xref: /openbmc/qemu/include/exec/ram_addr.h (revision ffe98631)
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  *  @readonly: true to open @path for reading, false for read/write.
114  *  @errp: pointer to Error*, to store an error if it happens
115  *
116  * Return:
117  *  On success, return a pointer to the ram block.
118  *  On failure, return NULL.
119  */
120 RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr,
121                                    uint32_t ram_flags, const char *mem_path,
122                                    bool readonly, Error **errp);
123 RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr,
124                                  uint32_t ram_flags, int fd, off_t offset,
125                                  bool readonly, Error **errp);
126 
127 RAMBlock *qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
128                                   MemoryRegion *mr, Error **errp);
129 RAMBlock *qemu_ram_alloc(ram_addr_t size, uint32_t ram_flags, MemoryRegion *mr,
130                          Error **errp);
131 RAMBlock *qemu_ram_alloc_resizeable(ram_addr_t size, ram_addr_t max_size,
132                                     void (*resized)(const char*,
133                                                     uint64_t length,
134                                                     void *host),
135                                     MemoryRegion *mr, Error **errp);
136 void qemu_ram_free(RAMBlock *block);
137 
138 int qemu_ram_resize(RAMBlock *block, ram_addr_t newsize, Error **errp);
139 
140 void qemu_ram_msync(RAMBlock *block, ram_addr_t start, ram_addr_t length);
141 
142 /* Clear whole block of mem */
143 static inline void qemu_ram_block_writeback(RAMBlock *block)
144 {
145     qemu_ram_msync(block, 0, block->used_length);
146 }
147 
148 #define DIRTY_CLIENTS_ALL     ((1 << DIRTY_MEMORY_NUM) - 1)
149 #define DIRTY_CLIENTS_NOCODE  (DIRTY_CLIENTS_ALL & ~(1 << DIRTY_MEMORY_CODE))
150 
151 static inline bool cpu_physical_memory_get_dirty(ram_addr_t start,
152                                                  ram_addr_t length,
153                                                  unsigned client)
154 {
155     DirtyMemoryBlocks *blocks;
156     unsigned long end, page;
157     unsigned long idx, offset, base;
158     bool dirty = false;
159 
160     assert(client < DIRTY_MEMORY_NUM);
161 
162     end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
163     page = start >> TARGET_PAGE_BITS;
164 
165     WITH_RCU_READ_LOCK_GUARD() {
166         blocks = qatomic_rcu_read(&ram_list.dirty_memory[client]);
167 
168         idx = page / DIRTY_MEMORY_BLOCK_SIZE;
169         offset = page % DIRTY_MEMORY_BLOCK_SIZE;
170         base = page - offset;
171         while (page < end) {
172             unsigned long next = MIN(end, base + DIRTY_MEMORY_BLOCK_SIZE);
173             unsigned long num = next - base;
174             unsigned long found = find_next_bit(blocks->blocks[idx],
175                                                 num, offset);
176             if (found < num) {
177                 dirty = true;
178                 break;
179             }
180 
181             page = next;
182             idx++;
183             offset = 0;
184             base += DIRTY_MEMORY_BLOCK_SIZE;
185         }
186     }
187 
188     return dirty;
189 }
190 
191 static inline bool cpu_physical_memory_all_dirty(ram_addr_t start,
192                                                  ram_addr_t length,
193                                                  unsigned client)
194 {
195     DirtyMemoryBlocks *blocks;
196     unsigned long end, page;
197     unsigned long idx, offset, base;
198     bool dirty = true;
199 
200     assert(client < DIRTY_MEMORY_NUM);
201 
202     end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
203     page = start >> TARGET_PAGE_BITS;
204 
205     RCU_READ_LOCK_GUARD();
206 
207     blocks = qatomic_rcu_read(&ram_list.dirty_memory[client]);
208 
209     idx = page / DIRTY_MEMORY_BLOCK_SIZE;
210     offset = page % DIRTY_MEMORY_BLOCK_SIZE;
211     base = page - offset;
212     while (page < end) {
213         unsigned long next = MIN(end, base + DIRTY_MEMORY_BLOCK_SIZE);
214         unsigned long num = next - base;
215         unsigned long found = find_next_zero_bit(blocks->blocks[idx], num, offset);
216         if (found < num) {
217             dirty = false;
218             break;
219         }
220 
221         page = next;
222         idx++;
223         offset = 0;
224         base += DIRTY_MEMORY_BLOCK_SIZE;
225     }
226 
227     return dirty;
228 }
229 
230 static inline bool cpu_physical_memory_get_dirty_flag(ram_addr_t addr,
231                                                       unsigned client)
232 {
233     return cpu_physical_memory_get_dirty(addr, 1, client);
234 }
235 
236 static inline bool cpu_physical_memory_is_clean(ram_addr_t addr)
237 {
238     bool vga = cpu_physical_memory_get_dirty_flag(addr, DIRTY_MEMORY_VGA);
239     bool code = cpu_physical_memory_get_dirty_flag(addr, DIRTY_MEMORY_CODE);
240     bool migration =
241         cpu_physical_memory_get_dirty_flag(addr, DIRTY_MEMORY_MIGRATION);
242     return !(vga && code && migration);
243 }
244 
245 static inline uint8_t cpu_physical_memory_range_includes_clean(ram_addr_t start,
246                                                                ram_addr_t length,
247                                                                uint8_t mask)
248 {
249     uint8_t ret = 0;
250 
251     if (mask & (1 << DIRTY_MEMORY_VGA) &&
252         !cpu_physical_memory_all_dirty(start, length, DIRTY_MEMORY_VGA)) {
253         ret |= (1 << DIRTY_MEMORY_VGA);
254     }
255     if (mask & (1 << DIRTY_MEMORY_CODE) &&
256         !cpu_physical_memory_all_dirty(start, length, DIRTY_MEMORY_CODE)) {
257         ret |= (1 << DIRTY_MEMORY_CODE);
258     }
259     if (mask & (1 << DIRTY_MEMORY_MIGRATION) &&
260         !cpu_physical_memory_all_dirty(start, length, DIRTY_MEMORY_MIGRATION)) {
261         ret |= (1 << DIRTY_MEMORY_MIGRATION);
262     }
263     return ret;
264 }
265 
266 static inline void cpu_physical_memory_set_dirty_flag(ram_addr_t addr,
267                                                       unsigned client)
268 {
269     unsigned long page, idx, offset;
270     DirtyMemoryBlocks *blocks;
271 
272     assert(client < DIRTY_MEMORY_NUM);
273 
274     page = addr >> TARGET_PAGE_BITS;
275     idx = page / DIRTY_MEMORY_BLOCK_SIZE;
276     offset = page % DIRTY_MEMORY_BLOCK_SIZE;
277 
278     RCU_READ_LOCK_GUARD();
279 
280     blocks = qatomic_rcu_read(&ram_list.dirty_memory[client]);
281 
282     set_bit_atomic(offset, blocks->blocks[idx]);
283 }
284 
285 static inline void cpu_physical_memory_set_dirty_range(ram_addr_t start,
286                                                        ram_addr_t length,
287                                                        uint8_t mask)
288 {
289     DirtyMemoryBlocks *blocks[DIRTY_MEMORY_NUM];
290     unsigned long end, page;
291     unsigned long idx, offset, base;
292     int i;
293 
294     if (!mask && !xen_enabled()) {
295         return;
296     }
297 
298     end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
299     page = start >> TARGET_PAGE_BITS;
300 
301     WITH_RCU_READ_LOCK_GUARD() {
302         for (i = 0; i < DIRTY_MEMORY_NUM; i++) {
303             blocks[i] = qatomic_rcu_read(&ram_list.dirty_memory[i]);
304         }
305 
306         idx = page / DIRTY_MEMORY_BLOCK_SIZE;
307         offset = page % DIRTY_MEMORY_BLOCK_SIZE;
308         base = page - offset;
309         while (page < end) {
310             unsigned long next = MIN(end, base + DIRTY_MEMORY_BLOCK_SIZE);
311 
312             if (likely(mask & (1 << DIRTY_MEMORY_MIGRATION))) {
313                 bitmap_set_atomic(blocks[DIRTY_MEMORY_MIGRATION]->blocks[idx],
314                                   offset, next - page);
315             }
316             if (unlikely(mask & (1 << DIRTY_MEMORY_VGA))) {
317                 bitmap_set_atomic(blocks[DIRTY_MEMORY_VGA]->blocks[idx],
318                                   offset, next - page);
319             }
320             if (unlikely(mask & (1 << DIRTY_MEMORY_CODE))) {
321                 bitmap_set_atomic(blocks[DIRTY_MEMORY_CODE]->blocks[idx],
322                                   offset, next - page);
323             }
324 
325             page = next;
326             idx++;
327             offset = 0;
328             base += DIRTY_MEMORY_BLOCK_SIZE;
329         }
330     }
331 
332     xen_hvm_modified_memory(start, length);
333 }
334 
335 #if !defined(_WIN32)
336 static inline void cpu_physical_memory_set_dirty_lebitmap(unsigned long *bitmap,
337                                                           ram_addr_t start,
338                                                           ram_addr_t pages)
339 {
340     unsigned long i, j;
341     unsigned long page_number, c;
342     hwaddr addr;
343     ram_addr_t ram_addr;
344     unsigned long len = (pages + HOST_LONG_BITS - 1) / HOST_LONG_BITS;
345     unsigned long hpratio = qemu_real_host_page_size() / TARGET_PAGE_SIZE;
346     unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS);
347 
348     /* start address is aligned at the start of a word? */
349     if ((((page * BITS_PER_LONG) << TARGET_PAGE_BITS) == start) &&
350         (hpratio == 1)) {
351         unsigned long **blocks[DIRTY_MEMORY_NUM];
352         unsigned long idx;
353         unsigned long offset;
354         long k;
355         long nr = BITS_TO_LONGS(pages);
356 
357         idx = (start >> TARGET_PAGE_BITS) / DIRTY_MEMORY_BLOCK_SIZE;
358         offset = BIT_WORD((start >> TARGET_PAGE_BITS) %
359                           DIRTY_MEMORY_BLOCK_SIZE);
360 
361         WITH_RCU_READ_LOCK_GUARD() {
362             for (i = 0; i < DIRTY_MEMORY_NUM; i++) {
363                 blocks[i] =
364                     qatomic_rcu_read(&ram_list.dirty_memory[i])->blocks;
365             }
366 
367             for (k = 0; k < nr; k++) {
368                 if (bitmap[k]) {
369                     unsigned long temp = leul_to_cpu(bitmap[k]);
370 
371                     qatomic_or(&blocks[DIRTY_MEMORY_VGA][idx][offset], temp);
372 
373                     if (global_dirty_tracking) {
374                         qatomic_or(
375                                 &blocks[DIRTY_MEMORY_MIGRATION][idx][offset],
376                                 temp);
377                         if (unlikely(
378                             global_dirty_tracking & GLOBAL_DIRTY_DIRTY_RATE)) {
379                             total_dirty_pages += ctpopl(temp);
380                         }
381                     }
382 
383                     if (tcg_enabled()) {
384                         qatomic_or(&blocks[DIRTY_MEMORY_CODE][idx][offset],
385                                    temp);
386                     }
387                 }
388 
389                 if (++offset >= BITS_TO_LONGS(DIRTY_MEMORY_BLOCK_SIZE)) {
390                     offset = 0;
391                     idx++;
392                 }
393             }
394         }
395 
396         xen_hvm_modified_memory(start, pages << TARGET_PAGE_BITS);
397     } else {
398         uint8_t clients = tcg_enabled() ? DIRTY_CLIENTS_ALL : DIRTY_CLIENTS_NOCODE;
399 
400         if (!global_dirty_tracking) {
401             clients &= ~(1 << DIRTY_MEMORY_MIGRATION);
402         }
403 
404         /*
405          * bitmap-traveling is faster than memory-traveling (for addr...)
406          * especially when most of the memory is not dirty.
407          */
408         for (i = 0; i < len; i++) {
409             if (bitmap[i] != 0) {
410                 c = leul_to_cpu(bitmap[i]);
411                 if (unlikely(global_dirty_tracking & GLOBAL_DIRTY_DIRTY_RATE)) {
412                     total_dirty_pages += ctpopl(c);
413                 }
414                 do {
415                     j = ctzl(c);
416                     c &= ~(1ul << j);
417                     page_number = (i * HOST_LONG_BITS + j) * hpratio;
418                     addr = page_number * TARGET_PAGE_SIZE;
419                     ram_addr = start + addr;
420                     cpu_physical_memory_set_dirty_range(ram_addr,
421                                        TARGET_PAGE_SIZE * hpratio, clients);
422                 } while (c != 0);
423             }
424         }
425     }
426 }
427 #endif /* not _WIN32 */
428 
429 bool cpu_physical_memory_test_and_clear_dirty(ram_addr_t start,
430                                               ram_addr_t length,
431                                               unsigned client);
432 
433 DirtyBitmapSnapshot *cpu_physical_memory_snapshot_and_clear_dirty
434     (MemoryRegion *mr, hwaddr offset, hwaddr length, unsigned client);
435 
436 bool cpu_physical_memory_snapshot_get_dirty(DirtyBitmapSnapshot *snap,
437                                             ram_addr_t start,
438                                             ram_addr_t length);
439 
440 static inline void cpu_physical_memory_clear_dirty_range(ram_addr_t start,
441                                                          ram_addr_t length)
442 {
443     cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_MIGRATION);
444     cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_VGA);
445     cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_CODE);
446 }
447 
448 
449 /* Called with RCU critical section */
450 static inline
451 uint64_t cpu_physical_memory_sync_dirty_bitmap(RAMBlock *rb,
452                                                ram_addr_t start,
453                                                ram_addr_t length)
454 {
455     ram_addr_t addr;
456     unsigned long word = BIT_WORD((start + rb->offset) >> TARGET_PAGE_BITS);
457     uint64_t num_dirty = 0;
458     unsigned long *dest = rb->bmap;
459 
460     /* start address and length is aligned at the start of a word? */
461     if (((word * BITS_PER_LONG) << TARGET_PAGE_BITS) ==
462          (start + rb->offset) &&
463         !(length & ((BITS_PER_LONG << TARGET_PAGE_BITS) - 1))) {
464         int k;
465         int nr = BITS_TO_LONGS(length >> TARGET_PAGE_BITS);
466         unsigned long * const *src;
467         unsigned long idx = (word * BITS_PER_LONG) / DIRTY_MEMORY_BLOCK_SIZE;
468         unsigned long offset = BIT_WORD((word * BITS_PER_LONG) %
469                                         DIRTY_MEMORY_BLOCK_SIZE);
470         unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS);
471 
472         src = qatomic_rcu_read(
473                 &ram_list.dirty_memory[DIRTY_MEMORY_MIGRATION])->blocks;
474 
475         for (k = page; k < page + nr; k++) {
476             if (src[idx][offset]) {
477                 unsigned long bits = qatomic_xchg(&src[idx][offset], 0);
478                 unsigned long new_dirty;
479                 new_dirty = ~dest[k];
480                 dest[k] |= bits;
481                 new_dirty &= bits;
482                 num_dirty += ctpopl(new_dirty);
483             }
484 
485             if (++offset >= BITS_TO_LONGS(DIRTY_MEMORY_BLOCK_SIZE)) {
486                 offset = 0;
487                 idx++;
488             }
489         }
490 
491         if (rb->clear_bmap) {
492             /*
493              * Postpone the dirty bitmap clear to the point before we
494              * really send the pages, also we will split the clear
495              * dirty procedure into smaller chunks.
496              */
497             clear_bmap_set(rb, start >> TARGET_PAGE_BITS,
498                            length >> TARGET_PAGE_BITS);
499         } else {
500             /* Slow path - still do that in a huge chunk */
501             memory_region_clear_dirty_bitmap(rb->mr, start, length);
502         }
503     } else {
504         ram_addr_t offset = rb->offset;
505 
506         for (addr = 0; addr < length; addr += TARGET_PAGE_SIZE) {
507             if (cpu_physical_memory_test_and_clear_dirty(
508                         start + addr + offset,
509                         TARGET_PAGE_SIZE,
510                         DIRTY_MEMORY_MIGRATION)) {
511                 long k = (start + addr) >> TARGET_PAGE_BITS;
512                 if (!test_and_set_bit(k, dest)) {
513                     num_dirty++;
514                 }
515             }
516         }
517     }
518 
519     return num_dirty;
520 }
521 #endif
522 #endif
523