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1 | /* | |
2 | * Copyright (C) 2011 Citrix Ltd. | |
3 | * | |
4 | * This work is licensed under the terms of the GNU GPL, version 2. See | |
5 | * the COPYING file in the top-level directory. | |
6 | * | |
7 | * Contributions after 2012-01-13 are licensed under the terms of the | |
8 | * GNU GPL, version 2 or (at your option) any later version. | |
9 | */ | |
10 | ||
11 | #include "qemu/osdep.h" | |
12 | ||
13 | #include <sys/resource.h> | |
14 | ||
15 | #include "hw/xen/xen_backend.h" | |
16 | #include "sysemu/blockdev.h" | |
17 | #include "qemu/bitmap.h" | |
18 | ||
19 | #include <xen/hvm/params.h> | |
20 | #include <sys/mman.h> | |
21 | ||
22 | #include "sysemu/xen-mapcache.h" | |
23 | #include "trace.h" | |
24 | ||
25 | ||
26 | //#define MAPCACHE_DEBUG | |
27 | ||
28 | #ifdef MAPCACHE_DEBUG | |
29 | # define DPRINTF(fmt, ...) do { \ | |
30 | fprintf(stderr, "xen_mapcache: " fmt, ## __VA_ARGS__); \ | |
31 | } while (0) | |
32 | #else | |
33 | # define DPRINTF(fmt, ...) do { } while (0) | |
34 | #endif | |
35 | ||
36 | #if HOST_LONG_BITS == 32 | |
37 | # define MCACHE_BUCKET_SHIFT 16 | |
38 | # define MCACHE_MAX_SIZE (1UL<<31) /* 2GB Cap */ | |
39 | #else | |
40 | # define MCACHE_BUCKET_SHIFT 20 | |
41 | # define MCACHE_MAX_SIZE (1UL<<35) /* 32GB Cap */ | |
42 | #endif | |
43 | #define MCACHE_BUCKET_SIZE (1UL << MCACHE_BUCKET_SHIFT) | |
44 | ||
45 | /* This is the size of the virtual address space reserve to QEMU that will not | |
46 | * be use by MapCache. | |
47 | * From empirical tests I observed that qemu use 75MB more than the | |
48 | * max_mcache_size. | |
49 | */ | |
50 | #define NON_MCACHE_MEMORY_SIZE (80 * 1024 * 1024) | |
51 | ||
52 | typedef struct MapCacheEntry { | |
53 | hwaddr paddr_index; | |
54 | uint8_t *vaddr_base; | |
55 | unsigned long *valid_mapping; | |
56 | uint8_t lock; | |
57 | hwaddr size; | |
58 | struct MapCacheEntry *next; | |
59 | } MapCacheEntry; | |
60 | ||
61 | typedef struct MapCacheRev { | |
62 | uint8_t *vaddr_req; | |
63 | hwaddr paddr_index; | |
64 | hwaddr size; | |
65 | QTAILQ_ENTRY(MapCacheRev) next; | |
66 | } MapCacheRev; | |
67 | ||
68 | typedef struct MapCache { | |
69 | MapCacheEntry *entry; | |
70 | unsigned long nr_buckets; | |
71 | QTAILQ_HEAD(map_cache_head, MapCacheRev) locked_entries; | |
72 | ||
73 | /* For most cases (>99.9%), the page address is the same. */ | |
74 | MapCacheEntry *last_entry; | |
75 | unsigned long max_mcache_size; | |
76 | unsigned int mcache_bucket_shift; | |
77 | ||
78 | phys_offset_to_gaddr_t phys_offset_to_gaddr; | |
79 | QemuMutex lock; | |
80 | void *opaque; | |
81 | } MapCache; | |
82 | ||
83 | static MapCache *mapcache; | |
84 | ||
85 | static inline void mapcache_lock(void) | |
86 | { | |
87 | qemu_mutex_lock(&mapcache->lock); | |
88 | } | |
89 | ||
90 | static inline void mapcache_unlock(void) | |
91 | { | |
92 | qemu_mutex_unlock(&mapcache->lock); | |
93 | } | |
94 | ||
95 | static inline int test_bits(int nr, int size, const unsigned long *addr) | |
96 | { | |
97 | unsigned long res = find_next_zero_bit(addr, size + nr, nr); | |
98 | if (res >= nr + size) | |
99 | return 1; | |
100 | else | |
101 | return 0; | |
102 | } | |
103 | ||
104 | void xen_map_cache_init(phys_offset_to_gaddr_t f, void *opaque) | |
105 | { | |
106 | unsigned long size; | |
107 | struct rlimit rlimit_as; | |
108 | ||
109 | mapcache = g_malloc0(sizeof (MapCache)); | |
110 | ||
111 | mapcache->phys_offset_to_gaddr = f; | |
112 | mapcache->opaque = opaque; | |
113 | qemu_mutex_init(&mapcache->lock); | |
114 | ||
115 | QTAILQ_INIT(&mapcache->locked_entries); | |
116 | ||
117 | if (geteuid() == 0) { | |
118 | rlimit_as.rlim_cur = RLIM_INFINITY; | |
119 | rlimit_as.rlim_max = RLIM_INFINITY; | |
120 | mapcache->max_mcache_size = MCACHE_MAX_SIZE; | |
121 | } else { | |
122 | getrlimit(RLIMIT_AS, &rlimit_as); | |
123 | rlimit_as.rlim_cur = rlimit_as.rlim_max; | |
124 | ||
125 | if (rlimit_as.rlim_max != RLIM_INFINITY) { | |
126 | fprintf(stderr, "Warning: QEMU's maximum size of virtual" | |
127 | " memory is not infinity.\n"); | |
128 | } | |
129 | if (rlimit_as.rlim_max < MCACHE_MAX_SIZE + NON_MCACHE_MEMORY_SIZE) { | |
130 | mapcache->max_mcache_size = rlimit_as.rlim_max - | |
131 | NON_MCACHE_MEMORY_SIZE; | |
132 | } else { | |
133 | mapcache->max_mcache_size = MCACHE_MAX_SIZE; | |
134 | } | |
135 | } | |
136 | ||
137 | setrlimit(RLIMIT_AS, &rlimit_as); | |
138 | ||
139 | mapcache->nr_buckets = | |
140 | (((mapcache->max_mcache_size >> XC_PAGE_SHIFT) + | |
141 | (1UL << (MCACHE_BUCKET_SHIFT - XC_PAGE_SHIFT)) - 1) >> | |
142 | (MCACHE_BUCKET_SHIFT - XC_PAGE_SHIFT)); | |
143 | ||
144 | size = mapcache->nr_buckets * sizeof (MapCacheEntry); | |
145 | size = (size + XC_PAGE_SIZE - 1) & ~(XC_PAGE_SIZE - 1); | |
146 | DPRINTF("%s, nr_buckets = %lx size %lu\n", __func__, | |
147 | mapcache->nr_buckets, size); | |
148 | mapcache->entry = g_malloc0(size); | |
149 | } | |
150 | ||
151 | static void xen_remap_bucket(MapCacheEntry *entry, | |
152 | hwaddr size, | |
153 | hwaddr address_index) | |
154 | { | |
155 | uint8_t *vaddr_base; | |
156 | xen_pfn_t *pfns; | |
157 | int *err; | |
158 | unsigned int i; | |
159 | hwaddr nb_pfn = size >> XC_PAGE_SHIFT; | |
160 | ||
161 | trace_xen_remap_bucket(address_index); | |
162 | ||
163 | pfns = g_malloc0(nb_pfn * sizeof (xen_pfn_t)); | |
164 | err = g_malloc0(nb_pfn * sizeof (int)); | |
165 | ||
166 | if (entry->vaddr_base != NULL) { | |
167 | if (munmap(entry->vaddr_base, entry->size) != 0) { | |
168 | perror("unmap fails"); | |
169 | exit(-1); | |
170 | } | |
171 | } | |
172 | g_free(entry->valid_mapping); | |
173 | entry->valid_mapping = NULL; | |
174 | ||
175 | for (i = 0; i < nb_pfn; i++) { | |
176 | pfns[i] = (address_index << (MCACHE_BUCKET_SHIFT-XC_PAGE_SHIFT)) + i; | |
177 | } | |
178 | ||
179 | vaddr_base = xenforeignmemory_map(xen_fmem, xen_domid, PROT_READ|PROT_WRITE, | |
180 | nb_pfn, pfns, err); | |
181 | if (vaddr_base == NULL) { | |
182 | perror("xenforeignmemory_map"); | |
183 | exit(-1); | |
184 | } | |
185 | ||
186 | entry->vaddr_base = vaddr_base; | |
187 | entry->paddr_index = address_index; | |
188 | entry->size = size; | |
189 | entry->valid_mapping = (unsigned long *) g_malloc0(sizeof(unsigned long) * | |
190 | BITS_TO_LONGS(size >> XC_PAGE_SHIFT)); | |
191 | ||
192 | bitmap_zero(entry->valid_mapping, nb_pfn); | |
193 | for (i = 0; i < nb_pfn; i++) { | |
194 | if (!err[i]) { | |
195 | bitmap_set(entry->valid_mapping, i, 1); | |
196 | } | |
197 | } | |
198 | ||
199 | g_free(pfns); | |
200 | g_free(err); | |
201 | } | |
202 | ||
203 | static uint8_t *xen_map_cache_unlocked(hwaddr phys_addr, hwaddr size, | |
204 | uint8_t lock) | |
205 | { | |
206 | MapCacheEntry *entry, *pentry = NULL; | |
207 | hwaddr address_index; | |
208 | hwaddr address_offset; | |
209 | hwaddr cache_size = size; | |
210 | hwaddr test_bit_size; | |
211 | bool translated = false; | |
212 | ||
213 | tryagain: | |
214 | address_index = phys_addr >> MCACHE_BUCKET_SHIFT; | |
215 | address_offset = phys_addr & (MCACHE_BUCKET_SIZE - 1); | |
216 | ||
217 | trace_xen_map_cache(phys_addr); | |
218 | ||
219 | /* test_bit_size is always a multiple of XC_PAGE_SIZE */ | |
220 | if (size) { | |
221 | test_bit_size = size + (phys_addr & (XC_PAGE_SIZE - 1)); | |
222 | ||
223 | if (test_bit_size % XC_PAGE_SIZE) { | |
224 | test_bit_size += XC_PAGE_SIZE - (test_bit_size % XC_PAGE_SIZE); | |
225 | } | |
226 | } else { | |
227 | test_bit_size = XC_PAGE_SIZE; | |
228 | } | |
229 | ||
230 | if (mapcache->last_entry != NULL && | |
231 | mapcache->last_entry->paddr_index == address_index && | |
232 | !lock && !size && | |
233 | test_bits(address_offset >> XC_PAGE_SHIFT, | |
234 | test_bit_size >> XC_PAGE_SHIFT, | |
235 | mapcache->last_entry->valid_mapping)) { | |
236 | trace_xen_map_cache_return(mapcache->last_entry->vaddr_base + address_offset); | |
237 | return mapcache->last_entry->vaddr_base + address_offset; | |
238 | } | |
239 | ||
240 | /* size is always a multiple of MCACHE_BUCKET_SIZE */ | |
241 | if (size) { | |
242 | cache_size = size + address_offset; | |
243 | if (cache_size % MCACHE_BUCKET_SIZE) { | |
244 | cache_size += MCACHE_BUCKET_SIZE - (cache_size % MCACHE_BUCKET_SIZE); | |
245 | } | |
246 | } else { | |
247 | cache_size = MCACHE_BUCKET_SIZE; | |
248 | } | |
249 | ||
250 | entry = &mapcache->entry[address_index % mapcache->nr_buckets]; | |
251 | ||
252 | while (entry && entry->lock && entry->vaddr_base && | |
253 | (entry->paddr_index != address_index || entry->size != cache_size || | |
254 | !test_bits(address_offset >> XC_PAGE_SHIFT, | |
255 | test_bit_size >> XC_PAGE_SHIFT, | |
256 | entry->valid_mapping))) { | |
257 | pentry = entry; | |
258 | entry = entry->next; | |
259 | } | |
260 | if (!entry) { | |
261 | entry = g_malloc0(sizeof (MapCacheEntry)); | |
262 | pentry->next = entry; | |
263 | xen_remap_bucket(entry, cache_size, address_index); | |
264 | } else if (!entry->lock) { | |
265 | if (!entry->vaddr_base || entry->paddr_index != address_index || | |
266 | entry->size != cache_size || | |
267 | !test_bits(address_offset >> XC_PAGE_SHIFT, | |
268 | test_bit_size >> XC_PAGE_SHIFT, | |
269 | entry->valid_mapping)) { | |
270 | xen_remap_bucket(entry, cache_size, address_index); | |
271 | } | |
272 | } | |
273 | ||
274 | if(!test_bits(address_offset >> XC_PAGE_SHIFT, | |
275 | test_bit_size >> XC_PAGE_SHIFT, | |
276 | entry->valid_mapping)) { | |
277 | mapcache->last_entry = NULL; | |
278 | if (!translated && mapcache->phys_offset_to_gaddr) { | |
279 | phys_addr = mapcache->phys_offset_to_gaddr(phys_addr, size, mapcache->opaque); | |
280 | translated = true; | |
281 | goto tryagain; | |
282 | } | |
283 | trace_xen_map_cache_return(NULL); | |
284 | return NULL; | |
285 | } | |
286 | ||
287 | mapcache->last_entry = entry; | |
288 | if (lock) { | |
289 | MapCacheRev *reventry = g_malloc0(sizeof(MapCacheRev)); | |
290 | entry->lock++; | |
291 | reventry->vaddr_req = mapcache->last_entry->vaddr_base + address_offset; | |
292 | reventry->paddr_index = mapcache->last_entry->paddr_index; | |
293 | reventry->size = entry->size; | |
294 | QTAILQ_INSERT_HEAD(&mapcache->locked_entries, reventry, next); | |
295 | } | |
296 | ||
297 | trace_xen_map_cache_return(mapcache->last_entry->vaddr_base + address_offset); | |
298 | return mapcache->last_entry->vaddr_base + address_offset; | |
299 | } | |
300 | ||
301 | uint8_t *xen_map_cache(hwaddr phys_addr, hwaddr size, | |
302 | uint8_t lock) | |
303 | { | |
304 | uint8_t *p; | |
305 | ||
306 | mapcache_lock(); | |
307 | p = xen_map_cache_unlocked(phys_addr, size, lock); | |
308 | mapcache_unlock(); | |
309 | return p; | |
310 | } | |
311 | ||
312 | ram_addr_t xen_ram_addr_from_mapcache(void *ptr) | |
313 | { | |
314 | MapCacheEntry *entry = NULL; | |
315 | MapCacheRev *reventry; | |
316 | hwaddr paddr_index; | |
317 | hwaddr size; | |
318 | ram_addr_t raddr; | |
319 | int found = 0; | |
320 | ||
321 | mapcache_lock(); | |
322 | QTAILQ_FOREACH(reventry, &mapcache->locked_entries, next) { | |
323 | if (reventry->vaddr_req == ptr) { | |
324 | paddr_index = reventry->paddr_index; | |
325 | size = reventry->size; | |
326 | found = 1; | |
327 | break; | |
328 | } | |
329 | } | |
330 | if (!found) { | |
331 | fprintf(stderr, "%s, could not find %p\n", __func__, ptr); | |
332 | QTAILQ_FOREACH(reventry, &mapcache->locked_entries, next) { | |
333 | DPRINTF(" "TARGET_FMT_plx" -> %p is present\n", reventry->paddr_index, | |
334 | reventry->vaddr_req); | |
335 | } | |
336 | abort(); | |
337 | return 0; | |
338 | } | |
339 | ||
340 | entry = &mapcache->entry[paddr_index % mapcache->nr_buckets]; | |
341 | while (entry && (entry->paddr_index != paddr_index || entry->size != size)) { | |
342 | entry = entry->next; | |
343 | } | |
344 | if (!entry) { | |
345 | DPRINTF("Trying to find address %p that is not in the mapcache!\n", ptr); | |
346 | raddr = 0; | |
347 | } else { | |
348 | raddr = (reventry->paddr_index << MCACHE_BUCKET_SHIFT) + | |
349 | ((unsigned long) ptr - (unsigned long) entry->vaddr_base); | |
350 | } | |
351 | mapcache_unlock(); | |
352 | return raddr; | |
353 | } | |
354 | ||
355 | static void xen_invalidate_map_cache_entry_unlocked(uint8_t *buffer) | |
356 | { | |
357 | MapCacheEntry *entry = NULL, *pentry = NULL; | |
358 | MapCacheRev *reventry; | |
359 | hwaddr paddr_index; | |
360 | hwaddr size; | |
361 | int found = 0; | |
362 | ||
363 | QTAILQ_FOREACH(reventry, &mapcache->locked_entries, next) { | |
364 | if (reventry->vaddr_req == buffer) { | |
365 | paddr_index = reventry->paddr_index; | |
366 | size = reventry->size; | |
367 | found = 1; | |
368 | break; | |
369 | } | |
370 | } | |
371 | if (!found) { | |
372 | DPRINTF("%s, could not find %p\n", __func__, buffer); | |
373 | QTAILQ_FOREACH(reventry, &mapcache->locked_entries, next) { | |
374 | DPRINTF(" "TARGET_FMT_plx" -> %p is present\n", reventry->paddr_index, reventry->vaddr_req); | |
375 | } | |
376 | return; | |
377 | } | |
378 | QTAILQ_REMOVE(&mapcache->locked_entries, reventry, next); | |
379 | g_free(reventry); | |
380 | ||
381 | if (mapcache->last_entry != NULL && | |
382 | mapcache->last_entry->paddr_index == paddr_index) { | |
383 | mapcache->last_entry = NULL; | |
384 | } | |
385 | ||
386 | entry = &mapcache->entry[paddr_index % mapcache->nr_buckets]; | |
387 | while (entry && (entry->paddr_index != paddr_index || entry->size != size)) { | |
388 | pentry = entry; | |
389 | entry = entry->next; | |
390 | } | |
391 | if (!entry) { | |
392 | DPRINTF("Trying to unmap address %p that is not in the mapcache!\n", buffer); | |
393 | return; | |
394 | } | |
395 | entry->lock--; | |
396 | if (entry->lock > 0 || pentry == NULL) { | |
397 | return; | |
398 | } | |
399 | ||
400 | pentry->next = entry->next; | |
401 | if (munmap(entry->vaddr_base, entry->size) != 0) { | |
402 | perror("unmap fails"); | |
403 | exit(-1); | |
404 | } | |
405 | g_free(entry->valid_mapping); | |
406 | g_free(entry); | |
407 | } | |
408 | ||
409 | void xen_invalidate_map_cache_entry(uint8_t *buffer) | |
410 | { | |
411 | mapcache_lock(); | |
412 | xen_invalidate_map_cache_entry_unlocked(buffer); | |
413 | mapcache_unlock(); | |
414 | } | |
415 | ||
416 | void xen_invalidate_map_cache(void) | |
417 | { | |
418 | unsigned long i; | |
419 | MapCacheRev *reventry; | |
420 | ||
421 | /* Flush pending AIO before destroying the mapcache */ | |
422 | bdrv_drain_all(); | |
423 | ||
424 | mapcache_lock(); | |
425 | ||
426 | QTAILQ_FOREACH(reventry, &mapcache->locked_entries, next) { | |
427 | DPRINTF("There should be no locked mappings at this time, " | |
428 | "but "TARGET_FMT_plx" -> %p is present\n", | |
429 | reventry->paddr_index, reventry->vaddr_req); | |
430 | } | |
431 | ||
432 | for (i = 0; i < mapcache->nr_buckets; i++) { | |
433 | MapCacheEntry *entry = &mapcache->entry[i]; | |
434 | ||
435 | if (entry->vaddr_base == NULL) { | |
436 | continue; | |
437 | } | |
438 | if (entry->lock > 0) { | |
439 | continue; | |
440 | } | |
441 | ||
442 | if (munmap(entry->vaddr_base, entry->size) != 0) { | |
443 | perror("unmap fails"); | |
444 | exit(-1); | |
445 | } | |
446 | ||
447 | entry->paddr_index = 0; | |
448 | entry->vaddr_base = NULL; | |
449 | entry->size = 0; | |
450 | g_free(entry->valid_mapping); | |
451 | entry->valid_mapping = NULL; | |
452 | } | |
453 | ||
454 | mapcache->last_entry = NULL; | |
455 | ||
456 | mapcache_unlock(); | |
457 | } |