xref: /qemu/include/exec/ram_addr.h (revision e8c5503a)
1 /*
2  * Declarations for cpu physical memory functions
3  *
4  * Copyright 2011 Red Hat, Inc. and/or its affiliates
5  *
6  * Authors:
7  *  Avi Kivity <avi@redhat.com>
8  *
9  * This work is licensed under the terms of the GNU GPL, version 2 or
10  * later.  See the COPYING file in the top-level directory.
11  *
12  */
13 
14 /*
15  * This header is for use by exec.c and memory.c ONLY.  Do not include it.
16  * The functions declared here will be removed soon.
17  */
18 
19 #ifndef RAM_ADDR_H
20 #define RAM_ADDR_H
21 
22 #ifndef CONFIG_USER_ONLY
23 #include "cpu.h"
24 #include "sysemu/xen.h"
25 #include "sysemu/tcg.h"
26 #include "exec/ramlist.h"
27 #include "exec/ramblock.h"
28 #include "exec/exec-all.h"
29 
30 extern uint64_t total_dirty_pages;
31 
32 /**
33  * clear_bmap_size: calculate clear bitmap size
34  *
35  * @pages: number of guest pages
36  * @shift: guest page number shift
37  *
38  * Returns: number of bits for the clear bitmap
39  */
40 static inline long clear_bmap_size(uint64_t pages, uint8_t shift)
41 {
42     return DIV_ROUND_UP(pages, 1UL << shift);
43 }
44 
45 /**
46  * clear_bmap_set: set clear bitmap for the page range.  Must be with
47  * bitmap_mutex held.
48  *
49  * @rb: the ramblock to operate on
50  * @start: the start page number
51  * @size: number of pages to set in the bitmap
52  *
53  * Returns: None
54  */
55 static inline void clear_bmap_set(RAMBlock *rb, uint64_t start,
56                                   uint64_t npages)
57 {
58     uint8_t shift = rb->clear_bmap_shift;
59 
60     bitmap_set(rb->clear_bmap, start >> shift, clear_bmap_size(npages, shift));
61 }
62 
63 /**
64  * clear_bmap_test_and_clear: test clear bitmap for the page, clear if set.
65  * Must be with bitmap_mutex held.
66  *
67  * @rb: the ramblock to operate on
68  * @page: the page number to check
69  *
70  * Returns: true if the bit was set, false otherwise
71  */
72 static inline bool clear_bmap_test_and_clear(RAMBlock *rb, uint64_t page)
73 {
74     uint8_t shift = rb->clear_bmap_shift;
75 
76     return bitmap_test_and_clear(rb->clear_bmap, page >> shift, 1);
77 }
78 
79 static inline bool offset_in_ramblock(RAMBlock *b, ram_addr_t offset)
80 {
81     return (b && b->host && offset < b->used_length) ? true : false;
82 }
83 
84 static inline void *ramblock_ptr(RAMBlock *block, ram_addr_t offset)
85 {
86     assert(offset_in_ramblock(block, offset));
87     return (char *)block->host + offset;
88 }
89 
90 static inline unsigned long int ramblock_recv_bitmap_offset(void *host_addr,
91                                                             RAMBlock *rb)
92 {
93     uint64_t host_addr_offset =
94             (uint64_t)(uintptr_t)(host_addr - (void *)rb->host);
95     return host_addr_offset >> TARGET_PAGE_BITS;
96 }
97 
98 bool ramblock_is_pmem(RAMBlock *rb);
99 
100 long qemu_minrampagesize(void);
101 long qemu_maxrampagesize(void);
102 
103 /**
104  * qemu_ram_alloc_from_file,
105  * qemu_ram_alloc_from_fd:  Allocate a ram block from the specified backing
106  *                          file or device
107  *
108  * Parameters:
109  *  @size: the size in bytes of the ram block
110  *  @mr: the memory region where the ram block is
111  *  @ram_flags: RamBlock flags. Supported flags: RAM_SHARED, RAM_PMEM,
112  *              RAM_NORESERVE, RAM_PROTECTED, RAM_NAMED_FILE, RAM_READONLY,
113  *              RAM_READONLY_FD
114  *  @mem_path or @fd: specify the backing file or device
115  *  @offset: Offset into target file
116  *  @errp: pointer to Error*, to store an error if it happens
117  *
118  * Return:
119  *  On success, return a pointer to the ram block.
120  *  On failure, return NULL.
121  */
122 RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr,
123                                    uint32_t ram_flags, const char *mem_path,
124                                    off_t offset, Error **errp);
125 RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr,
126                                  uint32_t ram_flags, int fd, off_t offset,
127                                  Error **errp);
128 
129 RAMBlock *qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
130                                   MemoryRegion *mr, Error **errp);
131 RAMBlock *qemu_ram_alloc(ram_addr_t size, uint32_t ram_flags, MemoryRegion *mr,
132                          Error **errp);
133 RAMBlock *qemu_ram_alloc_resizeable(ram_addr_t size, ram_addr_t max_size,
134                                     void (*resized)(const char*,
135                                                     uint64_t length,
136                                                     void *host),
137                                     MemoryRegion *mr, Error **errp);
138 void qemu_ram_free(RAMBlock *block);
139 
140 int qemu_ram_resize(RAMBlock *block, ram_addr_t newsize, Error **errp);
141 
142 void qemu_ram_msync(RAMBlock *block, ram_addr_t start, ram_addr_t length);
143 
144 /* Clear whole block of mem */
145 static inline void qemu_ram_block_writeback(RAMBlock *block)
146 {
147     qemu_ram_msync(block, 0, block->used_length);
148 }
149 
150 #define DIRTY_CLIENTS_ALL     ((1 << DIRTY_MEMORY_NUM) - 1)
151 #define DIRTY_CLIENTS_NOCODE  (DIRTY_CLIENTS_ALL & ~(1 << DIRTY_MEMORY_CODE))
152 
153 static inline bool cpu_physical_memory_get_dirty(ram_addr_t start,
154                                                  ram_addr_t length,
155                                                  unsigned client)
156 {
157     DirtyMemoryBlocks *blocks;
158     unsigned long end, page;
159     unsigned long idx, offset, base;
160     bool dirty = false;
161 
162     assert(client < DIRTY_MEMORY_NUM);
163 
164     end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
165     page = start >> TARGET_PAGE_BITS;
166 
167     WITH_RCU_READ_LOCK_GUARD() {
168         blocks = qatomic_rcu_read(&ram_list.dirty_memory[client]);
169 
170         idx = page / DIRTY_MEMORY_BLOCK_SIZE;
171         offset = page % DIRTY_MEMORY_BLOCK_SIZE;
172         base = page - offset;
173         while (page < end) {
174             unsigned long next = MIN(end, base + DIRTY_MEMORY_BLOCK_SIZE);
175             unsigned long num = next - base;
176             unsigned long found = find_next_bit(blocks->blocks[idx],
177                                                 num, offset);
178             if (found < num) {
179                 dirty = true;
180                 break;
181             }
182 
183             page = next;
184             idx++;
185             offset = 0;
186             base += DIRTY_MEMORY_BLOCK_SIZE;
187         }
188     }
189 
190     return dirty;
191 }
192 
193 static inline bool cpu_physical_memory_all_dirty(ram_addr_t start,
194                                                  ram_addr_t length,
195                                                  unsigned client)
196 {
197     DirtyMemoryBlocks *blocks;
198     unsigned long end, page;
199     unsigned long idx, offset, base;
200     bool dirty = true;
201 
202     assert(client < DIRTY_MEMORY_NUM);
203 
204     end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
205     page = start >> TARGET_PAGE_BITS;
206 
207     RCU_READ_LOCK_GUARD();
208 
209     blocks = qatomic_rcu_read(&ram_list.dirty_memory[client]);
210 
211     idx = page / DIRTY_MEMORY_BLOCK_SIZE;
212     offset = page % DIRTY_MEMORY_BLOCK_SIZE;
213     base = page - offset;
214     while (page < end) {
215         unsigned long next = MIN(end, base + DIRTY_MEMORY_BLOCK_SIZE);
216         unsigned long num = next - base;
217         unsigned long found = find_next_zero_bit(blocks->blocks[idx], num, offset);
218         if (found < num) {
219             dirty = false;
220             break;
221         }
222 
223         page = next;
224         idx++;
225         offset = 0;
226         base += DIRTY_MEMORY_BLOCK_SIZE;
227     }
228 
229     return dirty;
230 }
231 
232 static inline bool cpu_physical_memory_get_dirty_flag(ram_addr_t addr,
233                                                       unsigned client)
234 {
235     return cpu_physical_memory_get_dirty(addr, 1, client);
236 }
237 
238 static inline bool cpu_physical_memory_is_clean(ram_addr_t addr)
239 {
240     bool vga = cpu_physical_memory_get_dirty_flag(addr, DIRTY_MEMORY_VGA);
241     bool code = cpu_physical_memory_get_dirty_flag(addr, DIRTY_MEMORY_CODE);
242     bool migration =
243         cpu_physical_memory_get_dirty_flag(addr, DIRTY_MEMORY_MIGRATION);
244     return !(vga && code && migration);
245 }
246 
247 static inline uint8_t cpu_physical_memory_range_includes_clean(ram_addr_t start,
248                                                                ram_addr_t length,
249                                                                uint8_t mask)
250 {
251     uint8_t ret = 0;
252 
253     if (mask & (1 << DIRTY_MEMORY_VGA) &&
254         !cpu_physical_memory_all_dirty(start, length, DIRTY_MEMORY_VGA)) {
255         ret |= (1 << DIRTY_MEMORY_VGA);
256     }
257     if (mask & (1 << DIRTY_MEMORY_CODE) &&
258         !cpu_physical_memory_all_dirty(start, length, DIRTY_MEMORY_CODE)) {
259         ret |= (1 << DIRTY_MEMORY_CODE);
260     }
261     if (mask & (1 << DIRTY_MEMORY_MIGRATION) &&
262         !cpu_physical_memory_all_dirty(start, length, DIRTY_MEMORY_MIGRATION)) {
263         ret |= (1 << DIRTY_MEMORY_MIGRATION);
264     }
265     return ret;
266 }
267 
268 static inline void cpu_physical_memory_set_dirty_flag(ram_addr_t addr,
269                                                       unsigned client)
270 {
271     unsigned long page, idx, offset;
272     DirtyMemoryBlocks *blocks;
273 
274     assert(client < DIRTY_MEMORY_NUM);
275 
276     page = addr >> TARGET_PAGE_BITS;
277     idx = page / DIRTY_MEMORY_BLOCK_SIZE;
278     offset = page % DIRTY_MEMORY_BLOCK_SIZE;
279 
280     RCU_READ_LOCK_GUARD();
281 
282     blocks = qatomic_rcu_read(&ram_list.dirty_memory[client]);
283 
284     set_bit_atomic(offset, blocks->blocks[idx]);
285 }
286 
287 static inline void cpu_physical_memory_set_dirty_range(ram_addr_t start,
288                                                        ram_addr_t length,
289                                                        uint8_t mask)
290 {
291     DirtyMemoryBlocks *blocks[DIRTY_MEMORY_NUM];
292     unsigned long end, page;
293     unsigned long idx, offset, base;
294     int i;
295 
296     if (!mask && !xen_enabled()) {
297         return;
298     }
299 
300     end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
301     page = start >> TARGET_PAGE_BITS;
302 
303     WITH_RCU_READ_LOCK_GUARD() {
304         for (i = 0; i < DIRTY_MEMORY_NUM; i++) {
305             blocks[i] = qatomic_rcu_read(&ram_list.dirty_memory[i]);
306         }
307 
308         idx = page / DIRTY_MEMORY_BLOCK_SIZE;
309         offset = page % DIRTY_MEMORY_BLOCK_SIZE;
310         base = page - offset;
311         while (page < end) {
312             unsigned long next = MIN(end, base + DIRTY_MEMORY_BLOCK_SIZE);
313 
314             if (likely(mask & (1 << DIRTY_MEMORY_MIGRATION))) {
315                 bitmap_set_atomic(blocks[DIRTY_MEMORY_MIGRATION]->blocks[idx],
316                                   offset, next - page);
317             }
318             if (unlikely(mask & (1 << DIRTY_MEMORY_VGA))) {
319                 bitmap_set_atomic(blocks[DIRTY_MEMORY_VGA]->blocks[idx],
320                                   offset, next - page);
321             }
322             if (unlikely(mask & (1 << DIRTY_MEMORY_CODE))) {
323                 bitmap_set_atomic(blocks[DIRTY_MEMORY_CODE]->blocks[idx],
324                                   offset, next - page);
325             }
326 
327             page = next;
328             idx++;
329             offset = 0;
330             base += DIRTY_MEMORY_BLOCK_SIZE;
331         }
332     }
333 
334     xen_hvm_modified_memory(start, length);
335 }
336 
337 #if !defined(_WIN32)
338 
339 /*
340  * Contrary to cpu_physical_memory_sync_dirty_bitmap() this function returns
341  * the number of dirty pages in @bitmap passed as argument. On the other hand,
342  * cpu_physical_memory_sync_dirty_bitmap() returns newly dirtied pages that
343  * weren't set in the global migration bitmap.
344  */
345 static inline
346 uint64_t cpu_physical_memory_set_dirty_lebitmap(unsigned long *bitmap,
347                                                 ram_addr_t start,
348                                                 ram_addr_t pages)
349 {
350     unsigned long i, j;
351     unsigned long page_number, c, nbits;
352     hwaddr addr;
353     ram_addr_t ram_addr;
354     uint64_t num_dirty = 0;
355     unsigned long len = (pages + HOST_LONG_BITS - 1) / HOST_LONG_BITS;
356     unsigned long hpratio = qemu_real_host_page_size() / TARGET_PAGE_SIZE;
357     unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS);
358 
359     /* start address is aligned at the start of a word? */
360     if ((((page * BITS_PER_LONG) << TARGET_PAGE_BITS) == start) &&
361         (hpratio == 1)) {
362         unsigned long **blocks[DIRTY_MEMORY_NUM];
363         unsigned long idx;
364         unsigned long offset;
365         long k;
366         long nr = BITS_TO_LONGS(pages);
367 
368         idx = (start >> TARGET_PAGE_BITS) / DIRTY_MEMORY_BLOCK_SIZE;
369         offset = BIT_WORD((start >> TARGET_PAGE_BITS) %
370                           DIRTY_MEMORY_BLOCK_SIZE);
371 
372         WITH_RCU_READ_LOCK_GUARD() {
373             for (i = 0; i < DIRTY_MEMORY_NUM; i++) {
374                 blocks[i] =
375                     qatomic_rcu_read(&ram_list.dirty_memory[i])->blocks;
376             }
377 
378             for (k = 0; k < nr; k++) {
379                 if (bitmap[k]) {
380                     unsigned long temp = leul_to_cpu(bitmap[k]);
381 
382                     nbits = ctpopl(temp);
383                     qatomic_or(&blocks[DIRTY_MEMORY_VGA][idx][offset], temp);
384 
385                     if (global_dirty_tracking) {
386                         qatomic_or(
387                                 &blocks[DIRTY_MEMORY_MIGRATION][idx][offset],
388                                 temp);
389                         if (unlikely(
390                             global_dirty_tracking & GLOBAL_DIRTY_DIRTY_RATE)) {
391                             total_dirty_pages += nbits;
392                         }
393                     }
394 
395                     num_dirty += nbits;
396 
397                     if (tcg_enabled()) {
398                         qatomic_or(&blocks[DIRTY_MEMORY_CODE][idx][offset],
399                                    temp);
400                     }
401                 }
402 
403                 if (++offset >= BITS_TO_LONGS(DIRTY_MEMORY_BLOCK_SIZE)) {
404                     offset = 0;
405                     idx++;
406                 }
407             }
408         }
409 
410         xen_hvm_modified_memory(start, pages << TARGET_PAGE_BITS);
411     } else {
412         uint8_t clients = tcg_enabled() ? DIRTY_CLIENTS_ALL : DIRTY_CLIENTS_NOCODE;
413 
414         if (!global_dirty_tracking) {
415             clients &= ~(1 << DIRTY_MEMORY_MIGRATION);
416         }
417 
418         /*
419          * bitmap-traveling is faster than memory-traveling (for addr...)
420          * especially when most of the memory is not dirty.
421          */
422         for (i = 0; i < len; i++) {
423             if (bitmap[i] != 0) {
424                 c = leul_to_cpu(bitmap[i]);
425                 nbits = ctpopl(c);
426                 if (unlikely(global_dirty_tracking & GLOBAL_DIRTY_DIRTY_RATE)) {
427                     total_dirty_pages += nbits;
428                 }
429                 num_dirty += nbits;
430                 do {
431                     j = ctzl(c);
432                     c &= ~(1ul << j);
433                     page_number = (i * HOST_LONG_BITS + j) * hpratio;
434                     addr = page_number * TARGET_PAGE_SIZE;
435                     ram_addr = start + addr;
436                     cpu_physical_memory_set_dirty_range(ram_addr,
437                                        TARGET_PAGE_SIZE * hpratio, clients);
438                 } while (c != 0);
439             }
440         }
441     }
442 
443     return num_dirty;
444 }
445 #endif /* not _WIN32 */
446 
447 static inline void cpu_physical_memory_dirty_bits_cleared(ram_addr_t start,
448                                                           ram_addr_t length)
449 {
450     if (tcg_enabled()) {
451         tlb_reset_dirty_range_all(start, length);
452     }
453 
454 }
455 bool cpu_physical_memory_test_and_clear_dirty(ram_addr_t start,
456                                               ram_addr_t length,
457                                               unsigned client);
458 
459 DirtyBitmapSnapshot *cpu_physical_memory_snapshot_and_clear_dirty
460     (MemoryRegion *mr, hwaddr offset, hwaddr length, unsigned client);
461 
462 bool cpu_physical_memory_snapshot_get_dirty(DirtyBitmapSnapshot *snap,
463                                             ram_addr_t start,
464                                             ram_addr_t length);
465 
466 static inline void cpu_physical_memory_clear_dirty_range(ram_addr_t start,
467                                                          ram_addr_t length)
468 {
469     cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_MIGRATION);
470     cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_VGA);
471     cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_CODE);
472 }
473 
474 
475 /* Called with RCU critical section */
476 static inline
477 uint64_t cpu_physical_memory_sync_dirty_bitmap(RAMBlock *rb,
478                                                ram_addr_t start,
479                                                ram_addr_t length)
480 {
481     ram_addr_t addr;
482     unsigned long word = BIT_WORD((start + rb->offset) >> TARGET_PAGE_BITS);
483     uint64_t num_dirty = 0;
484     unsigned long *dest = rb->bmap;
485 
486     /* start address and length is aligned at the start of a word? */
487     if (((word * BITS_PER_LONG) << TARGET_PAGE_BITS) ==
488          (start + rb->offset) &&
489         !(length & ((BITS_PER_LONG << TARGET_PAGE_BITS) - 1))) {
490         int k;
491         int nr = BITS_TO_LONGS(length >> TARGET_PAGE_BITS);
492         unsigned long * const *src;
493         unsigned long idx = (word * BITS_PER_LONG) / DIRTY_MEMORY_BLOCK_SIZE;
494         unsigned long offset = BIT_WORD((word * BITS_PER_LONG) %
495                                         DIRTY_MEMORY_BLOCK_SIZE);
496         unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS);
497 
498         src = qatomic_rcu_read(
499                 &ram_list.dirty_memory[DIRTY_MEMORY_MIGRATION])->blocks;
500 
501         for (k = page; k < page + nr; k++) {
502             if (src[idx][offset]) {
503                 unsigned long bits = qatomic_xchg(&src[idx][offset], 0);
504                 unsigned long new_dirty;
505                 new_dirty = ~dest[k];
506                 dest[k] |= bits;
507                 new_dirty &= bits;
508                 num_dirty += ctpopl(new_dirty);
509             }
510 
511             if (++offset >= BITS_TO_LONGS(DIRTY_MEMORY_BLOCK_SIZE)) {
512                 offset = 0;
513                 idx++;
514             }
515         }
516         if (num_dirty) {
517             cpu_physical_memory_dirty_bits_cleared(start, length);
518         }
519 
520         if (rb->clear_bmap) {
521             /*
522              * Postpone the dirty bitmap clear to the point before we
523              * really send the pages, also we will split the clear
524              * dirty procedure into smaller chunks.
525              */
526             clear_bmap_set(rb, start >> TARGET_PAGE_BITS,
527                            length >> TARGET_PAGE_BITS);
528         } else {
529             /* Slow path - still do that in a huge chunk */
530             memory_region_clear_dirty_bitmap(rb->mr, start, length);
531         }
532     } else {
533         ram_addr_t offset = rb->offset;
534 
535         for (addr = 0; addr < length; addr += TARGET_PAGE_SIZE) {
536             if (cpu_physical_memory_test_and_clear_dirty(
537                         start + addr + offset,
538                         TARGET_PAGE_SIZE,
539                         DIRTY_MEMORY_MIGRATION)) {
540                 long k = (start + addr) >> TARGET_PAGE_BITS;
541                 if (!test_and_set_bit(k, dest)) {
542                     num_dirty++;
543                 }
544             }
545         }
546     }
547 
548     return num_dirty;
549 }
550 #endif
551 #endif
552