xref: /openbmc/qemu/accel/tcg/translate-all.c (revision dae9e03a)
1 /*
2  *  Host code generation
3  *
4  *  Copyright (c) 2003 Fabrice Bellard
5  *
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.
10  *
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.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18  */
19 #ifdef _WIN32
20 #include <windows.h>
21 #endif
22 #include "qemu/osdep.h"
23 
24 
25 #include "qemu-common.h"
26 #define NO_CPU_IO_DEFS
27 #include "cpu.h"
28 #include "trace.h"
29 #include "disas/disas.h"
30 #include "exec/exec-all.h"
31 #include "tcg.h"
32 #if defined(CONFIG_USER_ONLY)
33 #include "qemu.h"
34 #include "exec/exec-all.h"
35 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
36 #include <sys/param.h>
37 #if __FreeBSD_version >= 700104
38 #define HAVE_KINFO_GETVMMAP
39 #define sigqueue sigqueue_freebsd  /* avoid redefinition */
40 #include <sys/proc.h>
41 #include <machine/profile.h>
42 #define _KERNEL
43 #include <sys/user.h>
44 #undef _KERNEL
45 #undef sigqueue
46 #include <libutil.h>
47 #endif
48 #endif
49 #else
50 #include "exec/address-spaces.h"
51 #endif
52 
53 #include "exec/cputlb.h"
54 #include "exec/tb-hash.h"
55 #include "translate-all.h"
56 #include "qemu/bitmap.h"
57 #include "qemu/error-report.h"
58 #include "qemu/timer.h"
59 #include "qemu/main-loop.h"
60 #include "exec/log.h"
61 #include "sysemu/cpus.h"
62 
63 /* #define DEBUG_TB_INVALIDATE */
64 /* #define DEBUG_TB_FLUSH */
65 /* make various TB consistency checks */
66 /* #define DEBUG_TB_CHECK */
67 
68 #ifdef DEBUG_TB_INVALIDATE
69 #define DEBUG_TB_INVALIDATE_GATE 1
70 #else
71 #define DEBUG_TB_INVALIDATE_GATE 0
72 #endif
73 
74 #ifdef DEBUG_TB_FLUSH
75 #define DEBUG_TB_FLUSH_GATE 1
76 #else
77 #define DEBUG_TB_FLUSH_GATE 0
78 #endif
79 
80 #if !defined(CONFIG_USER_ONLY)
81 /* TB consistency checks only implemented for usermode emulation.  */
82 #undef DEBUG_TB_CHECK
83 #endif
84 
85 /* Access to the various translations structures need to be serialised via locks
86  * for consistency. This is automatic for SoftMMU based system
87  * emulation due to its single threaded nature. In user-mode emulation
88  * access to the memory related structures are protected with the
89  * mmap_lock.
90  */
91 #ifdef CONFIG_SOFTMMU
92 #define assert_memory_lock() tcg_debug_assert(have_tb_lock)
93 #else
94 #define assert_memory_lock() tcg_debug_assert(have_mmap_lock())
95 #endif
96 
97 #define SMC_BITMAP_USE_THRESHOLD 10
98 
99 typedef struct PageDesc {
100     /* list of TBs intersecting this ram page */
101     TranslationBlock *first_tb;
102 #ifdef CONFIG_SOFTMMU
103     /* in order to optimize self modifying code, we count the number
104        of lookups we do to a given page to use a bitmap */
105     unsigned int code_write_count;
106     unsigned long *code_bitmap;
107 #else
108     unsigned long flags;
109 #endif
110 } PageDesc;
111 
112 /* In system mode we want L1_MAP to be based on ram offsets,
113    while in user mode we want it to be based on virtual addresses.  */
114 #if !defined(CONFIG_USER_ONLY)
115 #if HOST_LONG_BITS < TARGET_PHYS_ADDR_SPACE_BITS
116 # define L1_MAP_ADDR_SPACE_BITS  HOST_LONG_BITS
117 #else
118 # define L1_MAP_ADDR_SPACE_BITS  TARGET_PHYS_ADDR_SPACE_BITS
119 #endif
120 #else
121 # define L1_MAP_ADDR_SPACE_BITS  TARGET_VIRT_ADDR_SPACE_BITS
122 #endif
123 
124 /* Size of the L2 (and L3, etc) page tables.  */
125 #define V_L2_BITS 10
126 #define V_L2_SIZE (1 << V_L2_BITS)
127 
128 /* Make sure all possible CPU event bits fit in tb->trace_vcpu_dstate */
129 QEMU_BUILD_BUG_ON(CPU_TRACE_DSTATE_MAX_EVENTS >
130                   sizeof(((TranslationBlock *)0)->trace_vcpu_dstate)
131                   * BITS_PER_BYTE);
132 
133 /*
134  * L1 Mapping properties
135  */
136 static int v_l1_size;
137 static int v_l1_shift;
138 static int v_l2_levels;
139 
140 /* The bottom level has pointers to PageDesc, and is indexed by
141  * anything from 4 to (V_L2_BITS + 3) bits, depending on target page size.
142  */
143 #define V_L1_MIN_BITS 4
144 #define V_L1_MAX_BITS (V_L2_BITS + 3)
145 #define V_L1_MAX_SIZE (1 << V_L1_MAX_BITS)
146 
147 static void *l1_map[V_L1_MAX_SIZE];
148 
149 /* code generation context */
150 TCGContext tcg_ctx;
151 bool parallel_cpus;
152 
153 /* translation block context */
154 static __thread int have_tb_lock;
155 
156 static void page_table_config_init(void)
157 {
158     uint32_t v_l1_bits;
159 
160     assert(TARGET_PAGE_BITS);
161     /* The bits remaining after N lower levels of page tables.  */
162     v_l1_bits = (L1_MAP_ADDR_SPACE_BITS - TARGET_PAGE_BITS) % V_L2_BITS;
163     if (v_l1_bits < V_L1_MIN_BITS) {
164         v_l1_bits += V_L2_BITS;
165     }
166 
167     v_l1_size = 1 << v_l1_bits;
168     v_l1_shift = L1_MAP_ADDR_SPACE_BITS - TARGET_PAGE_BITS - v_l1_bits;
169     v_l2_levels = v_l1_shift / V_L2_BITS - 1;
170 
171     assert(v_l1_bits <= V_L1_MAX_BITS);
172     assert(v_l1_shift % V_L2_BITS == 0);
173     assert(v_l2_levels >= 0);
174 }
175 
176 #define assert_tb_locked() tcg_debug_assert(have_tb_lock)
177 #define assert_tb_unlocked() tcg_debug_assert(!have_tb_lock)
178 
179 void tb_lock(void)
180 {
181     assert_tb_unlocked();
182     qemu_mutex_lock(&tcg_ctx.tb_ctx.tb_lock);
183     have_tb_lock++;
184 }
185 
186 void tb_unlock(void)
187 {
188     assert_tb_locked();
189     have_tb_lock--;
190     qemu_mutex_unlock(&tcg_ctx.tb_ctx.tb_lock);
191 }
192 
193 void tb_lock_reset(void)
194 {
195     if (have_tb_lock) {
196         qemu_mutex_unlock(&tcg_ctx.tb_ctx.tb_lock);
197         have_tb_lock = 0;
198     }
199 }
200 
201 static TranslationBlock *tb_find_pc(uintptr_t tc_ptr);
202 
203 void cpu_gen_init(void)
204 {
205     tcg_context_init(&tcg_ctx);
206 }
207 
208 /* Encode VAL as a signed leb128 sequence at P.
209    Return P incremented past the encoded value.  */
210 static uint8_t *encode_sleb128(uint8_t *p, target_long val)
211 {
212     int more, byte;
213 
214     do {
215         byte = val & 0x7f;
216         val >>= 7;
217         more = !((val == 0 && (byte & 0x40) == 0)
218                  || (val == -1 && (byte & 0x40) != 0));
219         if (more) {
220             byte |= 0x80;
221         }
222         *p++ = byte;
223     } while (more);
224 
225     return p;
226 }
227 
228 /* Decode a signed leb128 sequence at *PP; increment *PP past the
229    decoded value.  Return the decoded value.  */
230 static target_long decode_sleb128(uint8_t **pp)
231 {
232     uint8_t *p = *pp;
233     target_long val = 0;
234     int byte, shift = 0;
235 
236     do {
237         byte = *p++;
238         val |= (target_ulong)(byte & 0x7f) << shift;
239         shift += 7;
240     } while (byte & 0x80);
241     if (shift < TARGET_LONG_BITS && (byte & 0x40)) {
242         val |= -(target_ulong)1 << shift;
243     }
244 
245     *pp = p;
246     return val;
247 }
248 
249 /* Encode the data collected about the instructions while compiling TB.
250    Place the data at BLOCK, and return the number of bytes consumed.
251 
252    The logical table consisits of TARGET_INSN_START_WORDS target_ulong's,
253    which come from the target's insn_start data, followed by a uintptr_t
254    which comes from the host pc of the end of the code implementing the insn.
255 
256    Each line of the table is encoded as sleb128 deltas from the previous
257    line.  The seed for the first line is { tb->pc, 0..., tb->tc_ptr }.
258    That is, the first column is seeded with the guest pc, the last column
259    with the host pc, and the middle columns with zeros.  */
260 
261 static int encode_search(TranslationBlock *tb, uint8_t *block)
262 {
263     uint8_t *highwater = tcg_ctx.code_gen_highwater;
264     uint8_t *p = block;
265     int i, j, n;
266 
267     tb->tc_search = block;
268 
269     for (i = 0, n = tb->icount; i < n; ++i) {
270         target_ulong prev;
271 
272         for (j = 0; j < TARGET_INSN_START_WORDS; ++j) {
273             if (i == 0) {
274                 prev = (j == 0 ? tb->pc : 0);
275             } else {
276                 prev = tcg_ctx.gen_insn_data[i - 1][j];
277             }
278             p = encode_sleb128(p, tcg_ctx.gen_insn_data[i][j] - prev);
279         }
280         prev = (i == 0 ? 0 : tcg_ctx.gen_insn_end_off[i - 1]);
281         p = encode_sleb128(p, tcg_ctx.gen_insn_end_off[i] - prev);
282 
283         /* Test for (pending) buffer overflow.  The assumption is that any
284            one row beginning below the high water mark cannot overrun
285            the buffer completely.  Thus we can test for overflow after
286            encoding a row without having to check during encoding.  */
287         if (unlikely(p > highwater)) {
288             return -1;
289         }
290     }
291 
292     return p - block;
293 }
294 
295 /* The cpu state corresponding to 'searched_pc' is restored.
296  * Called with tb_lock held.
297  */
298 static int cpu_restore_state_from_tb(CPUState *cpu, TranslationBlock *tb,
299                                      uintptr_t searched_pc)
300 {
301     target_ulong data[TARGET_INSN_START_WORDS] = { tb->pc };
302     uintptr_t host_pc = (uintptr_t)tb->tc_ptr;
303     CPUArchState *env = cpu->env_ptr;
304     uint8_t *p = tb->tc_search;
305     int i, j, num_insns = tb->icount;
306 #ifdef CONFIG_PROFILER
307     int64_t ti = profile_getclock();
308 #endif
309 
310     searched_pc -= GETPC_ADJ;
311 
312     if (searched_pc < host_pc) {
313         return -1;
314     }
315 
316     /* Reconstruct the stored insn data while looking for the point at
317        which the end of the insn exceeds the searched_pc.  */
318     for (i = 0; i < num_insns; ++i) {
319         for (j = 0; j < TARGET_INSN_START_WORDS; ++j) {
320             data[j] += decode_sleb128(&p);
321         }
322         host_pc += decode_sleb128(&p);
323         if (host_pc > searched_pc) {
324             goto found;
325         }
326     }
327     return -1;
328 
329  found:
330     if (tb->cflags & CF_USE_ICOUNT) {
331         assert(use_icount);
332         /* Reset the cycle counter to the start of the block.  */
333         cpu->icount_decr.u16.low += num_insns;
334         /* Clear the IO flag.  */
335         cpu->can_do_io = 0;
336     }
337     cpu->icount_decr.u16.low -= i;
338     restore_state_to_opc(env, tb, data);
339 
340 #ifdef CONFIG_PROFILER
341     tcg_ctx.restore_time += profile_getclock() - ti;
342     tcg_ctx.restore_count++;
343 #endif
344     return 0;
345 }
346 
347 bool cpu_restore_state(CPUState *cpu, uintptr_t retaddr)
348 {
349     TranslationBlock *tb;
350     bool r = false;
351 
352     /* A retaddr of zero is invalid so we really shouldn't have ended
353      * up here. The target code has likely forgotten to check retaddr
354      * != 0 before attempting to restore state. We return early to
355      * avoid blowing up on a recursive tb_lock(). The target must have
356      * previously survived a failed cpu_restore_state because
357      * tb_find_pc(0) would have failed anyway. It still should be
358      * fixed though.
359      */
360 
361     if (!retaddr) {
362         return r;
363     }
364 
365     tb_lock();
366     tb = tb_find_pc(retaddr);
367     if (tb) {
368         cpu_restore_state_from_tb(cpu, tb, retaddr);
369         if (tb->cflags & CF_NOCACHE) {
370             /* one-shot translation, invalidate it immediately */
371             tb_phys_invalidate(tb, -1);
372             tb_free(tb);
373         }
374         r = true;
375     }
376     tb_unlock();
377 
378     return r;
379 }
380 
381 static void page_init(void)
382 {
383     page_size_init();
384     page_table_config_init();
385 
386 #if defined(CONFIG_BSD) && defined(CONFIG_USER_ONLY)
387     {
388 #ifdef HAVE_KINFO_GETVMMAP
389         struct kinfo_vmentry *freep;
390         int i, cnt;
391 
392         freep = kinfo_getvmmap(getpid(), &cnt);
393         if (freep) {
394             mmap_lock();
395             for (i = 0; i < cnt; i++) {
396                 unsigned long startaddr, endaddr;
397 
398                 startaddr = freep[i].kve_start;
399                 endaddr = freep[i].kve_end;
400                 if (h2g_valid(startaddr)) {
401                     startaddr = h2g(startaddr) & TARGET_PAGE_MASK;
402 
403                     if (h2g_valid(endaddr)) {
404                         endaddr = h2g(endaddr);
405                         page_set_flags(startaddr, endaddr, PAGE_RESERVED);
406                     } else {
407 #if TARGET_ABI_BITS <= L1_MAP_ADDR_SPACE_BITS
408                         endaddr = ~0ul;
409                         page_set_flags(startaddr, endaddr, PAGE_RESERVED);
410 #endif
411                     }
412                 }
413             }
414             free(freep);
415             mmap_unlock();
416         }
417 #else
418         FILE *f;
419 
420         last_brk = (unsigned long)sbrk(0);
421 
422         f = fopen("/compat/linux/proc/self/maps", "r");
423         if (f) {
424             mmap_lock();
425 
426             do {
427                 unsigned long startaddr, endaddr;
428                 int n;
429 
430                 n = fscanf(f, "%lx-%lx %*[^\n]\n", &startaddr, &endaddr);
431 
432                 if (n == 2 && h2g_valid(startaddr)) {
433                     startaddr = h2g(startaddr) & TARGET_PAGE_MASK;
434 
435                     if (h2g_valid(endaddr)) {
436                         endaddr = h2g(endaddr);
437                     } else {
438                         endaddr = ~0ul;
439                     }
440                     page_set_flags(startaddr, endaddr, PAGE_RESERVED);
441                 }
442             } while (!feof(f));
443 
444             fclose(f);
445             mmap_unlock();
446         }
447 #endif
448     }
449 #endif
450 }
451 
452 /* If alloc=1:
453  * Called with tb_lock held for system emulation.
454  * Called with mmap_lock held for user-mode emulation.
455  */
456 static PageDesc *page_find_alloc(tb_page_addr_t index, int alloc)
457 {
458     PageDesc *pd;
459     void **lp;
460     int i;
461 
462     if (alloc) {
463         assert_memory_lock();
464     }
465 
466     /* Level 1.  Always allocated.  */
467     lp = l1_map + ((index >> v_l1_shift) & (v_l1_size - 1));
468 
469     /* Level 2..N-1.  */
470     for (i = v_l2_levels; i > 0; i--) {
471         void **p = atomic_rcu_read(lp);
472 
473         if (p == NULL) {
474             if (!alloc) {
475                 return NULL;
476             }
477             p = g_new0(void *, V_L2_SIZE);
478             atomic_rcu_set(lp, p);
479         }
480 
481         lp = p + ((index >> (i * V_L2_BITS)) & (V_L2_SIZE - 1));
482     }
483 
484     pd = atomic_rcu_read(lp);
485     if (pd == NULL) {
486         if (!alloc) {
487             return NULL;
488         }
489         pd = g_new0(PageDesc, V_L2_SIZE);
490         atomic_rcu_set(lp, pd);
491     }
492 
493     return pd + (index & (V_L2_SIZE - 1));
494 }
495 
496 static inline PageDesc *page_find(tb_page_addr_t index)
497 {
498     return page_find_alloc(index, 0);
499 }
500 
501 #if defined(CONFIG_USER_ONLY)
502 /* Currently it is not recommended to allocate big chunks of data in
503    user mode. It will change when a dedicated libc will be used.  */
504 /* ??? 64-bit hosts ought to have no problem mmaping data outside the
505    region in which the guest needs to run.  Revisit this.  */
506 #define USE_STATIC_CODE_GEN_BUFFER
507 #endif
508 
509 /* Minimum size of the code gen buffer.  This number is randomly chosen,
510    but not so small that we can't have a fair number of TB's live.  */
511 #define MIN_CODE_GEN_BUFFER_SIZE     (1024u * 1024)
512 
513 /* Maximum size of the code gen buffer we'd like to use.  Unless otherwise
514    indicated, this is constrained by the range of direct branches on the
515    host cpu, as used by the TCG implementation of goto_tb.  */
516 #if defined(__x86_64__)
517 # define MAX_CODE_GEN_BUFFER_SIZE  (2ul * 1024 * 1024 * 1024)
518 #elif defined(__sparc__)
519 # define MAX_CODE_GEN_BUFFER_SIZE  (2ul * 1024 * 1024 * 1024)
520 #elif defined(__powerpc64__)
521 # define MAX_CODE_GEN_BUFFER_SIZE  (2ul * 1024 * 1024 * 1024)
522 #elif defined(__powerpc__)
523 # define MAX_CODE_GEN_BUFFER_SIZE  (32u * 1024 * 1024)
524 #elif defined(__aarch64__)
525 # define MAX_CODE_GEN_BUFFER_SIZE  (2ul * 1024 * 1024 * 1024)
526 #elif defined(__s390x__)
527   /* We have a +- 4GB range on the branches; leave some slop.  */
528 # define MAX_CODE_GEN_BUFFER_SIZE  (3ul * 1024 * 1024 * 1024)
529 #elif defined(__mips__)
530   /* We have a 256MB branch region, but leave room to make sure the
531      main executable is also within that region.  */
532 # define MAX_CODE_GEN_BUFFER_SIZE  (128ul * 1024 * 1024)
533 #else
534 # define MAX_CODE_GEN_BUFFER_SIZE  ((size_t)-1)
535 #endif
536 
537 #define DEFAULT_CODE_GEN_BUFFER_SIZE_1 (32u * 1024 * 1024)
538 
539 #define DEFAULT_CODE_GEN_BUFFER_SIZE \
540   (DEFAULT_CODE_GEN_BUFFER_SIZE_1 < MAX_CODE_GEN_BUFFER_SIZE \
541    ? DEFAULT_CODE_GEN_BUFFER_SIZE_1 : MAX_CODE_GEN_BUFFER_SIZE)
542 
543 static inline size_t size_code_gen_buffer(size_t tb_size)
544 {
545     /* Size the buffer.  */
546     if (tb_size == 0) {
547 #ifdef USE_STATIC_CODE_GEN_BUFFER
548         tb_size = DEFAULT_CODE_GEN_BUFFER_SIZE;
549 #else
550         /* ??? Needs adjustments.  */
551         /* ??? If we relax the requirement that CONFIG_USER_ONLY use the
552            static buffer, we could size this on RESERVED_VA, on the text
553            segment size of the executable, or continue to use the default.  */
554         tb_size = (unsigned long)(ram_size / 4);
555 #endif
556     }
557     if (tb_size < MIN_CODE_GEN_BUFFER_SIZE) {
558         tb_size = MIN_CODE_GEN_BUFFER_SIZE;
559     }
560     if (tb_size > MAX_CODE_GEN_BUFFER_SIZE) {
561         tb_size = MAX_CODE_GEN_BUFFER_SIZE;
562     }
563     return tb_size;
564 }
565 
566 #ifdef __mips__
567 /* In order to use J and JAL within the code_gen_buffer, we require
568    that the buffer not cross a 256MB boundary.  */
569 static inline bool cross_256mb(void *addr, size_t size)
570 {
571     return ((uintptr_t)addr ^ ((uintptr_t)addr + size)) & ~0x0ffffffful;
572 }
573 
574 /* We weren't able to allocate a buffer without crossing that boundary,
575    so make do with the larger portion of the buffer that doesn't cross.
576    Returns the new base of the buffer, and adjusts code_gen_buffer_size.  */
577 static inline void *split_cross_256mb(void *buf1, size_t size1)
578 {
579     void *buf2 = (void *)(((uintptr_t)buf1 + size1) & ~0x0ffffffful);
580     size_t size2 = buf1 + size1 - buf2;
581 
582     size1 = buf2 - buf1;
583     if (size1 < size2) {
584         size1 = size2;
585         buf1 = buf2;
586     }
587 
588     tcg_ctx.code_gen_buffer_size = size1;
589     return buf1;
590 }
591 #endif
592 
593 #ifdef USE_STATIC_CODE_GEN_BUFFER
594 static uint8_t static_code_gen_buffer[DEFAULT_CODE_GEN_BUFFER_SIZE]
595     __attribute__((aligned(CODE_GEN_ALIGN)));
596 
597 # ifdef _WIN32
598 static inline void do_protect(void *addr, long size, int prot)
599 {
600     DWORD old_protect;
601     VirtualProtect(addr, size, prot, &old_protect);
602 }
603 
604 static inline void map_exec(void *addr, long size)
605 {
606     do_protect(addr, size, PAGE_EXECUTE_READWRITE);
607 }
608 
609 static inline void map_none(void *addr, long size)
610 {
611     do_protect(addr, size, PAGE_NOACCESS);
612 }
613 # else
614 static inline void do_protect(void *addr, long size, int prot)
615 {
616     uintptr_t start, end;
617 
618     start = (uintptr_t)addr;
619     start &= qemu_real_host_page_mask;
620 
621     end = (uintptr_t)addr + size;
622     end = ROUND_UP(end, qemu_real_host_page_size);
623 
624     mprotect((void *)start, end - start, prot);
625 }
626 
627 static inline void map_exec(void *addr, long size)
628 {
629     do_protect(addr, size, PROT_READ | PROT_WRITE | PROT_EXEC);
630 }
631 
632 static inline void map_none(void *addr, long size)
633 {
634     do_protect(addr, size, PROT_NONE);
635 }
636 # endif /* WIN32 */
637 
638 static inline void *alloc_code_gen_buffer(void)
639 {
640     void *buf = static_code_gen_buffer;
641     size_t full_size, size;
642 
643     /* The size of the buffer, rounded down to end on a page boundary.  */
644     full_size = (((uintptr_t)buf + sizeof(static_code_gen_buffer))
645                  & qemu_real_host_page_mask) - (uintptr_t)buf;
646 
647     /* Reserve a guard page.  */
648     size = full_size - qemu_real_host_page_size;
649 
650     /* Honor a command-line option limiting the size of the buffer.  */
651     if (size > tcg_ctx.code_gen_buffer_size) {
652         size = (((uintptr_t)buf + tcg_ctx.code_gen_buffer_size)
653                 & qemu_real_host_page_mask) - (uintptr_t)buf;
654     }
655     tcg_ctx.code_gen_buffer_size = size;
656 
657 #ifdef __mips__
658     if (cross_256mb(buf, size)) {
659         buf = split_cross_256mb(buf, size);
660         size = tcg_ctx.code_gen_buffer_size;
661     }
662 #endif
663 
664     map_exec(buf, size);
665     map_none(buf + size, qemu_real_host_page_size);
666     qemu_madvise(buf, size, QEMU_MADV_HUGEPAGE);
667 
668     return buf;
669 }
670 #elif defined(_WIN32)
671 static inline void *alloc_code_gen_buffer(void)
672 {
673     size_t size = tcg_ctx.code_gen_buffer_size;
674     void *buf1, *buf2;
675 
676     /* Perform the allocation in two steps, so that the guard page
677        is reserved but uncommitted.  */
678     buf1 = VirtualAlloc(NULL, size + qemu_real_host_page_size,
679                         MEM_RESERVE, PAGE_NOACCESS);
680     if (buf1 != NULL) {
681         buf2 = VirtualAlloc(buf1, size, MEM_COMMIT, PAGE_EXECUTE_READWRITE);
682         assert(buf1 == buf2);
683     }
684 
685     return buf1;
686 }
687 #else
688 static inline void *alloc_code_gen_buffer(void)
689 {
690     int flags = MAP_PRIVATE | MAP_ANONYMOUS;
691     uintptr_t start = 0;
692     size_t size = tcg_ctx.code_gen_buffer_size;
693     void *buf;
694 
695     /* Constrain the position of the buffer based on the host cpu.
696        Note that these addresses are chosen in concert with the
697        addresses assigned in the relevant linker script file.  */
698 # if defined(__PIE__) || defined(__PIC__)
699     /* Don't bother setting a preferred location if we're building
700        a position-independent executable.  We're more likely to get
701        an address near the main executable if we let the kernel
702        choose the address.  */
703 # elif defined(__x86_64__) && defined(MAP_32BIT)
704     /* Force the memory down into low memory with the executable.
705        Leave the choice of exact location with the kernel.  */
706     flags |= MAP_32BIT;
707     /* Cannot expect to map more than 800MB in low memory.  */
708     if (size > 800u * 1024 * 1024) {
709         tcg_ctx.code_gen_buffer_size = size = 800u * 1024 * 1024;
710     }
711 # elif defined(__sparc__)
712     start = 0x40000000ul;
713 # elif defined(__s390x__)
714     start = 0x90000000ul;
715 # elif defined(__mips__)
716 #  if _MIPS_SIM == _ABI64
717     start = 0x128000000ul;
718 #  else
719     start = 0x08000000ul;
720 #  endif
721 # endif
722 
723     buf = mmap((void *)start, size + qemu_real_host_page_size,
724                PROT_NONE, flags, -1, 0);
725     if (buf == MAP_FAILED) {
726         return NULL;
727     }
728 
729 #ifdef __mips__
730     if (cross_256mb(buf, size)) {
731         /* Try again, with the original still mapped, to avoid re-acquiring
732            that 256mb crossing.  This time don't specify an address.  */
733         size_t size2;
734         void *buf2 = mmap(NULL, size + qemu_real_host_page_size,
735                           PROT_NONE, flags, -1, 0);
736         switch ((int)(buf2 != MAP_FAILED)) {
737         case 1:
738             if (!cross_256mb(buf2, size)) {
739                 /* Success!  Use the new buffer.  */
740                 munmap(buf, size + qemu_real_host_page_size);
741                 break;
742             }
743             /* Failure.  Work with what we had.  */
744             munmap(buf2, size + qemu_real_host_page_size);
745             /* fallthru */
746         default:
747             /* Split the original buffer.  Free the smaller half.  */
748             buf2 = split_cross_256mb(buf, size);
749             size2 = tcg_ctx.code_gen_buffer_size;
750             if (buf == buf2) {
751                 munmap(buf + size2 + qemu_real_host_page_size, size - size2);
752             } else {
753                 munmap(buf, size - size2);
754             }
755             size = size2;
756             break;
757         }
758         buf = buf2;
759     }
760 #endif
761 
762     /* Make the final buffer accessible.  The guard page at the end
763        will remain inaccessible with PROT_NONE.  */
764     mprotect(buf, size, PROT_WRITE | PROT_READ | PROT_EXEC);
765 
766     /* Request large pages for the buffer.  */
767     qemu_madvise(buf, size, QEMU_MADV_HUGEPAGE);
768 
769     return buf;
770 }
771 #endif /* USE_STATIC_CODE_GEN_BUFFER, WIN32, POSIX */
772 
773 static inline void code_gen_alloc(size_t tb_size)
774 {
775     tcg_ctx.code_gen_buffer_size = size_code_gen_buffer(tb_size);
776     tcg_ctx.code_gen_buffer = alloc_code_gen_buffer();
777     if (tcg_ctx.code_gen_buffer == NULL) {
778         fprintf(stderr, "Could not allocate dynamic translator buffer\n");
779         exit(1);
780     }
781 
782     /* size this conservatively -- realloc later if needed */
783     tcg_ctx.tb_ctx.tbs_size =
784         tcg_ctx.code_gen_buffer_size / CODE_GEN_AVG_BLOCK_SIZE / 8;
785     if (unlikely(!tcg_ctx.tb_ctx.tbs_size)) {
786         tcg_ctx.tb_ctx.tbs_size = 64 * 1024;
787     }
788     tcg_ctx.tb_ctx.tbs = g_new(TranslationBlock *, tcg_ctx.tb_ctx.tbs_size);
789 
790     qemu_mutex_init(&tcg_ctx.tb_ctx.tb_lock);
791 }
792 
793 static void tb_htable_init(void)
794 {
795     unsigned int mode = QHT_MODE_AUTO_RESIZE;
796 
797     qht_init(&tcg_ctx.tb_ctx.htable, CODE_GEN_HTABLE_SIZE, mode);
798 }
799 
800 /* Must be called before using the QEMU cpus. 'tb_size' is the size
801    (in bytes) allocated to the translation buffer. Zero means default
802    size. */
803 void tcg_exec_init(unsigned long tb_size)
804 {
805     tcg_allowed = true;
806     cpu_gen_init();
807     page_init();
808     tb_htable_init();
809     code_gen_alloc(tb_size);
810 #if defined(CONFIG_SOFTMMU)
811     /* There's no guest base to take into account, so go ahead and
812        initialize the prologue now.  */
813     tcg_prologue_init(&tcg_ctx);
814 #endif
815 }
816 
817 /*
818  * Allocate a new translation block. Flush the translation buffer if
819  * too many translation blocks or too much generated code.
820  *
821  * Called with tb_lock held.
822  */
823 static TranslationBlock *tb_alloc(target_ulong pc)
824 {
825     TranslationBlock *tb;
826     TBContext *ctx;
827 
828     assert_tb_locked();
829 
830     tb = tcg_tb_alloc(&tcg_ctx);
831     if (unlikely(tb == NULL)) {
832         return NULL;
833     }
834     ctx = &tcg_ctx.tb_ctx;
835     if (unlikely(ctx->nb_tbs == ctx->tbs_size)) {
836         ctx->tbs_size *= 2;
837         ctx->tbs = g_renew(TranslationBlock *, ctx->tbs, ctx->tbs_size);
838     }
839     ctx->tbs[ctx->nb_tbs++] = tb;
840     return tb;
841 }
842 
843 /* Called with tb_lock held.  */
844 void tb_free(TranslationBlock *tb)
845 {
846     assert_tb_locked();
847 
848     /* In practice this is mostly used for single use temporary TB
849        Ignore the hard cases and just back up if this TB happens to
850        be the last one generated.  */
851     if (tcg_ctx.tb_ctx.nb_tbs > 0 &&
852             tb == tcg_ctx.tb_ctx.tbs[tcg_ctx.tb_ctx.nb_tbs - 1]) {
853         size_t struct_size = ROUND_UP(sizeof(*tb), qemu_icache_linesize);
854 
855         tcg_ctx.code_gen_ptr = tb->tc_ptr - struct_size;
856         tcg_ctx.tb_ctx.nb_tbs--;
857     }
858 }
859 
860 static inline void invalidate_page_bitmap(PageDesc *p)
861 {
862 #ifdef CONFIG_SOFTMMU
863     g_free(p->code_bitmap);
864     p->code_bitmap = NULL;
865     p->code_write_count = 0;
866 #endif
867 }
868 
869 /* Set to NULL all the 'first_tb' fields in all PageDescs. */
870 static void page_flush_tb_1(int level, void **lp)
871 {
872     int i;
873 
874     if (*lp == NULL) {
875         return;
876     }
877     if (level == 0) {
878         PageDesc *pd = *lp;
879 
880         for (i = 0; i < V_L2_SIZE; ++i) {
881             pd[i].first_tb = NULL;
882             invalidate_page_bitmap(pd + i);
883         }
884     } else {
885         void **pp = *lp;
886 
887         for (i = 0; i < V_L2_SIZE; ++i) {
888             page_flush_tb_1(level - 1, pp + i);
889         }
890     }
891 }
892 
893 static void page_flush_tb(void)
894 {
895     int i, l1_sz = v_l1_size;
896 
897     for (i = 0; i < l1_sz; i++) {
898         page_flush_tb_1(v_l2_levels, l1_map + i);
899     }
900 }
901 
902 /* flush all the translation blocks */
903 static void do_tb_flush(CPUState *cpu, run_on_cpu_data tb_flush_count)
904 {
905     tb_lock();
906 
907     /* If it is already been done on request of another CPU,
908      * just retry.
909      */
910     if (tcg_ctx.tb_ctx.tb_flush_count != tb_flush_count.host_int) {
911         goto done;
912     }
913 
914     if (DEBUG_TB_FLUSH_GATE) {
915         printf("qemu: flush code_size=%td nb_tbs=%d avg_tb_size=%td\n",
916                tcg_ctx.code_gen_ptr - tcg_ctx.code_gen_buffer,
917                tcg_ctx.tb_ctx.nb_tbs, tcg_ctx.tb_ctx.nb_tbs > 0 ?
918                (tcg_ctx.code_gen_ptr - tcg_ctx.code_gen_buffer) /
919                tcg_ctx.tb_ctx.nb_tbs : 0);
920     }
921     if ((unsigned long)(tcg_ctx.code_gen_ptr - tcg_ctx.code_gen_buffer)
922         > tcg_ctx.code_gen_buffer_size) {
923         cpu_abort(cpu, "Internal error: code buffer overflow\n");
924     }
925 
926     CPU_FOREACH(cpu) {
927         cpu_tb_jmp_cache_clear(cpu);
928     }
929 
930     tcg_ctx.tb_ctx.nb_tbs = 0;
931     qht_reset_size(&tcg_ctx.tb_ctx.htable, CODE_GEN_HTABLE_SIZE);
932     page_flush_tb();
933 
934     tcg_ctx.code_gen_ptr = tcg_ctx.code_gen_buffer;
935     /* XXX: flush processor icache at this point if cache flush is
936        expensive */
937     atomic_mb_set(&tcg_ctx.tb_ctx.tb_flush_count,
938                   tcg_ctx.tb_ctx.tb_flush_count + 1);
939 
940 done:
941     tb_unlock();
942 }
943 
944 void tb_flush(CPUState *cpu)
945 {
946     if (tcg_enabled()) {
947         unsigned tb_flush_count = atomic_mb_read(&tcg_ctx.tb_ctx.tb_flush_count);
948         async_safe_run_on_cpu(cpu, do_tb_flush,
949                               RUN_ON_CPU_HOST_INT(tb_flush_count));
950     }
951 }
952 
953 #ifdef DEBUG_TB_CHECK
954 
955 static void
956 do_tb_invalidate_check(struct qht *ht, void *p, uint32_t hash, void *userp)
957 {
958     TranslationBlock *tb = p;
959     target_ulong addr = *(target_ulong *)userp;
960 
961     if (!(addr + TARGET_PAGE_SIZE <= tb->pc || addr >= tb->pc + tb->size)) {
962         printf("ERROR invalidate: address=" TARGET_FMT_lx
963                " PC=%08lx size=%04x\n", addr, (long)tb->pc, tb->size);
964     }
965 }
966 
967 /* verify that all the pages have correct rights for code
968  *
969  * Called with tb_lock held.
970  */
971 static void tb_invalidate_check(target_ulong address)
972 {
973     address &= TARGET_PAGE_MASK;
974     qht_iter(&tcg_ctx.tb_ctx.htable, do_tb_invalidate_check, &address);
975 }
976 
977 static void
978 do_tb_page_check(struct qht *ht, void *p, uint32_t hash, void *userp)
979 {
980     TranslationBlock *tb = p;
981     int flags1, flags2;
982 
983     flags1 = page_get_flags(tb->pc);
984     flags2 = page_get_flags(tb->pc + tb->size - 1);
985     if ((flags1 & PAGE_WRITE) || (flags2 & PAGE_WRITE)) {
986         printf("ERROR page flags: PC=%08lx size=%04x f1=%x f2=%x\n",
987                (long)tb->pc, tb->size, flags1, flags2);
988     }
989 }
990 
991 /* verify that all the pages have correct rights for code */
992 static void tb_page_check(void)
993 {
994     qht_iter(&tcg_ctx.tb_ctx.htable, do_tb_page_check, NULL);
995 }
996 
997 #endif
998 
999 static inline void tb_page_remove(TranslationBlock **ptb, TranslationBlock *tb)
1000 {
1001     TranslationBlock *tb1;
1002     unsigned int n1;
1003 
1004     for (;;) {
1005         tb1 = *ptb;
1006         n1 = (uintptr_t)tb1 & 3;
1007         tb1 = (TranslationBlock *)((uintptr_t)tb1 & ~3);
1008         if (tb1 == tb) {
1009             *ptb = tb1->page_next[n1];
1010             break;
1011         }
1012         ptb = &tb1->page_next[n1];
1013     }
1014 }
1015 
1016 /* remove the TB from a list of TBs jumping to the n-th jump target of the TB */
1017 static inline void tb_remove_from_jmp_list(TranslationBlock *tb, int n)
1018 {
1019     TranslationBlock *tb1;
1020     uintptr_t *ptb, ntb;
1021     unsigned int n1;
1022 
1023     ptb = &tb->jmp_list_next[n];
1024     if (*ptb) {
1025         /* find tb(n) in circular list */
1026         for (;;) {
1027             ntb = *ptb;
1028             n1 = ntb & 3;
1029             tb1 = (TranslationBlock *)(ntb & ~3);
1030             if (n1 == n && tb1 == tb) {
1031                 break;
1032             }
1033             if (n1 == 2) {
1034                 ptb = &tb1->jmp_list_first;
1035             } else {
1036                 ptb = &tb1->jmp_list_next[n1];
1037             }
1038         }
1039         /* now we can suppress tb(n) from the list */
1040         *ptb = tb->jmp_list_next[n];
1041 
1042         tb->jmp_list_next[n] = (uintptr_t)NULL;
1043     }
1044 }
1045 
1046 /* reset the jump entry 'n' of a TB so that it is not chained to
1047    another TB */
1048 static inline void tb_reset_jump(TranslationBlock *tb, int n)
1049 {
1050     uintptr_t addr = (uintptr_t)(tb->tc_ptr + tb->jmp_reset_offset[n]);
1051     tb_set_jmp_target(tb, n, addr);
1052 }
1053 
1054 /* remove any jumps to the TB */
1055 static inline void tb_jmp_unlink(TranslationBlock *tb)
1056 {
1057     TranslationBlock *tb1;
1058     uintptr_t *ptb, ntb;
1059     unsigned int n1;
1060 
1061     ptb = &tb->jmp_list_first;
1062     for (;;) {
1063         ntb = *ptb;
1064         n1 = ntb & 3;
1065         tb1 = (TranslationBlock *)(ntb & ~3);
1066         if (n1 == 2) {
1067             break;
1068         }
1069         tb_reset_jump(tb1, n1);
1070         *ptb = tb1->jmp_list_next[n1];
1071         tb1->jmp_list_next[n1] = (uintptr_t)NULL;
1072     }
1073 }
1074 
1075 /* invalidate one TB
1076  *
1077  * Called with tb_lock held.
1078  */
1079 void tb_phys_invalidate(TranslationBlock *tb, tb_page_addr_t page_addr)
1080 {
1081     CPUState *cpu;
1082     PageDesc *p;
1083     uint32_t h;
1084     tb_page_addr_t phys_pc;
1085 
1086     assert_tb_locked();
1087 
1088     atomic_set(&tb->cflags, tb->cflags | CF_INVALID);
1089 
1090     /* remove the TB from the hash list */
1091     phys_pc = tb->page_addr[0] + (tb->pc & ~TARGET_PAGE_MASK);
1092     h = tb_hash_func(phys_pc, tb->pc, tb->flags, tb->trace_vcpu_dstate);
1093     qht_remove(&tcg_ctx.tb_ctx.htable, tb, h);
1094 
1095     /* remove the TB from the page list */
1096     if (tb->page_addr[0] != page_addr) {
1097         p = page_find(tb->page_addr[0] >> TARGET_PAGE_BITS);
1098         tb_page_remove(&p->first_tb, tb);
1099         invalidate_page_bitmap(p);
1100     }
1101     if (tb->page_addr[1] != -1 && tb->page_addr[1] != page_addr) {
1102         p = page_find(tb->page_addr[1] >> TARGET_PAGE_BITS);
1103         tb_page_remove(&p->first_tb, tb);
1104         invalidate_page_bitmap(p);
1105     }
1106 
1107     /* remove the TB from the hash list */
1108     h = tb_jmp_cache_hash_func(tb->pc);
1109     CPU_FOREACH(cpu) {
1110         if (atomic_read(&cpu->tb_jmp_cache[h]) == tb) {
1111             atomic_set(&cpu->tb_jmp_cache[h], NULL);
1112         }
1113     }
1114 
1115     /* suppress this TB from the two jump lists */
1116     tb_remove_from_jmp_list(tb, 0);
1117     tb_remove_from_jmp_list(tb, 1);
1118 
1119     /* suppress any remaining jumps to this TB */
1120     tb_jmp_unlink(tb);
1121 
1122     tcg_ctx.tb_ctx.tb_phys_invalidate_count++;
1123 }
1124 
1125 #ifdef CONFIG_SOFTMMU
1126 static void build_page_bitmap(PageDesc *p)
1127 {
1128     int n, tb_start, tb_end;
1129     TranslationBlock *tb;
1130 
1131     p->code_bitmap = bitmap_new(TARGET_PAGE_SIZE);
1132 
1133     tb = p->first_tb;
1134     while (tb != NULL) {
1135         n = (uintptr_t)tb & 3;
1136         tb = (TranslationBlock *)((uintptr_t)tb & ~3);
1137         /* NOTE: this is subtle as a TB may span two physical pages */
1138         if (n == 0) {
1139             /* NOTE: tb_end may be after the end of the page, but
1140                it is not a problem */
1141             tb_start = tb->pc & ~TARGET_PAGE_MASK;
1142             tb_end = tb_start + tb->size;
1143             if (tb_end > TARGET_PAGE_SIZE) {
1144                 tb_end = TARGET_PAGE_SIZE;
1145              }
1146         } else {
1147             tb_start = 0;
1148             tb_end = ((tb->pc + tb->size) & ~TARGET_PAGE_MASK);
1149         }
1150         bitmap_set(p->code_bitmap, tb_start, tb_end - tb_start);
1151         tb = tb->page_next[n];
1152     }
1153 }
1154 #endif
1155 
1156 /* add the tb in the target page and protect it if necessary
1157  *
1158  * Called with mmap_lock held for user-mode emulation.
1159  */
1160 static inline void tb_alloc_page(TranslationBlock *tb,
1161                                  unsigned int n, tb_page_addr_t page_addr)
1162 {
1163     PageDesc *p;
1164 #ifndef CONFIG_USER_ONLY
1165     bool page_already_protected;
1166 #endif
1167 
1168     assert_memory_lock();
1169 
1170     tb->page_addr[n] = page_addr;
1171     p = page_find_alloc(page_addr >> TARGET_PAGE_BITS, 1);
1172     tb->page_next[n] = p->first_tb;
1173 #ifndef CONFIG_USER_ONLY
1174     page_already_protected = p->first_tb != NULL;
1175 #endif
1176     p->first_tb = (TranslationBlock *)((uintptr_t)tb | n);
1177     invalidate_page_bitmap(p);
1178 
1179 #if defined(CONFIG_USER_ONLY)
1180     if (p->flags & PAGE_WRITE) {
1181         target_ulong addr;
1182         PageDesc *p2;
1183         int prot;
1184 
1185         /* force the host page as non writable (writes will have a
1186            page fault + mprotect overhead) */
1187         page_addr &= qemu_host_page_mask;
1188         prot = 0;
1189         for (addr = page_addr; addr < page_addr + qemu_host_page_size;
1190             addr += TARGET_PAGE_SIZE) {
1191 
1192             p2 = page_find(addr >> TARGET_PAGE_BITS);
1193             if (!p2) {
1194                 continue;
1195             }
1196             prot |= p2->flags;
1197             p2->flags &= ~PAGE_WRITE;
1198           }
1199         mprotect(g2h(page_addr), qemu_host_page_size,
1200                  (prot & PAGE_BITS) & ~PAGE_WRITE);
1201         if (DEBUG_TB_INVALIDATE_GATE) {
1202             printf("protecting code page: 0x" TB_PAGE_ADDR_FMT "\n", page_addr);
1203         }
1204     }
1205 #else
1206     /* if some code is already present, then the pages are already
1207        protected. So we handle the case where only the first TB is
1208        allocated in a physical page */
1209     if (!page_already_protected) {
1210         tlb_protect_code(page_addr);
1211     }
1212 #endif
1213 }
1214 
1215 /* add a new TB and link it to the physical page tables. phys_page2 is
1216  * (-1) to indicate that only one page contains the TB.
1217  *
1218  * Called with mmap_lock held for user-mode emulation.
1219  */
1220 static void tb_link_page(TranslationBlock *tb, tb_page_addr_t phys_pc,
1221                          tb_page_addr_t phys_page2)
1222 {
1223     uint32_t h;
1224 
1225     assert_memory_lock();
1226 
1227     /* add in the page list */
1228     tb_alloc_page(tb, 0, phys_pc & TARGET_PAGE_MASK);
1229     if (phys_page2 != -1) {
1230         tb_alloc_page(tb, 1, phys_page2);
1231     } else {
1232         tb->page_addr[1] = -1;
1233     }
1234 
1235     /* add in the hash table */
1236     h = tb_hash_func(phys_pc, tb->pc, tb->flags, tb->trace_vcpu_dstate);
1237     qht_insert(&tcg_ctx.tb_ctx.htable, tb, h);
1238 
1239 #ifdef DEBUG_TB_CHECK
1240     tb_page_check();
1241 #endif
1242 }
1243 
1244 /* Called with mmap_lock held for user mode emulation.  */
1245 TranslationBlock *tb_gen_code(CPUState *cpu,
1246                               target_ulong pc, target_ulong cs_base,
1247                               uint32_t flags, int cflags)
1248 {
1249     CPUArchState *env = cpu->env_ptr;
1250     TranslationBlock *tb;
1251     tb_page_addr_t phys_pc, phys_page2;
1252     target_ulong virt_page2;
1253     tcg_insn_unit *gen_code_buf;
1254     int gen_code_size, search_size;
1255 #ifdef CONFIG_PROFILER
1256     int64_t ti;
1257 #endif
1258     assert_memory_lock();
1259 
1260     phys_pc = get_page_addr_code(env, pc);
1261     if (use_icount && !(cflags & CF_IGNORE_ICOUNT)) {
1262         cflags |= CF_USE_ICOUNT;
1263     }
1264 
1265     tb = tb_alloc(pc);
1266     if (unlikely(!tb)) {
1267  buffer_overflow:
1268         /* flush must be done */
1269         tb_flush(cpu);
1270         mmap_unlock();
1271         /* Make the execution loop process the flush as soon as possible.  */
1272         cpu->exception_index = EXCP_INTERRUPT;
1273         cpu_loop_exit(cpu);
1274     }
1275 
1276     gen_code_buf = tcg_ctx.code_gen_ptr;
1277     tb->tc_ptr = gen_code_buf;
1278     tb->pc = pc;
1279     tb->cs_base = cs_base;
1280     tb->flags = flags;
1281     tb->cflags = cflags;
1282     tb->trace_vcpu_dstate = *cpu->trace_dstate;
1283 
1284 #ifdef CONFIG_PROFILER
1285     tcg_ctx.tb_count1++; /* includes aborted translations because of
1286                        exceptions */
1287     ti = profile_getclock();
1288 #endif
1289 
1290     tcg_func_start(&tcg_ctx);
1291 
1292     tcg_ctx.cpu = ENV_GET_CPU(env);
1293     gen_intermediate_code(cpu, tb);
1294     tcg_ctx.cpu = NULL;
1295 
1296     trace_translate_block(tb, tb->pc, tb->tc_ptr);
1297 
1298     /* generate machine code */
1299     tb->jmp_reset_offset[0] = TB_JMP_RESET_OFFSET_INVALID;
1300     tb->jmp_reset_offset[1] = TB_JMP_RESET_OFFSET_INVALID;
1301     tcg_ctx.tb_jmp_reset_offset = tb->jmp_reset_offset;
1302     if (TCG_TARGET_HAS_direct_jump) {
1303         tcg_ctx.tb_jmp_insn_offset = tb->jmp_target_arg;
1304         tcg_ctx.tb_jmp_target_addr = NULL;
1305     } else {
1306         tcg_ctx.tb_jmp_insn_offset = NULL;
1307         tcg_ctx.tb_jmp_target_addr = tb->jmp_target_arg;
1308     }
1309 
1310 #ifdef CONFIG_PROFILER
1311     tcg_ctx.tb_count++;
1312     tcg_ctx.interm_time += profile_getclock() - ti;
1313     ti = profile_getclock();
1314 #endif
1315 
1316     /* ??? Overflow could be handled better here.  In particular, we
1317        don't need to re-do gen_intermediate_code, nor should we re-do
1318        the tcg optimization currently hidden inside tcg_gen_code.  All
1319        that should be required is to flush the TBs, allocate a new TB,
1320        re-initialize it per above, and re-do the actual code generation.  */
1321     gen_code_size = tcg_gen_code(&tcg_ctx, tb);
1322     if (unlikely(gen_code_size < 0)) {
1323         goto buffer_overflow;
1324     }
1325     search_size = encode_search(tb, (void *)gen_code_buf + gen_code_size);
1326     if (unlikely(search_size < 0)) {
1327         goto buffer_overflow;
1328     }
1329 
1330 #ifdef CONFIG_PROFILER
1331     tcg_ctx.code_time += profile_getclock() - ti;
1332     tcg_ctx.code_in_len += tb->size;
1333     tcg_ctx.code_out_len += gen_code_size;
1334     tcg_ctx.search_out_len += search_size;
1335 #endif
1336 
1337 #ifdef DEBUG_DISAS
1338     if (qemu_loglevel_mask(CPU_LOG_TB_OUT_ASM) &&
1339         qemu_log_in_addr_range(tb->pc)) {
1340         qemu_log_lock();
1341         qemu_log("OUT: [size=%d]\n", gen_code_size);
1342         if (tcg_ctx.data_gen_ptr) {
1343             size_t code_size = tcg_ctx.data_gen_ptr - tb->tc_ptr;
1344             size_t data_size = gen_code_size - code_size;
1345             size_t i;
1346 
1347             log_disas(tb->tc_ptr, code_size);
1348 
1349             for (i = 0; i < data_size; i += sizeof(tcg_target_ulong)) {
1350                 if (sizeof(tcg_target_ulong) == 8) {
1351                     qemu_log("0x%08" PRIxPTR ":  .quad  0x%016" PRIx64 "\n",
1352                              (uintptr_t)tcg_ctx.data_gen_ptr + i,
1353                              *(uint64_t *)(tcg_ctx.data_gen_ptr + i));
1354                 } else {
1355                     qemu_log("0x%08" PRIxPTR ":  .long  0x%08x\n",
1356                              (uintptr_t)tcg_ctx.data_gen_ptr + i,
1357                              *(uint32_t *)(tcg_ctx.data_gen_ptr + i));
1358                 }
1359             }
1360         } else {
1361             log_disas(tb->tc_ptr, gen_code_size);
1362         }
1363         qemu_log("\n");
1364         qemu_log_flush();
1365         qemu_log_unlock();
1366     }
1367 #endif
1368 
1369     tcg_ctx.code_gen_ptr = (void *)
1370         ROUND_UP((uintptr_t)gen_code_buf + gen_code_size + search_size,
1371                  CODE_GEN_ALIGN);
1372 
1373     /* init jump list */
1374     assert(((uintptr_t)tb & 3) == 0);
1375     tb->jmp_list_first = (uintptr_t)tb | 2;
1376     tb->jmp_list_next[0] = (uintptr_t)NULL;
1377     tb->jmp_list_next[1] = (uintptr_t)NULL;
1378 
1379     /* init original jump addresses wich has been set during tcg_gen_code() */
1380     if (tb->jmp_reset_offset[0] != TB_JMP_RESET_OFFSET_INVALID) {
1381         tb_reset_jump(tb, 0);
1382     }
1383     if (tb->jmp_reset_offset[1] != TB_JMP_RESET_OFFSET_INVALID) {
1384         tb_reset_jump(tb, 1);
1385     }
1386 
1387     /* check next page if needed */
1388     virt_page2 = (pc + tb->size - 1) & TARGET_PAGE_MASK;
1389     phys_page2 = -1;
1390     if ((pc & TARGET_PAGE_MASK) != virt_page2) {
1391         phys_page2 = get_page_addr_code(env, virt_page2);
1392     }
1393     /* As long as consistency of the TB stuff is provided by tb_lock in user
1394      * mode and is implicit in single-threaded softmmu emulation, no explicit
1395      * memory barrier is required before tb_link_page() makes the TB visible
1396      * through the physical hash table and physical page list.
1397      */
1398     tb_link_page(tb, phys_pc, phys_page2);
1399     return tb;
1400 }
1401 
1402 /*
1403  * Invalidate all TBs which intersect with the target physical address range
1404  * [start;end[. NOTE: start and end may refer to *different* physical pages.
1405  * 'is_cpu_write_access' should be true if called from a real cpu write
1406  * access: the virtual CPU will exit the current TB if code is modified inside
1407  * this TB.
1408  *
1409  * Called with mmap_lock held for user-mode emulation, grabs tb_lock
1410  * Called with tb_lock held for system-mode emulation
1411  */
1412 static void tb_invalidate_phys_range_1(tb_page_addr_t start, tb_page_addr_t end)
1413 {
1414     while (start < end) {
1415         tb_invalidate_phys_page_range(start, end, 0);
1416         start &= TARGET_PAGE_MASK;
1417         start += TARGET_PAGE_SIZE;
1418     }
1419 }
1420 
1421 #ifdef CONFIG_SOFTMMU
1422 void tb_invalidate_phys_range(tb_page_addr_t start, tb_page_addr_t end)
1423 {
1424     assert_tb_locked();
1425     tb_invalidate_phys_range_1(start, end);
1426 }
1427 #else
1428 void tb_invalidate_phys_range(tb_page_addr_t start, tb_page_addr_t end)
1429 {
1430     assert_memory_lock();
1431     tb_lock();
1432     tb_invalidate_phys_range_1(start, end);
1433     tb_unlock();
1434 }
1435 #endif
1436 /*
1437  * Invalidate all TBs which intersect with the target physical address range
1438  * [start;end[. NOTE: start and end must refer to the *same* physical page.
1439  * 'is_cpu_write_access' should be true if called from a real cpu write
1440  * access: the virtual CPU will exit the current TB if code is modified inside
1441  * this TB.
1442  *
1443  * Called with tb_lock/mmap_lock held for user-mode emulation
1444  * Called with tb_lock held for system-mode emulation
1445  */
1446 void tb_invalidate_phys_page_range(tb_page_addr_t start, tb_page_addr_t end,
1447                                    int is_cpu_write_access)
1448 {
1449     TranslationBlock *tb, *tb_next;
1450 #if defined(TARGET_HAS_PRECISE_SMC)
1451     CPUState *cpu = current_cpu;
1452     CPUArchState *env = NULL;
1453 #endif
1454     tb_page_addr_t tb_start, tb_end;
1455     PageDesc *p;
1456     int n;
1457 #ifdef TARGET_HAS_PRECISE_SMC
1458     int current_tb_not_found = is_cpu_write_access;
1459     TranslationBlock *current_tb = NULL;
1460     int current_tb_modified = 0;
1461     target_ulong current_pc = 0;
1462     target_ulong current_cs_base = 0;
1463     uint32_t current_flags = 0;
1464 #endif /* TARGET_HAS_PRECISE_SMC */
1465 
1466     assert_memory_lock();
1467     assert_tb_locked();
1468 
1469     p = page_find(start >> TARGET_PAGE_BITS);
1470     if (!p) {
1471         return;
1472     }
1473 #if defined(TARGET_HAS_PRECISE_SMC)
1474     if (cpu != NULL) {
1475         env = cpu->env_ptr;
1476     }
1477 #endif
1478 
1479     /* we remove all the TBs in the range [start, end[ */
1480     /* XXX: see if in some cases it could be faster to invalidate all
1481        the code */
1482     tb = p->first_tb;
1483     while (tb != NULL) {
1484         n = (uintptr_t)tb & 3;
1485         tb = (TranslationBlock *)((uintptr_t)tb & ~3);
1486         tb_next = tb->page_next[n];
1487         /* NOTE: this is subtle as a TB may span two physical pages */
1488         if (n == 0) {
1489             /* NOTE: tb_end may be after the end of the page, but
1490                it is not a problem */
1491             tb_start = tb->page_addr[0] + (tb->pc & ~TARGET_PAGE_MASK);
1492             tb_end = tb_start + tb->size;
1493         } else {
1494             tb_start = tb->page_addr[1];
1495             tb_end = tb_start + ((tb->pc + tb->size) & ~TARGET_PAGE_MASK);
1496         }
1497         if (!(tb_end <= start || tb_start >= end)) {
1498 #ifdef TARGET_HAS_PRECISE_SMC
1499             if (current_tb_not_found) {
1500                 current_tb_not_found = 0;
1501                 current_tb = NULL;
1502                 if (cpu->mem_io_pc) {
1503                     /* now we have a real cpu fault */
1504                     current_tb = tb_find_pc(cpu->mem_io_pc);
1505                 }
1506             }
1507             if (current_tb == tb &&
1508                 (current_tb->cflags & CF_COUNT_MASK) != 1) {
1509                 /* If we are modifying the current TB, we must stop
1510                 its execution. We could be more precise by checking
1511                 that the modification is after the current PC, but it
1512                 would require a specialized function to partially
1513                 restore the CPU state */
1514 
1515                 current_tb_modified = 1;
1516                 cpu_restore_state_from_tb(cpu, current_tb, cpu->mem_io_pc);
1517                 cpu_get_tb_cpu_state(env, &current_pc, &current_cs_base,
1518                                      &current_flags);
1519             }
1520 #endif /* TARGET_HAS_PRECISE_SMC */
1521             tb_phys_invalidate(tb, -1);
1522         }
1523         tb = tb_next;
1524     }
1525 #if !defined(CONFIG_USER_ONLY)
1526     /* if no code remaining, no need to continue to use slow writes */
1527     if (!p->first_tb) {
1528         invalidate_page_bitmap(p);
1529         tlb_unprotect_code(start);
1530     }
1531 #endif
1532 #ifdef TARGET_HAS_PRECISE_SMC
1533     if (current_tb_modified) {
1534         /* we generate a block containing just the instruction
1535            modifying the memory. It will ensure that it cannot modify
1536            itself */
1537         tb_gen_code(cpu, current_pc, current_cs_base, current_flags, 1);
1538         cpu_loop_exit_noexc(cpu);
1539     }
1540 #endif
1541 }
1542 
1543 #ifdef CONFIG_SOFTMMU
1544 /* len must be <= 8 and start must be a multiple of len.
1545  * Called via softmmu_template.h when code areas are written to with
1546  * iothread mutex not held.
1547  */
1548 void tb_invalidate_phys_page_fast(tb_page_addr_t start, int len)
1549 {
1550     PageDesc *p;
1551 
1552 #if 0
1553     if (1) {
1554         qemu_log("modifying code at 0x%x size=%d EIP=%x PC=%08x\n",
1555                   cpu_single_env->mem_io_vaddr, len,
1556                   cpu_single_env->eip,
1557                   cpu_single_env->eip +
1558                   (intptr_t)cpu_single_env->segs[R_CS].base);
1559     }
1560 #endif
1561     assert_memory_lock();
1562 
1563     p = page_find(start >> TARGET_PAGE_BITS);
1564     if (!p) {
1565         return;
1566     }
1567     if (!p->code_bitmap &&
1568         ++p->code_write_count >= SMC_BITMAP_USE_THRESHOLD) {
1569         /* build code bitmap.  FIXME: writes should be protected by
1570          * tb_lock, reads by tb_lock or RCU.
1571          */
1572         build_page_bitmap(p);
1573     }
1574     if (p->code_bitmap) {
1575         unsigned int nr;
1576         unsigned long b;
1577 
1578         nr = start & ~TARGET_PAGE_MASK;
1579         b = p->code_bitmap[BIT_WORD(nr)] >> (nr & (BITS_PER_LONG - 1));
1580         if (b & ((1 << len) - 1)) {
1581             goto do_invalidate;
1582         }
1583     } else {
1584     do_invalidate:
1585         tb_invalidate_phys_page_range(start, start + len, 1);
1586     }
1587 }
1588 #else
1589 /* Called with mmap_lock held. If pc is not 0 then it indicates the
1590  * host PC of the faulting store instruction that caused this invalidate.
1591  * Returns true if the caller needs to abort execution of the current
1592  * TB (because it was modified by this store and the guest CPU has
1593  * precise-SMC semantics).
1594  */
1595 static bool tb_invalidate_phys_page(tb_page_addr_t addr, uintptr_t pc)
1596 {
1597     TranslationBlock *tb;
1598     PageDesc *p;
1599     int n;
1600 #ifdef TARGET_HAS_PRECISE_SMC
1601     TranslationBlock *current_tb = NULL;
1602     CPUState *cpu = current_cpu;
1603     CPUArchState *env = NULL;
1604     int current_tb_modified = 0;
1605     target_ulong current_pc = 0;
1606     target_ulong current_cs_base = 0;
1607     uint32_t current_flags = 0;
1608 #endif
1609 
1610     assert_memory_lock();
1611 
1612     addr &= TARGET_PAGE_MASK;
1613     p = page_find(addr >> TARGET_PAGE_BITS);
1614     if (!p) {
1615         return false;
1616     }
1617 
1618     tb_lock();
1619     tb = p->first_tb;
1620 #ifdef TARGET_HAS_PRECISE_SMC
1621     if (tb && pc != 0) {
1622         current_tb = tb_find_pc(pc);
1623     }
1624     if (cpu != NULL) {
1625         env = cpu->env_ptr;
1626     }
1627 #endif
1628     while (tb != NULL) {
1629         n = (uintptr_t)tb & 3;
1630         tb = (TranslationBlock *)((uintptr_t)tb & ~3);
1631 #ifdef TARGET_HAS_PRECISE_SMC
1632         if (current_tb == tb &&
1633             (current_tb->cflags & CF_COUNT_MASK) != 1) {
1634                 /* If we are modifying the current TB, we must stop
1635                    its execution. We could be more precise by checking
1636                    that the modification is after the current PC, but it
1637                    would require a specialized function to partially
1638                    restore the CPU state */
1639 
1640             current_tb_modified = 1;
1641             cpu_restore_state_from_tb(cpu, current_tb, pc);
1642             cpu_get_tb_cpu_state(env, &current_pc, &current_cs_base,
1643                                  &current_flags);
1644         }
1645 #endif /* TARGET_HAS_PRECISE_SMC */
1646         tb_phys_invalidate(tb, addr);
1647         tb = tb->page_next[n];
1648     }
1649     p->first_tb = NULL;
1650 #ifdef TARGET_HAS_PRECISE_SMC
1651     if (current_tb_modified) {
1652         /* we generate a block containing just the instruction
1653            modifying the memory. It will ensure that it cannot modify
1654            itself */
1655         tb_gen_code(cpu, current_pc, current_cs_base, current_flags, 1);
1656         /* tb_lock will be reset after cpu_loop_exit_noexc longjmps
1657          * back into the cpu_exec loop. */
1658         return true;
1659     }
1660 #endif
1661     tb_unlock();
1662 
1663     return false;
1664 }
1665 #endif
1666 
1667 /* find the TB 'tb' such that tb[0].tc_ptr <= tc_ptr <
1668    tb[1].tc_ptr. Return NULL if not found */
1669 static TranslationBlock *tb_find_pc(uintptr_t tc_ptr)
1670 {
1671     int m_min, m_max, m;
1672     uintptr_t v;
1673     TranslationBlock *tb;
1674 
1675     if (tcg_ctx.tb_ctx.nb_tbs <= 0) {
1676         return NULL;
1677     }
1678     if (tc_ptr < (uintptr_t)tcg_ctx.code_gen_buffer ||
1679         tc_ptr >= (uintptr_t)tcg_ctx.code_gen_ptr) {
1680         return NULL;
1681     }
1682     /* binary search (cf Knuth) */
1683     m_min = 0;
1684     m_max = tcg_ctx.tb_ctx.nb_tbs - 1;
1685     while (m_min <= m_max) {
1686         m = (m_min + m_max) >> 1;
1687         tb = tcg_ctx.tb_ctx.tbs[m];
1688         v = (uintptr_t)tb->tc_ptr;
1689         if (v == tc_ptr) {
1690             return tb;
1691         } else if (tc_ptr < v) {
1692             m_max = m - 1;
1693         } else {
1694             m_min = m + 1;
1695         }
1696     }
1697     return tcg_ctx.tb_ctx.tbs[m_max];
1698 }
1699 
1700 #if !defined(CONFIG_USER_ONLY)
1701 void tb_invalidate_phys_addr(AddressSpace *as, hwaddr addr)
1702 {
1703     ram_addr_t ram_addr;
1704     MemoryRegion *mr;
1705     hwaddr l = 1;
1706 
1707     rcu_read_lock();
1708     mr = address_space_translate(as, addr, &addr, &l, false);
1709     if (!(memory_region_is_ram(mr)
1710           || memory_region_is_romd(mr))) {
1711         rcu_read_unlock();
1712         return;
1713     }
1714     ram_addr = memory_region_get_ram_addr(mr) + addr;
1715     tb_lock();
1716     tb_invalidate_phys_page_range(ram_addr, ram_addr + 1, 0);
1717     tb_unlock();
1718     rcu_read_unlock();
1719 }
1720 #endif /* !defined(CONFIG_USER_ONLY) */
1721 
1722 /* Called with tb_lock held.  */
1723 void tb_check_watchpoint(CPUState *cpu)
1724 {
1725     TranslationBlock *tb;
1726 
1727     tb = tb_find_pc(cpu->mem_io_pc);
1728     if (tb) {
1729         /* We can use retranslation to find the PC.  */
1730         cpu_restore_state_from_tb(cpu, tb, cpu->mem_io_pc);
1731         tb_phys_invalidate(tb, -1);
1732     } else {
1733         /* The exception probably happened in a helper.  The CPU state should
1734            have been saved before calling it. Fetch the PC from there.  */
1735         CPUArchState *env = cpu->env_ptr;
1736         target_ulong pc, cs_base;
1737         tb_page_addr_t addr;
1738         uint32_t flags;
1739 
1740         cpu_get_tb_cpu_state(env, &pc, &cs_base, &flags);
1741         addr = get_page_addr_code(env, pc);
1742         tb_invalidate_phys_range(addr, addr + 1);
1743     }
1744 }
1745 
1746 #ifndef CONFIG_USER_ONLY
1747 /* in deterministic execution mode, instructions doing device I/Os
1748  * must be at the end of the TB.
1749  *
1750  * Called by softmmu_template.h, with iothread mutex not held.
1751  */
1752 void cpu_io_recompile(CPUState *cpu, uintptr_t retaddr)
1753 {
1754 #if defined(TARGET_MIPS) || defined(TARGET_SH4)
1755     CPUArchState *env = cpu->env_ptr;
1756 #endif
1757     TranslationBlock *tb;
1758     uint32_t n, cflags;
1759     target_ulong pc, cs_base;
1760     uint32_t flags;
1761 
1762     tb_lock();
1763     tb = tb_find_pc(retaddr);
1764     if (!tb) {
1765         cpu_abort(cpu, "cpu_io_recompile: could not find TB for pc=%p",
1766                   (void *)retaddr);
1767     }
1768     n = cpu->icount_decr.u16.low + tb->icount;
1769     cpu_restore_state_from_tb(cpu, tb, retaddr);
1770     /* Calculate how many instructions had been executed before the fault
1771        occurred.  */
1772     n = n - cpu->icount_decr.u16.low;
1773     /* Generate a new TB ending on the I/O insn.  */
1774     n++;
1775     /* On MIPS and SH, delay slot instructions can only be restarted if
1776        they were already the first instruction in the TB.  If this is not
1777        the first instruction in a TB then re-execute the preceding
1778        branch.  */
1779 #if defined(TARGET_MIPS)
1780     if ((env->hflags & MIPS_HFLAG_BMASK) != 0 && n > 1) {
1781         env->active_tc.PC -= (env->hflags & MIPS_HFLAG_B16 ? 2 : 4);
1782         cpu->icount_decr.u16.low++;
1783         env->hflags &= ~MIPS_HFLAG_BMASK;
1784     }
1785 #elif defined(TARGET_SH4)
1786     if ((env->flags & ((DELAY_SLOT | DELAY_SLOT_CONDITIONAL))) != 0
1787             && n > 1) {
1788         env->pc -= 2;
1789         cpu->icount_decr.u16.low++;
1790         env->flags &= ~(DELAY_SLOT | DELAY_SLOT_CONDITIONAL);
1791     }
1792 #endif
1793     /* This should never happen.  */
1794     if (n > CF_COUNT_MASK) {
1795         cpu_abort(cpu, "TB too big during recompile");
1796     }
1797 
1798     cflags = n | CF_LAST_IO;
1799     pc = tb->pc;
1800     cs_base = tb->cs_base;
1801     flags = tb->flags;
1802     tb_phys_invalidate(tb, -1);
1803     if (tb->cflags & CF_NOCACHE) {
1804         if (tb->orig_tb) {
1805             /* Invalidate original TB if this TB was generated in
1806              * cpu_exec_nocache() */
1807             tb_phys_invalidate(tb->orig_tb, -1);
1808         }
1809         tb_free(tb);
1810     }
1811     /* FIXME: In theory this could raise an exception.  In practice
1812        we have already translated the block once so it's probably ok.  */
1813     tb_gen_code(cpu, pc, cs_base, flags, cflags);
1814 
1815     /* TODO: If env->pc != tb->pc (i.e. the faulting instruction was not
1816      * the first in the TB) then we end up generating a whole new TB and
1817      *  repeating the fault, which is horribly inefficient.
1818      *  Better would be to execute just this insn uncached, or generate a
1819      *  second new TB.
1820      *
1821      * cpu_loop_exit_noexc will longjmp back to cpu_exec where the
1822      * tb_lock gets reset.
1823      */
1824     cpu_loop_exit_noexc(cpu);
1825 }
1826 
1827 static void tb_jmp_cache_clear_page(CPUState *cpu, target_ulong page_addr)
1828 {
1829     unsigned int i, i0 = tb_jmp_cache_hash_page(page_addr);
1830 
1831     for (i = 0; i < TB_JMP_PAGE_SIZE; i++) {
1832         atomic_set(&cpu->tb_jmp_cache[i0 + i], NULL);
1833     }
1834 }
1835 
1836 void tb_flush_jmp_cache(CPUState *cpu, target_ulong addr)
1837 {
1838     /* Discard jump cache entries for any tb which might potentially
1839        overlap the flushed page.  */
1840     tb_jmp_cache_clear_page(cpu, addr - TARGET_PAGE_SIZE);
1841     tb_jmp_cache_clear_page(cpu, addr);
1842 }
1843 
1844 static void print_qht_statistics(FILE *f, fprintf_function cpu_fprintf,
1845                                  struct qht_stats hst)
1846 {
1847     uint32_t hgram_opts;
1848     size_t hgram_bins;
1849     char *hgram;
1850 
1851     if (!hst.head_buckets) {
1852         return;
1853     }
1854     cpu_fprintf(f, "TB hash buckets     %zu/%zu (%0.2f%% head buckets used)\n",
1855                 hst.used_head_buckets, hst.head_buckets,
1856                 (double)hst.used_head_buckets / hst.head_buckets * 100);
1857 
1858     hgram_opts =  QDIST_PR_BORDER | QDIST_PR_LABELS;
1859     hgram_opts |= QDIST_PR_100X   | QDIST_PR_PERCENT;
1860     if (qdist_xmax(&hst.occupancy) - qdist_xmin(&hst.occupancy) == 1) {
1861         hgram_opts |= QDIST_PR_NODECIMAL;
1862     }
1863     hgram = qdist_pr(&hst.occupancy, 10, hgram_opts);
1864     cpu_fprintf(f, "TB hash occupancy   %0.2f%% avg chain occ. Histogram: %s\n",
1865                 qdist_avg(&hst.occupancy) * 100, hgram);
1866     g_free(hgram);
1867 
1868     hgram_opts = QDIST_PR_BORDER | QDIST_PR_LABELS;
1869     hgram_bins = qdist_xmax(&hst.chain) - qdist_xmin(&hst.chain);
1870     if (hgram_bins > 10) {
1871         hgram_bins = 10;
1872     } else {
1873         hgram_bins = 0;
1874         hgram_opts |= QDIST_PR_NODECIMAL | QDIST_PR_NOBINRANGE;
1875     }
1876     hgram = qdist_pr(&hst.chain, hgram_bins, hgram_opts);
1877     cpu_fprintf(f, "TB hash avg chain   %0.3f buckets. Histogram: %s\n",
1878                 qdist_avg(&hst.chain), hgram);
1879     g_free(hgram);
1880 }
1881 
1882 void dump_exec_info(FILE *f, fprintf_function cpu_fprintf)
1883 {
1884     int i, target_code_size, max_target_code_size;
1885     int direct_jmp_count, direct_jmp2_count, cross_page;
1886     TranslationBlock *tb;
1887     struct qht_stats hst;
1888 
1889     tb_lock();
1890 
1891     target_code_size = 0;
1892     max_target_code_size = 0;
1893     cross_page = 0;
1894     direct_jmp_count = 0;
1895     direct_jmp2_count = 0;
1896     for (i = 0; i < tcg_ctx.tb_ctx.nb_tbs; i++) {
1897         tb = tcg_ctx.tb_ctx.tbs[i];
1898         target_code_size += tb->size;
1899         if (tb->size > max_target_code_size) {
1900             max_target_code_size = tb->size;
1901         }
1902         if (tb->page_addr[1] != -1) {
1903             cross_page++;
1904         }
1905         if (tb->jmp_reset_offset[0] != TB_JMP_RESET_OFFSET_INVALID) {
1906             direct_jmp_count++;
1907             if (tb->jmp_reset_offset[1] != TB_JMP_RESET_OFFSET_INVALID) {
1908                 direct_jmp2_count++;
1909             }
1910         }
1911     }
1912     /* XXX: avoid using doubles ? */
1913     cpu_fprintf(f, "Translation buffer state:\n");
1914     cpu_fprintf(f, "gen code size       %td/%zd\n",
1915                 tcg_ctx.code_gen_ptr - tcg_ctx.code_gen_buffer,
1916                 tcg_ctx.code_gen_highwater - tcg_ctx.code_gen_buffer);
1917     cpu_fprintf(f, "TB count            %d\n", tcg_ctx.tb_ctx.nb_tbs);
1918     cpu_fprintf(f, "TB avg target size  %d max=%d bytes\n",
1919             tcg_ctx.tb_ctx.nb_tbs ? target_code_size /
1920                     tcg_ctx.tb_ctx.nb_tbs : 0,
1921             max_target_code_size);
1922     cpu_fprintf(f, "TB avg host size    %td bytes (expansion ratio: %0.1f)\n",
1923             tcg_ctx.tb_ctx.nb_tbs ? (tcg_ctx.code_gen_ptr -
1924                                      tcg_ctx.code_gen_buffer) /
1925                                      tcg_ctx.tb_ctx.nb_tbs : 0,
1926                 target_code_size ? (double) (tcg_ctx.code_gen_ptr -
1927                                              tcg_ctx.code_gen_buffer) /
1928                                              target_code_size : 0);
1929     cpu_fprintf(f, "cross page TB count %d (%d%%)\n", cross_page,
1930             tcg_ctx.tb_ctx.nb_tbs ? (cross_page * 100) /
1931                                     tcg_ctx.tb_ctx.nb_tbs : 0);
1932     cpu_fprintf(f, "direct jump count   %d (%d%%) (2 jumps=%d %d%%)\n",
1933                 direct_jmp_count,
1934                 tcg_ctx.tb_ctx.nb_tbs ? (direct_jmp_count * 100) /
1935                         tcg_ctx.tb_ctx.nb_tbs : 0,
1936                 direct_jmp2_count,
1937                 tcg_ctx.tb_ctx.nb_tbs ? (direct_jmp2_count * 100) /
1938                         tcg_ctx.tb_ctx.nb_tbs : 0);
1939 
1940     qht_statistics_init(&tcg_ctx.tb_ctx.htable, &hst);
1941     print_qht_statistics(f, cpu_fprintf, hst);
1942     qht_statistics_destroy(&hst);
1943 
1944     cpu_fprintf(f, "\nStatistics:\n");
1945     cpu_fprintf(f, "TB flush count      %u\n",
1946             atomic_read(&tcg_ctx.tb_ctx.tb_flush_count));
1947     cpu_fprintf(f, "TB invalidate count %d\n",
1948             tcg_ctx.tb_ctx.tb_phys_invalidate_count);
1949     cpu_fprintf(f, "TLB flush count     %zu\n", tlb_flush_count());
1950     tcg_dump_info(f, cpu_fprintf);
1951 
1952     tb_unlock();
1953 }
1954 
1955 void dump_opcount_info(FILE *f, fprintf_function cpu_fprintf)
1956 {
1957     tcg_dump_op_count(f, cpu_fprintf);
1958 }
1959 
1960 #else /* CONFIG_USER_ONLY */
1961 
1962 void cpu_interrupt(CPUState *cpu, int mask)
1963 {
1964     g_assert(qemu_mutex_iothread_locked());
1965     cpu->interrupt_request |= mask;
1966     cpu->icount_decr.u16.high = -1;
1967 }
1968 
1969 /*
1970  * Walks guest process memory "regions" one by one
1971  * and calls callback function 'fn' for each region.
1972  */
1973 struct walk_memory_regions_data {
1974     walk_memory_regions_fn fn;
1975     void *priv;
1976     target_ulong start;
1977     int prot;
1978 };
1979 
1980 static int walk_memory_regions_end(struct walk_memory_regions_data *data,
1981                                    target_ulong end, int new_prot)
1982 {
1983     if (data->start != -1u) {
1984         int rc = data->fn(data->priv, data->start, end, data->prot);
1985         if (rc != 0) {
1986             return rc;
1987         }
1988     }
1989 
1990     data->start = (new_prot ? end : -1u);
1991     data->prot = new_prot;
1992 
1993     return 0;
1994 }
1995 
1996 static int walk_memory_regions_1(struct walk_memory_regions_data *data,
1997                                  target_ulong base, int level, void **lp)
1998 {
1999     target_ulong pa;
2000     int i, rc;
2001 
2002     if (*lp == NULL) {
2003         return walk_memory_regions_end(data, base, 0);
2004     }
2005 
2006     if (level == 0) {
2007         PageDesc *pd = *lp;
2008 
2009         for (i = 0; i < V_L2_SIZE; ++i) {
2010             int prot = pd[i].flags;
2011 
2012             pa = base | (i << TARGET_PAGE_BITS);
2013             if (prot != data->prot) {
2014                 rc = walk_memory_regions_end(data, pa, prot);
2015                 if (rc != 0) {
2016                     return rc;
2017                 }
2018             }
2019         }
2020     } else {
2021         void **pp = *lp;
2022 
2023         for (i = 0; i < V_L2_SIZE; ++i) {
2024             pa = base | ((target_ulong)i <<
2025                 (TARGET_PAGE_BITS + V_L2_BITS * level));
2026             rc = walk_memory_regions_1(data, pa, level - 1, pp + i);
2027             if (rc != 0) {
2028                 return rc;
2029             }
2030         }
2031     }
2032 
2033     return 0;
2034 }
2035 
2036 int walk_memory_regions(void *priv, walk_memory_regions_fn fn)
2037 {
2038     struct walk_memory_regions_data data;
2039     uintptr_t i, l1_sz = v_l1_size;
2040 
2041     data.fn = fn;
2042     data.priv = priv;
2043     data.start = -1u;
2044     data.prot = 0;
2045 
2046     for (i = 0; i < l1_sz; i++) {
2047         target_ulong base = i << (v_l1_shift + TARGET_PAGE_BITS);
2048         int rc = walk_memory_regions_1(&data, base, v_l2_levels, l1_map + i);
2049         if (rc != 0) {
2050             return rc;
2051         }
2052     }
2053 
2054     return walk_memory_regions_end(&data, 0, 0);
2055 }
2056 
2057 static int dump_region(void *priv, target_ulong start,
2058     target_ulong end, unsigned long prot)
2059 {
2060     FILE *f = (FILE *)priv;
2061 
2062     (void) fprintf(f, TARGET_FMT_lx"-"TARGET_FMT_lx
2063         " "TARGET_FMT_lx" %c%c%c\n",
2064         start, end, end - start,
2065         ((prot & PAGE_READ) ? 'r' : '-'),
2066         ((prot & PAGE_WRITE) ? 'w' : '-'),
2067         ((prot & PAGE_EXEC) ? 'x' : '-'));
2068 
2069     return 0;
2070 }
2071 
2072 /* dump memory mappings */
2073 void page_dump(FILE *f)
2074 {
2075     const int length = sizeof(target_ulong) * 2;
2076     (void) fprintf(f, "%-*s %-*s %-*s %s\n",
2077             length, "start", length, "end", length, "size", "prot");
2078     walk_memory_regions(f, dump_region);
2079 }
2080 
2081 int page_get_flags(target_ulong address)
2082 {
2083     PageDesc *p;
2084 
2085     p = page_find(address >> TARGET_PAGE_BITS);
2086     if (!p) {
2087         return 0;
2088     }
2089     return p->flags;
2090 }
2091 
2092 /* Modify the flags of a page and invalidate the code if necessary.
2093    The flag PAGE_WRITE_ORG is positioned automatically depending
2094    on PAGE_WRITE.  The mmap_lock should already be held.  */
2095 void page_set_flags(target_ulong start, target_ulong end, int flags)
2096 {
2097     target_ulong addr, len;
2098 
2099     /* This function should never be called with addresses outside the
2100        guest address space.  If this assert fires, it probably indicates
2101        a missing call to h2g_valid.  */
2102 #if TARGET_ABI_BITS > L1_MAP_ADDR_SPACE_BITS
2103     assert(end < ((target_ulong)1 << L1_MAP_ADDR_SPACE_BITS));
2104 #endif
2105     assert(start < end);
2106     assert_memory_lock();
2107 
2108     start = start & TARGET_PAGE_MASK;
2109     end = TARGET_PAGE_ALIGN(end);
2110 
2111     if (flags & PAGE_WRITE) {
2112         flags |= PAGE_WRITE_ORG;
2113     }
2114 
2115     for (addr = start, len = end - start;
2116          len != 0;
2117          len -= TARGET_PAGE_SIZE, addr += TARGET_PAGE_SIZE) {
2118         PageDesc *p = page_find_alloc(addr >> TARGET_PAGE_BITS, 1);
2119 
2120         /* If the write protection bit is set, then we invalidate
2121            the code inside.  */
2122         if (!(p->flags & PAGE_WRITE) &&
2123             (flags & PAGE_WRITE) &&
2124             p->first_tb) {
2125             tb_invalidate_phys_page(addr, 0);
2126         }
2127         p->flags = flags;
2128     }
2129 }
2130 
2131 int page_check_range(target_ulong start, target_ulong len, int flags)
2132 {
2133     PageDesc *p;
2134     target_ulong end;
2135     target_ulong addr;
2136 
2137     /* This function should never be called with addresses outside the
2138        guest address space.  If this assert fires, it probably indicates
2139        a missing call to h2g_valid.  */
2140 #if TARGET_ABI_BITS > L1_MAP_ADDR_SPACE_BITS
2141     assert(start < ((target_ulong)1 << L1_MAP_ADDR_SPACE_BITS));
2142 #endif
2143 
2144     if (len == 0) {
2145         return 0;
2146     }
2147     if (start + len - 1 < start) {
2148         /* We've wrapped around.  */
2149         return -1;
2150     }
2151 
2152     /* must do before we loose bits in the next step */
2153     end = TARGET_PAGE_ALIGN(start + len);
2154     start = start & TARGET_PAGE_MASK;
2155 
2156     for (addr = start, len = end - start;
2157          len != 0;
2158          len -= TARGET_PAGE_SIZE, addr += TARGET_PAGE_SIZE) {
2159         p = page_find(addr >> TARGET_PAGE_BITS);
2160         if (!p) {
2161             return -1;
2162         }
2163         if (!(p->flags & PAGE_VALID)) {
2164             return -1;
2165         }
2166 
2167         if ((flags & PAGE_READ) && !(p->flags & PAGE_READ)) {
2168             return -1;
2169         }
2170         if (flags & PAGE_WRITE) {
2171             if (!(p->flags & PAGE_WRITE_ORG)) {
2172                 return -1;
2173             }
2174             /* unprotect the page if it was put read-only because it
2175                contains translated code */
2176             if (!(p->flags & PAGE_WRITE)) {
2177                 if (!page_unprotect(addr, 0)) {
2178                     return -1;
2179                 }
2180             }
2181         }
2182     }
2183     return 0;
2184 }
2185 
2186 /* called from signal handler: invalidate the code and unprotect the
2187  * page. Return 0 if the fault was not handled, 1 if it was handled,
2188  * and 2 if it was handled but the caller must cause the TB to be
2189  * immediately exited. (We can only return 2 if the 'pc' argument is
2190  * non-zero.)
2191  */
2192 int page_unprotect(target_ulong address, uintptr_t pc)
2193 {
2194     unsigned int prot;
2195     bool current_tb_invalidated;
2196     PageDesc *p;
2197     target_ulong host_start, host_end, addr;
2198 
2199     /* Technically this isn't safe inside a signal handler.  However we
2200        know this only ever happens in a synchronous SEGV handler, so in
2201        practice it seems to be ok.  */
2202     mmap_lock();
2203 
2204     p = page_find(address >> TARGET_PAGE_BITS);
2205     if (!p) {
2206         mmap_unlock();
2207         return 0;
2208     }
2209 
2210     /* if the page was really writable, then we change its
2211        protection back to writable */
2212     if ((p->flags & PAGE_WRITE_ORG) && !(p->flags & PAGE_WRITE)) {
2213         host_start = address & qemu_host_page_mask;
2214         host_end = host_start + qemu_host_page_size;
2215 
2216         prot = 0;
2217         current_tb_invalidated = false;
2218         for (addr = host_start ; addr < host_end ; addr += TARGET_PAGE_SIZE) {
2219             p = page_find(addr >> TARGET_PAGE_BITS);
2220             p->flags |= PAGE_WRITE;
2221             prot |= p->flags;
2222 
2223             /* and since the content will be modified, we must invalidate
2224                the corresponding translated code. */
2225             current_tb_invalidated |= tb_invalidate_phys_page(addr, pc);
2226 #ifdef DEBUG_TB_CHECK
2227             tb_invalidate_check(addr);
2228 #endif
2229         }
2230         mprotect((void *)g2h(host_start), qemu_host_page_size,
2231                  prot & PAGE_BITS);
2232 
2233         mmap_unlock();
2234         /* If current TB was invalidated return to main loop */
2235         return current_tb_invalidated ? 2 : 1;
2236     }
2237     mmap_unlock();
2238     return 0;
2239 }
2240 #endif /* CONFIG_USER_ONLY */
2241 
2242 /* This is a wrapper for common code that can not use CONFIG_SOFTMMU */
2243 void tcg_flush_softmmu_tlb(CPUState *cs)
2244 {
2245 #ifdef CONFIG_SOFTMMU
2246     tlb_flush(cs);
2247 #endif
2248 }
2249