab_free_count += extra_entries; |
798 | ||
799 | nr_grant_frames = new_nr_grant_frames; | |
800 | ||
801 | check_free_callbacks(); | |
802 | ||
803 | return 0; | |
804 | ||
805 | grow_nomem: | |
bbc60c18 | 806 | for ( ; i >= nr_glist_frames; i--) |
ad9a8612 JF |
807 | free_page((unsigned long) gnttab_list[i]); |
808 | return -ENOMEM; | |
809 | } | |
810 | ||
811 | static unsigned int __max_nr_grant_frames(void) | |
812 | { | |
813 | struct gnttab_query_size query; | |
814 | int rc; | |
815 | ||
816 | query.dom = DOMID_SELF; | |
817 | ||
818 | rc = HYPERVISOR_grant_table_op(GNTTABOP_query_size, &query, 1); | |
819 | if ((rc < 0) || (query.status != GNTST_okay)) | |
820 | return 4; /* Legacy max supported number of frames */ | |
821 | ||
822 | return query.max_nr_frames; | |
823 | } | |
824 | ||
183d03cc | 825 | unsigned int gnttab_max_grant_frames(void) |
ad9a8612 JF |
826 | { |
827 | unsigned int xen_max = __max_nr_grant_frames(); | |
828 | ||
829 | if (xen_max > boot_max_nr_grant_frames) | |
830 | return boot_max_nr_grant_frames; | |
831 | return xen_max; | |
832 | } | |
183d03cc | 833 | EXPORT_SYMBOL_GPL(gnttab_max_grant_frames); |
ad9a8612 | 834 | |
c571898f ALC |
835 | /* Handling of paged out grant targets (GNTST_eagain) */ |
836 | #define MAX_DELAY 256 | |
837 | static inline void | |
838 | gnttab_retry_eagain_gop(unsigned int cmd, void *gop, int16_t *status, | |
839 | const char *func) | |
840 | { | |
841 | unsigned delay = 1; | |
842 | ||
843 | do { | |
844 | BUG_ON(HYPERVISOR_grant_table_op(cmd, gop, 1)); | |
845 | if (*status == GNTST_eagain) | |
846 | msleep(delay++); | |
847 | } while ((*status == GNTST_eagain) && (delay < MAX_DELAY)); | |
848 | ||
849 | if (delay >= MAX_DELAY) { | |
850 | printk(KERN_ERR "%s: %s eagain grant\n", func, current->comm); | |
851 | *status = GNTST_bad_page; | |
852 | } | |
853 | } | |
854 | ||
855 | void gnttab_batch_map(struct gnttab_map_grant_ref *batch, unsigned count) | |
856 | { | |
857 | struct gnttab_map_grant_ref *op; | |
858 | ||
859 | if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, batch, count)) | |
860 | BUG(); | |
861 | for (op = batch; op < batch + count; op++) | |
862 | if (op->status == GNTST_eagain) | |
863 | gnttab_retry_eagain_gop(GNTTABOP_map_grant_ref, op, | |
864 | &op->status, __func__); | |
865 | } | |
866 | EXPORT_SYMBOL_GPL(gnttab_batch_map); | |
867 | ||
868 | void gnttab_batch_copy(struct gnttab_copy *batch, unsigned count) | |
869 | { | |
870 | struct gnttab_copy *op; | |
871 | ||
872 | if (HYPERVISOR_grant_table_op(GNTTABOP_copy, batch, count)) | |
873 | BUG(); | |
874 | for (op = batch; op < batch + count; op++) | |
875 | if (op->status == GNTST_eagain) | |
876 | gnttab_retry_eagain_gop(GNTTABOP_copy, op, | |
877 | &op->status, __func__); | |
878 | } | |
879 | EXPORT_SYMBOL_GPL(gnttab_batch_copy); | |
880 | ||
289b777e | 881 | int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, |
c123799a AL |
882 | struct gnttab_map_grant_ref *kmap_ops, |
883 | struct page **pages, unsigned int count) | |
289b777e SS |
884 | { |
885 | int i, ret; | |
f62805f1 | 886 | bool lazy = false; |
289b777e SS |
887 | pte_t *pte; |
888 | unsigned long mfn; | |
889 | ||
890 | ret = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, map_ops, count); | |
87f1d40a JF |
891 | if (ret) |
892 | return ret; | |
289b777e | 893 | |
c571898f ALC |
894 | /* Retry eagain maps */ |
895 | for (i = 0; i < count; i++) | |
896 | if (map_ops[i].status == GNTST_eagain) | |
897 | gnttab_retry_eagain_gop(GNTTABOP_map_grant_ref, map_ops + i, | |
898 | &map_ops[i].status, __func__); | |
899 | ||
aab8f11a DDG |
900 | if (xen_feature(XENFEAT_auto_translated_physmap)) |
901 | return ret; | |
902 | ||
f62805f1 SS |
903 | if (!in_interrupt() && paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) { |
904 | arch_enter_lazy_mmu_mode(); | |
905 | lazy = true; | |
906 | } | |
907 | ||
289b777e | 908 | for (i = 0; i < count; i++) { |
dc4972a4 IC |
909 | /* Do not add to override if the map failed. */ |
910 | if (map_ops[i].status) | |
911 | continue; | |
912 | ||
cf8d9163 KRW |
913 | if (map_ops[i].flags & GNTMAP_contains_pte) { |
914 | pte = (pte_t *) (mfn_to_virt(PFN_DOWN(map_ops[i].host_addr)) + | |
289b777e | 915 | (map_ops[i].host_addr & ~PAGE_MASK)); |
cf8d9163 KRW |
916 | mfn = pte_mfn(*pte); |
917 | } else { | |
7d17e84b | 918 | mfn = PFN_DOWN(map_ops[i].dev_bus_addr); |
cf8d9163 | 919 | } |
7d17e84b DDG |
920 | ret = m2p_add_override(mfn, pages[i], kmap_ops ? |
921 | &kmap_ops[i] : NULL); | |
87f1d40a | 922 | if (ret) |
c5234807 | 923 | goto out; |
289b777e SS |
924 | } |
925 | ||
c5234807 | 926 | out: |
f62805f1 SS |
927 | if (lazy) |
928 | arch_leave_lazy_mmu_mode(); | |
929 | ||
289b777e SS |
930 | return ret; |
931 | } | |
932 | EXPORT_SYMBOL_GPL(gnttab_map_refs); | |
933 | ||
934 | int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, | |
2fc136ee SS |
935 | struct gnttab_map_grant_ref *kmap_ops, |
936 | struct page **pages, unsigned int count) | |
289b777e SS |
937 | { |
938 | int i, ret; | |
f62805f1 | 939 | bool lazy = false; |
289b777e SS |
940 | |
941 | ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap_ops, count); | |
87f1d40a JF |
942 | if (ret) |
943 | return ret; | |
944 | ||
aab8f11a DDG |
945 | if (xen_feature(XENFEAT_auto_translated_physmap)) |
946 | return ret; | |
947 | ||
f62805f1 SS |
948 | if (!in_interrupt() && paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) { |
949 | arch_enter_lazy_mmu_mode(); | |
950 | lazy = true; | |
951 | } | |
952 | ||
87f1d40a | 953 | for (i = 0; i < count; i++) { |
2fc136ee SS |
954 | ret = m2p_remove_override(pages[i], kmap_ops ? |
955 | &kmap_ops[i] : NULL); | |
87f1d40a | 956 | if (ret) |
c5234807 | 957 | goto out; |
87f1d40a | 958 | } |
289b777e | 959 | |
c5234807 | 960 | out: |
f62805f1 SS |
961 | if (lazy) |
962 | arch_leave_lazy_mmu_mode(); | |
963 | ||
289b777e SS |
964 | return ret; |
965 | } | |
966 | EXPORT_SYMBOL_GPL(gnttab_unmap_refs); | |
967 | ||
85ff6acb AL |
968 | static unsigned nr_status_frames(unsigned nr_grant_frames) |
969 | { | |
d0b4d64a MW |
970 | BUG_ON(grefs_per_grant_frame == 0); |
971 | return (nr_grant_frames * grefs_per_grant_frame + SPP - 1) / SPP; | |
85ff6acb AL |
972 | } |
973 | ||
ef32f892 | 974 | static int gnttab_map_frames_v1(xen_pfn_t *frames, unsigned int nr_gframes) |
0f9f5a95 AL |
975 | { |
976 | int rc; | |
977 | ||
978 | rc = arch_gnttab_map_shared(frames, nr_gframes, | |
979 | gnttab_max_grant_frames(), | |
980 | &gnttab_shared.addr); | |
981 | BUG_ON(rc); | |
982 | ||
983 | return 0; | |
984 | } | |
985 | ||
986 | static void gnttab_unmap_frames_v1(void) | |
987 | { | |
85ff6acb AL |
988 | arch_gnttab_unmap(gnttab_shared.addr, nr_grant_frames); |
989 | } | |
990 | ||
ef32f892 | 991 | static int gnttab_map_frames_v2(xen_pfn_t *frames, unsigned int nr_gframes) |
85ff6acb AL |
992 | { |
993 | uint64_t *sframes; | |
994 | unsigned int nr_sframes; | |
995 | struct gnttab_get_status_frames getframes; | |
996 | int rc; | |
997 | ||
998 | nr_sframes = nr_status_frames(nr_gframes); | |
999 | ||
1000 | /* No need for kzalloc as it is initialized in following hypercall | |
1001 | * GNTTABOP_get_status_frames. | |
1002 | */ | |
1003 | sframes = kmalloc(nr_sframes * sizeof(uint64_t), GFP_ATOMIC); | |
1004 | if (!sframes) | |
1005 | return -ENOMEM; | |
1006 | ||
1007 | getframes.dom = DOMID_SELF; | |
1008 | getframes.nr_frames = nr_sframes; | |
1009 | set_xen_guest_handle(getframes.frame_list, sframes); | |
1010 | ||
1011 | rc = HYPERVISOR_grant_table_op(GNTTABOP_get_status_frames, | |
1012 | &getframes, 1); | |
1013 | if (rc == -ENOSYS) { | |
1014 | kfree(sframes); | |
1015 | return -ENOSYS; | |
1016 | } | |
1017 | ||
1018 | BUG_ON(rc || getframes.status); | |
1019 | ||
1020 | rc = arch_gnttab_map_status(sframes, nr_sframes, | |
1021 | nr_status_frames(gnttab_max_grant_frames()), | |
1022 | &grstatus); | |
1023 | BUG_ON(rc); | |
1024 | kfree(sframes); | |
1025 | ||
1026 | rc = arch_gnttab_map_shared(frames, nr_gframes, | |
1027 | gnttab_max_grant_frames(), | |
1028 | &gnttab_shared.addr); | |
1029 | BUG_ON(rc); | |
1030 | ||
1031 | return 0; | |
1032 | } | |
1033 | ||
1034 | static void gnttab_unmap_frames_v2(void) | |
1035 | { | |
1036 | arch_gnttab_unmap(gnttab_shared.addr, nr_grant_frames); | |
1037 | arch_gnttab_unmap(grstatus, nr_status_frames(nr_grant_frames)); | |
0f9f5a95 AL |
1038 | } |
1039 | ||
ad9a8612 JF |
1040 | static int gnttab_map(unsigned int start_idx, unsigned int end_idx) |
1041 | { | |
1042 | struct gnttab_setup_table setup; | |
ef32f892 | 1043 | xen_pfn_t *frames; |
ad9a8612 JF |
1044 | unsigned int nr_gframes = end_idx + 1; |
1045 | int rc; | |
1046 | ||
183d03cc SS |
1047 | if (xen_hvm_domain()) { |
1048 | struct xen_add_to_physmap xatp; | |
1049 | unsigned int i = end_idx; | |
1050 | rc = 0; | |
1051 | /* | |
1052 | * Loop backwards, so that the first hypercall has the largest | |
1053 | * index, ensuring that the table will grow only once. | |
1054 | */ | |
1055 | do { | |
1056 | xatp.domid = DOMID_SELF; | |
1057 | xatp.idx = i; | |
1058 | xatp.space = XENMAPSPACE_grant_table; | |
1059 | xatp.gpfn = (xen_hvm_resume_frames >> PAGE_SHIFT) + i; | |
1060 | rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp); | |
1061 | if (rc != 0) { | |
1062 | printk(KERN_WARNING | |
1063 | "grant table add_to_physmap failed, err=%d\n", rc); | |
1064 | break; | |
1065 | } | |
1066 | } while (i-- > start_idx); | |
1067 | ||
1068 | return rc; | |
1069 | } | |
1070 | ||
85ff6acb AL |
1071 | /* No need for kzalloc as it is initialized in following hypercall |
1072 | * GNTTABOP_setup_table. | |
1073 | */ | |
ad9a8612 JF |
1074 | frames = kmalloc(nr_gframes * sizeof(unsigned long), GFP_ATOMIC); |
1075 | if (!frames) | |
1076 | return -ENOMEM; | |
1077 | ||
1078 | setup.dom = DOMID_SELF; | |
1079 | setup.nr_frames = nr_gframes; | |
87e27cf6 | 1080 | set_xen_guest_handle(setup.frame_list, frames); |
ad9a8612 JF |
1081 | |
1082 | rc = HYPERVISOR_grant_table_op(GNTTABOP_setup_table, &setup, 1); | |
1083 | if (rc == -ENOSYS) { | |
1084 | kfree(frames); | |
1085 | return -ENOSYS; | |
1086 | } | |
1087 | ||
1088 | BUG_ON(rc || setup.status); | |
1089 | ||
0f9f5a95 | 1090 | rc = gnttab_interface->map_frames(frames, nr_gframes); |
ad9a8612 JF |
1091 | |
1092 | kfree(frames); | |
1093 | ||
0f9f5a95 AL |
1094 | return rc; |
1095 | } | |
1096 | ||
1097 | static struct gnttab_ops gnttab_v1_ops = { | |
1098 | .map_frames = gnttab_map_frames_v1, | |
1099 | .unmap_frames = gnttab_unmap_frames_v1, | |
1100 | .update_entry = gnttab_update_entry_v1, | |
1101 | .end_foreign_access_ref = gnttab_end_foreign_access_ref_v1, | |
1102 | .end_foreign_transfer_ref = gnttab_end_foreign_transfer_ref_v1, | |
1103 | .query_foreign_access = gnttab_query_foreign_access_v1, | |
1104 | }; | |
1105 | ||
85ff6acb AL |
1106 | static struct gnttab_ops gnttab_v2_ops = { |
1107 | .map_frames = gnttab_map_frames_v2, | |
1108 | .unmap_frames = gnttab_unmap_frames_v2, | |
1109 | .update_entry = gnttab_update_entry_v2, | |
1110 | .end_foreign_access_ref = gnttab_end_foreign_access_ref_v2, | |
1111 | .end_foreign_transfer_ref = gnttab_end_foreign_transfer_ref_v2, | |
1112 | .query_foreign_access = gnttab_query_foreign_access_v2, | |
6666754b | 1113 | .update_subpage_entry = gnttab_update_subpage_entry_v2, |
9438ce9d | 1114 | .update_trans_entry = gnttab_update_trans_entry_v2, |
85ff6acb AL |
1115 | }; |
1116 | ||
0f9f5a95 AL |
1117 | static void gnttab_request_version(void) |
1118 | { | |
85ff6acb AL |
1119 | int rc; |
1120 | struct gnttab_set_version gsv; | |
1121 | ||
69e8f430 KRW |
1122 | if (xen_hvm_domain()) |
1123 | gsv.version = 1; | |
1124 | else | |
1125 | gsv.version = 2; | |
85ff6acb | 1126 | rc = HYPERVISOR_grant_table_op(GNTTABOP_set_version, &gsv, 1); |
69e8f430 | 1127 | if (rc == 0 && gsv.version == 2) { |
85ff6acb | 1128 | grant_table_version = 2; |
d0b4d64a | 1129 | grefs_per_grant_frame = PAGE_SIZE / sizeof(union grant_entry_v2); |
85ff6acb AL |
1130 | gnttab_interface = &gnttab_v2_ops; |
1131 | } else if (grant_table_version == 2) { | |
1132 | /* | |
1133 | * If we've already used version 2 features, | |
1134 | * but then suddenly discover that they're not | |
1135 | * available (e.g. migrating to an older | |
1136 | * version of Xen), almost unbounded badness | |
1137 | * can happen. | |
1138 | */ | |
1139 | panic("we need grant tables version 2, but only version 1 is available"); | |
1140 | } else { | |
1141 | grant_table_version = 1; | |
d0b4d64a | 1142 | grefs_per_grant_frame = PAGE_SIZE / sizeof(struct grant_entry_v1); |
85ff6acb AL |
1143 | gnttab_interface = &gnttab_v1_ops; |
1144 | } | |
0f9f5a95 AL |
1145 | printk(KERN_INFO "Grant tables using version %d layout.\n", |
1146 | grant_table_version); | |
ad9a8612 JF |
1147 | } |
1148 | ||
d0b4d64a | 1149 | static int gnttab_setup(void) |
ad9a8612 | 1150 | { |
183d03cc SS |
1151 | unsigned int max_nr_gframes; |
1152 | ||
1153 | max_nr_gframes = gnttab_max_grant_frames(); | |
1154 | if (max_nr_gframes < nr_grant_frames) | |
ad9a8612 | 1155 | return -ENOSYS; |
183d03cc SS |
1156 | |
1157 | if (xen_pv_domain()) | |
1158 | return gnttab_map(0, nr_grant_frames - 1); | |
1159 | ||
0f9f5a95 | 1160 | if (gnttab_shared.addr == NULL) { |
3216dceb | 1161 | gnttab_shared.addr = xen_remap(xen_hvm_resume_frames, |
0f9f5a95 AL |
1162 | PAGE_SIZE * max_nr_gframes); |
1163 | if (gnttab_shared.addr == NULL) { | |
183d03cc SS |
1164 | printk(KERN_WARNING |
1165 | "Failed to ioremap gnttab share frames!"); | |
1166 | return -ENOMEM; | |
1167 | } | |
1168 | } | |
1169 | ||
1170 | gnttab_map(0, nr_grant_frames - 1); | |
1171 | ||
1172 | return 0; | |
ad9a8612 JF |
1173 | } |
1174 | ||
d0b4d64a MW |
1175 | int gnttab_resume(void) |
1176 | { | |
1177 | gnttab_request_version(); | |
1178 | return gnttab_setup(); | |
1179 | } | |
1180 | ||
0e91398f | 1181 | int gnttab_suspend(void) |
ad9a8612 | 1182 | { |
0f9f5a95 | 1183 | gnttab_interface->unmap_frames(); |
ad9a8612 JF |
1184 | return 0; |
1185 | } | |
1186 | ||
1187 | static int gnttab_expand(unsigned int req_entries) | |
1188 | { | |
1189 | int rc; | |
1190 | unsigned int cur, extra; | |
1191 | ||
d0b4d64a | 1192 | BUG_ON(grefs_per_grant_frame == 0); |
ad9a8612 | 1193 | cur = nr_grant_frames; |
d0b4d64a MW |
1194 | extra = ((req_entries + (grefs_per_grant_frame-1)) / |
1195 | grefs_per_grant_frame); | |
183d03cc | 1196 | if (cur + extra > gnttab_max_grant_frames()) |
ad9a8612 JF |
1197 | return -ENOSPC; |
1198 | ||
1199 | rc = gnttab_map(cur, cur + extra - 1); | |
1200 | if (rc == 0) | |
1201 | rc = grow_gnttab_list(extra); | |
1202 | ||
1203 | return rc; | |
1204 | } | |
1205 | ||
183d03cc | 1206 | int gnttab_init(void) |
ad9a8612 JF |
1207 | { |
1208 | int i; | |
bbc60c18 | 1209 | unsigned int max_nr_glist_frames, nr_glist_frames; |
ad9a8612 | 1210 | unsigned int nr_init_grefs; |
6b5e7d9e | 1211 | int ret; |
ad9a8612 | 1212 | |
d0b4d64a | 1213 | gnttab_request_version(); |
ad9a8612 JF |
1214 | nr_grant_frames = 1; |
1215 | boot_max_nr_grant_frames = __max_nr_grant_frames(); | |
1216 | ||
1217 | /* Determine the maximum number of frames required for the | |
1218 | * grant reference free list on the current hypervisor. | |
1219 | */ | |
d0b4d64a | 1220 | BUG_ON(grefs_per_grant_frame == 0); |
ad9a8612 | 1221 | max_nr_glist_frames = (boot_max_nr_grant_frames * |
d0b4d64a | 1222 | grefs_per_grant_frame / RPP); |
ad9a8612 JF |
1223 | |
1224 | gnttab_list = kmalloc(max_nr_glist_frames * sizeof(grant_ref_t *), | |
1225 | GFP_KERNEL); | |
1226 | if (gnttab_list == NULL) | |
1227 | return -ENOMEM; | |
1228 | ||
d0b4d64a | 1229 | nr_glist_frames = (nr_grant_frames * grefs_per_grant_frame + RPP - 1) / RPP; |
bbc60c18 | 1230 | for (i = 0; i < nr_glist_frames; i++) { |
ad9a8612 | 1231 | gnttab_list[i] = (grant_ref_t *)__get_free_page(GFP_KERNEL); |
6b5e7d9e JL |
1232 | if (gnttab_list[i] == NULL) { |
1233 | ret = -ENOMEM; | |
ad9a8612 | 1234 | goto ini_nomem; |
6b5e7d9e | 1235 | } |
ad9a8612 JF |
1236 | } |
1237 | ||
d0b4d64a | 1238 | if (gnttab_setup() < 0) { |
6b5e7d9e JL |
1239 | ret = -ENODEV; |
1240 | goto ini_nomem; | |
1241 | } | |
ad9a8612 | 1242 | |
d0b4d64a | 1243 | nr_init_grefs = nr_grant_frames * grefs_per_grant_frame; |
ad9a8612 JF |
1244 | |
1245 | for (i = NR_RESERVED_ENTRIES; i < nr_init_grefs - 1; i++) | |
1246 | gnttab_entry(i) = i + 1; | |
1247 | ||
1248 | gnttab_entry(nr_init_grefs - 1) = GNTTAB_LIST_END; | |
1249 | gnttab_free_count = nr_init_grefs - NR_RESERVED_ENTRIES; | |
1250 | gnttab_free_head = NR_RESERVED_ENTRIES; | |
1251 | ||
1252 | printk("Grant table initialized\n"); | |
1253 | return 0; | |
1254 | ||
1255 | ini_nomem: | |
1256 | for (i--; i >= 0; i--) | |
1257 | free_page((unsigned long)gnttab_list[i]); | |
1258 | kfree(gnttab_list); | |
6b5e7d9e | 1259 | return ret; |
ad9a8612 | 1260 | } |
183d03cc SS |
1261 | EXPORT_SYMBOL_GPL(gnttab_init); |
1262 | ||
345a5255 | 1263 | static int __gnttab_init(void) |
183d03cc SS |
1264 | { |
1265 | /* Delay grant-table initialization in the PV on HVM case */ | |
1266 | if (xen_hvm_domain()) | |
1267 | return 0; | |
1268 | ||
1269 | if (!xen_pv_domain()) | |
1270 | return -ENODEV; | |
1271 | ||
1272 | return gnttab_init(); | |
1273 | } | |
ad9a8612 | 1274 | |
183d03cc | 1275 | core_initcall(__gnttab_init); |