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