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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 "config.h" | |
12 | ||
13 | #include <sys/resource.h> | |
14 | ||
15 | #include "hw/xen_backend.h" | |
16 | #include "blockdev.h" | |
17 | #include "bitmap.h" | |
18 | ||
19 | #include <xen/hvm/params.h> | |
20 | #include <sys/mman.h> | |
21 | ||
22 | #include "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 defined(__i386__) | |
37 | # define MCACHE_BUCKET_SHIFT 16 | |
38 | # define MCACHE_MAX_SIZE (1UL<<31) /* 2GB Cap */ | |
39 | #elif defined(__x86_64__) | |
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 | #define mapcache_lock() ((void)0) | |
53 | #define mapcache_unlock() ((void)0) | |
54 | ||
55 | typedef struct MapCacheEntry { | |
56 | target_phys_addr_t paddr_index; | |
57 | uint8_t *vaddr_base; | |
58 | unsigned long *valid_mapping; | |
59 | uint8_t lock; | |
60 | target_phys_addr_t size; | |
61 | struct MapCacheEntry *next; | |
62 | } MapCacheEntry; | |
63 | ||
64 | typedef struct MapCacheRev { | |
65 | uint8_t *vaddr_req; | |
66 | target_phys_addr_t paddr_index; | |
67 | target_phys_addr_t size; | |
68 | QTAILQ_ENTRY(MapCacheRev) next; | |
69 | } MapCacheRev; | |
70 | ||
71 | typedef struct MapCache { | |
72 | MapCacheEntry *entry; | |
73 | unsigned long nr_buckets; | |
74 | QTAILQ_HEAD(map_cache_head, MapCacheRev) locked_entries; | |
75 | ||
76 | /* For most cases (>99.9%), the page address is the same. */ | |
77 | target_phys_addr_t last_address_index; | |
78 | uint8_t *last_address_vaddr; | |
79 | unsigned long max_mcache_size; | |
80 | unsigned int mcache_bucket_shift; | |
81 | } MapCache; | |
82 | ||
83 | static MapCache *mapcache; | |
84 | ||
85 | static inline int test_bits(int nr, int size, const unsigned long *addr) | |
86 | { | |
87 | unsigned long res = find_next_zero_bit(addr, size + nr, nr); | |
88 | if (res >= nr + size) | |
89 | return 1; | |
90 | else | |
91 | return 0; | |
92 | } | |
93 | ||
94 | void xen_map_cache_init(void) | |
95 | { | |
96 | unsigned long size; | |
97 | struct rlimit rlimit_as; | |
98 | ||
99 | mapcache = g_malloc0(sizeof (MapCache)); | |
100 | ||
101 | QTAILQ_INIT(&mapcache->locked_entries); | |
102 | mapcache->last_address_index = -1; | |
103 | ||
104 | if (geteuid() == 0) { | |
105 | rlimit_as.rlim_cur = RLIM_INFINITY; | |
106 | rlimit_as.rlim_max = RLIM_INFINITY; | |
107 | mapcache->max_mcache_size = MCACHE_MAX_SIZE; | |
108 | } else { | |
109 | getrlimit(RLIMIT_AS, &rlimit_as); | |
110 | rlimit_as.rlim_cur = rlimit_as.rlim_max; | |
111 | ||
112 | if (rlimit_as.rlim_max != RLIM_INFINITY) { | |
113 | fprintf(stderr, "Warning: QEMU's maximum size of virtual" | |
114 | " memory is not infinity.\n"); | |
115 | } | |
116 | if (rlimit_as.rlim_max < MCACHE_MAX_SIZE + NON_MCACHE_MEMORY_SIZE) { | |
117 | mapcache->max_mcache_size = rlimit_as.rlim_max - | |
118 | NON_MCACHE_MEMORY_SIZE; | |
119 | } else { | |
120 | mapcache->max_mcache_size = MCACHE_MAX_SIZE; | |
121 | } | |
122 | } | |
123 | ||
124 | setrlimit(RLIMIT_AS, &rlimit_as); | |
125 | ||
126 | mapcache->nr_buckets = | |
127 | (((mapcache->max_mcache_size >> XC_PAGE_SHIFT) + | |
128 | (1UL << (MCACHE_BUCKET_SHIFT - XC_PAGE_SHIFT)) - 1) >> | |
129 | (MCACHE_BUCKET_SHIFT - XC_PAGE_SHIFT)); | |
130 | ||
131 | size = mapcache->nr_buckets * sizeof (MapCacheEntry); | |
132 | size = (size + XC_PAGE_SIZE - 1) & ~(XC_PAGE_SIZE - 1); | |
133 | DPRINTF("%s, nr_buckets = %lx size %lu\n", __func__, | |
134 | mapcache->nr_buckets, size); | |
135 | mapcache->entry = g_malloc0(size); | |
136 | } | |
137 | ||
138 | static void xen_remap_bucket(MapCacheEntry *entry, | |
139 | target_phys_addr_t size, | |
140 | target_phys_addr_t address_index) | |
141 | { | |
142 | uint8_t *vaddr_base; | |
143 | xen_pfn_t *pfns; | |
144 | int *err; | |
145 | unsigned int i; | |
146 | target_phys_addr_t nb_pfn = size >> XC_PAGE_SHIFT; | |
147 | ||
148 | trace_xen_remap_bucket(address_index); | |
149 | ||
150 | pfns = g_malloc0(nb_pfn * sizeof (xen_pfn_t)); | |
151 | err = g_malloc0(nb_pfn * sizeof (int)); | |
152 | ||
153 | if (entry->vaddr_base != NULL) { | |
154 | if (munmap(entry->vaddr_base, entry->size) != 0) { | |
155 | perror("unmap fails"); | |
156 | exit(-1); | |
157 | } | |
158 | } | |
159 | if (entry->valid_mapping != NULL) { | |
160 | g_free(entry->valid_mapping); | |
161 | entry->valid_mapping = NULL; | |
162 | } | |
163 | ||
164 | for (i = 0; i < nb_pfn; i++) { | |
165 | pfns[i] = (address_index << (MCACHE_BUCKET_SHIFT-XC_PAGE_SHIFT)) + i; | |
166 | } | |
167 | ||
168 | vaddr_base = xc_map_foreign_bulk(xen_xc, xen_domid, PROT_READ|PROT_WRITE, | |
169 | pfns, err, nb_pfn); | |
170 | if (vaddr_base == NULL) { | |
171 | perror("xc_map_foreign_bulk"); | |
172 | exit(-1); | |
173 | } | |
174 | ||
175 | entry->vaddr_base = vaddr_base; | |
176 | entry->paddr_index = address_index; | |
177 | entry->size = size; | |
178 | entry->valid_mapping = (unsigned long *) g_malloc0(sizeof(unsigned long) * | |
179 | BITS_TO_LONGS(size >> XC_PAGE_SHIFT)); | |
180 | ||
181 | bitmap_zero(entry->valid_mapping, nb_pfn); | |
182 | for (i = 0; i < nb_pfn; i++) { | |
183 | if (!err[i]) { | |
184 | bitmap_set(entry->valid_mapping, i, 1); | |
185 | } | |
186 | } | |
187 | ||
188 | g_free(pfns); | |
189 | g_free(err); | |
190 | } | |
191 | ||
192 | uint8_t *xen_map_cache(target_phys_addr_t phys_addr, target_phys_addr_t size, | |
193 | uint8_t lock) | |
194 | { | |
195 | MapCacheEntry *entry, *pentry = NULL; | |
196 | target_phys_addr_t address_index = phys_addr >> MCACHE_BUCKET_SHIFT; | |
197 | target_phys_addr_t address_offset = phys_addr & (MCACHE_BUCKET_SIZE - 1); | |
198 | target_phys_addr_t __size = size; | |
199 | ||
200 | trace_xen_map_cache(phys_addr); | |
201 | ||
202 | if (address_index == mapcache->last_address_index && !lock && !__size) { | |
203 | trace_xen_map_cache_return(mapcache->last_address_vaddr + address_offset); | |
204 | return mapcache->last_address_vaddr + address_offset; | |
205 | } | |
206 | ||
207 | /* size is always a multiple of MCACHE_BUCKET_SIZE */ | |
208 | if ((address_offset + (__size % MCACHE_BUCKET_SIZE)) > MCACHE_BUCKET_SIZE) | |
209 | __size += MCACHE_BUCKET_SIZE; | |
210 | if (__size % MCACHE_BUCKET_SIZE) | |
211 | __size += MCACHE_BUCKET_SIZE - (__size % MCACHE_BUCKET_SIZE); | |
212 | if (!__size) | |
213 | __size = MCACHE_BUCKET_SIZE; | |
214 | ||
215 | entry = &mapcache->entry[address_index % mapcache->nr_buckets]; | |
216 | ||
217 | while (entry && entry->lock && entry->vaddr_base && | |
218 | (entry->paddr_index != address_index || entry->size != __size || | |
219 | !test_bits(address_offset >> XC_PAGE_SHIFT, size >> XC_PAGE_SHIFT, | |
220 | entry->valid_mapping))) { | |
221 | pentry = entry; | |
222 | entry = entry->next; | |
223 | } | |
224 | if (!entry) { | |
225 | entry = g_malloc0(sizeof (MapCacheEntry)); | |
226 | pentry->next = entry; | |
227 | xen_remap_bucket(entry, __size, address_index); | |
228 | } else if (!entry->lock) { | |
229 | if (!entry->vaddr_base || entry->paddr_index != address_index || | |
230 | entry->size != __size || | |
231 | !test_bits(address_offset >> XC_PAGE_SHIFT, size >> XC_PAGE_SHIFT, | |
232 | entry->valid_mapping)) { | |
233 | xen_remap_bucket(entry, __size, address_index); | |
234 | } | |
235 | } | |
236 | ||
237 | if(!test_bits(address_offset >> XC_PAGE_SHIFT, size >> XC_PAGE_SHIFT, | |
238 | entry->valid_mapping)) { | |
239 | mapcache->last_address_index = -1; | |
240 | trace_xen_map_cache_return(NULL); | |
241 | return NULL; | |
242 | } | |
243 | ||
244 | mapcache->last_address_index = address_index; | |
245 | mapcache->last_address_vaddr = entry->vaddr_base; | |
246 | if (lock) { | |
247 | MapCacheRev *reventry = g_malloc0(sizeof(MapCacheRev)); | |
248 | entry->lock++; | |
249 | reventry->vaddr_req = mapcache->last_address_vaddr + address_offset; | |
250 | reventry->paddr_index = mapcache->last_address_index; | |
251 | reventry->size = entry->size; | |
252 | QTAILQ_INSERT_HEAD(&mapcache->locked_entries, reventry, next); | |
253 | } | |
254 | ||
255 | trace_xen_map_cache_return(mapcache->last_address_vaddr + address_offset); | |
256 | return mapcache->last_address_vaddr + address_offset; | |
257 | } | |
258 | ||
259 | ram_addr_t xen_ram_addr_from_mapcache(void *ptr) | |
260 | { | |
261 | MapCacheEntry *entry = NULL; | |
262 | MapCacheRev *reventry; | |
263 | target_phys_addr_t paddr_index; | |
264 | target_phys_addr_t size; | |
265 | int found = 0; | |
266 | ||
267 | QTAILQ_FOREACH(reventry, &mapcache->locked_entries, next) { | |
268 | if (reventry->vaddr_req == ptr) { | |
269 | paddr_index = reventry->paddr_index; | |
270 | size = reventry->size; | |
271 | found = 1; | |
272 | break; | |
273 | } | |
274 | } | |
275 | if (!found) { | |
276 | fprintf(stderr, "%s, could not find %p\n", __func__, ptr); | |
277 | QTAILQ_FOREACH(reventry, &mapcache->locked_entries, next) { | |
278 | DPRINTF(" "TARGET_FMT_plx" -> %p is present\n", reventry->paddr_index, | |
279 | reventry->vaddr_req); | |
280 | } | |
281 | abort(); | |
282 | return 0; | |
283 | } | |
284 | ||
285 | entry = &mapcache->entry[paddr_index % mapcache->nr_buckets]; | |
286 | while (entry && (entry->paddr_index != paddr_index || entry->size != size)) { | |
287 | entry = entry->next; | |
288 | } | |
289 | if (!entry) { | |
290 | DPRINTF("Trying to find address %p that is not in the mapcache!\n", ptr); | |
291 | return 0; | |
292 | } | |
293 | return (reventry->paddr_index << MCACHE_BUCKET_SHIFT) + | |
294 | ((unsigned long) ptr - (unsigned long) entry->vaddr_base); | |
295 | } | |
296 | ||
297 | void xen_invalidate_map_cache_entry(uint8_t *buffer) | |
298 | { | |
299 | MapCacheEntry *entry = NULL, *pentry = NULL; | |
300 | MapCacheRev *reventry; | |
301 | target_phys_addr_t paddr_index; | |
302 | target_phys_addr_t size; | |
303 | int found = 0; | |
304 | ||
305 | if (mapcache->last_address_vaddr == buffer) { | |
306 | mapcache->last_address_index = -1; | |
307 | } | |
308 | ||
309 | QTAILQ_FOREACH(reventry, &mapcache->locked_entries, next) { | |
310 | if (reventry->vaddr_req == buffer) { | |
311 | paddr_index = reventry->paddr_index; | |
312 | size = reventry->size; | |
313 | found = 1; | |
314 | break; | |
315 | } | |
316 | } | |
317 | if (!found) { | |
318 | DPRINTF("%s, could not find %p\n", __func__, buffer); | |
319 | QTAILQ_FOREACH(reventry, &mapcache->locked_entries, next) { | |
320 | DPRINTF(" "TARGET_FMT_plx" -> %p is present\n", reventry->paddr_index, reventry->vaddr_req); | |
321 | } | |
322 | return; | |
323 | } | |
324 | QTAILQ_REMOVE(&mapcache->locked_entries, reventry, next); | |
325 | g_free(reventry); | |
326 | ||
327 | entry = &mapcache->entry[paddr_index % mapcache->nr_buckets]; | |
328 | while (entry && (entry->paddr_index != paddr_index || entry->size != size)) { | |
329 | pentry = entry; | |
330 | entry = entry->next; | |
331 | } | |
332 | if (!entry) { | |
333 | DPRINTF("Trying to unmap address %p that is not in the mapcache!\n", buffer); | |
334 | return; | |
335 | } | |
336 | entry->lock--; | |
337 | if (entry->lock > 0 || pentry == NULL) { | |
338 | return; | |
339 | } | |
340 | ||
341 | pentry->next = entry->next; | |
342 | if (munmap(entry->vaddr_base, entry->size) != 0) { | |
343 | perror("unmap fails"); | |
344 | exit(-1); | |
345 | } | |
346 | g_free(entry->valid_mapping); | |
347 | g_free(entry); | |
348 | } | |
349 | ||
350 | void xen_invalidate_map_cache(void) | |
351 | { | |
352 | unsigned long i; | |
353 | MapCacheRev *reventry; | |
354 | ||
355 | /* Flush pending AIO before destroying the mapcache */ | |
356 | bdrv_drain_all(); | |
357 | ||
358 | QTAILQ_FOREACH(reventry, &mapcache->locked_entries, next) { | |
359 | DPRINTF("There should be no locked mappings at this time, " | |
360 | "but "TARGET_FMT_plx" -> %p is present\n", | |
361 | reventry->paddr_index, reventry->vaddr_req); | |
362 | } | |
363 | ||
364 | mapcache_lock(); | |
365 | ||
366 | for (i = 0; i < mapcache->nr_buckets; i++) { | |
367 | MapCacheEntry *entry = &mapcache->entry[i]; | |
368 | ||
369 | if (entry->vaddr_base == NULL) { | |
370 | continue; | |
371 | } | |
372 | ||
373 | if (munmap(entry->vaddr_base, entry->size) != 0) { | |
374 | perror("unmap fails"); | |
375 | exit(-1); | |
376 | } | |
377 | ||
378 | entry->paddr_index = 0; | |
379 | entry->vaddr_base = NULL; | |
380 | entry->size = 0; | |
381 | g_free(entry->valid_mapping); | |
382 | entry->valid_mapping = NULL; | |
383 | } | |
384 | ||
385 | mapcache->last_address_index = -1; | |
386 | mapcache->last_address_vaddr = NULL; | |
387 | ||
388 | mapcache_unlock(); | |
389 | } |