xref: /openbmc/qemu/include/exec/ram_addr.h (revision 6edfca9e)
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 
29 extern uint64_t total_dirty_pages;
30 
31 /**
32  * clear_bmap_size: calculate clear bitmap size
33  *
34  * @pages: number of guest pages
35  * @shift: guest page number shift
36  *
37  * Returns: number of bits for the clear bitmap
38  */
39 static inline long clear_bmap_size(uint64_t pages, uint8_t shift)
40 {
41     return DIV_ROUND_UP(pages, 1UL << shift);
42 }
43 
44 /**
45  * clear_bmap_set: set clear bitmap for the page range.  Must be with
46  * bitmap_mutex held.
47  *
48  * @rb: the ramblock to operate on
49  * @start: the start page number
50  * @size: number of pages to set in the bitmap
51  *
52  * Returns: None
53  */
54 static inline void clear_bmap_set(RAMBlock *rb, uint64_t start,
55                                   uint64_t npages)
56 {
57     uint8_t shift = rb->clear_bmap_shift;
58 
59     bitmap_set(rb->clear_bmap, start >> shift, clear_bmap_size(npages, shift));
60 }
61 
62 /**
63  * clear_bmap_test_and_clear: test clear bitmap for the page, clear if set.
64  * Must be with bitmap_mutex held.
65  *
66  * @rb: the ramblock to operate on
67  * @page: the page number to check
68  *
69  * Returns: true if the bit was set, false otherwise
70  */
71 static inline bool clear_bmap_test_and_clear(RAMBlock *rb, uint64_t page)
72 {
73     uint8_t shift = rb->clear_bmap_shift;
74 
75     return bitmap_test_and_clear(rb->clear_bmap, page >> shift, 1);
76 }
77 
78 static inline bool offset_in_ramblock(RAMBlock *b, ram_addr_t offset)
79 {
80     return (b && b->host && offset < b->used_length) ? true : false;
81 }
82 
83 static inline void *ramblock_ptr(RAMBlock *block, ram_addr_t offset)
84 {
85     assert(offset_in_ramblock(block, offset));
86     return (char *)block->host + offset;
87 }
88 
89 static inline unsigned long int ramblock_recv_bitmap_offset(void *host_addr,
90                                                             RAMBlock *rb)
91 {
92     uint64_t host_addr_offset =
93             (uint64_t)(uintptr_t)(host_addr - (void *)rb->host);
94     return host_addr_offset >> TARGET_PAGE_BITS;
95 }
96 
97 bool ramblock_is_pmem(RAMBlock *rb);
98 
99 long qemu_minrampagesize(void);
100 long qemu_maxrampagesize(void);
101 
102 /**
103  * qemu_ram_alloc_from_file,
104  * qemu_ram_alloc_from_fd:  Allocate a ram block from the specified backing
105  *                          file or device
106  *
107  * Parameters:
108  *  @size: the size in bytes of the ram block
109  *  @mr: the memory region where the ram block is
110  *  @ram_flags: RamBlock flags. Supported flags: RAM_SHARED, RAM_PMEM,
111  *              RAM_NORESERVE.
112  *  @mem_path or @fd: specify the backing file or device
113  *  @offset: Offset into target file
114  *  @readonly: true to open @path for reading, false for read/write.
115  *  @errp: pointer to Error*, to store an error if it happens
116  *
117  * Return:
118  *  On success, return a pointer to the ram block.
119  *  On failure, return NULL.
120  */
121 RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr,
122                                    uint32_t ram_flags, const char *mem_path,
123                                    off_t offset, bool readonly, Error **errp);
124 RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr,
125                                  uint32_t ram_flags, int fd, off_t offset,
126                                  bool readonly, Error **errp);
127 
128 RAMBlock *qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
129                                   MemoryRegion *mr, Error **errp);
130 RAMBlock *qemu_ram_alloc(ram_addr_t size, uint32_t ram_flags, MemoryRegion *mr,
131                          Error **errp);
132 RAMBlock *qemu_ram_alloc_resizeable(ram_addr_t size, ram_addr_t max_size,
133                                     void (*resized)(const char*,
134                                                     uint64_t length,
135                                                     void *host),
136                                     MemoryRegion *mr, Error **errp);
137 void qemu_ram_free(RAMBlock *block);
138 
139 int qemu_ram_resize(RAMBlock *block, ram_addr_t newsize, Error **errp);
140 
141 void qemu_ram_msync(RAMBlock *block, ram_addr_t start, ram_addr_t length);
142 
143 /* Clear whole block of mem */
144 static inline void qemu_ram_block_writeback(RAMBlock *block)
145 {
146     qemu_ram_msync(block, 0, block->used_length);
147 }
148 
149 #define DIRTY_CLIENTS_ALL     ((1 << DIRTY_MEMORY_NUM) - 1)
150 #define DIRTY_CLIENTS_NOCODE  (DIRTY_CLIENTS_ALL & ~(1 << DIRTY_MEMORY_CODE))
151 
152 static inline bool cpu_physical_memory_get_dirty(ram_addr_t start,
153                                                  ram_addr_t length,
154                                                  unsigned client)
155 {
156     DirtyMemoryBlocks *blocks;
157     unsigned long end, page;
158     unsigned long idx, offset, base;
159     bool dirty = false;
160 
161     assert(client < DIRTY_MEMORY_NUM);
162 
163     end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
164     page = start >> TARGET_PAGE_BITS;
165 
166     WITH_RCU_READ_LOCK_GUARD() {
167         blocks = qatomic_rcu_read(&ram_list.dirty_memory[client]);
168 
169         idx = page / DIRTY_MEMORY_BLOCK_SIZE;
170         offset = page % DIRTY_MEMORY_BLOCK_SIZE;
171         base = page - offset;
172         while (page < end) {
173             unsigned long next = MIN(end, base + DIRTY_MEMORY_BLOCK_SIZE);
174             unsigned long num = next - base;
175             unsigned long found = find_next_bit(blocks->blocks[idx],
176                                                 num, offset);
177             if (found < num) {
178                 dirty = true;
179                 break;
180             }
181 
182             page = next;
183             idx++;
184             offset = 0;
185             base += DIRTY_MEMORY_BLOCK_SIZE;
186         }
187     }
188 
189     return dirty;
190 }
191 
192 static inline bool cpu_physical_memory_all_dirty(ram_addr_t start,
193                                                  ram_addr_t length,
194                                                  unsigned client)
195 {
196     DirtyMemoryBlocks *blocks;
197     unsigned long end, page;
198     unsigned long idx, offset, base;
199     bool dirty = true;
200 
201     assert(client < DIRTY_MEMORY_NUM);
202 
203     end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
204     page = start >> TARGET_PAGE_BITS;
205 
206     RCU_READ_LOCK_GUARD();
207 
208     blocks = qatomic_rcu_read(&ram_list.dirty_memory[client]);
209 
210     idx = page / DIRTY_MEMORY_BLOCK_SIZE;
211     offset = page % DIRTY_MEMORY_BLOCK_SIZE;
212     base = page - offset;
213     while (page < end) {
214         unsigned long next = MIN(end, base + DIRTY_MEMORY_BLOCK_SIZE);
215         unsigned long num = next - base;
216         unsigned long found = find_next_zero_bit(blocks->blocks[idx], num, offset);
217         if (found < num) {
218             dirty = false;
219             break;
220         }
221 
222         page = next;
223         idx++;
224         offset = 0;
225         base += DIRTY_MEMORY_BLOCK_SIZE;
226     }
227 
228     return dirty;
229 }
230 
231 static inline bool cpu_physical_memory_get_dirty_flag(ram_addr_t addr,
232                                                       unsigned client)
233 {
234     return cpu_physical_memory_get_dirty(addr, 1, client);
235 }
236 
237 static inline bool cpu_physical_memory_is_clean(ram_addr_t addr)
238 {
239     bool vga = cpu_physical_memory_get_dirty_flag(addr, DIRTY_MEMORY_VGA);
240     bool code = cpu_physical_memory_get_dirty_flag(addr, DIRTY_MEMORY_CODE);
241     bool migration =
242         cpu_physical_memory_get_dirty_flag(addr, DIRTY_MEMORY_MIGRATION);
243     return !(vga && code && migration);
244 }
245 
246 static inline uint8_t cpu_physical_memory_range_includes_clean(ram_addr_t start,
247                                                                ram_addr_t length,
248                                                                uint8_t mask)
249 {
250     uint8_t ret = 0;
251 
252     if (mask & (1 << DIRTY_MEMORY_VGA) &&
253         !cpu_physical_memory_all_dirty(start, length, DIRTY_MEMORY_VGA)) {
254         ret |= (1 << DIRTY_MEMORY_VGA);
255     }
256     if (mask & (1 << DIRTY_MEMORY_CODE) &&
257         !cpu_physical_memory_all_dirty(start, length, DIRTY_MEMORY_CODE)) {
258         ret |= (1 << DIRTY_MEMORY_CODE);
259     }
260     if (mask & (1 << DIRTY_MEMORY_MIGRATION) &&
261         !cpu_physical_memory_all_dirty(start, length, DIRTY_MEMORY_MIGRATION)) {
262         ret |= (1 << DIRTY_MEMORY_MIGRATION);
263     }
264     return ret;
265 }
266 
267 static inline void cpu_physical_memory_set_dirty_flag(ram_addr_t addr,
268                                                       unsigned client)
269 {
270     unsigned long page, idx, offset;
271     DirtyMemoryBlocks *blocks;
272 
273     assert(client < DIRTY_MEMORY_NUM);
274 
275     page = addr >> TARGET_PAGE_BITS;
276     idx = page / DIRTY_MEMORY_BLOCK_SIZE;
277     offset = page % DIRTY_MEMORY_BLOCK_SIZE;
278 
279     RCU_READ_LOCK_GUARD();
280 
281     blocks = qatomic_rcu_read(&ram_list.dirty_memory[client]);
282 
283     set_bit_atomic(offset, blocks->blocks[idx]);
284 }
285 
286 static inline void cpu_physical_memory_set_dirty_range(ram_addr_t start,
287                                                        ram_addr_t length,
288                                                        uint8_t mask)
289 {
290     DirtyMemoryBlocks *blocks[DIRTY_MEMORY_NUM];
291     unsigned long end, page;
292     unsigned long idx, offset, base;
293     int i;
294 
295     if (!mask && !xen_enabled()) {
296         return;
297     }
298 
299     end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
300     page = start >> TARGET_PAGE_BITS;
301 
302     WITH_RCU_READ_LOCK_GUARD() {
303         for (i = 0; i < DIRTY_MEMORY_NUM; i++) {
304             blocks[i] = qatomic_rcu_read(&ram_list.dirty_memory[i]);
305         }
306 
307         idx = page / DIRTY_MEMORY_BLOCK_SIZE;
308         offset = page % DIRTY_MEMORY_BLOCK_SIZE;
309         base = page - offset;
310         while (page < end) {
311             unsigned long next = MIN(end, base + DIRTY_MEMORY_BLOCK_SIZE);
312 
313             if (likely(mask & (1 << DIRTY_MEMORY_MIGRATION))) {
314                 bitmap_set_atomic(blocks[DIRTY_MEMORY_MIGRATION]->blocks[idx],
315                                   offset, next - page);
316             }
317             if (unlikely(mask & (1 << DIRTY_MEMORY_VGA))) {
318                 bitmap_set_atomic(blocks[DIRTY_MEMORY_VGA]->blocks[idx],
319                                   offset, next - page);
320             }
321             if (unlikely(mask & (1 << DIRTY_MEMORY_CODE))) {
322                 bitmap_set_atomic(blocks[DIRTY_MEMORY_CODE]->blocks[idx],
323                                   offset, next - page);
324             }
325 
326             page = next;
327             idx++;
328             offset = 0;
329             base += DIRTY_MEMORY_BLOCK_SIZE;
330         }
331     }
332 
333     xen_hvm_modified_memory(start, length);
334 }
335 
336 #if !defined(_WIN32)
337 
338 /*
339  * Contrary to cpu_physical_memory_sync_dirty_bitmap() this function returns
340  * the number of dirty pages in @bitmap passed as argument. On the other hand,
341  * cpu_physical_memory_sync_dirty_bitmap() returns newly dirtied pages that
342  * weren't set in the global migration bitmap.
343  */
344 static inline
345 uint64_t cpu_physical_memory_set_dirty_lebitmap(unsigned long *bitmap,
346                                                 ram_addr_t start,
347                                                 ram_addr_t pages)
348 {
349     unsigned long i, j;
350     unsigned long page_number, c, nbits;
351     hwaddr addr;
352     ram_addr_t ram_addr;
353     uint64_t num_dirty = 0;
354     unsigned long len = (pages + HOST_LONG_BITS - 1) / HOST_LONG_BITS;
355     unsigned long hpratio = qemu_real_host_page_size() / TARGET_PAGE_SIZE;
356     unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS);
357 
358     /* start address is aligned at the start of a word? */
359     if ((((page * BITS_PER_LONG) << TARGET_PAGE_BITS) == start) &&
360         (hpratio == 1)) {
361         unsigned long **blocks[DIRTY_MEMORY_NUM];
362         unsigned long idx;
363         unsigned long offset;
364         long k;
365         long nr = BITS_TO_LONGS(pages);
366 
367         idx = (start >> TARGET_PAGE_BITS) / DIRTY_MEMORY_BLOCK_SIZE;
368         offset = BIT_WORD((start >> TARGET_PAGE_BITS) %
369                           DIRTY_MEMORY_BLOCK_SIZE);
370 
371         WITH_RCU_READ_LOCK_GUARD() {
372             for (i = 0; i < DIRTY_MEMORY_NUM; i++) {
373                 blocks[i] =
374                     qatomic_rcu_read(&ram_list.dirty_memory[i])->blocks;
375             }
376 
377             for (k = 0; k < nr; k++) {
378                 if (bitmap[k]) {
379                     unsigned long temp = leul_to_cpu(bitmap[k]);
380 
381                     nbits = ctpopl(temp);
382                     qatomic_or(&blocks[DIRTY_MEMORY_VGA][idx][offset], temp);
383 
384                     if (global_dirty_tracking) {
385                         qatomic_or(
386                                 &blocks[DIRTY_MEMORY_MIGRATION][idx][offset],
387                                 temp);
388                         if (unlikely(
389                             global_dirty_tracking & GLOBAL_DIRTY_DIRTY_RATE)) {
390                             total_dirty_pages += nbits;
391                         }
392                     }
393 
394                     num_dirty += nbits;
395 
396                     if (tcg_enabled()) {
397                         qatomic_or(&blocks[DIRTY_MEMORY_CODE][idx][offset],
398                                    temp);
399                     }
400                 }
401 
402                 if (++offset >= BITS_TO_LONGS(DIRTY_MEMORY_BLOCK_SIZE)) {
403                     offset = 0;
404                     idx++;
405                 }
406             }
407         }
408 
409         xen_hvm_modified_memory(start, pages << TARGET_PAGE_BITS);
410     } else {
411         uint8_t clients = tcg_enabled() ? DIRTY_CLIENTS_ALL : DIRTY_CLIENTS_NOCODE;
412 
413         if (!global_dirty_tracking) {
414             clients &= ~(1 << DIRTY_MEMORY_MIGRATION);
415         }
416 
417         /*
418          * bitmap-traveling is faster than memory-traveling (for addr...)
419          * especially when most of the memory is not dirty.
420          */
421         for (i = 0; i < len; i++) {
422             if (bitmap[i] != 0) {
423                 c = leul_to_cpu(bitmap[i]);
424                 nbits = ctpopl(c);
425                 if (unlikely(global_dirty_tracking & GLOBAL_DIRTY_DIRTY_RATE)) {
426                     total_dirty_pages += nbits;
427                 }
428                 num_dirty += nbits;
429                 do {
430                     j = ctzl(c);
431                     c &= ~(1ul << j);
432                     page_number = (i * HOST_LONG_BITS + j) * hpratio;
433                     addr = page_number * TARGET_PAGE_SIZE;
434                     ram_addr = start + addr;
435                     cpu_physical_memory_set_dirty_range(ram_addr,
436                                        TARGET_PAGE_SIZE * hpratio, clients);
437                 } while (c != 0);
438             }
439         }
440     }
441 
442     return num_dirty;
443 }
444 #endif /* not _WIN32 */
445 
446 bool cpu_physical_memory_test_and_clear_dirty(ram_addr_t start,
447                                               ram_addr_t length,
448                                               unsigned client);
449 
450 DirtyBitmapSnapshot *cpu_physical_memory_snapshot_and_clear_dirty
451     (MemoryRegion *mr, hwaddr offset, hwaddr length, unsigned client);
452 
453 bool cpu_physical_memory_snapshot_get_dirty(DirtyBitmapSnapshot *snap,
454                                             ram_addr_t start,
455                                             ram_addr_t length);
456 
457 static inline void cpu_physical_memory_clear_dirty_range(ram_addr_t start,
458                                                          ram_addr_t length)
459 {
460     cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_MIGRATION);
461     cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_VGA);
462     cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_CODE);
463 }
464 
465 
466 /* Called with RCU critical section */
467 static inline
468 uint64_t cpu_physical_memory_sync_dirty_bitmap(RAMBlock *rb,
469                                                ram_addr_t start,
470                                                ram_addr_t length)
471 {
472     ram_addr_t addr;
473     unsigned long word = BIT_WORD((start + rb->offset) >> TARGET_PAGE_BITS);
474     uint64_t num_dirty = 0;
475     unsigned long *dest = rb->bmap;
476 
477     /* start address and length is aligned at the start of a word? */
478     if (((word * BITS_PER_LONG) << TARGET_PAGE_BITS) ==
479          (start + rb->offset) &&
480         !(length & ((BITS_PER_LONG << TARGET_PAGE_BITS) - 1))) {
481         int k;
482         int nr = BITS_TO_LONGS(length >> TARGET_PAGE_BITS);
483         unsigned long * const *src;
484         unsigned long idx = (word * BITS_PER_LONG) / DIRTY_MEMORY_BLOCK_SIZE;
485         unsigned long offset = BIT_WORD((word * BITS_PER_LONG) %
486                                         DIRTY_MEMORY_BLOCK_SIZE);
487         unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS);
488 
489         src = qatomic_rcu_read(
490                 &ram_list.dirty_memory[DIRTY_MEMORY_MIGRATION])->blocks;
491 
492         for (k = page; k < page + nr; k++) {
493             if (src[idx][offset]) {
494                 unsigned long bits = qatomic_xchg(&src[idx][offset], 0);
495                 unsigned long new_dirty;
496                 new_dirty = ~dest[k];
497                 dest[k] |= bits;
498                 new_dirty &= bits;
499                 num_dirty += ctpopl(new_dirty);
500             }
501 
502             if (++offset >= BITS_TO_LONGS(DIRTY_MEMORY_BLOCK_SIZE)) {
503                 offset = 0;
504                 idx++;
505             }
506         }
507 
508         if (rb->clear_bmap) {
509             /*
510              * Postpone the dirty bitmap clear to the point before we
511              * really send the pages, also we will split the clear
512              * dirty procedure into smaller chunks.
513              */
514             clear_bmap_set(rb, start >> TARGET_PAGE_BITS,
515                            length >> TARGET_PAGE_BITS);
516         } else {
517             /* Slow path - still do that in a huge chunk */
518             memory_region_clear_dirty_bitmap(rb->mr, start, length);
519         }
520     } else {
521         ram_addr_t offset = rb->offset;
522 
523         for (addr = 0; addr < length; addr += TARGET_PAGE_SIZE) {
524             if (cpu_physical_memory_test_and_clear_dirty(
525                         start + addr + offset,
526                         TARGET_PAGE_SIZE,
527                         DIRTY_MEMORY_MIGRATION)) {
528                 long k = (start + addr) >> TARGET_PAGE_BITS;
529                 if (!test_and_set_bit(k, dest)) {
530                     num_dirty++;
531                 }
532             }
533         }
534     }
535 
536     return num_dirty;
537 }
538 #endif
539 #endif
540