xref: /openbmc/qemu/include/exec/ram_addr.h (revision 4011a686)
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 /**
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  *  @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, bool share, 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 void tb_invalidate_phys_range(ram_addr_t start, ram_addr_t end);
152 
153 static inline bool cpu_physical_memory_get_dirty(ram_addr_t start,
154                                                  ram_addr_t length,
155                                                  unsigned client)
156 {
157     DirtyMemoryBlocks *blocks;
158     unsigned long end, page;
159     unsigned long idx, offset, base;
160     bool dirty = false;
161 
162     assert(client < DIRTY_MEMORY_NUM);
163 
164     end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
165     page = start >> TARGET_PAGE_BITS;
166 
167     WITH_RCU_READ_LOCK_GUARD() {
168         blocks = qatomic_rcu_read(&ram_list.dirty_memory[client]);
169 
170         idx = page / DIRTY_MEMORY_BLOCK_SIZE;
171         offset = page % DIRTY_MEMORY_BLOCK_SIZE;
172         base = page - offset;
173         while (page < end) {
174             unsigned long next = MIN(end, base + DIRTY_MEMORY_BLOCK_SIZE);
175             unsigned long num = next - base;
176             unsigned long found = find_next_bit(blocks->blocks[idx],
177                                                 num, offset);
178             if (found < num) {
179                 dirty = true;
180                 break;
181             }
182 
183             page = next;
184             idx++;
185             offset = 0;
186             base += DIRTY_MEMORY_BLOCK_SIZE;
187         }
188     }
189 
190     return dirty;
191 }
192 
193 static inline bool cpu_physical_memory_all_dirty(ram_addr_t start,
194                                                  ram_addr_t length,
195                                                  unsigned client)
196 {
197     DirtyMemoryBlocks *blocks;
198     unsigned long end, page;
199     unsigned long idx, offset, base;
200     bool dirty = true;
201 
202     assert(client < DIRTY_MEMORY_NUM);
203 
204     end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
205     page = start >> TARGET_PAGE_BITS;
206 
207     RCU_READ_LOCK_GUARD();
208 
209     blocks = qatomic_rcu_read(&ram_list.dirty_memory[client]);
210 
211     idx = page / DIRTY_MEMORY_BLOCK_SIZE;
212     offset = page % DIRTY_MEMORY_BLOCK_SIZE;
213     base = page - offset;
214     while (page < end) {
215         unsigned long next = MIN(end, base + DIRTY_MEMORY_BLOCK_SIZE);
216         unsigned long num = next - base;
217         unsigned long found = find_next_zero_bit(blocks->blocks[idx], num, offset);
218         if (found < num) {
219             dirty = false;
220             break;
221         }
222 
223         page = next;
224         idx++;
225         offset = 0;
226         base += DIRTY_MEMORY_BLOCK_SIZE;
227     }
228 
229     return dirty;
230 }
231 
232 static inline bool cpu_physical_memory_get_dirty_flag(ram_addr_t addr,
233                                                       unsigned client)
234 {
235     return cpu_physical_memory_get_dirty(addr, 1, client);
236 }
237 
238 static inline bool cpu_physical_memory_is_clean(ram_addr_t addr)
239 {
240     bool vga = cpu_physical_memory_get_dirty_flag(addr, DIRTY_MEMORY_VGA);
241     bool code = cpu_physical_memory_get_dirty_flag(addr, DIRTY_MEMORY_CODE);
242     bool migration =
243         cpu_physical_memory_get_dirty_flag(addr, DIRTY_MEMORY_MIGRATION);
244     return !(vga && code && migration);
245 }
246 
247 static inline uint8_t cpu_physical_memory_range_includes_clean(ram_addr_t start,
248                                                                ram_addr_t length,
249                                                                uint8_t mask)
250 {
251     uint8_t ret = 0;
252 
253     if (mask & (1 << DIRTY_MEMORY_VGA) &&
254         !cpu_physical_memory_all_dirty(start, length, DIRTY_MEMORY_VGA)) {
255         ret |= (1 << DIRTY_MEMORY_VGA);
256     }
257     if (mask & (1 << DIRTY_MEMORY_CODE) &&
258         !cpu_physical_memory_all_dirty(start, length, DIRTY_MEMORY_CODE)) {
259         ret |= (1 << DIRTY_MEMORY_CODE);
260     }
261     if (mask & (1 << DIRTY_MEMORY_MIGRATION) &&
262         !cpu_physical_memory_all_dirty(start, length, DIRTY_MEMORY_MIGRATION)) {
263         ret |= (1 << DIRTY_MEMORY_MIGRATION);
264     }
265     return ret;
266 }
267 
268 static inline void cpu_physical_memory_set_dirty_flag(ram_addr_t addr,
269                                                       unsigned client)
270 {
271     unsigned long page, idx, offset;
272     DirtyMemoryBlocks *blocks;
273 
274     assert(client < DIRTY_MEMORY_NUM);
275 
276     page = addr >> TARGET_PAGE_BITS;
277     idx = page / DIRTY_MEMORY_BLOCK_SIZE;
278     offset = page % DIRTY_MEMORY_BLOCK_SIZE;
279 
280     RCU_READ_LOCK_GUARD();
281 
282     blocks = qatomic_rcu_read(&ram_list.dirty_memory[client]);
283 
284     set_bit_atomic(offset, blocks->blocks[idx]);
285 }
286 
287 static inline void cpu_physical_memory_set_dirty_range(ram_addr_t start,
288                                                        ram_addr_t length,
289                                                        uint8_t mask)
290 {
291     DirtyMemoryBlocks *blocks[DIRTY_MEMORY_NUM];
292     unsigned long end, page;
293     unsigned long idx, offset, base;
294     int i;
295 
296     if (!mask && !xen_enabled()) {
297         return;
298     }
299 
300     end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
301     page = start >> TARGET_PAGE_BITS;
302 
303     WITH_RCU_READ_LOCK_GUARD() {
304         for (i = 0; i < DIRTY_MEMORY_NUM; i++) {
305             blocks[i] = qatomic_rcu_read(&ram_list.dirty_memory[i]);
306         }
307 
308         idx = page / DIRTY_MEMORY_BLOCK_SIZE;
309         offset = page % DIRTY_MEMORY_BLOCK_SIZE;
310         base = page - offset;
311         while (page < end) {
312             unsigned long next = MIN(end, base + DIRTY_MEMORY_BLOCK_SIZE);
313 
314             if (likely(mask & (1 << DIRTY_MEMORY_MIGRATION))) {
315                 bitmap_set_atomic(blocks[DIRTY_MEMORY_MIGRATION]->blocks[idx],
316                                   offset, next - page);
317             }
318             if (unlikely(mask & (1 << DIRTY_MEMORY_VGA))) {
319                 bitmap_set_atomic(blocks[DIRTY_MEMORY_VGA]->blocks[idx],
320                                   offset, next - page);
321             }
322             if (unlikely(mask & (1 << DIRTY_MEMORY_CODE))) {
323                 bitmap_set_atomic(blocks[DIRTY_MEMORY_CODE]->blocks[idx],
324                                   offset, next - page);
325             }
326 
327             page = next;
328             idx++;
329             offset = 0;
330             base += DIRTY_MEMORY_BLOCK_SIZE;
331         }
332     }
333 
334     xen_hvm_modified_memory(start, length);
335 }
336 
337 #if !defined(_WIN32)
338 static inline void cpu_physical_memory_set_dirty_lebitmap(unsigned long *bitmap,
339                                                           ram_addr_t start,
340                                                           ram_addr_t pages)
341 {
342     unsigned long i, j;
343     unsigned long page_number, c;
344     hwaddr addr;
345     ram_addr_t ram_addr;
346     unsigned long len = (pages + HOST_LONG_BITS - 1) / HOST_LONG_BITS;
347     unsigned long hpratio = qemu_real_host_page_size / TARGET_PAGE_SIZE;
348     unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS);
349 
350     /* start address is aligned at the start of a word? */
351     if ((((page * BITS_PER_LONG) << TARGET_PAGE_BITS) == start) &&
352         (hpratio == 1)) {
353         unsigned long **blocks[DIRTY_MEMORY_NUM];
354         unsigned long idx;
355         unsigned long offset;
356         long k;
357         long nr = BITS_TO_LONGS(pages);
358 
359         idx = (start >> TARGET_PAGE_BITS) / DIRTY_MEMORY_BLOCK_SIZE;
360         offset = BIT_WORD((start >> TARGET_PAGE_BITS) %
361                           DIRTY_MEMORY_BLOCK_SIZE);
362 
363         WITH_RCU_READ_LOCK_GUARD() {
364             for (i = 0; i < DIRTY_MEMORY_NUM; i++) {
365                 blocks[i] =
366                     qatomic_rcu_read(&ram_list.dirty_memory[i])->blocks;
367             }
368 
369             for (k = 0; k < nr; k++) {
370                 if (bitmap[k]) {
371                     unsigned long temp = leul_to_cpu(bitmap[k]);
372 
373                     qatomic_or(&blocks[DIRTY_MEMORY_VGA][idx][offset], temp);
374 
375                     if (global_dirty_log) {
376                         qatomic_or(
377                                 &blocks[DIRTY_MEMORY_MIGRATION][idx][offset],
378                                 temp);
379                     }
380 
381                     if (tcg_enabled()) {
382                         qatomic_or(&blocks[DIRTY_MEMORY_CODE][idx][offset],
383                                    temp);
384                     }
385                 }
386 
387                 if (++offset >= BITS_TO_LONGS(DIRTY_MEMORY_BLOCK_SIZE)) {
388                     offset = 0;
389                     idx++;
390                 }
391             }
392         }
393 
394         xen_hvm_modified_memory(start, pages << TARGET_PAGE_BITS);
395     } else {
396         uint8_t clients = tcg_enabled() ? DIRTY_CLIENTS_ALL : DIRTY_CLIENTS_NOCODE;
397 
398         if (!global_dirty_log) {
399             clients &= ~(1 << DIRTY_MEMORY_MIGRATION);
400         }
401 
402         /*
403          * bitmap-traveling is faster than memory-traveling (for addr...)
404          * especially when most of the memory is not dirty.
405          */
406         for (i = 0; i < len; i++) {
407             if (bitmap[i] != 0) {
408                 c = leul_to_cpu(bitmap[i]);
409                 do {
410                     j = ctzl(c);
411                     c &= ~(1ul << j);
412                     page_number = (i * HOST_LONG_BITS + j) * hpratio;
413                     addr = page_number * TARGET_PAGE_SIZE;
414                     ram_addr = start + addr;
415                     cpu_physical_memory_set_dirty_range(ram_addr,
416                                        TARGET_PAGE_SIZE * hpratio, clients);
417                 } while (c != 0);
418             }
419         }
420     }
421 }
422 #endif /* not _WIN32 */
423 
424 bool cpu_physical_memory_test_and_clear_dirty(ram_addr_t start,
425                                               ram_addr_t length,
426                                               unsigned client);
427 
428 DirtyBitmapSnapshot *cpu_physical_memory_snapshot_and_clear_dirty
429     (MemoryRegion *mr, hwaddr offset, hwaddr length, unsigned client);
430 
431 bool cpu_physical_memory_snapshot_get_dirty(DirtyBitmapSnapshot *snap,
432                                             ram_addr_t start,
433                                             ram_addr_t length);
434 
435 static inline void cpu_physical_memory_clear_dirty_range(ram_addr_t start,
436                                                          ram_addr_t length)
437 {
438     cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_MIGRATION);
439     cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_VGA);
440     cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_CODE);
441 }
442 
443 
444 /* Called with RCU critical section */
445 static inline
446 uint64_t cpu_physical_memory_sync_dirty_bitmap(RAMBlock *rb,
447                                                ram_addr_t start,
448                                                ram_addr_t length)
449 {
450     ram_addr_t addr;
451     unsigned long word = BIT_WORD((start + rb->offset) >> TARGET_PAGE_BITS);
452     uint64_t num_dirty = 0;
453     unsigned long *dest = rb->bmap;
454 
455     /* start address and length is aligned at the start of a word? */
456     if (((word * BITS_PER_LONG) << TARGET_PAGE_BITS) ==
457          (start + rb->offset) &&
458         !(length & ((BITS_PER_LONG << TARGET_PAGE_BITS) - 1))) {
459         int k;
460         int nr = BITS_TO_LONGS(length >> TARGET_PAGE_BITS);
461         unsigned long * const *src;
462         unsigned long idx = (word * BITS_PER_LONG) / DIRTY_MEMORY_BLOCK_SIZE;
463         unsigned long offset = BIT_WORD((word * BITS_PER_LONG) %
464                                         DIRTY_MEMORY_BLOCK_SIZE);
465         unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS);
466 
467         src = qatomic_rcu_read(
468                 &ram_list.dirty_memory[DIRTY_MEMORY_MIGRATION])->blocks;
469 
470         for (k = page; k < page + nr; k++) {
471             if (src[idx][offset]) {
472                 unsigned long bits = qatomic_xchg(&src[idx][offset], 0);
473                 unsigned long new_dirty;
474                 new_dirty = ~dest[k];
475                 dest[k] |= bits;
476                 new_dirty &= bits;
477                 num_dirty += ctpopl(new_dirty);
478             }
479 
480             if (++offset >= BITS_TO_LONGS(DIRTY_MEMORY_BLOCK_SIZE)) {
481                 offset = 0;
482                 idx++;
483             }
484         }
485 
486         if (rb->clear_bmap) {
487             /*
488              * Postpone the dirty bitmap clear to the point before we
489              * really send the pages, also we will split the clear
490              * dirty procedure into smaller chunks.
491              */
492             clear_bmap_set(rb, start >> TARGET_PAGE_BITS,
493                            length >> TARGET_PAGE_BITS);
494         } else {
495             /* Slow path - still do that in a huge chunk */
496             memory_region_clear_dirty_bitmap(rb->mr, start, length);
497         }
498     } else {
499         ram_addr_t offset = rb->offset;
500 
501         for (addr = 0; addr < length; addr += TARGET_PAGE_SIZE) {
502             if (cpu_physical_memory_test_and_clear_dirty(
503                         start + addr + offset,
504                         TARGET_PAGE_SIZE,
505                         DIRTY_MEMORY_MIGRATION)) {
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