xref: /openbmc/qemu/include/exec/ram_addr.h (revision c5614ee3)
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 #include "qemu/rcu.h"
30 
31 extern uint64_t total_dirty_pages;
32 
33 /**
34  * clear_bmap_size: calculate clear bitmap size
35  *
36  * @pages: number of guest pages
37  * @shift: guest page number shift
38  *
39  * Returns: number of bits for the clear bitmap
40  */
41 static inline long clear_bmap_size(uint64_t pages, uint8_t shift)
42 {
43     return DIV_ROUND_UP(pages, 1UL << shift);
44 }
45 
46 /**
47  * clear_bmap_set: set clear bitmap for the page range.  Must be with
48  * bitmap_mutex held.
49  *
50  * @rb: the ramblock to operate on
51  * @start: the start page number
52  * @size: number of pages to set in the bitmap
53  *
54  * Returns: None
55  */
56 static inline void clear_bmap_set(RAMBlock *rb, uint64_t start,
57                                   uint64_t npages)
58 {
59     uint8_t shift = rb->clear_bmap_shift;
60 
61     bitmap_set(rb->clear_bmap, start >> shift, clear_bmap_size(npages, shift));
62 }
63 
64 /**
65  * clear_bmap_test_and_clear: test clear bitmap for the page, clear if set.
66  * Must be with bitmap_mutex held.
67  *
68  * @rb: the ramblock to operate on
69  * @page: the page number to check
70  *
71  * Returns: true if the bit was set, false otherwise
72  */
73 static inline bool clear_bmap_test_and_clear(RAMBlock *rb, uint64_t page)
74 {
75     uint8_t shift = rb->clear_bmap_shift;
76 
77     return bitmap_test_and_clear(rb->clear_bmap, page >> shift, 1);
78 }
79 
80 static inline bool offset_in_ramblock(RAMBlock *b, ram_addr_t offset)
81 {
82     return (b && b->host && offset < b->used_length) ? true : false;
83 }
84 
85 static inline void *ramblock_ptr(RAMBlock *block, ram_addr_t offset)
86 {
87     assert(offset_in_ramblock(block, offset));
88     return (char *)block->host + offset;
89 }
90 
91 static inline unsigned long int ramblock_recv_bitmap_offset(void *host_addr,
92                                                             RAMBlock *rb)
93 {
94     uint64_t host_addr_offset =
95             (uint64_t)(uintptr_t)(host_addr - (void *)rb->host);
96     return host_addr_offset >> TARGET_PAGE_BITS;
97 }
98 
99 bool ramblock_is_pmem(RAMBlock *rb);
100 
101 long qemu_minrampagesize(void);
102 long qemu_maxrampagesize(void);
103 
104 /**
105  * qemu_ram_alloc_from_file,
106  * qemu_ram_alloc_from_fd:  Allocate a ram block from the specified backing
107  *                          file or device
108  *
109  * Parameters:
110  *  @size: the size in bytes of the ram block
111  *  @mr: the memory region where the ram block is
112  *  @ram_flags: RamBlock flags. Supported flags: RAM_SHARED, RAM_PMEM,
113  *              RAM_NORESERVE, RAM_PROTECTED, RAM_NAMED_FILE, RAM_READONLY,
114  *              RAM_READONLY_FD, RAM_GUEST_MEMFD
115  *  @mem_path or @fd: specify the backing file or device
116  *  @offset: Offset into target file
117  *  @errp: pointer to Error*, to store an error if it happens
118  *
119  * Return:
120  *  On success, return a pointer to the ram block.
121  *  On failure, return NULL.
122  */
123 RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr,
124                                    uint32_t ram_flags, const char *mem_path,
125                                    off_t offset, Error **errp);
126 RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr,
127                                  uint32_t ram_flags, int fd, off_t offset,
128                                  Error **errp);
129 
130 RAMBlock *qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
131                                   MemoryRegion *mr, Error **errp);
132 RAMBlock *qemu_ram_alloc(ram_addr_t size, uint32_t ram_flags, MemoryRegion *mr,
133                          Error **errp);
134 RAMBlock *qemu_ram_alloc_resizeable(ram_addr_t size, ram_addr_t max_size,
135                                     void (*resized)(const char*,
136                                                     uint64_t length,
137                                                     void *host),
138                                     MemoryRegion *mr, Error **errp);
139 void qemu_ram_free(RAMBlock *block);
140 
141 int qemu_ram_resize(RAMBlock *block, ram_addr_t newsize, Error **errp);
142 
143 void qemu_ram_msync(RAMBlock *block, ram_addr_t start, ram_addr_t length);
144 
145 /* Clear whole block of mem */
146 static inline void qemu_ram_block_writeback(RAMBlock *block)
147 {
148     qemu_ram_msync(block, 0, block->used_length);
149 }
150 
151 #define DIRTY_CLIENTS_ALL     ((1 << DIRTY_MEMORY_NUM) - 1)
152 #define DIRTY_CLIENTS_NOCODE  (DIRTY_CLIENTS_ALL & ~(1 << DIRTY_MEMORY_CODE))
153 
154 static inline bool cpu_physical_memory_get_dirty(ram_addr_t start,
155                                                  ram_addr_t length,
156                                                  unsigned client)
157 {
158     DirtyMemoryBlocks *blocks;
159     unsigned long end, page;
160     unsigned long idx, offset, base;
161     bool dirty = false;
162 
163     assert(client < DIRTY_MEMORY_NUM);
164 
165     end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
166     page = start >> TARGET_PAGE_BITS;
167 
168     WITH_RCU_READ_LOCK_GUARD() {
169         blocks = qatomic_rcu_read(&ram_list.dirty_memory[client]);
170 
171         idx = page / DIRTY_MEMORY_BLOCK_SIZE;
172         offset = page % DIRTY_MEMORY_BLOCK_SIZE;
173         base = page - offset;
174         while (page < end) {
175             unsigned long next = MIN(end, base + DIRTY_MEMORY_BLOCK_SIZE);
176             unsigned long num = next - base;
177             unsigned long found = find_next_bit(blocks->blocks[idx],
178                                                 num, offset);
179             if (found < num) {
180                 dirty = true;
181                 break;
182             }
183 
184             page = next;
185             idx++;
186             offset = 0;
187             base += DIRTY_MEMORY_BLOCK_SIZE;
188         }
189     }
190 
191     return dirty;
192 }
193 
194 static inline bool cpu_physical_memory_all_dirty(ram_addr_t start,
195                                                  ram_addr_t length,
196                                                  unsigned client)
197 {
198     DirtyMemoryBlocks *blocks;
199     unsigned long end, page;
200     unsigned long idx, offset, base;
201     bool dirty = true;
202 
203     assert(client < DIRTY_MEMORY_NUM);
204 
205     end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
206     page = start >> TARGET_PAGE_BITS;
207 
208     RCU_READ_LOCK_GUARD();
209 
210     blocks = qatomic_rcu_read(&ram_list.dirty_memory[client]);
211 
212     idx = page / DIRTY_MEMORY_BLOCK_SIZE;
213     offset = page % DIRTY_MEMORY_BLOCK_SIZE;
214     base = page - offset;
215     while (page < end) {
216         unsigned long next = MIN(end, base + DIRTY_MEMORY_BLOCK_SIZE);
217         unsigned long num = next - base;
218         unsigned long found = find_next_zero_bit(blocks->blocks[idx], num, offset);
219         if (found < num) {
220             dirty = false;
221             break;
222         }
223 
224         page = next;
225         idx++;
226         offset = 0;
227         base += DIRTY_MEMORY_BLOCK_SIZE;
228     }
229 
230     return dirty;
231 }
232 
233 static inline bool cpu_physical_memory_get_dirty_flag(ram_addr_t addr,
234                                                       unsigned client)
235 {
236     return cpu_physical_memory_get_dirty(addr, 1, client);
237 }
238 
239 static inline bool cpu_physical_memory_is_clean(ram_addr_t addr)
240 {
241     bool vga = cpu_physical_memory_get_dirty_flag(addr, DIRTY_MEMORY_VGA);
242     bool code = cpu_physical_memory_get_dirty_flag(addr, DIRTY_MEMORY_CODE);
243     bool migration =
244         cpu_physical_memory_get_dirty_flag(addr, DIRTY_MEMORY_MIGRATION);
245     return !(vga && code && migration);
246 }
247 
248 static inline uint8_t cpu_physical_memory_range_includes_clean(ram_addr_t start,
249                                                                ram_addr_t length,
250                                                                uint8_t mask)
251 {
252     uint8_t ret = 0;
253 
254     if (mask & (1 << DIRTY_MEMORY_VGA) &&
255         !cpu_physical_memory_all_dirty(start, length, DIRTY_MEMORY_VGA)) {
256         ret |= (1 << DIRTY_MEMORY_VGA);
257     }
258     if (mask & (1 << DIRTY_MEMORY_CODE) &&
259         !cpu_physical_memory_all_dirty(start, length, DIRTY_MEMORY_CODE)) {
260         ret |= (1 << DIRTY_MEMORY_CODE);
261     }
262     if (mask & (1 << DIRTY_MEMORY_MIGRATION) &&
263         !cpu_physical_memory_all_dirty(start, length, DIRTY_MEMORY_MIGRATION)) {
264         ret |= (1 << DIRTY_MEMORY_MIGRATION);
265     }
266     return ret;
267 }
268 
269 static inline void cpu_physical_memory_set_dirty_flag(ram_addr_t addr,
270                                                       unsigned client)
271 {
272     unsigned long page, idx, offset;
273     DirtyMemoryBlocks *blocks;
274 
275     assert(client < DIRTY_MEMORY_NUM);
276 
277     page = addr >> TARGET_PAGE_BITS;
278     idx = page / DIRTY_MEMORY_BLOCK_SIZE;
279     offset = page % DIRTY_MEMORY_BLOCK_SIZE;
280 
281     RCU_READ_LOCK_GUARD();
282 
283     blocks = qatomic_rcu_read(&ram_list.dirty_memory[client]);
284 
285     set_bit_atomic(offset, blocks->blocks[idx]);
286 }
287 
288 static inline void cpu_physical_memory_set_dirty_range(ram_addr_t start,
289                                                        ram_addr_t length,
290                                                        uint8_t mask)
291 {
292     DirtyMemoryBlocks *blocks[DIRTY_MEMORY_NUM];
293     unsigned long end, page;
294     unsigned long idx, offset, base;
295     int i;
296 
297     if (!mask && !xen_enabled()) {
298         return;
299     }
300 
301     end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
302     page = start >> TARGET_PAGE_BITS;
303 
304     WITH_RCU_READ_LOCK_GUARD() {
305         for (i = 0; i < DIRTY_MEMORY_NUM; i++) {
306             blocks[i] = qatomic_rcu_read(&ram_list.dirty_memory[i]);
307         }
308 
309         idx = page / DIRTY_MEMORY_BLOCK_SIZE;
310         offset = page % DIRTY_MEMORY_BLOCK_SIZE;
311         base = page - offset;
312         while (page < end) {
313             unsigned long next = MIN(end, base + DIRTY_MEMORY_BLOCK_SIZE);
314 
315             if (likely(mask & (1 << DIRTY_MEMORY_MIGRATION))) {
316                 bitmap_set_atomic(blocks[DIRTY_MEMORY_MIGRATION]->blocks[idx],
317                                   offset, next - page);
318             }
319             if (unlikely(mask & (1 << DIRTY_MEMORY_VGA))) {
320                 bitmap_set_atomic(blocks[DIRTY_MEMORY_VGA]->blocks[idx],
321                                   offset, next - page);
322             }
323             if (unlikely(mask & (1 << DIRTY_MEMORY_CODE))) {
324                 bitmap_set_atomic(blocks[DIRTY_MEMORY_CODE]->blocks[idx],
325                                   offset, next - page);
326             }
327 
328             page = next;
329             idx++;
330             offset = 0;
331             base += DIRTY_MEMORY_BLOCK_SIZE;
332         }
333     }
334 
335     xen_hvm_modified_memory(start, length);
336 }
337 
338 #if !defined(_WIN32)
339 
340 /*
341  * Contrary to cpu_physical_memory_sync_dirty_bitmap() this function returns
342  * the number of dirty pages in @bitmap passed as argument. On the other hand,
343  * cpu_physical_memory_sync_dirty_bitmap() returns newly dirtied pages that
344  * weren't set in the global migration bitmap.
345  */
346 static inline
347 uint64_t cpu_physical_memory_set_dirty_lebitmap(unsigned long *bitmap,
348                                                 ram_addr_t start,
349                                                 ram_addr_t pages)
350 {
351     unsigned long i, j;
352     unsigned long page_number, c, nbits;
353     hwaddr addr;
354     ram_addr_t ram_addr;
355     uint64_t num_dirty = 0;
356     unsigned long len = (pages + HOST_LONG_BITS - 1) / HOST_LONG_BITS;
357     unsigned long hpratio = qemu_real_host_page_size() / TARGET_PAGE_SIZE;
358     unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS);
359 
360     /* start address is aligned at the start of a word? */
361     if ((((page * BITS_PER_LONG) << TARGET_PAGE_BITS) == start) &&
362         (hpratio == 1)) {
363         unsigned long **blocks[DIRTY_MEMORY_NUM];
364         unsigned long idx;
365         unsigned long offset;
366         long k;
367         long nr = BITS_TO_LONGS(pages);
368 
369         idx = (start >> TARGET_PAGE_BITS) / DIRTY_MEMORY_BLOCK_SIZE;
370         offset = BIT_WORD((start >> TARGET_PAGE_BITS) %
371                           DIRTY_MEMORY_BLOCK_SIZE);
372 
373         WITH_RCU_READ_LOCK_GUARD() {
374             for (i = 0; i < DIRTY_MEMORY_NUM; i++) {
375                 blocks[i] =
376                     qatomic_rcu_read(&ram_list.dirty_memory[i])->blocks;
377             }
378 
379             for (k = 0; k < nr; k++) {
380                 if (bitmap[k]) {
381                     unsigned long temp = leul_to_cpu(bitmap[k]);
382 
383                     nbits = ctpopl(temp);
384                     qatomic_or(&blocks[DIRTY_MEMORY_VGA][idx][offset], temp);
385 
386                     if (global_dirty_tracking) {
387                         qatomic_or(
388                                 &blocks[DIRTY_MEMORY_MIGRATION][idx][offset],
389                                 temp);
390                         if (unlikely(
391                             global_dirty_tracking & GLOBAL_DIRTY_DIRTY_RATE)) {
392                             total_dirty_pages += nbits;
393                         }
394                     }
395 
396                     num_dirty += nbits;
397 
398                     if (tcg_enabled()) {
399                         qatomic_or(&blocks[DIRTY_MEMORY_CODE][idx][offset],
400                                    temp);
401                     }
402                 }
403 
404                 if (++offset >= BITS_TO_LONGS(DIRTY_MEMORY_BLOCK_SIZE)) {
405                     offset = 0;
406                     idx++;
407                 }
408             }
409         }
410 
411         xen_hvm_modified_memory(start, pages << TARGET_PAGE_BITS);
412     } else {
413         uint8_t clients = tcg_enabled() ? DIRTY_CLIENTS_ALL : DIRTY_CLIENTS_NOCODE;
414 
415         if (!global_dirty_tracking) {
416             clients &= ~(1 << DIRTY_MEMORY_MIGRATION);
417         }
418 
419         /*
420          * bitmap-traveling is faster than memory-traveling (for addr...)
421          * especially when most of the memory is not dirty.
422          */
423         for (i = 0; i < len; i++) {
424             if (bitmap[i] != 0) {
425                 c = leul_to_cpu(bitmap[i]);
426                 nbits = ctpopl(c);
427                 if (unlikely(global_dirty_tracking & GLOBAL_DIRTY_DIRTY_RATE)) {
428                     total_dirty_pages += nbits;
429                 }
430                 num_dirty += nbits;
431                 do {
432                     j = ctzl(c);
433                     c &= ~(1ul << j);
434                     page_number = (i * HOST_LONG_BITS + j) * hpratio;
435                     addr = page_number * TARGET_PAGE_SIZE;
436                     ram_addr = start + addr;
437                     cpu_physical_memory_set_dirty_range(ram_addr,
438                                        TARGET_PAGE_SIZE * hpratio, clients);
439                 } while (c != 0);
440             }
441         }
442     }
443 
444     return num_dirty;
445 }
446 #endif /* not _WIN32 */
447 
448 static inline void cpu_physical_memory_dirty_bits_cleared(ram_addr_t start,
449                                                           ram_addr_t length)
450 {
451     if (tcg_enabled()) {
452         tlb_reset_dirty_range_all(start, length);
453     }
454 
455 }
456 bool cpu_physical_memory_test_and_clear_dirty(ram_addr_t start,
457                                               ram_addr_t length,
458                                               unsigned client);
459 
460 DirtyBitmapSnapshot *cpu_physical_memory_snapshot_and_clear_dirty
461     (MemoryRegion *mr, hwaddr offset, hwaddr length, unsigned client);
462 
463 bool cpu_physical_memory_snapshot_get_dirty(DirtyBitmapSnapshot *snap,
464                                             ram_addr_t start,
465                                             ram_addr_t length);
466 
467 static inline void cpu_physical_memory_clear_dirty_range(ram_addr_t start,
468                                                          ram_addr_t length)
469 {
470     cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_MIGRATION);
471     cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_VGA);
472     cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_CODE);
473 }
474 
475 
476 /* Called with RCU critical section */
477 static inline
478 uint64_t cpu_physical_memory_sync_dirty_bitmap(RAMBlock *rb,
479                                                ram_addr_t start,
480                                                ram_addr_t length)
481 {
482     ram_addr_t addr;
483     unsigned long word = BIT_WORD((start + rb->offset) >> TARGET_PAGE_BITS);
484     uint64_t num_dirty = 0;
485     unsigned long *dest = rb->bmap;
486 
487     /* start address and length is aligned at the start of a word? */
488     if (((word * BITS_PER_LONG) << TARGET_PAGE_BITS) ==
489          (start + rb->offset) &&
490         !(length & ((BITS_PER_LONG << TARGET_PAGE_BITS) - 1))) {
491         int k;
492         int nr = BITS_TO_LONGS(length >> TARGET_PAGE_BITS);
493         unsigned long * const *src;
494         unsigned long idx = (word * BITS_PER_LONG) / DIRTY_MEMORY_BLOCK_SIZE;
495         unsigned long offset = BIT_WORD((word * BITS_PER_LONG) %
496                                         DIRTY_MEMORY_BLOCK_SIZE);
497         unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS);
498 
499         src = qatomic_rcu_read(
500                 &ram_list.dirty_memory[DIRTY_MEMORY_MIGRATION])->blocks;
501 
502         for (k = page; k < page + nr; k++) {
503             if (src[idx][offset]) {
504                 unsigned long bits = qatomic_xchg(&src[idx][offset], 0);
505                 unsigned long new_dirty;
506                 new_dirty = ~dest[k];
507                 dest[k] |= bits;
508                 new_dirty &= bits;
509                 num_dirty += ctpopl(new_dirty);
510             }
511 
512             if (++offset >= BITS_TO_LONGS(DIRTY_MEMORY_BLOCK_SIZE)) {
513                 offset = 0;
514                 idx++;
515             }
516         }
517         if (num_dirty) {
518             cpu_physical_memory_dirty_bits_cleared(start, length);
519         }
520 
521         if (rb->clear_bmap) {
522             /*
523              * Postpone the dirty bitmap clear to the point before we
524              * really send the pages, also we will split the clear
525              * dirty procedure into smaller chunks.
526              */
527             clear_bmap_set(rb, start >> TARGET_PAGE_BITS,
528                            length >> TARGET_PAGE_BITS);
529         } else {
530             /* Slow path - still do that in a huge chunk */
531             memory_region_clear_dirty_bitmap(rb->mr, start, length);
532         }
533     } else {
534         ram_addr_t offset = rb->offset;
535 
536         for (addr = 0; addr < length; addr += TARGET_PAGE_SIZE) {
537             if (cpu_physical_memory_test_and_clear_dirty(
538                         start + addr + offset,
539                         TARGET_PAGE_SIZE,
540                         DIRTY_MEMORY_MIGRATION)) {
541                 long k = (start + addr) >> TARGET_PAGE_BITS;
542                 if (!test_and_set_bit(k, dest)) {
543                     num_dirty++;
544                 }
545             }
546         }
547     }
548 
549     return num_dirty;
550 }
551 #endif
552 #endif
553