xref: /openbmc/qemu/include/exec/ram_addr.h (revision 174d2d68)
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 "hw/xen/xen.h"
25 #include "sysemu/tcg.h"
26 #include "exec/ramlist.h"
27 #include "exec/ramblock.h"
28 
29 /**
30  * clear_bmap_size: calculate clear bitmap size
31  *
32  * @pages: number of guest pages
33  * @shift: guest page number shift
34  *
35  * Returns: number of bits for the clear bitmap
36  */
37 static inline long clear_bmap_size(uint64_t pages, uint8_t shift)
38 {
39     return DIV_ROUND_UP(pages, 1UL << shift);
40 }
41 
42 /**
43  * clear_bmap_set: set clear bitmap for the page range
44  *
45  * @rb: the ramblock to operate on
46  * @start: the start page number
47  * @size: number of pages to set in the bitmap
48  *
49  * Returns: None
50  */
51 static inline void clear_bmap_set(RAMBlock *rb, uint64_t start,
52                                   uint64_t npages)
53 {
54     uint8_t shift = rb->clear_bmap_shift;
55 
56     bitmap_set_atomic(rb->clear_bmap, start >> shift,
57                       clear_bmap_size(npages, shift));
58 }
59 
60 /**
61  * clear_bmap_test_and_clear: test clear bitmap for the page, clear if set
62  *
63  * @rb: the ramblock to operate on
64  * @page: the page number to check
65  *
66  * Returns: true if the bit was set, false otherwise
67  */
68 static inline bool clear_bmap_test_and_clear(RAMBlock *rb, uint64_t page)
69 {
70     uint8_t shift = rb->clear_bmap_shift;
71 
72     return bitmap_test_and_clear_atomic(rb->clear_bmap, page >> shift, 1);
73 }
74 
75 static inline bool offset_in_ramblock(RAMBlock *b, ram_addr_t offset)
76 {
77     return (b && b->host && offset < b->used_length) ? true : false;
78 }
79 
80 static inline void *ramblock_ptr(RAMBlock *block, ram_addr_t offset)
81 {
82     assert(offset_in_ramblock(block, offset));
83     return (char *)block->host + offset;
84 }
85 
86 static inline unsigned long int ramblock_recv_bitmap_offset(void *host_addr,
87                                                             RAMBlock *rb)
88 {
89     uint64_t host_addr_offset =
90             (uint64_t)(uintptr_t)(host_addr - (void *)rb->host);
91     return host_addr_offset >> TARGET_PAGE_BITS;
92 }
93 
94 bool ramblock_is_pmem(RAMBlock *rb);
95 
96 long qemu_minrampagesize(void);
97 long qemu_maxrampagesize(void);
98 
99 /**
100  * qemu_ram_alloc_from_file,
101  * qemu_ram_alloc_from_fd:  Allocate a ram block from the specified backing
102  *                          file or device
103  *
104  * Parameters:
105  *  @size: the size in bytes of the ram block
106  *  @mr: the memory region where the ram block is
107  *  @ram_flags: specify the properties of the ram block, which can be one
108  *              or bit-or of following values
109  *              - RAM_SHARED: mmap the backing file or device with MAP_SHARED
110  *              - RAM_PMEM: the backend @mem_path or @fd is persistent memory
111  *              Other bits are ignored.
112  *  @mem_path or @fd: specify the backing file or device
113  *  @errp: pointer to Error*, to store an error if it happens
114  *
115  * Return:
116  *  On success, return a pointer to the ram block.
117  *  On failure, return NULL.
118  */
119 RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr,
120                                    uint32_t ram_flags, const char *mem_path,
121                                    Error **errp);
122 RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr,
123                                  uint32_t ram_flags, int fd,
124                                  Error **errp);
125 
126 RAMBlock *qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
127                                   MemoryRegion *mr, Error **errp);
128 RAMBlock *qemu_ram_alloc(ram_addr_t size, bool share, MemoryRegion *mr,
129                          Error **errp);
130 RAMBlock *qemu_ram_alloc_resizeable(ram_addr_t size, ram_addr_t max_size,
131                                     void (*resized)(const char*,
132                                                     uint64_t length,
133                                                     void *host),
134                                     MemoryRegion *mr, Error **errp);
135 void qemu_ram_free(RAMBlock *block);
136 
137 int qemu_ram_resize(RAMBlock *block, ram_addr_t newsize, Error **errp);
138 
139 void qemu_ram_writeback(RAMBlock *block, ram_addr_t start, ram_addr_t length);
140 
141 /* Clear whole block of mem */
142 static inline void qemu_ram_block_writeback(RAMBlock *block)
143 {
144     qemu_ram_writeback(block, 0, block->used_length);
145 }
146 
147 #define DIRTY_CLIENTS_ALL     ((1 << DIRTY_MEMORY_NUM) - 1)
148 #define DIRTY_CLIENTS_NOCODE  (DIRTY_CLIENTS_ALL & ~(1 << DIRTY_MEMORY_CODE))
149 
150 void tb_invalidate_phys_range(ram_addr_t start, ram_addr_t end);
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 = atomic_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 = atomic_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 = atomic_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] = atomic_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 static inline void cpu_physical_memory_set_dirty_lebitmap(unsigned long *bitmap,
338                                                           ram_addr_t start,
339                                                           ram_addr_t pages)
340 {
341     unsigned long i, j;
342     unsigned long page_number, c;
343     hwaddr addr;
344     ram_addr_t ram_addr;
345     unsigned long len = (pages + HOST_LONG_BITS - 1) / HOST_LONG_BITS;
346     unsigned long hpratio = qemu_real_host_page_size / TARGET_PAGE_SIZE;
347     unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS);
348 
349     /* start address is aligned at the start of a word? */
350     if ((((page * BITS_PER_LONG) << TARGET_PAGE_BITS) == start) &&
351         (hpratio == 1)) {
352         unsigned long **blocks[DIRTY_MEMORY_NUM];
353         unsigned long idx;
354         unsigned long offset;
355         long k;
356         long nr = BITS_TO_LONGS(pages);
357 
358         idx = (start >> TARGET_PAGE_BITS) / DIRTY_MEMORY_BLOCK_SIZE;
359         offset = BIT_WORD((start >> TARGET_PAGE_BITS) %
360                           DIRTY_MEMORY_BLOCK_SIZE);
361 
362         WITH_RCU_READ_LOCK_GUARD() {
363             for (i = 0; i < DIRTY_MEMORY_NUM; i++) {
364                 blocks[i] = atomic_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                     atomic_or(&blocks[DIRTY_MEMORY_VGA][idx][offset], temp);
372 
373                     if (global_dirty_log) {
374                         atomic_or(&blocks[DIRTY_MEMORY_MIGRATION][idx][offset],
375                                   temp);
376                     }
377 
378                     if (tcg_enabled()) {
379                         atomic_or(&blocks[DIRTY_MEMORY_CODE][idx][offset],
380                                   temp);
381                     }
382                 }
383 
384                 if (++offset >= BITS_TO_LONGS(DIRTY_MEMORY_BLOCK_SIZE)) {
385                     offset = 0;
386                     idx++;
387                 }
388             }
389         }
390 
391         xen_hvm_modified_memory(start, pages << TARGET_PAGE_BITS);
392     } else {
393         uint8_t clients = tcg_enabled() ? DIRTY_CLIENTS_ALL : DIRTY_CLIENTS_NOCODE;
394 
395         if (!global_dirty_log) {
396             clients &= ~(1 << DIRTY_MEMORY_MIGRATION);
397         }
398 
399         /*
400          * bitmap-traveling is faster than memory-traveling (for addr...)
401          * especially when most of the memory is not dirty.
402          */
403         for (i = 0; i < len; i++) {
404             if (bitmap[i] != 0) {
405                 c = leul_to_cpu(bitmap[i]);
406                 do {
407                     j = ctzl(c);
408                     c &= ~(1ul << j);
409                     page_number = (i * HOST_LONG_BITS + j) * hpratio;
410                     addr = page_number * TARGET_PAGE_SIZE;
411                     ram_addr = start + addr;
412                     cpu_physical_memory_set_dirty_range(ram_addr,
413                                        TARGET_PAGE_SIZE * hpratio, clients);
414                 } while (c != 0);
415             }
416         }
417     }
418 }
419 #endif /* not _WIN32 */
420 
421 bool cpu_physical_memory_test_and_clear_dirty(ram_addr_t start,
422                                               ram_addr_t length,
423                                               unsigned client);
424 
425 DirtyBitmapSnapshot *cpu_physical_memory_snapshot_and_clear_dirty
426     (MemoryRegion *mr, hwaddr offset, hwaddr length, unsigned client);
427 
428 bool cpu_physical_memory_snapshot_get_dirty(DirtyBitmapSnapshot *snap,
429                                             ram_addr_t start,
430                                             ram_addr_t length);
431 
432 static inline void cpu_physical_memory_clear_dirty_range(ram_addr_t start,
433                                                          ram_addr_t length)
434 {
435     cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_MIGRATION);
436     cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_VGA);
437     cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_CODE);
438 }
439 
440 
441 /* Called with RCU critical section */
442 static inline
443 uint64_t cpu_physical_memory_sync_dirty_bitmap(RAMBlock *rb,
444                                                ram_addr_t start,
445                                                ram_addr_t length,
446                                                uint64_t *real_dirty_pages)
447 {
448     ram_addr_t addr;
449     unsigned long word = BIT_WORD((start + rb->offset) >> TARGET_PAGE_BITS);
450     uint64_t num_dirty = 0;
451     unsigned long *dest = rb->bmap;
452 
453     /* start address and length is aligned at the start of a word? */
454     if (((word * BITS_PER_LONG) << TARGET_PAGE_BITS) ==
455          (start + rb->offset) &&
456         !(length & ((BITS_PER_LONG << TARGET_PAGE_BITS) - 1))) {
457         int k;
458         int nr = BITS_TO_LONGS(length >> TARGET_PAGE_BITS);
459         unsigned long * const *src;
460         unsigned long idx = (word * BITS_PER_LONG) / DIRTY_MEMORY_BLOCK_SIZE;
461         unsigned long offset = BIT_WORD((word * BITS_PER_LONG) %
462                                         DIRTY_MEMORY_BLOCK_SIZE);
463         unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS);
464 
465         src = atomic_rcu_read(
466                 &ram_list.dirty_memory[DIRTY_MEMORY_MIGRATION])->blocks;
467 
468         for (k = page; k < page + nr; k++) {
469             if (src[idx][offset]) {
470                 unsigned long bits = atomic_xchg(&src[idx][offset], 0);
471                 unsigned long new_dirty;
472                 *real_dirty_pages += ctpopl(bits);
473                 new_dirty = ~dest[k];
474                 dest[k] |= bits;
475                 new_dirty &= bits;
476                 num_dirty += ctpopl(new_dirty);
477             }
478 
479             if (++offset >= BITS_TO_LONGS(DIRTY_MEMORY_BLOCK_SIZE)) {
480                 offset = 0;
481                 idx++;
482             }
483         }
484 
485         if (rb->clear_bmap) {
486             /*
487              * Postpone the dirty bitmap clear to the point before we
488              * really send the pages, also we will split the clear
489              * dirty procedure into smaller chunks.
490              */
491             clear_bmap_set(rb, start >> TARGET_PAGE_BITS,
492                            length >> TARGET_PAGE_BITS);
493         } else {
494             /* Slow path - still do that in a huge chunk */
495             memory_region_clear_dirty_bitmap(rb->mr, start, length);
496         }
497     } else {
498         ram_addr_t offset = rb->offset;
499 
500         for (addr = 0; addr < length; addr += TARGET_PAGE_SIZE) {
501             if (cpu_physical_memory_test_and_clear_dirty(
502                         start + addr + offset,
503                         TARGET_PAGE_SIZE,
504                         DIRTY_MEMORY_MIGRATION)) {
505                 *real_dirty_pages += 1;
506                 long k = (start + addr) >> TARGET_PAGE_BITS;
507                 if (!test_and_set_bit(k, dest)) {
508                     num_dirty++;
509                 }
510             }
511         }
512     }
513 
514     return num_dirty;
515 }
516 #endif
517 #endif
518