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2 * virtual page mapping and translated block handling
4 * Copyright (c) 2003 Fabrice Bellard
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
38 //#define DEBUG_TB_INVALIDATE
41 /* make various TB consistency checks */
42 //#define DEBUG_TB_CHECK
44 /* threshold to flush the translated code buffer */
45 #define CODE_GEN_BUFFER_MAX_SIZE (CODE_GEN_BUFFER_SIZE - CODE_GEN_MAX_SIZE)
47 #define CODE_GEN_MAX_BLOCKS (CODE_GEN_BUFFER_SIZE / 64)
49 TranslationBlock tbs
[CODE_GEN_MAX_BLOCKS
];
50 TranslationBlock
*tb_hash
[CODE_GEN_HASH_SIZE
];
52 /* any access to the tbs or the page table must use this lock */
53 spinlock_t tb_lock
= SPIN_LOCK_UNLOCKED
;
55 uint8_t code_gen_buffer
[CODE_GEN_BUFFER_SIZE
];
56 uint8_t *code_gen_ptr
;
58 /* XXX: pack the flags in the low bits of the pointer ? */
59 typedef struct PageDesc
{
61 TranslationBlock
*first_tb
;
65 #define L1_BITS (32 - L2_BITS - TARGET_PAGE_BITS)
67 #define L1_SIZE (1 << L1_BITS)
68 #define L2_SIZE (1 << L2_BITS)
70 static void tb_invalidate_page(unsigned long address
);
72 unsigned long real_host_page_size
;
73 unsigned long host_page_bits
;
74 unsigned long host_page_size
;
75 unsigned long host_page_mask
;
77 static PageDesc
*l1_map
[L1_SIZE
];
79 static void page_init(void)
81 /* NOTE: we can always suppose that host_page_size >=
83 real_host_page_size
= getpagesize();
84 if (host_page_size
== 0)
85 host_page_size
= real_host_page_size
;
86 if (host_page_size
< TARGET_PAGE_SIZE
)
87 host_page_size
= TARGET_PAGE_SIZE
;
89 while ((1 << host_page_bits
) < host_page_size
)
91 host_page_mask
= ~(host_page_size
- 1);
94 /* dump memory mappings */
95 void page_dump(FILE *f
)
97 unsigned long start
, end
;
98 int i
, j
, prot
, prot1
;
101 fprintf(f
, "%-8s %-8s %-8s %s\n",
102 "start", "end", "size", "prot");
106 for(i
= 0; i
<= L1_SIZE
; i
++) {
111 for(j
= 0;j
< L2_SIZE
; j
++) {
117 end
= (i
<< (32 - L1_BITS
)) | (j
<< TARGET_PAGE_BITS
);
119 fprintf(f
, "%08lx-%08lx %08lx %c%c%c\n",
120 start
, end
, end
- start
,
121 prot
& PAGE_READ
? 'r' : '-',
122 prot
& PAGE_WRITE
? 'w' : '-',
123 prot
& PAGE_EXEC
? 'x' : '-');
137 static inline PageDesc
*page_find_alloc(unsigned int index
)
141 lp
= &l1_map
[index
>> L2_BITS
];
144 /* allocate if not found */
145 p
= malloc(sizeof(PageDesc
) * L2_SIZE
);
146 memset(p
, 0, sizeof(PageDesc
) * L2_SIZE
);
149 return p
+ (index
& (L2_SIZE
- 1));
152 static inline PageDesc
*page_find(unsigned int index
)
156 p
= l1_map
[index
>> L2_BITS
];
159 return p
+ (index
& (L2_SIZE
- 1));
162 int page_get_flags(unsigned long address
)
166 p
= page_find(address
>> TARGET_PAGE_BITS
);
172 /* modify the flags of a page and invalidate the code if
173 necessary. The flag PAGE_WRITE_ORG is positionned automatically
174 depending on PAGE_WRITE */
175 void page_set_flags(unsigned long start
, unsigned long end
, int flags
)
180 start
= start
& TARGET_PAGE_MASK
;
181 end
= TARGET_PAGE_ALIGN(end
);
182 if (flags
& PAGE_WRITE
)
183 flags
|= PAGE_WRITE_ORG
;
185 for(addr
= start
; addr
< end
; addr
+= TARGET_PAGE_SIZE
) {
186 p
= page_find_alloc(addr
>> TARGET_PAGE_BITS
);
187 /* if the write protection is set, then we invalidate the code
189 if (!(p
->flags
& PAGE_WRITE
) &&
190 (flags
& PAGE_WRITE
) &&
192 tb_invalidate_page(addr
);
196 spin_unlock(&tb_lock
);
199 void cpu_exec_init(void)
202 code_gen_ptr
= code_gen_buffer
;
207 /* set to NULL all the 'first_tb' fields in all PageDescs */
208 static void page_flush_tb(void)
213 for(i
= 0; i
< L1_SIZE
; i
++) {
216 for(j
= 0; j
< L2_SIZE
; j
++)
217 p
[j
].first_tb
= NULL
;
222 /* flush all the translation blocks */
223 /* XXX: tb_flush is currently not thread safe */
228 printf("qemu: flush code_size=%d nb_tbs=%d avg_tb_size=%d\n",
229 code_gen_ptr
- code_gen_buffer
,
231 (code_gen_ptr
- code_gen_buffer
) / nb_tbs
);
234 for(i
= 0;i
< CODE_GEN_HASH_SIZE
; i
++)
237 code_gen_ptr
= code_gen_buffer
;
238 /* XXX: flush processor icache at this point if cache flush is
242 #ifdef DEBUG_TB_CHECK
244 static void tb_invalidate_check(unsigned long address
)
246 TranslationBlock
*tb
;
248 address
&= TARGET_PAGE_MASK
;
249 for(i
= 0;i
< CODE_GEN_HASH_SIZE
; i
++) {
250 for(tb
= tb_hash
[i
]; tb
!= NULL
; tb
= tb
->hash_next
) {
251 if (!(address
+ TARGET_PAGE_SIZE
<= tb
->pc
||
252 address
>= tb
->pc
+ tb
->size
)) {
253 printf("ERROR invalidate: address=%08lx PC=%08lx size=%04x\n",
254 address
, tb
->pc
, tb
->size
);
260 /* verify that all the pages have correct rights for code */
261 static void tb_page_check(void)
263 TranslationBlock
*tb
;
264 int i
, flags1
, flags2
;
266 for(i
= 0;i
< CODE_GEN_HASH_SIZE
; i
++) {
267 for(tb
= tb_hash
[i
]; tb
!= NULL
; tb
= tb
->hash_next
) {
268 flags1
= page_get_flags(tb
->pc
);
269 flags2
= page_get_flags(tb
->pc
+ tb
->size
- 1);
270 if ((flags1
& PAGE_WRITE
) || (flags2
& PAGE_WRITE
)) {
271 printf("ERROR page flags: PC=%08lx size=%04x f1=%x f2=%x\n",
272 tb
->pc
, tb
->size
, flags1
, flags2
);
278 void tb_jmp_check(TranslationBlock
*tb
)
280 TranslationBlock
*tb1
;
283 /* suppress any remaining jumps to this TB */
287 tb1
= (TranslationBlock
*)((long)tb1
& ~3);
290 tb1
= tb1
->jmp_next
[n1
];
292 /* check end of list */
294 printf("ERROR: jmp_list from 0x%08lx\n", (long)tb
);
300 /* invalidate one TB */
301 static inline void tb_remove(TranslationBlock
**ptb
, TranslationBlock
*tb
,
304 TranslationBlock
*tb1
;
308 *ptb
= *(TranslationBlock
**)((char *)tb1
+ next_offset
);
311 ptb
= (TranslationBlock
**)((char *)tb1
+ next_offset
);
315 static inline void tb_jmp_remove(TranslationBlock
*tb
, int n
)
317 TranslationBlock
*tb1
, **ptb
;
320 ptb
= &tb
->jmp_next
[n
];
323 /* find tb(n) in circular list */
327 tb1
= (TranslationBlock
*)((long)tb1
& ~3);
328 if (n1
== n
&& tb1
== tb
)
331 ptb
= &tb1
->jmp_first
;
333 ptb
= &tb1
->jmp_next
[n1
];
336 /* now we can suppress tb(n) from the list */
337 *ptb
= tb
->jmp_next
[n
];
339 tb
->jmp_next
[n
] = NULL
;
343 /* reset the jump entry 'n' of a TB so that it is not chained to
345 static inline void tb_reset_jump(TranslationBlock
*tb
, int n
)
347 tb_set_jmp_target(tb
, n
, (unsigned long)(tb
->tc_ptr
+ tb
->tb_next_offset
[n
]));
350 static inline void tb_invalidate(TranslationBlock
*tb
, int parity
)
353 unsigned int page_index1
, page_index2
;
355 TranslationBlock
*tb1
, *tb2
;
357 /* remove the TB from the hash list */
358 h
= tb_hash_func(tb
->pc
);
359 tb_remove(&tb_hash
[h
], tb
,
360 offsetof(TranslationBlock
, hash_next
));
361 /* remove the TB from the page list */
362 page_index1
= tb
->pc
>> TARGET_PAGE_BITS
;
363 if ((page_index1
& 1) == parity
) {
364 p
= page_find(page_index1
);
365 tb_remove(&p
->first_tb
, tb
,
366 offsetof(TranslationBlock
, page_next
[page_index1
& 1]));
368 page_index2
= (tb
->pc
+ tb
->size
- 1) >> TARGET_PAGE_BITS
;
369 if ((page_index2
& 1) == parity
) {
370 p
= page_find(page_index2
);
371 tb_remove(&p
->first_tb
, tb
,
372 offsetof(TranslationBlock
, page_next
[page_index2
& 1]));
375 /* suppress this TB from the two jump lists */
376 tb_jmp_remove(tb
, 0);
377 tb_jmp_remove(tb
, 1);
379 /* suppress any remaining jumps to this TB */
385 tb1
= (TranslationBlock
*)((long)tb1
& ~3);
386 tb2
= tb1
->jmp_next
[n1
];
387 tb_reset_jump(tb1
, n1
);
388 tb1
->jmp_next
[n1
] = NULL
;
391 tb
->jmp_first
= (TranslationBlock
*)((long)tb
| 2); /* fail safe */
394 /* invalidate all TBs which intersect with the target page starting at addr */
395 static void tb_invalidate_page(unsigned long address
)
397 TranslationBlock
*tb_next
, *tb
;
398 unsigned int page_index
;
399 int parity1
, parity2
;
401 #ifdef DEBUG_TB_INVALIDATE
402 printf("tb_invalidate_page: %lx\n", address
);
405 page_index
= address
>> TARGET_PAGE_BITS
;
406 p
= page_find(page_index
);
410 parity1
= page_index
& 1;
411 parity2
= parity1
^ 1;
413 tb_next
= tb
->page_next
[parity1
];
414 tb_invalidate(tb
, parity2
);
420 /* add the tb in the target page and protect it if necessary */
421 static inline void tb_alloc_page(TranslationBlock
*tb
, unsigned int page_index
)
424 unsigned long host_start
, host_end
, addr
, page_addr
;
427 p
= page_find_alloc(page_index
);
428 tb
->page_next
[page_index
& 1] = p
->first_tb
;
430 if (p
->flags
& PAGE_WRITE
) {
431 /* force the host page as non writable (writes will have a
432 page fault + mprotect overhead) */
433 page_addr
= (page_index
<< TARGET_PAGE_BITS
);
434 host_start
= page_addr
& host_page_mask
;
435 host_end
= host_start
+ host_page_size
;
437 for(addr
= host_start
; addr
< host_end
; addr
+= TARGET_PAGE_SIZE
)
438 prot
|= page_get_flags(addr
);
439 mprotect((void *)host_start
, host_page_size
,
440 (prot
& PAGE_BITS
) & ~PAGE_WRITE
);
441 #ifdef DEBUG_TB_INVALIDATE
442 printf("protecting code page: 0x%08lx\n",
445 p
->flags
&= ~PAGE_WRITE
;
446 #ifdef DEBUG_TB_CHECK
452 /* Allocate a new translation block. Flush the translation buffer if
453 too many translation blocks or too much generated code. */
454 TranslationBlock
*tb_alloc(unsigned long pc
)
456 TranslationBlock
*tb
;
458 if (nb_tbs
>= CODE_GEN_MAX_BLOCKS
||
459 (code_gen_ptr
- code_gen_buffer
) >= CODE_GEN_BUFFER_MAX_SIZE
)
466 /* link the tb with the other TBs */
467 void tb_link(TranslationBlock
*tb
)
469 unsigned int page_index1
, page_index2
;
471 /* add in the page list */
472 page_index1
= tb
->pc
>> TARGET_PAGE_BITS
;
473 tb_alloc_page(tb
, page_index1
);
474 page_index2
= (tb
->pc
+ tb
->size
- 1) >> TARGET_PAGE_BITS
;
475 if (page_index2
!= page_index1
) {
476 tb_alloc_page(tb
, page_index2
);
478 tb
->jmp_first
= (TranslationBlock
*)((long)tb
| 2);
479 tb
->jmp_next
[0] = NULL
;
480 tb
->jmp_next
[1] = NULL
;
482 /* init original jump addresses */
483 if (tb
->tb_next_offset
[0] != 0xffff)
484 tb_reset_jump(tb
, 0);
485 if (tb
->tb_next_offset
[1] != 0xffff)
486 tb_reset_jump(tb
, 1);
489 /* called from signal handler: invalidate the code and unprotect the
490 page. Return TRUE if the fault was succesfully handled. */
491 int page_unprotect(unsigned long address
)
493 unsigned int page_index
, prot
, pindex
;
495 unsigned long host_start
, host_end
, addr
;
497 host_start
= address
& host_page_mask
;
498 page_index
= host_start
>> TARGET_PAGE_BITS
;
499 p1
= page_find(page_index
);
502 host_end
= host_start
+ host_page_size
;
505 for(addr
= host_start
;addr
< host_end
; addr
+= TARGET_PAGE_SIZE
) {
509 /* if the page was really writable, then we change its
510 protection back to writable */
511 if (prot
& PAGE_WRITE_ORG
) {
512 mprotect((void *)host_start
, host_page_size
,
513 (prot
& PAGE_BITS
) | PAGE_WRITE
);
514 pindex
= (address
- host_start
) >> TARGET_PAGE_BITS
;
515 p1
[pindex
].flags
|= PAGE_WRITE
;
516 /* and since the content will be modified, we must invalidate
517 the corresponding translated code. */
518 tb_invalidate_page(address
);
519 #ifdef DEBUG_TB_CHECK
520 tb_invalidate_check(address
);
528 /* call this function when system calls directly modify a memory area */
529 void page_unprotect_range(uint8_t *data
, unsigned long data_size
)
531 unsigned long start
, end
, addr
;
533 start
= (unsigned long)data
;
534 end
= start
+ data_size
;
535 start
&= TARGET_PAGE_MASK
;
536 end
= TARGET_PAGE_ALIGN(end
);
537 for(addr
= start
; addr
< end
; addr
+= TARGET_PAGE_SIZE
) {
538 page_unprotect(addr
);
542 /* find the TB 'tb' such that tb[0].tc_ptr <= tc_ptr <
543 tb[1].tc_ptr. Return NULL if not found */
544 TranslationBlock
*tb_find_pc(unsigned long tc_ptr
)
548 TranslationBlock
*tb
;
552 if (tc_ptr
< (unsigned long)code_gen_buffer
||
553 tc_ptr
>= (unsigned long)code_gen_ptr
)
555 /* binary search (cf Knuth) */
558 while (m_min
<= m_max
) {
559 m
= (m_min
+ m_max
) >> 1;
561 v
= (unsigned long)tb
->tc_ptr
;
564 else if (tc_ptr
< v
) {
573 static void tb_reset_jump_recursive(TranslationBlock
*tb
);
575 static inline void tb_reset_jump_recursive2(TranslationBlock
*tb
, int n
)
577 TranslationBlock
*tb1
, *tb_next
, **ptb
;
580 tb1
= tb
->jmp_next
[n
];
582 /* find head of list */
585 tb1
= (TranslationBlock
*)((long)tb1
& ~3);
588 tb1
= tb1
->jmp_next
[n1
];
590 /* we are now sure now that tb jumps to tb1 */
593 /* remove tb from the jmp_first list */
594 ptb
= &tb_next
->jmp_first
;
598 tb1
= (TranslationBlock
*)((long)tb1
& ~3);
599 if (n1
== n
&& tb1
== tb
)
601 ptb
= &tb1
->jmp_next
[n1
];
603 *ptb
= tb
->jmp_next
[n
];
604 tb
->jmp_next
[n
] = NULL
;
606 /* suppress the jump to next tb in generated code */
607 tb_reset_jump(tb
, n
);
609 /* suppress jumps in the tb on which we could have jump */
610 tb_reset_jump_recursive(tb_next
);
614 static void tb_reset_jump_recursive(TranslationBlock
*tb
)
616 tb_reset_jump_recursive2(tb
, 0);
617 tb_reset_jump_recursive2(tb
, 1);
620 /* mask must never be zero */
621 void cpu_interrupt(CPUState
*env
, int mask
)
623 TranslationBlock
*tb
;
625 env
->interrupt_request
|= mask
;
626 /* if the cpu is currently executing code, we must unlink it and
627 all the potentially executing TB */
628 tb
= env
->current_tb
;
630 tb_reset_jump_recursive(tb
);
635 void cpu_abort(CPUState
*env
, const char *fmt
, ...)
640 fprintf(stderr
, "qemu: fatal: ");
641 vfprintf(stderr
, fmt
, ap
);
642 fprintf(stderr
, "\n");
644 cpu_x86_dump_state(env
, stderr
, X86_DUMP_FPU
| X86_DUMP_CCOP
);
651 /* unmap all maped pages and flush all associated code */
652 void page_unmap(void)
658 for(i
= 0; i
< L1_SIZE
; i
++) {
662 for(j
= 0;j
< L2_SIZE
;) {
663 if (p
->flags
& PAGE_VALID
) {
664 addr
= (i
<< (32 - L1_BITS
)) | (j
<< TARGET_PAGE_BITS
);
665 /* we try to find a range to make less syscalls */
669 while (j
< L2_SIZE
&& (p
->flags
& PAGE_VALID
)) {
673 ret
= munmap((void *)addr
, (j
- j1
) << TARGET_PAGE_BITS
);
675 fprintf(stderr
, "Could not unmap page 0x%08lx\n", addr
);