xref: /openbmc/qemu/include/exec/ram_addr.h (revision 0f66536a012b2d1b02818bbb2d24485205fc2f64)
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 "system/xen.h"
25 #include "system/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 #include "exec/hwaddr.h"
32 #include "exec/cpu-common.h"
33 
34 extern uint64_t total_dirty_pages;
35 
36 /**
37  * clear_bmap_size: calculate clear bitmap size
38  *
39  * @pages: number of guest pages
40  * @shift: guest page number shift
41  *
42  * Returns: number of bits for the clear bitmap
43  */
44 static inline long clear_bmap_size(uint64_t pages, uint8_t shift)
45 {
46     return DIV_ROUND_UP(pages, 1UL << shift);
47 }
48 
49 /**
50  * clear_bmap_set: set clear bitmap for the page range.  Must be with
51  * bitmap_mutex held.
52  *
53  * @rb: the ramblock to operate on
54  * @start: the start page number
55  * @size: number of pages to set in the bitmap
56  *
57  * Returns: None
58  */
59 static inline void clear_bmap_set(RAMBlock *rb, uint64_t start,
60                                   uint64_t npages)
61 {
62     uint8_t shift = rb->clear_bmap_shift;
63 
64     bitmap_set(rb->clear_bmap, start >> shift, clear_bmap_size(npages, shift));
65 }
66 
67 /**
68  * clear_bmap_test_and_clear: test clear bitmap for the page, clear if set.
69  * Must be with bitmap_mutex held.
70  *
71  * @rb: the ramblock to operate on
72  * @page: the page number to check
73  *
74  * Returns: true if the bit was set, false otherwise
75  */
76 static inline bool clear_bmap_test_and_clear(RAMBlock *rb, uint64_t page)
77 {
78     uint8_t shift = rb->clear_bmap_shift;
79 
80     return bitmap_test_and_clear(rb->clear_bmap, page >> shift, 1);
81 }
82 
83 static inline bool offset_in_ramblock(RAMBlock *b, ram_addr_t offset)
84 {
85     return (b && b->host && offset < b->used_length) ? true : false;
86 }
87 
88 static inline void *ramblock_ptr(RAMBlock *block, ram_addr_t offset)
89 {
90     assert(offset_in_ramblock(block, offset));
91     return (char *)block->host + offset;
92 }
93 
94 static inline unsigned long int ramblock_recv_bitmap_offset(void *host_addr,
95                                                             RAMBlock *rb)
96 {
97     uint64_t host_addr_offset =
98             (uint64_t)(uintptr_t)(host_addr - (void *)rb->host);
99     return host_addr_offset >> TARGET_PAGE_BITS;
100 }
101 
102 bool ramblock_is_pmem(RAMBlock *rb);
103 
104 long qemu_minrampagesize(void);
105 long qemu_maxrampagesize(void);
106 
107 /**
108  * qemu_ram_alloc_from_file,
109  * qemu_ram_alloc_from_fd:  Allocate a ram block from the specified backing
110  *                          file or device
111  *
112  * Parameters:
113  *  @size: the size in bytes of the ram block
114  *  @max_size: the maximum size of the block after resizing
115  *  @mr: the memory region where the ram block is
116  *  @resized: callback after calls to qemu_ram_resize
117  *  @ram_flags: RamBlock flags. Supported flags: RAM_SHARED, RAM_PMEM,
118  *              RAM_NORESERVE, RAM_PROTECTED, RAM_NAMED_FILE, RAM_READONLY,
119  *              RAM_READONLY_FD, RAM_GUEST_MEMFD
120  *  @mem_path or @fd: specify the backing file or device
121  *  @offset: Offset into target file
122  *  @grow: extend file if necessary (but an empty file is always extended).
123  *  @errp: pointer to Error*, to store an error if it happens
124  *
125  * Return:
126  *  On success, return a pointer to the ram block.
127  *  On failure, return NULL.
128  */
129 typedef void (*qemu_ram_resize_cb)(const char *, uint64_t length, void *host);
130 
131 RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr,
132                                    uint32_t ram_flags, const char *mem_path,
133                                    off_t offset, Error **errp);
134 RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, ram_addr_t max_size,
135                                  qemu_ram_resize_cb resized, MemoryRegion *mr,
136                                  uint32_t ram_flags, int fd, off_t offset,
137                                  bool grow,
138                                  Error **errp);
139 
140 RAMBlock *qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
141                                   MemoryRegion *mr, Error **errp);
142 RAMBlock *qemu_ram_alloc(ram_addr_t size, uint32_t ram_flags, MemoryRegion *mr,
143                          Error **errp);
144 RAMBlock *qemu_ram_alloc_resizeable(ram_addr_t size, ram_addr_t max_size,
145                                     qemu_ram_resize_cb resized,
146                                     MemoryRegion *mr, Error **errp);
147 void qemu_ram_free(RAMBlock *block);
148 
149 int qemu_ram_resize(RAMBlock *block, ram_addr_t newsize, Error **errp);
150 
151 void qemu_ram_msync(RAMBlock *block, ram_addr_t start, ram_addr_t length);
152 
153 /* Clear whole block of mem */
154 static inline void qemu_ram_block_writeback(RAMBlock *block)
155 {
156     qemu_ram_msync(block, 0, block->used_length);
157 }
158 
159 #define DIRTY_CLIENTS_ALL     ((1 << DIRTY_MEMORY_NUM) - 1)
160 #define DIRTY_CLIENTS_NOCODE  (DIRTY_CLIENTS_ALL & ~(1 << DIRTY_MEMORY_CODE))
161 
162 static inline bool cpu_physical_memory_get_dirty(ram_addr_t start,
163                                                  ram_addr_t length,
164                                                  unsigned client)
165 {
166     DirtyMemoryBlocks *blocks;
167     unsigned long end, page;
168     unsigned long idx, offset, base;
169     bool dirty = false;
170 
171     assert(client < DIRTY_MEMORY_NUM);
172 
173     end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
174     page = start >> TARGET_PAGE_BITS;
175 
176     WITH_RCU_READ_LOCK_GUARD() {
177         blocks = qatomic_rcu_read(&ram_list.dirty_memory[client]);
178 
179         idx = page / DIRTY_MEMORY_BLOCK_SIZE;
180         offset = page % DIRTY_MEMORY_BLOCK_SIZE;
181         base = page - offset;
182         while (page < end) {
183             unsigned long next = MIN(end, base + DIRTY_MEMORY_BLOCK_SIZE);
184             unsigned long num = next - base;
185             unsigned long found = find_next_bit(blocks->blocks[idx],
186                                                 num, offset);
187             if (found < num) {
188                 dirty = true;
189                 break;
190             }
191 
192             page = next;
193             idx++;
194             offset = 0;
195             base += DIRTY_MEMORY_BLOCK_SIZE;
196         }
197     }
198 
199     return dirty;
200 }
201 
202 static inline bool cpu_physical_memory_all_dirty(ram_addr_t start,
203                                                  ram_addr_t length,
204                                                  unsigned client)
205 {
206     DirtyMemoryBlocks *blocks;
207     unsigned long end, page;
208     unsigned long idx, offset, base;
209     bool dirty = true;
210 
211     assert(client < DIRTY_MEMORY_NUM);
212 
213     end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
214     page = start >> TARGET_PAGE_BITS;
215 
216     RCU_READ_LOCK_GUARD();
217 
218     blocks = qatomic_rcu_read(&ram_list.dirty_memory[client]);
219 
220     idx = page / DIRTY_MEMORY_BLOCK_SIZE;
221     offset = page % DIRTY_MEMORY_BLOCK_SIZE;
222     base = page - offset;
223     while (page < end) {
224         unsigned long next = MIN(end, base + DIRTY_MEMORY_BLOCK_SIZE);
225         unsigned long num = next - base;
226         unsigned long found = find_next_zero_bit(blocks->blocks[idx], num, offset);
227         if (found < num) {
228             dirty = false;
229             break;
230         }
231 
232         page = next;
233         idx++;
234         offset = 0;
235         base += DIRTY_MEMORY_BLOCK_SIZE;
236     }
237 
238     return dirty;
239 }
240 
241 static inline bool cpu_physical_memory_get_dirty_flag(ram_addr_t addr,
242                                                       unsigned client)
243 {
244     return cpu_physical_memory_get_dirty(addr, 1, client);
245 }
246 
247 static inline bool cpu_physical_memory_is_clean(ram_addr_t addr)
248 {
249     bool vga = cpu_physical_memory_get_dirty_flag(addr, DIRTY_MEMORY_VGA);
250     bool code = cpu_physical_memory_get_dirty_flag(addr, DIRTY_MEMORY_CODE);
251     bool migration =
252         cpu_physical_memory_get_dirty_flag(addr, DIRTY_MEMORY_MIGRATION);
253     return !(vga && code && migration);
254 }
255 
256 static inline uint8_t cpu_physical_memory_range_includes_clean(ram_addr_t start,
257                                                                ram_addr_t length,
258                                                                uint8_t mask)
259 {
260     uint8_t ret = 0;
261 
262     if (mask & (1 << DIRTY_MEMORY_VGA) &&
263         !cpu_physical_memory_all_dirty(start, length, DIRTY_MEMORY_VGA)) {
264         ret |= (1 << DIRTY_MEMORY_VGA);
265     }
266     if (mask & (1 << DIRTY_MEMORY_CODE) &&
267         !cpu_physical_memory_all_dirty(start, length, DIRTY_MEMORY_CODE)) {
268         ret |= (1 << DIRTY_MEMORY_CODE);
269     }
270     if (mask & (1 << DIRTY_MEMORY_MIGRATION) &&
271         !cpu_physical_memory_all_dirty(start, length, DIRTY_MEMORY_MIGRATION)) {
272         ret |= (1 << DIRTY_MEMORY_MIGRATION);
273     }
274     return ret;
275 }
276 
277 static inline void cpu_physical_memory_set_dirty_flag(ram_addr_t addr,
278                                                       unsigned client)
279 {
280     unsigned long page, idx, offset;
281     DirtyMemoryBlocks *blocks;
282 
283     assert(client < DIRTY_MEMORY_NUM);
284 
285     page = addr >> TARGET_PAGE_BITS;
286     idx = page / DIRTY_MEMORY_BLOCK_SIZE;
287     offset = page % DIRTY_MEMORY_BLOCK_SIZE;
288 
289     RCU_READ_LOCK_GUARD();
290 
291     blocks = qatomic_rcu_read(&ram_list.dirty_memory[client]);
292 
293     set_bit_atomic(offset, blocks->blocks[idx]);
294 }
295 
296 static inline void cpu_physical_memory_set_dirty_range(ram_addr_t start,
297                                                        ram_addr_t length,
298                                                        uint8_t mask)
299 {
300     DirtyMemoryBlocks *blocks[DIRTY_MEMORY_NUM];
301     unsigned long end, page;
302     unsigned long idx, offset, base;
303     int i;
304 
305     if (!mask && !xen_enabled()) {
306         return;
307     }
308 
309     end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
310     page = start >> TARGET_PAGE_BITS;
311 
312     WITH_RCU_READ_LOCK_GUARD() {
313         for (i = 0; i < DIRTY_MEMORY_NUM; i++) {
314             blocks[i] = qatomic_rcu_read(&ram_list.dirty_memory[i]);
315         }
316 
317         idx = page / DIRTY_MEMORY_BLOCK_SIZE;
318         offset = page % DIRTY_MEMORY_BLOCK_SIZE;
319         base = page - offset;
320         while (page < end) {
321             unsigned long next = MIN(end, base + DIRTY_MEMORY_BLOCK_SIZE);
322 
323             if (likely(mask & (1 << DIRTY_MEMORY_MIGRATION))) {
324                 bitmap_set_atomic(blocks[DIRTY_MEMORY_MIGRATION]->blocks[idx],
325                                   offset, next - page);
326             }
327             if (unlikely(mask & (1 << DIRTY_MEMORY_VGA))) {
328                 bitmap_set_atomic(blocks[DIRTY_MEMORY_VGA]->blocks[idx],
329                                   offset, next - page);
330             }
331             if (unlikely(mask & (1 << DIRTY_MEMORY_CODE))) {
332                 bitmap_set_atomic(blocks[DIRTY_MEMORY_CODE]->blocks[idx],
333                                   offset, next - page);
334             }
335 
336             page = next;
337             idx++;
338             offset = 0;
339             base += DIRTY_MEMORY_BLOCK_SIZE;
340         }
341     }
342 
343     xen_hvm_modified_memory(start, length);
344 }
345 
346 #if !defined(_WIN32)
347 
348 /*
349  * Contrary to cpu_physical_memory_sync_dirty_bitmap() this function returns
350  * the number of dirty pages in @bitmap passed as argument. On the other hand,
351  * cpu_physical_memory_sync_dirty_bitmap() returns newly dirtied pages that
352  * weren't set in the global migration bitmap.
353  */
354 static inline
355 uint64_t cpu_physical_memory_set_dirty_lebitmap(unsigned long *bitmap,
356                                                 ram_addr_t start,
357                                                 ram_addr_t pages)
358 {
359     unsigned long i, j;
360     unsigned long page_number, c, nbits;
361     hwaddr addr;
362     ram_addr_t ram_addr;
363     uint64_t num_dirty = 0;
364     unsigned long len = (pages + HOST_LONG_BITS - 1) / HOST_LONG_BITS;
365     unsigned long hpratio = qemu_real_host_page_size() / TARGET_PAGE_SIZE;
366     unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS);
367 
368     /* start address is aligned at the start of a word? */
369     if ((((page * BITS_PER_LONG) << TARGET_PAGE_BITS) == start) &&
370         (hpratio == 1)) {
371         unsigned long **blocks[DIRTY_MEMORY_NUM];
372         unsigned long idx;
373         unsigned long offset;
374         long k;
375         long nr = BITS_TO_LONGS(pages);
376 
377         idx = (start >> TARGET_PAGE_BITS) / DIRTY_MEMORY_BLOCK_SIZE;
378         offset = BIT_WORD((start >> TARGET_PAGE_BITS) %
379                           DIRTY_MEMORY_BLOCK_SIZE);
380 
381         WITH_RCU_READ_LOCK_GUARD() {
382             for (i = 0; i < DIRTY_MEMORY_NUM; i++) {
383                 blocks[i] =
384                     qatomic_rcu_read(&ram_list.dirty_memory[i])->blocks;
385             }
386 
387             for (k = 0; k < nr; k++) {
388                 if (bitmap[k]) {
389                     unsigned long temp = leul_to_cpu(bitmap[k]);
390 
391                     nbits = ctpopl(temp);
392                     qatomic_or(&blocks[DIRTY_MEMORY_VGA][idx][offset], temp);
393 
394                     if (global_dirty_tracking) {
395                         qatomic_or(
396                                 &blocks[DIRTY_MEMORY_MIGRATION][idx][offset],
397                                 temp);
398                         if (unlikely(
399                             global_dirty_tracking & GLOBAL_DIRTY_DIRTY_RATE)) {
400                             total_dirty_pages += nbits;
401                         }
402                     }
403 
404                     num_dirty += nbits;
405 
406                     if (tcg_enabled()) {
407                         qatomic_or(&blocks[DIRTY_MEMORY_CODE][idx][offset],
408                                    temp);
409                     }
410                 }
411 
412                 if (++offset >= BITS_TO_LONGS(DIRTY_MEMORY_BLOCK_SIZE)) {
413                     offset = 0;
414                     idx++;
415                 }
416             }
417         }
418 
419         xen_hvm_modified_memory(start, pages << TARGET_PAGE_BITS);
420     } else {
421         uint8_t clients = tcg_enabled() ? DIRTY_CLIENTS_ALL : DIRTY_CLIENTS_NOCODE;
422 
423         if (!global_dirty_tracking) {
424             clients &= ~(1 << DIRTY_MEMORY_MIGRATION);
425         }
426 
427         /*
428          * bitmap-traveling is faster than memory-traveling (for addr...)
429          * especially when most of the memory is not dirty.
430          */
431         for (i = 0; i < len; i++) {
432             if (bitmap[i] != 0) {
433                 c = leul_to_cpu(bitmap[i]);
434                 nbits = ctpopl(c);
435                 if (unlikely(global_dirty_tracking & GLOBAL_DIRTY_DIRTY_RATE)) {
436                     total_dirty_pages += nbits;
437                 }
438                 num_dirty += nbits;
439                 do {
440                     j = ctzl(c);
441                     c &= ~(1ul << j);
442                     page_number = (i * HOST_LONG_BITS + j) * hpratio;
443                     addr = page_number * TARGET_PAGE_SIZE;
444                     ram_addr = start + addr;
445                     cpu_physical_memory_set_dirty_range(ram_addr,
446                                        TARGET_PAGE_SIZE * hpratio, clients);
447                 } while (c != 0);
448             }
449         }
450     }
451 
452     return num_dirty;
453 }
454 #endif /* not _WIN32 */
455 
456 static inline void cpu_physical_memory_dirty_bits_cleared(ram_addr_t start,
457                                                           ram_addr_t length)
458 {
459     if (tcg_enabled()) {
460         tlb_reset_dirty_range_all(start, length);
461     }
462 
463 }
464 bool cpu_physical_memory_test_and_clear_dirty(ram_addr_t start,
465                                               ram_addr_t length,
466                                               unsigned client);
467 
468 DirtyBitmapSnapshot *cpu_physical_memory_snapshot_and_clear_dirty
469     (MemoryRegion *mr, hwaddr offset, hwaddr length, unsigned client);
470 
471 bool cpu_physical_memory_snapshot_get_dirty(DirtyBitmapSnapshot *snap,
472                                             ram_addr_t start,
473                                             ram_addr_t length);
474 
475 static inline void cpu_physical_memory_clear_dirty_range(ram_addr_t start,
476                                                          ram_addr_t length)
477 {
478     cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_MIGRATION);
479     cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_VGA);
480     cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_CODE);
481 }
482 
483 
484 /* Called with RCU critical section */
485 static inline
486 uint64_t cpu_physical_memory_sync_dirty_bitmap(RAMBlock *rb,
487                                                ram_addr_t start,
488                                                ram_addr_t length)
489 {
490     ram_addr_t addr;
491     unsigned long word = BIT_WORD((start + rb->offset) >> TARGET_PAGE_BITS);
492     uint64_t num_dirty = 0;
493     unsigned long *dest = rb->bmap;
494 
495     /* start address and length is aligned at the start of a word? */
496     if (((word * BITS_PER_LONG) << TARGET_PAGE_BITS) ==
497          (start + rb->offset) &&
498         !(length & ((BITS_PER_LONG << TARGET_PAGE_BITS) - 1))) {
499         int k;
500         int nr = BITS_TO_LONGS(length >> TARGET_PAGE_BITS);
501         unsigned long * const *src;
502         unsigned long idx = (word * BITS_PER_LONG) / DIRTY_MEMORY_BLOCK_SIZE;
503         unsigned long offset = BIT_WORD((word * BITS_PER_LONG) %
504                                         DIRTY_MEMORY_BLOCK_SIZE);
505         unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS);
506 
507         src = qatomic_rcu_read(
508                 &ram_list.dirty_memory[DIRTY_MEMORY_MIGRATION])->blocks;
509 
510         for (k = page; k < page + nr; k++) {
511             if (src[idx][offset]) {
512                 unsigned long bits = qatomic_xchg(&src[idx][offset], 0);
513                 unsigned long new_dirty;
514                 new_dirty = ~dest[k];
515                 dest[k] |= bits;
516                 new_dirty &= bits;
517                 num_dirty += ctpopl(new_dirty);
518             }
519 
520             if (++offset >= BITS_TO_LONGS(DIRTY_MEMORY_BLOCK_SIZE)) {
521                 offset = 0;
522                 idx++;
523             }
524         }
525         if (num_dirty) {
526             cpu_physical_memory_dirty_bits_cleared(start, length);
527         }
528 
529         if (rb->clear_bmap) {
530             /*
531              * Postpone the dirty bitmap clear to the point before we
532              * really send the pages, also we will split the clear
533              * dirty procedure into smaller chunks.
534              */
535             clear_bmap_set(rb, start >> TARGET_PAGE_BITS,
536                            length >> TARGET_PAGE_BITS);
537         } else {
538             /* Slow path - still do that in a huge chunk */
539             memory_region_clear_dirty_bitmap(rb->mr, start, length);
540         }
541     } else {
542         ram_addr_t offset = rb->offset;
543 
544         for (addr = 0; addr < length; addr += TARGET_PAGE_SIZE) {
545             if (cpu_physical_memory_test_and_clear_dirty(
546                         start + addr + offset,
547                         TARGET_PAGE_SIZE,
548                         DIRTY_MEMORY_MIGRATION)) {
549                 long k = (start + addr) >> TARGET_PAGE_BITS;
550                 if (!test_and_set_bit(k, dest)) {
551                     num_dirty++;
552                 }
553             }
554         }
555     }
556 
557     return num_dirty;
558 }
559 #endif
560 #endif
561