meson: convert hw/9pfs, cleanup
[qemu.git] / hw / i386 / xen / xen-mapcache.c
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 #include "qemu/units.h"
13 #include "qemu/error-report.h"
14
15 #include <sys/resource.h>
16
17 #include "hw/xen/xen-legacy-backend.h"
18 #include "qemu/bitmap.h"
19
20 #include "sysemu/runstate.h"
21 #include "sysemu/xen-mapcache.h"
22 #include "trace.h"
23
24
25 //#define MAPCACHE_DEBUG
26
27 #ifdef MAPCACHE_DEBUG
28 # define DPRINTF(fmt, ...) do { \
29 fprintf(stderr, "xen_mapcache: " fmt, ## __VA_ARGS__); \
30 } while (0)
31 #else
32 # define DPRINTF(fmt, ...) do { } while (0)
33 #endif
34
35 #if HOST_LONG_BITS == 32
36 # define MCACHE_BUCKET_SHIFT 16
37 # define MCACHE_MAX_SIZE (1UL<<31) /* 2GB Cap */
38 #else
39 # define MCACHE_BUCKET_SHIFT 20
40 # define MCACHE_MAX_SIZE (1UL<<35) /* 32GB Cap */
41 #endif
42 #define MCACHE_BUCKET_SIZE (1UL << MCACHE_BUCKET_SHIFT)
43
44 /* This is the size of the virtual address space reserve to QEMU that will not
45 * be use by MapCache.
46 * From empirical tests I observed that qemu use 75MB more than the
47 * max_mcache_size.
48 */
49 #define NON_MCACHE_MEMORY_SIZE (80 * MiB)
50
51 typedef struct MapCacheEntry {
52 hwaddr paddr_index;
53 uint8_t *vaddr_base;
54 unsigned long *valid_mapping;
55 uint8_t lock;
56 #define XEN_MAPCACHE_ENTRY_DUMMY (1 << 0)
57 uint8_t flags;
58 hwaddr size;
59 struct MapCacheEntry *next;
60 } MapCacheEntry;
61
62 typedef struct MapCacheRev {
63 uint8_t *vaddr_req;
64 hwaddr paddr_index;
65 hwaddr size;
66 QTAILQ_ENTRY(MapCacheRev) next;
67 bool dma;
68 } MapCacheRev;
69
70 typedef struct MapCache {
71 MapCacheEntry *entry;
72 unsigned long nr_buckets;
73 QTAILQ_HEAD(, MapCacheRev) locked_entries;
74
75 /* For most cases (>99.9%), the page address is the same. */
76 MapCacheEntry *last_entry;
77 unsigned long max_mcache_size;
78 unsigned int mcache_bucket_shift;
79
80 phys_offset_to_gaddr_t phys_offset_to_gaddr;
81 QemuMutex lock;
82 void *opaque;
83 } MapCache;
84
85 static MapCache *mapcache;
86
87 static inline void mapcache_lock(void)
88 {
89 qemu_mutex_lock(&mapcache->lock);
90 }
91
92 static inline void mapcache_unlock(void)
93 {
94 qemu_mutex_unlock(&mapcache->lock);
95 }
96
97 static inline int test_bits(int nr, int size, const unsigned long *addr)
98 {
99 unsigned long res = find_next_zero_bit(addr, size + nr, nr);
100 if (res >= nr + size)
101 return 1;
102 else
103 return 0;
104 }
105
106 void xen_map_cache_init(phys_offset_to_gaddr_t f, void *opaque)
107 {
108 unsigned long size;
109 struct rlimit rlimit_as;
110
111 mapcache = g_malloc0(sizeof (MapCache));
112
113 mapcache->phys_offset_to_gaddr = f;
114 mapcache->opaque = opaque;
115 qemu_mutex_init(&mapcache->lock);
116
117 QTAILQ_INIT(&mapcache->locked_entries);
118
119 if (geteuid() == 0) {
120 rlimit_as.rlim_cur = RLIM_INFINITY;
121 rlimit_as.rlim_max = RLIM_INFINITY;
122 mapcache->max_mcache_size = MCACHE_MAX_SIZE;
123 } else {
124 getrlimit(RLIMIT_AS, &rlimit_as);
125 rlimit_as.rlim_cur = rlimit_as.rlim_max;
126
127 if (rlimit_as.rlim_max != RLIM_INFINITY) {
128 warn_report("QEMU's maximum size of virtual"
129 " memory is not infinity");
130 }
131 if (rlimit_as.rlim_max < MCACHE_MAX_SIZE + NON_MCACHE_MEMORY_SIZE) {
132 mapcache->max_mcache_size = rlimit_as.rlim_max -
133 NON_MCACHE_MEMORY_SIZE;
134 } else {
135 mapcache->max_mcache_size = MCACHE_MAX_SIZE;
136 }
137 }
138
139 setrlimit(RLIMIT_AS, &rlimit_as);
140
141 mapcache->nr_buckets =
142 (((mapcache->max_mcache_size >> XC_PAGE_SHIFT) +
143 (1UL << (MCACHE_BUCKET_SHIFT - XC_PAGE_SHIFT)) - 1) >>
144 (MCACHE_BUCKET_SHIFT - XC_PAGE_SHIFT));
145
146 size = mapcache->nr_buckets * sizeof (MapCacheEntry);
147 size = (size + XC_PAGE_SIZE - 1) & ~(XC_PAGE_SIZE - 1);
148 DPRINTF("%s, nr_buckets = %lx size %lu\n", __func__,
149 mapcache->nr_buckets, size);
150 mapcache->entry = g_malloc0(size);
151 }
152
153 static void xen_remap_bucket(MapCacheEntry *entry,
154 void *vaddr,
155 hwaddr size,
156 hwaddr address_index,
157 bool dummy)
158 {
159 uint8_t *vaddr_base;
160 xen_pfn_t *pfns;
161 int *err;
162 unsigned int i;
163 hwaddr nb_pfn = size >> XC_PAGE_SHIFT;
164
165 trace_xen_remap_bucket(address_index);
166
167 pfns = g_malloc0(nb_pfn * sizeof (xen_pfn_t));
168 err = g_malloc0(nb_pfn * sizeof (int));
169
170 if (entry->vaddr_base != NULL) {
171 if (!(entry->flags & XEN_MAPCACHE_ENTRY_DUMMY)) {
172 ram_block_notify_remove(entry->vaddr_base, entry->size);
173 }
174 if (munmap(entry->vaddr_base, entry->size) != 0) {
175 perror("unmap fails");
176 exit(-1);
177 }
178 }
179 g_free(entry->valid_mapping);
180 entry->valid_mapping = NULL;
181
182 for (i = 0; i < nb_pfn; i++) {
183 pfns[i] = (address_index << (MCACHE_BUCKET_SHIFT-XC_PAGE_SHIFT)) + i;
184 }
185
186 /*
187 * If the caller has requested the mapping at a specific address use
188 * MAP_FIXED to make sure it's honored.
189 */
190 if (!dummy) {
191 vaddr_base = xenforeignmemory_map2(xen_fmem, xen_domid, vaddr,
192 PROT_READ | PROT_WRITE,
193 vaddr ? MAP_FIXED : 0,
194 nb_pfn, pfns, err);
195 if (vaddr_base == NULL) {
196 perror("xenforeignmemory_map2");
197 exit(-1);
198 }
199 } else {
200 /*
201 * We create dummy mappings where we are unable to create a foreign
202 * mapping immediately due to certain circumstances (i.e. on resume now)
203 */
204 vaddr_base = mmap(vaddr, size, PROT_READ | PROT_WRITE,
205 MAP_ANON | MAP_SHARED | (vaddr ? MAP_FIXED : 0),
206 -1, 0);
207 if (vaddr_base == MAP_FAILED) {
208 perror("mmap");
209 exit(-1);
210 }
211 }
212
213 if (!(entry->flags & XEN_MAPCACHE_ENTRY_DUMMY)) {
214 ram_block_notify_add(vaddr_base, size);
215 }
216
217 entry->vaddr_base = vaddr_base;
218 entry->paddr_index = address_index;
219 entry->size = size;
220 entry->valid_mapping = (unsigned long *) g_malloc0(sizeof(unsigned long) *
221 BITS_TO_LONGS(size >> XC_PAGE_SHIFT));
222
223 if (dummy) {
224 entry->flags |= XEN_MAPCACHE_ENTRY_DUMMY;
225 } else {
226 entry->flags &= ~(XEN_MAPCACHE_ENTRY_DUMMY);
227 }
228
229 bitmap_zero(entry->valid_mapping, nb_pfn);
230 for (i = 0; i < nb_pfn; i++) {
231 if (!err[i]) {
232 bitmap_set(entry->valid_mapping, i, 1);
233 }
234 }
235
236 g_free(pfns);
237 g_free(err);
238 }
239
240 static uint8_t *xen_map_cache_unlocked(hwaddr phys_addr, hwaddr size,
241 uint8_t lock, bool dma)
242 {
243 MapCacheEntry *entry, *pentry = NULL,
244 *free_entry = NULL, *free_pentry = NULL;
245 hwaddr address_index;
246 hwaddr address_offset;
247 hwaddr cache_size = size;
248 hwaddr test_bit_size;
249 bool translated G_GNUC_UNUSED = false;
250 bool dummy = false;
251
252 tryagain:
253 address_index = phys_addr >> MCACHE_BUCKET_SHIFT;
254 address_offset = phys_addr & (MCACHE_BUCKET_SIZE - 1);
255
256 trace_xen_map_cache(phys_addr);
257
258 /* test_bit_size is always a multiple of XC_PAGE_SIZE */
259 if (size) {
260 test_bit_size = size + (phys_addr & (XC_PAGE_SIZE - 1));
261
262 if (test_bit_size % XC_PAGE_SIZE) {
263 test_bit_size += XC_PAGE_SIZE - (test_bit_size % XC_PAGE_SIZE);
264 }
265 } else {
266 test_bit_size = XC_PAGE_SIZE;
267 }
268
269 if (mapcache->last_entry != NULL &&
270 mapcache->last_entry->paddr_index == address_index &&
271 !lock && !size &&
272 test_bits(address_offset >> XC_PAGE_SHIFT,
273 test_bit_size >> XC_PAGE_SHIFT,
274 mapcache->last_entry->valid_mapping)) {
275 trace_xen_map_cache_return(mapcache->last_entry->vaddr_base + address_offset);
276 return mapcache->last_entry->vaddr_base + address_offset;
277 }
278
279 /* size is always a multiple of MCACHE_BUCKET_SIZE */
280 if (size) {
281 cache_size = size + address_offset;
282 if (cache_size % MCACHE_BUCKET_SIZE) {
283 cache_size += MCACHE_BUCKET_SIZE - (cache_size % MCACHE_BUCKET_SIZE);
284 }
285 } else {
286 cache_size = MCACHE_BUCKET_SIZE;
287 }
288
289 entry = &mapcache->entry[address_index % mapcache->nr_buckets];
290
291 while (entry && (lock || entry->lock) && entry->vaddr_base &&
292 (entry->paddr_index != address_index || entry->size != cache_size ||
293 !test_bits(address_offset >> XC_PAGE_SHIFT,
294 test_bit_size >> XC_PAGE_SHIFT,
295 entry->valid_mapping))) {
296 if (!free_entry && !entry->lock) {
297 free_entry = entry;
298 free_pentry = pentry;
299 }
300 pentry = entry;
301 entry = entry->next;
302 }
303 if (!entry && free_entry) {
304 entry = free_entry;
305 pentry = free_pentry;
306 }
307 if (!entry) {
308 entry = g_malloc0(sizeof (MapCacheEntry));
309 pentry->next = entry;
310 xen_remap_bucket(entry, NULL, cache_size, address_index, dummy);
311 } else if (!entry->lock) {
312 if (!entry->vaddr_base || entry->paddr_index != address_index ||
313 entry->size != cache_size ||
314 !test_bits(address_offset >> XC_PAGE_SHIFT,
315 test_bit_size >> XC_PAGE_SHIFT,
316 entry->valid_mapping)) {
317 xen_remap_bucket(entry, NULL, cache_size, address_index, dummy);
318 }
319 }
320
321 if(!test_bits(address_offset >> XC_PAGE_SHIFT,
322 test_bit_size >> XC_PAGE_SHIFT,
323 entry->valid_mapping)) {
324 mapcache->last_entry = NULL;
325 #ifdef XEN_COMPAT_PHYSMAP
326 if (!translated && mapcache->phys_offset_to_gaddr) {
327 phys_addr = mapcache->phys_offset_to_gaddr(phys_addr, size);
328 translated = true;
329 goto tryagain;
330 }
331 #endif
332 if (!dummy && runstate_check(RUN_STATE_INMIGRATE)) {
333 dummy = true;
334 goto tryagain;
335 }
336 trace_xen_map_cache_return(NULL);
337 return NULL;
338 }
339
340 mapcache->last_entry = entry;
341 if (lock) {
342 MapCacheRev *reventry = g_malloc0(sizeof(MapCacheRev));
343 entry->lock++;
344 reventry->dma = dma;
345 reventry->vaddr_req = mapcache->last_entry->vaddr_base + address_offset;
346 reventry->paddr_index = mapcache->last_entry->paddr_index;
347 reventry->size = entry->size;
348 QTAILQ_INSERT_HEAD(&mapcache->locked_entries, reventry, next);
349 }
350
351 trace_xen_map_cache_return(mapcache->last_entry->vaddr_base + address_offset);
352 return mapcache->last_entry->vaddr_base + address_offset;
353 }
354
355 uint8_t *xen_map_cache(hwaddr phys_addr, hwaddr size,
356 uint8_t lock, bool dma)
357 {
358 uint8_t *p;
359
360 mapcache_lock();
361 p = xen_map_cache_unlocked(phys_addr, size, lock, dma);
362 mapcache_unlock();
363 return p;
364 }
365
366 ram_addr_t xen_ram_addr_from_mapcache(void *ptr)
367 {
368 MapCacheEntry *entry = NULL;
369 MapCacheRev *reventry;
370 hwaddr paddr_index;
371 hwaddr size;
372 ram_addr_t raddr;
373 int found = 0;
374
375 mapcache_lock();
376 QTAILQ_FOREACH(reventry, &mapcache->locked_entries, next) {
377 if (reventry->vaddr_req == ptr) {
378 paddr_index = reventry->paddr_index;
379 size = reventry->size;
380 found = 1;
381 break;
382 }
383 }
384 if (!found) {
385 fprintf(stderr, "%s, could not find %p\n", __func__, ptr);
386 QTAILQ_FOREACH(reventry, &mapcache->locked_entries, next) {
387 DPRINTF(" "TARGET_FMT_plx" -> %p is present\n", reventry->paddr_index,
388 reventry->vaddr_req);
389 }
390 abort();
391 return 0;
392 }
393
394 entry = &mapcache->entry[paddr_index % mapcache->nr_buckets];
395 while (entry && (entry->paddr_index != paddr_index || entry->size != size)) {
396 entry = entry->next;
397 }
398 if (!entry) {
399 DPRINTF("Trying to find address %p that is not in the mapcache!\n", ptr);
400 raddr = 0;
401 } else {
402 raddr = (reventry->paddr_index << MCACHE_BUCKET_SHIFT) +
403 ((unsigned long) ptr - (unsigned long) entry->vaddr_base);
404 }
405 mapcache_unlock();
406 return raddr;
407 }
408
409 static void xen_invalidate_map_cache_entry_unlocked(uint8_t *buffer)
410 {
411 MapCacheEntry *entry = NULL, *pentry = NULL;
412 MapCacheRev *reventry;
413 hwaddr paddr_index;
414 hwaddr size;
415 int found = 0;
416
417 QTAILQ_FOREACH(reventry, &mapcache->locked_entries, next) {
418 if (reventry->vaddr_req == buffer) {
419 paddr_index = reventry->paddr_index;
420 size = reventry->size;
421 found = 1;
422 break;
423 }
424 }
425 if (!found) {
426 DPRINTF("%s, could not find %p\n", __func__, buffer);
427 QTAILQ_FOREACH(reventry, &mapcache->locked_entries, next) {
428 DPRINTF(" "TARGET_FMT_plx" -> %p is present\n", reventry->paddr_index, reventry->vaddr_req);
429 }
430 return;
431 }
432 QTAILQ_REMOVE(&mapcache->locked_entries, reventry, next);
433 g_free(reventry);
434
435 if (mapcache->last_entry != NULL &&
436 mapcache->last_entry->paddr_index == paddr_index) {
437 mapcache->last_entry = NULL;
438 }
439
440 entry = &mapcache->entry[paddr_index % mapcache->nr_buckets];
441 while (entry && (entry->paddr_index != paddr_index || entry->size != size)) {
442 pentry = entry;
443 entry = entry->next;
444 }
445 if (!entry) {
446 DPRINTF("Trying to unmap address %p that is not in the mapcache!\n", buffer);
447 return;
448 }
449 entry->lock--;
450 if (entry->lock > 0 || pentry == NULL) {
451 return;
452 }
453
454 pentry->next = entry->next;
455 ram_block_notify_remove(entry->vaddr_base, entry->size);
456 if (munmap(entry->vaddr_base, entry->size) != 0) {
457 perror("unmap fails");
458 exit(-1);
459 }
460 g_free(entry->valid_mapping);
461 g_free(entry);
462 }
463
464 void xen_invalidate_map_cache_entry(uint8_t *buffer)
465 {
466 mapcache_lock();
467 xen_invalidate_map_cache_entry_unlocked(buffer);
468 mapcache_unlock();
469 }
470
471 void xen_invalidate_map_cache(void)
472 {
473 unsigned long i;
474 MapCacheRev *reventry;
475
476 /* Flush pending AIO before destroying the mapcache */
477 bdrv_drain_all();
478
479 mapcache_lock();
480
481 QTAILQ_FOREACH(reventry, &mapcache->locked_entries, next) {
482 if (!reventry->dma) {
483 continue;
484 }
485 fprintf(stderr, "Locked DMA mapping while invalidating mapcache!"
486 " "TARGET_FMT_plx" -> %p is present\n",
487 reventry->paddr_index, reventry->vaddr_req);
488 }
489
490 for (i = 0; i < mapcache->nr_buckets; i++) {
491 MapCacheEntry *entry = &mapcache->entry[i];
492
493 if (entry->vaddr_base == NULL) {
494 continue;
495 }
496 if (entry->lock > 0) {
497 continue;
498 }
499
500 if (munmap(entry->vaddr_base, entry->size) != 0) {
501 perror("unmap fails");
502 exit(-1);
503 }
504
505 entry->paddr_index = 0;
506 entry->vaddr_base = NULL;
507 entry->size = 0;
508 g_free(entry->valid_mapping);
509 entry->valid_mapping = NULL;
510 }
511
512 mapcache->last_entry = NULL;
513
514 mapcache_unlock();
515 }
516
517 static uint8_t *xen_replace_cache_entry_unlocked(hwaddr old_phys_addr,
518 hwaddr new_phys_addr,
519 hwaddr size)
520 {
521 MapCacheEntry *entry;
522 hwaddr address_index, address_offset;
523 hwaddr test_bit_size, cache_size = size;
524
525 address_index = old_phys_addr >> MCACHE_BUCKET_SHIFT;
526 address_offset = old_phys_addr & (MCACHE_BUCKET_SIZE - 1);
527
528 assert(size);
529 /* test_bit_size is always a multiple of XC_PAGE_SIZE */
530 test_bit_size = size + (old_phys_addr & (XC_PAGE_SIZE - 1));
531 if (test_bit_size % XC_PAGE_SIZE) {
532 test_bit_size += XC_PAGE_SIZE - (test_bit_size % XC_PAGE_SIZE);
533 }
534 cache_size = size + address_offset;
535 if (cache_size % MCACHE_BUCKET_SIZE) {
536 cache_size += MCACHE_BUCKET_SIZE - (cache_size % MCACHE_BUCKET_SIZE);
537 }
538
539 entry = &mapcache->entry[address_index % mapcache->nr_buckets];
540 while (entry && !(entry->paddr_index == address_index &&
541 entry->size == cache_size)) {
542 entry = entry->next;
543 }
544 if (!entry) {
545 DPRINTF("Trying to update an entry for "TARGET_FMT_plx \
546 "that is not in the mapcache!\n", old_phys_addr);
547 return NULL;
548 }
549
550 address_index = new_phys_addr >> MCACHE_BUCKET_SHIFT;
551 address_offset = new_phys_addr & (MCACHE_BUCKET_SIZE - 1);
552
553 fprintf(stderr, "Replacing a dummy mapcache entry for "TARGET_FMT_plx \
554 " with "TARGET_FMT_plx"\n", old_phys_addr, new_phys_addr);
555
556 xen_remap_bucket(entry, entry->vaddr_base,
557 cache_size, address_index, false);
558 if (!test_bits(address_offset >> XC_PAGE_SHIFT,
559 test_bit_size >> XC_PAGE_SHIFT,
560 entry->valid_mapping)) {
561 DPRINTF("Unable to update a mapcache entry for "TARGET_FMT_plx"!\n",
562 old_phys_addr);
563 return NULL;
564 }
565
566 return entry->vaddr_base + address_offset;
567 }
568
569 uint8_t *xen_replace_cache_entry(hwaddr old_phys_addr,
570 hwaddr new_phys_addr,
571 hwaddr size)
572 {
573 uint8_t *p;
574
575 mapcache_lock();
576 p = xen_replace_cache_entry_unlocked(old_phys_addr, new_phys_addr, size);
577 mapcache_unlock();
578 return p;
579 }