xref: /openbmc/qemu/accel/tcg/translate-all.c (revision 84f1c148)
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 #if !defined(CONFIG_USER_ONLY)
69 /* TB consistency checks only implemented for usermode emulation.  */
70 #undef DEBUG_TB_CHECK
71 #endif
72 
73 /* Access to the various translations structures need to be serialised via locks
74  * for consistency. This is automatic for SoftMMU based system
75  * emulation due to its single threaded nature. In user-mode emulation
76  * access to the memory related structures are protected with the
77  * mmap_lock.
78  */
79 #ifdef CONFIG_SOFTMMU
80 #define assert_memory_lock() tcg_debug_assert(have_tb_lock)
81 #else
82 #define assert_memory_lock() tcg_debug_assert(have_mmap_lock())
83 #endif
84 
85 #define SMC_BITMAP_USE_THRESHOLD 10
86 
87 typedef struct PageDesc {
88     /* list of TBs intersecting this ram page */
89     TranslationBlock *first_tb;
90 #ifdef CONFIG_SOFTMMU
91     /* in order to optimize self modifying code, we count the number
92        of lookups we do to a given page to use a bitmap */
93     unsigned int code_write_count;
94     unsigned long *code_bitmap;
95 #else
96     unsigned long flags;
97 #endif
98 } PageDesc;
99 
100 /* In system mode we want L1_MAP to be based on ram offsets,
101    while in user mode we want it to be based on virtual addresses.  */
102 #if !defined(CONFIG_USER_ONLY)
103 #if HOST_LONG_BITS < TARGET_PHYS_ADDR_SPACE_BITS
104 # define L1_MAP_ADDR_SPACE_BITS  HOST_LONG_BITS
105 #else
106 # define L1_MAP_ADDR_SPACE_BITS  TARGET_PHYS_ADDR_SPACE_BITS
107 #endif
108 #else
109 # define L1_MAP_ADDR_SPACE_BITS  TARGET_VIRT_ADDR_SPACE_BITS
110 #endif
111 
112 /* Size of the L2 (and L3, etc) page tables.  */
113 #define V_L2_BITS 10
114 #define V_L2_SIZE (1 << V_L2_BITS)
115 
116 /* Make sure all possible CPU event bits fit in tb->trace_vcpu_dstate */
117 QEMU_BUILD_BUG_ON(CPU_TRACE_DSTATE_MAX_EVENTS >
118                   sizeof(((TranslationBlock *)0)->trace_vcpu_dstate)
119                   * BITS_PER_BYTE);
120 
121 /*
122  * L1 Mapping properties
123  */
124 static int v_l1_size;
125 static int v_l1_shift;
126 static int v_l2_levels;
127 
128 /* The bottom level has pointers to PageDesc, and is indexed by
129  * anything from 4 to (V_L2_BITS + 3) bits, depending on target page size.
130  */
131 #define V_L1_MIN_BITS 4
132 #define V_L1_MAX_BITS (V_L2_BITS + 3)
133 #define V_L1_MAX_SIZE (1 << V_L1_MAX_BITS)
134 
135 static void *l1_map[V_L1_MAX_SIZE];
136 
137 /* code generation context */
138 TCGContext tcg_ctx;
139 bool parallel_cpus;
140 
141 /* translation block context */
142 static __thread int have_tb_lock;
143 
144 static void page_table_config_init(void)
145 {
146     uint32_t v_l1_bits;
147 
148     assert(TARGET_PAGE_BITS);
149     /* The bits remaining after N lower levels of page tables.  */
150     v_l1_bits = (L1_MAP_ADDR_SPACE_BITS - TARGET_PAGE_BITS) % V_L2_BITS;
151     if (v_l1_bits < V_L1_MIN_BITS) {
152         v_l1_bits += V_L2_BITS;
153     }
154 
155     v_l1_size = 1 << v_l1_bits;
156     v_l1_shift = L1_MAP_ADDR_SPACE_BITS - TARGET_PAGE_BITS - v_l1_bits;
157     v_l2_levels = v_l1_shift / V_L2_BITS - 1;
158 
159     assert(v_l1_bits <= V_L1_MAX_BITS);
160     assert(v_l1_shift % V_L2_BITS == 0);
161     assert(v_l2_levels >= 0);
162 }
163 
164 #define assert_tb_locked() tcg_debug_assert(have_tb_lock)
165 #define assert_tb_unlocked() tcg_debug_assert(!have_tb_lock)
166 
167 void tb_lock(void)
168 {
169     assert_tb_unlocked();
170     qemu_mutex_lock(&tcg_ctx.tb_ctx.tb_lock);
171     have_tb_lock++;
172 }
173 
174 void tb_unlock(void)
175 {
176     assert_tb_locked();
177     have_tb_lock--;
178     qemu_mutex_unlock(&tcg_ctx.tb_ctx.tb_lock);
179 }
180 
181 void tb_lock_reset(void)
182 {
183     if (have_tb_lock) {
184         qemu_mutex_unlock(&tcg_ctx.tb_ctx.tb_lock);
185         have_tb_lock = 0;
186     }
187 }
188 
189 static TranslationBlock *tb_find_pc(uintptr_t tc_ptr);
190 
191 void cpu_gen_init(void)
192 {
193     tcg_context_init(&tcg_ctx);
194 }
195 
196 /* Encode VAL as a signed leb128 sequence at P.
197    Return P incremented past the encoded value.  */
198 static uint8_t *encode_sleb128(uint8_t *p, target_long val)
199 {
200     int more, byte;
201 
202     do {
203         byte = val & 0x7f;
204         val >>= 7;
205         more = !((val == 0 && (byte & 0x40) == 0)
206                  || (val == -1 && (byte & 0x40) != 0));
207         if (more) {
208             byte |= 0x80;
209         }
210         *p++ = byte;
211     } while (more);
212 
213     return p;
214 }
215 
216 /* Decode a signed leb128 sequence at *PP; increment *PP past the
217    decoded value.  Return the decoded value.  */
218 static target_long decode_sleb128(uint8_t **pp)
219 {
220     uint8_t *p = *pp;
221     target_long val = 0;
222     int byte, shift = 0;
223 
224     do {
225         byte = *p++;
226         val |= (target_ulong)(byte & 0x7f) << shift;
227         shift += 7;
228     } while (byte & 0x80);
229     if (shift < TARGET_LONG_BITS && (byte & 0x40)) {
230         val |= -(target_ulong)1 << shift;
231     }
232 
233     *pp = p;
234     return val;
235 }
236 
237 /* Encode the data collected about the instructions while compiling TB.
238    Place the data at BLOCK, and return the number of bytes consumed.
239 
240    The logical table consisits of TARGET_INSN_START_WORDS target_ulong's,
241    which come from the target's insn_start data, followed by a uintptr_t
242    which comes from the host pc of the end of the code implementing the insn.
243 
244    Each line of the table is encoded as sleb128 deltas from the previous
245    line.  The seed for the first line is { tb->pc, 0..., tb->tc_ptr }.
246    That is, the first column is seeded with the guest pc, the last column
247    with the host pc, and the middle columns with zeros.  */
248 
249 static int encode_search(TranslationBlock *tb, uint8_t *block)
250 {
251     uint8_t *highwater = tcg_ctx.code_gen_highwater;
252     uint8_t *p = block;
253     int i, j, n;
254 
255     tb->tc_search = block;
256 
257     for (i = 0, n = tb->icount; i < n; ++i) {
258         target_ulong prev;
259 
260         for (j = 0; j < TARGET_INSN_START_WORDS; ++j) {
261             if (i == 0) {
262                 prev = (j == 0 ? tb->pc : 0);
263             } else {
264                 prev = tcg_ctx.gen_insn_data[i - 1][j];
265             }
266             p = encode_sleb128(p, tcg_ctx.gen_insn_data[i][j] - prev);
267         }
268         prev = (i == 0 ? 0 : tcg_ctx.gen_insn_end_off[i - 1]);
269         p = encode_sleb128(p, tcg_ctx.gen_insn_end_off[i] - prev);
270 
271         /* Test for (pending) buffer overflow.  The assumption is that any
272            one row beginning below the high water mark cannot overrun
273            the buffer completely.  Thus we can test for overflow after
274            encoding a row without having to check during encoding.  */
275         if (unlikely(p > highwater)) {
276             return -1;
277         }
278     }
279 
280     return p - block;
281 }
282 
283 /* The cpu state corresponding to 'searched_pc' is restored.
284  * Called with tb_lock held.
285  */
286 static int cpu_restore_state_from_tb(CPUState *cpu, TranslationBlock *tb,
287                                      uintptr_t searched_pc)
288 {
289     target_ulong data[TARGET_INSN_START_WORDS] = { tb->pc };
290     uintptr_t host_pc = (uintptr_t)tb->tc_ptr;
291     CPUArchState *env = cpu->env_ptr;
292     uint8_t *p = tb->tc_search;
293     int i, j, num_insns = tb->icount;
294 #ifdef CONFIG_PROFILER
295     int64_t ti = profile_getclock();
296 #endif
297 
298     searched_pc -= GETPC_ADJ;
299 
300     if (searched_pc < host_pc) {
301         return -1;
302     }
303 
304     /* Reconstruct the stored insn data while looking for the point at
305        which the end of the insn exceeds the searched_pc.  */
306     for (i = 0; i < num_insns; ++i) {
307         for (j = 0; j < TARGET_INSN_START_WORDS; ++j) {
308             data[j] += decode_sleb128(&p);
309         }
310         host_pc += decode_sleb128(&p);
311         if (host_pc > searched_pc) {
312             goto found;
313         }
314     }
315     return -1;
316 
317  found:
318     if (tb->cflags & CF_USE_ICOUNT) {
319         assert(use_icount);
320         /* Reset the cycle counter to the start of the block.  */
321         cpu->icount_decr.u16.low += num_insns;
322         /* Clear the IO flag.  */
323         cpu->can_do_io = 0;
324     }
325     cpu->icount_decr.u16.low -= i;
326     restore_state_to_opc(env, tb, data);
327 
328 #ifdef CONFIG_PROFILER
329     tcg_ctx.restore_time += profile_getclock() - ti;
330     tcg_ctx.restore_count++;
331 #endif
332     return 0;
333 }
334 
335 bool cpu_restore_state(CPUState *cpu, uintptr_t retaddr)
336 {
337     TranslationBlock *tb;
338     bool r = false;
339 
340     /* A retaddr of zero is invalid so we really shouldn't have ended
341      * up here. The target code has likely forgotten to check retaddr
342      * != 0 before attempting to restore state. We return early to
343      * avoid blowing up on a recursive tb_lock(). The target must have
344      * previously survived a failed cpu_restore_state because
345      * tb_find_pc(0) would have failed anyway. It still should be
346      * fixed though.
347      */
348 
349     if (!retaddr) {
350         return r;
351     }
352 
353     tb_lock();
354     tb = tb_find_pc(retaddr);
355     if (tb) {
356         cpu_restore_state_from_tb(cpu, tb, retaddr);
357         if (tb->cflags & CF_NOCACHE) {
358             /* one-shot translation, invalidate it immediately */
359             tb_phys_invalidate(tb, -1);
360             tb_free(tb);
361         }
362         r = true;
363     }
364     tb_unlock();
365 
366     return r;
367 }
368 
369 static void page_init(void)
370 {
371     page_size_init();
372     page_table_config_init();
373 
374 #if defined(CONFIG_BSD) && defined(CONFIG_USER_ONLY)
375     {
376 #ifdef HAVE_KINFO_GETVMMAP
377         struct kinfo_vmentry *freep;
378         int i, cnt;
379 
380         freep = kinfo_getvmmap(getpid(), &cnt);
381         if (freep) {
382             mmap_lock();
383             for (i = 0; i < cnt; i++) {
384                 unsigned long startaddr, endaddr;
385 
386                 startaddr = freep[i].kve_start;
387                 endaddr = freep[i].kve_end;
388                 if (h2g_valid(startaddr)) {
389                     startaddr = h2g(startaddr) & TARGET_PAGE_MASK;
390 
391                     if (h2g_valid(endaddr)) {
392                         endaddr = h2g(endaddr);
393                         page_set_flags(startaddr, endaddr, PAGE_RESERVED);
394                     } else {
395 #if TARGET_ABI_BITS <= L1_MAP_ADDR_SPACE_BITS
396                         endaddr = ~0ul;
397                         page_set_flags(startaddr, endaddr, PAGE_RESERVED);
398 #endif
399                     }
400                 }
401             }
402             free(freep);
403             mmap_unlock();
404         }
405 #else
406         FILE *f;
407 
408         last_brk = (unsigned long)sbrk(0);
409 
410         f = fopen("/compat/linux/proc/self/maps", "r");
411         if (f) {
412             mmap_lock();
413 
414             do {
415                 unsigned long startaddr, endaddr;
416                 int n;
417 
418                 n = fscanf(f, "%lx-%lx %*[^\n]\n", &startaddr, &endaddr);
419 
420                 if (n == 2 && h2g_valid(startaddr)) {
421                     startaddr = h2g(startaddr) & TARGET_PAGE_MASK;
422 
423                     if (h2g_valid(endaddr)) {
424                         endaddr = h2g(endaddr);
425                     } else {
426                         endaddr = ~0ul;
427                     }
428                     page_set_flags(startaddr, endaddr, PAGE_RESERVED);
429                 }
430             } while (!feof(f));
431 
432             fclose(f);
433             mmap_unlock();
434         }
435 #endif
436     }
437 #endif
438 }
439 
440 /* If alloc=1:
441  * Called with tb_lock held for system emulation.
442  * Called with mmap_lock held for user-mode emulation.
443  */
444 static PageDesc *page_find_alloc(tb_page_addr_t index, int alloc)
445 {
446     PageDesc *pd;
447     void **lp;
448     int i;
449 
450     if (alloc) {
451         assert_memory_lock();
452     }
453 
454     /* Level 1.  Always allocated.  */
455     lp = l1_map + ((index >> v_l1_shift) & (v_l1_size - 1));
456 
457     /* Level 2..N-1.  */
458     for (i = v_l2_levels; i > 0; i--) {
459         void **p = atomic_rcu_read(lp);
460 
461         if (p == NULL) {
462             if (!alloc) {
463                 return NULL;
464             }
465             p = g_new0(void *, V_L2_SIZE);
466             atomic_rcu_set(lp, p);
467         }
468 
469         lp = p + ((index >> (i * V_L2_BITS)) & (V_L2_SIZE - 1));
470     }
471 
472     pd = atomic_rcu_read(lp);
473     if (pd == NULL) {
474         if (!alloc) {
475             return NULL;
476         }
477         pd = g_new0(PageDesc, V_L2_SIZE);
478         atomic_rcu_set(lp, pd);
479     }
480 
481     return pd + (index & (V_L2_SIZE - 1));
482 }
483 
484 static inline PageDesc *page_find(tb_page_addr_t index)
485 {
486     return page_find_alloc(index, 0);
487 }
488 
489 #if defined(CONFIG_USER_ONLY)
490 /* Currently it is not recommended to allocate big chunks of data in
491    user mode. It will change when a dedicated libc will be used.  */
492 /* ??? 64-bit hosts ought to have no problem mmaping data outside the
493    region in which the guest needs to run.  Revisit this.  */
494 #define USE_STATIC_CODE_GEN_BUFFER
495 #endif
496 
497 /* Minimum size of the code gen buffer.  This number is randomly chosen,
498    but not so small that we can't have a fair number of TB's live.  */
499 #define MIN_CODE_GEN_BUFFER_SIZE     (1024u * 1024)
500 
501 /* Maximum size of the code gen buffer we'd like to use.  Unless otherwise
502    indicated, this is constrained by the range of direct branches on the
503    host cpu, as used by the TCG implementation of goto_tb.  */
504 #if defined(__x86_64__)
505 # define MAX_CODE_GEN_BUFFER_SIZE  (2ul * 1024 * 1024 * 1024)
506 #elif defined(__sparc__)
507 # define MAX_CODE_GEN_BUFFER_SIZE  (2ul * 1024 * 1024 * 1024)
508 #elif defined(__powerpc64__)
509 # define MAX_CODE_GEN_BUFFER_SIZE  (2ul * 1024 * 1024 * 1024)
510 #elif defined(__powerpc__)
511 # define MAX_CODE_GEN_BUFFER_SIZE  (32u * 1024 * 1024)
512 #elif defined(__aarch64__)
513 # define MAX_CODE_GEN_BUFFER_SIZE  (2ul * 1024 * 1024 * 1024)
514 #elif defined(__s390x__)
515   /* We have a +- 4GB range on the branches; leave some slop.  */
516 # define MAX_CODE_GEN_BUFFER_SIZE  (3ul * 1024 * 1024 * 1024)
517 #elif defined(__mips__)
518   /* We have a 256MB branch region, but leave room to make sure the
519      main executable is also within that region.  */
520 # define MAX_CODE_GEN_BUFFER_SIZE  (128ul * 1024 * 1024)
521 #else
522 # define MAX_CODE_GEN_BUFFER_SIZE  ((size_t)-1)
523 #endif
524 
525 #define DEFAULT_CODE_GEN_BUFFER_SIZE_1 (32u * 1024 * 1024)
526 
527 #define DEFAULT_CODE_GEN_BUFFER_SIZE \
528   (DEFAULT_CODE_GEN_BUFFER_SIZE_1 < MAX_CODE_GEN_BUFFER_SIZE \
529    ? DEFAULT_CODE_GEN_BUFFER_SIZE_1 : MAX_CODE_GEN_BUFFER_SIZE)
530 
531 static inline size_t size_code_gen_buffer(size_t tb_size)
532 {
533     /* Size the buffer.  */
534     if (tb_size == 0) {
535 #ifdef USE_STATIC_CODE_GEN_BUFFER
536         tb_size = DEFAULT_CODE_GEN_BUFFER_SIZE;
537 #else
538         /* ??? Needs adjustments.  */
539         /* ??? If we relax the requirement that CONFIG_USER_ONLY use the
540            static buffer, we could size this on RESERVED_VA, on the text
541            segment size of the executable, or continue to use the default.  */
542         tb_size = (unsigned long)(ram_size / 4);
543 #endif
544     }
545     if (tb_size < MIN_CODE_GEN_BUFFER_SIZE) {
546         tb_size = MIN_CODE_GEN_BUFFER_SIZE;
547     }
548     if (tb_size > MAX_CODE_GEN_BUFFER_SIZE) {
549         tb_size = MAX_CODE_GEN_BUFFER_SIZE;
550     }
551     return tb_size;
552 }
553 
554 #ifdef __mips__
555 /* In order to use J and JAL within the code_gen_buffer, we require
556    that the buffer not cross a 256MB boundary.  */
557 static inline bool cross_256mb(void *addr, size_t size)
558 {
559     return ((uintptr_t)addr ^ ((uintptr_t)addr + size)) & ~0x0ffffffful;
560 }
561 
562 /* We weren't able to allocate a buffer without crossing that boundary,
563    so make do with the larger portion of the buffer that doesn't cross.
564    Returns the new base of the buffer, and adjusts code_gen_buffer_size.  */
565 static inline void *split_cross_256mb(void *buf1, size_t size1)
566 {
567     void *buf2 = (void *)(((uintptr_t)buf1 + size1) & ~0x0ffffffful);
568     size_t size2 = buf1 + size1 - buf2;
569 
570     size1 = buf2 - buf1;
571     if (size1 < size2) {
572         size1 = size2;
573         buf1 = buf2;
574     }
575 
576     tcg_ctx.code_gen_buffer_size = size1;
577     return buf1;
578 }
579 #endif
580 
581 #ifdef USE_STATIC_CODE_GEN_BUFFER
582 static uint8_t static_code_gen_buffer[DEFAULT_CODE_GEN_BUFFER_SIZE]
583     __attribute__((aligned(CODE_GEN_ALIGN)));
584 
585 # ifdef _WIN32
586 static inline void do_protect(void *addr, long size, int prot)
587 {
588     DWORD old_protect;
589     VirtualProtect(addr, size, prot, &old_protect);
590 }
591 
592 static inline void map_exec(void *addr, long size)
593 {
594     do_protect(addr, size, PAGE_EXECUTE_READWRITE);
595 }
596 
597 static inline void map_none(void *addr, long size)
598 {
599     do_protect(addr, size, PAGE_NOACCESS);
600 }
601 # else
602 static inline void do_protect(void *addr, long size, int prot)
603 {
604     uintptr_t start, end;
605 
606     start = (uintptr_t)addr;
607     start &= qemu_real_host_page_mask;
608 
609     end = (uintptr_t)addr + size;
610     end = ROUND_UP(end, qemu_real_host_page_size);
611 
612     mprotect((void *)start, end - start, prot);
613 }
614 
615 static inline void map_exec(void *addr, long size)
616 {
617     do_protect(addr, size, PROT_READ | PROT_WRITE | PROT_EXEC);
618 }
619 
620 static inline void map_none(void *addr, long size)
621 {
622     do_protect(addr, size, PROT_NONE);
623 }
624 # endif /* WIN32 */
625 
626 static inline void *alloc_code_gen_buffer(void)
627 {
628     void *buf = static_code_gen_buffer;
629     size_t full_size, size;
630 
631     /* The size of the buffer, rounded down to end on a page boundary.  */
632     full_size = (((uintptr_t)buf + sizeof(static_code_gen_buffer))
633                  & qemu_real_host_page_mask) - (uintptr_t)buf;
634 
635     /* Reserve a guard page.  */
636     size = full_size - qemu_real_host_page_size;
637 
638     /* Honor a command-line option limiting the size of the buffer.  */
639     if (size > tcg_ctx.code_gen_buffer_size) {
640         size = (((uintptr_t)buf + tcg_ctx.code_gen_buffer_size)
641                 & qemu_real_host_page_mask) - (uintptr_t)buf;
642     }
643     tcg_ctx.code_gen_buffer_size = size;
644 
645 #ifdef __mips__
646     if (cross_256mb(buf, size)) {
647         buf = split_cross_256mb(buf, size);
648         size = tcg_ctx.code_gen_buffer_size;
649     }
650 #endif
651 
652     map_exec(buf, size);
653     map_none(buf + size, qemu_real_host_page_size);
654     qemu_madvise(buf, size, QEMU_MADV_HUGEPAGE);
655 
656     return buf;
657 }
658 #elif defined(_WIN32)
659 static inline void *alloc_code_gen_buffer(void)
660 {
661     size_t size = tcg_ctx.code_gen_buffer_size;
662     void *buf1, *buf2;
663 
664     /* Perform the allocation in two steps, so that the guard page
665        is reserved but uncommitted.  */
666     buf1 = VirtualAlloc(NULL, size + qemu_real_host_page_size,
667                         MEM_RESERVE, PAGE_NOACCESS);
668     if (buf1 != NULL) {
669         buf2 = VirtualAlloc(buf1, size, MEM_COMMIT, PAGE_EXECUTE_READWRITE);
670         assert(buf1 == buf2);
671     }
672 
673     return buf1;
674 }
675 #else
676 static inline void *alloc_code_gen_buffer(void)
677 {
678     int flags = MAP_PRIVATE | MAP_ANONYMOUS;
679     uintptr_t start = 0;
680     size_t size = tcg_ctx.code_gen_buffer_size;
681     void *buf;
682 
683     /* Constrain the position of the buffer based on the host cpu.
684        Note that these addresses are chosen in concert with the
685        addresses assigned in the relevant linker script file.  */
686 # if defined(__PIE__) || defined(__PIC__)
687     /* Don't bother setting a preferred location if we're building
688        a position-independent executable.  We're more likely to get
689        an address near the main executable if we let the kernel
690        choose the address.  */
691 # elif defined(__x86_64__) && defined(MAP_32BIT)
692     /* Force the memory down into low memory with the executable.
693        Leave the choice of exact location with the kernel.  */
694     flags |= MAP_32BIT;
695     /* Cannot expect to map more than 800MB in low memory.  */
696     if (size > 800u * 1024 * 1024) {
697         tcg_ctx.code_gen_buffer_size = size = 800u * 1024 * 1024;
698     }
699 # elif defined(__sparc__)
700     start = 0x40000000ul;
701 # elif defined(__s390x__)
702     start = 0x90000000ul;
703 # elif defined(__mips__)
704 #  if _MIPS_SIM == _ABI64
705     start = 0x128000000ul;
706 #  else
707     start = 0x08000000ul;
708 #  endif
709 # endif
710 
711     buf = mmap((void *)start, size + qemu_real_host_page_size,
712                PROT_NONE, flags, -1, 0);
713     if (buf == MAP_FAILED) {
714         return NULL;
715     }
716 
717 #ifdef __mips__
718     if (cross_256mb(buf, size)) {
719         /* Try again, with the original still mapped, to avoid re-acquiring
720            that 256mb crossing.  This time don't specify an address.  */
721         size_t size2;
722         void *buf2 = mmap(NULL, size + qemu_real_host_page_size,
723                           PROT_NONE, flags, -1, 0);
724         switch ((int)(buf2 != MAP_FAILED)) {
725         case 1:
726             if (!cross_256mb(buf2, size)) {
727                 /* Success!  Use the new buffer.  */
728                 munmap(buf, size + qemu_real_host_page_size);
729                 break;
730             }
731             /* Failure.  Work with what we had.  */
732             munmap(buf2, size + qemu_real_host_page_size);
733             /* fallthru */
734         default:
735             /* Split the original buffer.  Free the smaller half.  */
736             buf2 = split_cross_256mb(buf, size);
737             size2 = tcg_ctx.code_gen_buffer_size;
738             if (buf == buf2) {
739                 munmap(buf + size2 + qemu_real_host_page_size, size - size2);
740             } else {
741                 munmap(buf, size - size2);
742             }
743             size = size2;
744             break;
745         }
746         buf = buf2;
747     }
748 #endif
749 
750     /* Make the final buffer accessible.  The guard page at the end
751        will remain inaccessible with PROT_NONE.  */
752     mprotect(buf, size, PROT_WRITE | PROT_READ | PROT_EXEC);
753 
754     /* Request large pages for the buffer.  */
755     qemu_madvise(buf, size, QEMU_MADV_HUGEPAGE);
756 
757     return buf;
758 }
759 #endif /* USE_STATIC_CODE_GEN_BUFFER, WIN32, POSIX */
760 
761 static inline void code_gen_alloc(size_t tb_size)
762 {
763     tcg_ctx.code_gen_buffer_size = size_code_gen_buffer(tb_size);
764     tcg_ctx.code_gen_buffer = alloc_code_gen_buffer();
765     if (tcg_ctx.code_gen_buffer == NULL) {
766         fprintf(stderr, "Could not allocate dynamic translator buffer\n");
767         exit(1);
768     }
769 
770     /* size this conservatively -- realloc later if needed */
771     tcg_ctx.tb_ctx.tbs_size =
772         tcg_ctx.code_gen_buffer_size / CODE_GEN_AVG_BLOCK_SIZE / 8;
773     if (unlikely(!tcg_ctx.tb_ctx.tbs_size)) {
774         tcg_ctx.tb_ctx.tbs_size = 64 * 1024;
775     }
776     tcg_ctx.tb_ctx.tbs = g_new(TranslationBlock *, tcg_ctx.tb_ctx.tbs_size);
777 
778     qemu_mutex_init(&tcg_ctx.tb_ctx.tb_lock);
779 }
780 
781 static void tb_htable_init(void)
782 {
783     unsigned int mode = QHT_MODE_AUTO_RESIZE;
784 
785     qht_init(&tcg_ctx.tb_ctx.htable, CODE_GEN_HTABLE_SIZE, mode);
786 }
787 
788 /* Must be called before using the QEMU cpus. 'tb_size' is the size
789    (in bytes) allocated to the translation buffer. Zero means default
790    size. */
791 void tcg_exec_init(unsigned long tb_size)
792 {
793     tcg_allowed = true;
794     cpu_gen_init();
795     page_init();
796     tb_htable_init();
797     code_gen_alloc(tb_size);
798 #if defined(CONFIG_SOFTMMU)
799     /* There's no guest base to take into account, so go ahead and
800        initialize the prologue now.  */
801     tcg_prologue_init(&tcg_ctx);
802 #endif
803 }
804 
805 /*
806  * Allocate a new translation block. Flush the translation buffer if
807  * too many translation blocks or too much generated code.
808  *
809  * Called with tb_lock held.
810  */
811 static TranslationBlock *tb_alloc(target_ulong pc)
812 {
813     TranslationBlock *tb;
814     TBContext *ctx;
815 
816     assert_tb_locked();
817 
818     tb = tcg_tb_alloc(&tcg_ctx);
819     if (unlikely(tb == NULL)) {
820         return NULL;
821     }
822     ctx = &tcg_ctx.tb_ctx;
823     if (unlikely(ctx->nb_tbs == ctx->tbs_size)) {
824         ctx->tbs_size *= 2;
825         ctx->tbs = g_renew(TranslationBlock *, ctx->tbs, ctx->tbs_size);
826     }
827     ctx->tbs[ctx->nb_tbs++] = tb;
828     return tb;
829 }
830 
831 /* Called with tb_lock held.  */
832 void tb_free(TranslationBlock *tb)
833 {
834     assert_tb_locked();
835 
836     /* In practice this is mostly used for single use temporary TB
837        Ignore the hard cases and just back up if this TB happens to
838        be the last one generated.  */
839     if (tcg_ctx.tb_ctx.nb_tbs > 0 &&
840             tb == tcg_ctx.tb_ctx.tbs[tcg_ctx.tb_ctx.nb_tbs - 1]) {
841         size_t struct_size = ROUND_UP(sizeof(*tb), qemu_icache_linesize);
842 
843         tcg_ctx.code_gen_ptr = tb->tc_ptr - struct_size;
844         tcg_ctx.tb_ctx.nb_tbs--;
845     }
846 }
847 
848 static inline void invalidate_page_bitmap(PageDesc *p)
849 {
850 #ifdef CONFIG_SOFTMMU
851     g_free(p->code_bitmap);
852     p->code_bitmap = NULL;
853     p->code_write_count = 0;
854 #endif
855 }
856 
857 /* Set to NULL all the 'first_tb' fields in all PageDescs. */
858 static void page_flush_tb_1(int level, void **lp)
859 {
860     int i;
861 
862     if (*lp == NULL) {
863         return;
864     }
865     if (level == 0) {
866         PageDesc *pd = *lp;
867 
868         for (i = 0; i < V_L2_SIZE; ++i) {
869             pd[i].first_tb = NULL;
870             invalidate_page_bitmap(pd + i);
871         }
872     } else {
873         void **pp = *lp;
874 
875         for (i = 0; i < V_L2_SIZE; ++i) {
876             page_flush_tb_1(level - 1, pp + i);
877         }
878     }
879 }
880 
881 static void page_flush_tb(void)
882 {
883     int i, l1_sz = v_l1_size;
884 
885     for (i = 0; i < l1_sz; i++) {
886         page_flush_tb_1(v_l2_levels, l1_map + i);
887     }
888 }
889 
890 /* flush all the translation blocks */
891 static void do_tb_flush(CPUState *cpu, run_on_cpu_data tb_flush_count)
892 {
893     tb_lock();
894 
895     /* If it is already been done on request of another CPU,
896      * just retry.
897      */
898     if (tcg_ctx.tb_ctx.tb_flush_count != tb_flush_count.host_int) {
899         goto done;
900     }
901 
902 #if defined(DEBUG_TB_FLUSH)
903     printf("qemu: flush code_size=%ld nb_tbs=%d avg_tb_size=%ld\n",
904            (unsigned long)(tcg_ctx.code_gen_ptr - tcg_ctx.code_gen_buffer),
905            tcg_ctx.tb_ctx.nb_tbs, tcg_ctx.tb_ctx.nb_tbs > 0 ?
906            ((unsigned long)(tcg_ctx.code_gen_ptr - tcg_ctx.code_gen_buffer)) /
907            tcg_ctx.tb_ctx.nb_tbs : 0);
908 #endif
909     if ((unsigned long)(tcg_ctx.code_gen_ptr - tcg_ctx.code_gen_buffer)
910         > tcg_ctx.code_gen_buffer_size) {
911         cpu_abort(cpu, "Internal error: code buffer overflow\n");
912     }
913 
914     CPU_FOREACH(cpu) {
915         cpu_tb_jmp_cache_clear(cpu);
916     }
917 
918     tcg_ctx.tb_ctx.nb_tbs = 0;
919     qht_reset_size(&tcg_ctx.tb_ctx.htable, CODE_GEN_HTABLE_SIZE);
920     page_flush_tb();
921 
922     tcg_ctx.code_gen_ptr = tcg_ctx.code_gen_buffer;
923     /* XXX: flush processor icache at this point if cache flush is
924        expensive */
925     atomic_mb_set(&tcg_ctx.tb_ctx.tb_flush_count,
926                   tcg_ctx.tb_ctx.tb_flush_count + 1);
927 
928 done:
929     tb_unlock();
930 }
931 
932 void tb_flush(CPUState *cpu)
933 {
934     if (tcg_enabled()) {
935         unsigned tb_flush_count = atomic_mb_read(&tcg_ctx.tb_ctx.tb_flush_count);
936         async_safe_run_on_cpu(cpu, do_tb_flush,
937                               RUN_ON_CPU_HOST_INT(tb_flush_count));
938     }
939 }
940 
941 #ifdef DEBUG_TB_CHECK
942 
943 static void
944 do_tb_invalidate_check(struct qht *ht, void *p, uint32_t hash, void *userp)
945 {
946     TranslationBlock *tb = p;
947     target_ulong addr = *(target_ulong *)userp;
948 
949     if (!(addr + TARGET_PAGE_SIZE <= tb->pc || addr >= tb->pc + tb->size)) {
950         printf("ERROR invalidate: address=" TARGET_FMT_lx
951                " PC=%08lx size=%04x\n", addr, (long)tb->pc, tb->size);
952     }
953 }
954 
955 /* verify that all the pages have correct rights for code
956  *
957  * Called with tb_lock held.
958  */
959 static void tb_invalidate_check(target_ulong address)
960 {
961     address &= TARGET_PAGE_MASK;
962     qht_iter(&tcg_ctx.tb_ctx.htable, do_tb_invalidate_check, &address);
963 }
964 
965 static void
966 do_tb_page_check(struct qht *ht, void *p, uint32_t hash, void *userp)
967 {
968     TranslationBlock *tb = p;
969     int flags1, flags2;
970 
971     flags1 = page_get_flags(tb->pc);
972     flags2 = page_get_flags(tb->pc + tb->size - 1);
973     if ((flags1 & PAGE_WRITE) || (flags2 & PAGE_WRITE)) {
974         printf("ERROR page flags: PC=%08lx size=%04x f1=%x f2=%x\n",
975                (long)tb->pc, tb->size, flags1, flags2);
976     }
977 }
978 
979 /* verify that all the pages have correct rights for code */
980 static void tb_page_check(void)
981 {
982     qht_iter(&tcg_ctx.tb_ctx.htable, do_tb_page_check, NULL);
983 }
984 
985 #endif
986 
987 static inline void tb_page_remove(TranslationBlock **ptb, TranslationBlock *tb)
988 {
989     TranslationBlock *tb1;
990     unsigned int n1;
991 
992     for (;;) {
993         tb1 = *ptb;
994         n1 = (uintptr_t)tb1 & 3;
995         tb1 = (TranslationBlock *)((uintptr_t)tb1 & ~3);
996         if (tb1 == tb) {
997             *ptb = tb1->page_next[n1];
998             break;
999         }
1000         ptb = &tb1->page_next[n1];
1001     }
1002 }
1003 
1004 /* remove the TB from a list of TBs jumping to the n-th jump target of the TB */
1005 static inline void tb_remove_from_jmp_list(TranslationBlock *tb, int n)
1006 {
1007     TranslationBlock *tb1;
1008     uintptr_t *ptb, ntb;
1009     unsigned int n1;
1010 
1011     ptb = &tb->jmp_list_next[n];
1012     if (*ptb) {
1013         /* find tb(n) in circular list */
1014         for (;;) {
1015             ntb = *ptb;
1016             n1 = ntb & 3;
1017             tb1 = (TranslationBlock *)(ntb & ~3);
1018             if (n1 == n && tb1 == tb) {
1019                 break;
1020             }
1021             if (n1 == 2) {
1022                 ptb = &tb1->jmp_list_first;
1023             } else {
1024                 ptb = &tb1->jmp_list_next[n1];
1025             }
1026         }
1027         /* now we can suppress tb(n) from the list */
1028         *ptb = tb->jmp_list_next[n];
1029 
1030         tb->jmp_list_next[n] = (uintptr_t)NULL;
1031     }
1032 }
1033 
1034 /* reset the jump entry 'n' of a TB so that it is not chained to
1035    another TB */
1036 static inline void tb_reset_jump(TranslationBlock *tb, int n)
1037 {
1038     uintptr_t addr = (uintptr_t)(tb->tc_ptr + tb->jmp_reset_offset[n]);
1039     tb_set_jmp_target(tb, n, addr);
1040 }
1041 
1042 /* remove any jumps to the TB */
1043 static inline void tb_jmp_unlink(TranslationBlock *tb)
1044 {
1045     TranslationBlock *tb1;
1046     uintptr_t *ptb, ntb;
1047     unsigned int n1;
1048 
1049     ptb = &tb->jmp_list_first;
1050     for (;;) {
1051         ntb = *ptb;
1052         n1 = ntb & 3;
1053         tb1 = (TranslationBlock *)(ntb & ~3);
1054         if (n1 == 2) {
1055             break;
1056         }
1057         tb_reset_jump(tb1, n1);
1058         *ptb = tb1->jmp_list_next[n1];
1059         tb1->jmp_list_next[n1] = (uintptr_t)NULL;
1060     }
1061 }
1062 
1063 /* invalidate one TB
1064  *
1065  * Called with tb_lock held.
1066  */
1067 void tb_phys_invalidate(TranslationBlock *tb, tb_page_addr_t page_addr)
1068 {
1069     CPUState *cpu;
1070     PageDesc *p;
1071     uint32_t h;
1072     tb_page_addr_t phys_pc;
1073 
1074     assert_tb_locked();
1075 
1076     atomic_set(&tb->cflags, tb->cflags | CF_INVALID);
1077 
1078     /* remove the TB from the hash list */
1079     phys_pc = tb->page_addr[0] + (tb->pc & ~TARGET_PAGE_MASK);
1080     h = tb_hash_func(phys_pc, tb->pc, tb->flags, tb->trace_vcpu_dstate);
1081     qht_remove(&tcg_ctx.tb_ctx.htable, tb, h);
1082 
1083     /* remove the TB from the page list */
1084     if (tb->page_addr[0] != page_addr) {
1085         p = page_find(tb->page_addr[0] >> TARGET_PAGE_BITS);
1086         tb_page_remove(&p->first_tb, tb);
1087         invalidate_page_bitmap(p);
1088     }
1089     if (tb->page_addr[1] != -1 && tb->page_addr[1] != page_addr) {
1090         p = page_find(tb->page_addr[1] >> TARGET_PAGE_BITS);
1091         tb_page_remove(&p->first_tb, tb);
1092         invalidate_page_bitmap(p);
1093     }
1094 
1095     /* remove the TB from the hash list */
1096     h = tb_jmp_cache_hash_func(tb->pc);
1097     CPU_FOREACH(cpu) {
1098         if (atomic_read(&cpu->tb_jmp_cache[h]) == tb) {
1099             atomic_set(&cpu->tb_jmp_cache[h], NULL);
1100         }
1101     }
1102 
1103     /* suppress this TB from the two jump lists */
1104     tb_remove_from_jmp_list(tb, 0);
1105     tb_remove_from_jmp_list(tb, 1);
1106 
1107     /* suppress any remaining jumps to this TB */
1108     tb_jmp_unlink(tb);
1109 
1110     tcg_ctx.tb_ctx.tb_phys_invalidate_count++;
1111 }
1112 
1113 #ifdef CONFIG_SOFTMMU
1114 static void build_page_bitmap(PageDesc *p)
1115 {
1116     int n, tb_start, tb_end;
1117     TranslationBlock *tb;
1118 
1119     p->code_bitmap = bitmap_new(TARGET_PAGE_SIZE);
1120 
1121     tb = p->first_tb;
1122     while (tb != NULL) {
1123         n = (uintptr_t)tb & 3;
1124         tb = (TranslationBlock *)((uintptr_t)tb & ~3);
1125         /* NOTE: this is subtle as a TB may span two physical pages */
1126         if (n == 0) {
1127             /* NOTE: tb_end may be after the end of the page, but
1128                it is not a problem */
1129             tb_start = tb->pc & ~TARGET_PAGE_MASK;
1130             tb_end = tb_start + tb->size;
1131             if (tb_end > TARGET_PAGE_SIZE) {
1132                 tb_end = TARGET_PAGE_SIZE;
1133              }
1134         } else {
1135             tb_start = 0;
1136             tb_end = ((tb->pc + tb->size) & ~TARGET_PAGE_MASK);
1137         }
1138         bitmap_set(p->code_bitmap, tb_start, tb_end - tb_start);
1139         tb = tb->page_next[n];
1140     }
1141 }
1142 #endif
1143 
1144 /* add the tb in the target page and protect it if necessary
1145  *
1146  * Called with mmap_lock held for user-mode emulation.
1147  */
1148 static inline void tb_alloc_page(TranslationBlock *tb,
1149                                  unsigned int n, tb_page_addr_t page_addr)
1150 {
1151     PageDesc *p;
1152 #ifndef CONFIG_USER_ONLY
1153     bool page_already_protected;
1154 #endif
1155 
1156     assert_memory_lock();
1157 
1158     tb->page_addr[n] = page_addr;
1159     p = page_find_alloc(page_addr >> TARGET_PAGE_BITS, 1);
1160     tb->page_next[n] = p->first_tb;
1161 #ifndef CONFIG_USER_ONLY
1162     page_already_protected = p->first_tb != NULL;
1163 #endif
1164     p->first_tb = (TranslationBlock *)((uintptr_t)tb | n);
1165     invalidate_page_bitmap(p);
1166 
1167 #if defined(CONFIG_USER_ONLY)
1168     if (p->flags & PAGE_WRITE) {
1169         target_ulong addr;
1170         PageDesc *p2;
1171         int prot;
1172 
1173         /* force the host page as non writable (writes will have a
1174            page fault + mprotect overhead) */
1175         page_addr &= qemu_host_page_mask;
1176         prot = 0;
1177         for (addr = page_addr; addr < page_addr + qemu_host_page_size;
1178             addr += TARGET_PAGE_SIZE) {
1179 
1180             p2 = page_find(addr >> TARGET_PAGE_BITS);
1181             if (!p2) {
1182                 continue;
1183             }
1184             prot |= p2->flags;
1185             p2->flags &= ~PAGE_WRITE;
1186           }
1187         mprotect(g2h(page_addr), qemu_host_page_size,
1188                  (prot & PAGE_BITS) & ~PAGE_WRITE);
1189 #ifdef DEBUG_TB_INVALIDATE
1190         printf("protecting code page: 0x" TARGET_FMT_lx "\n",
1191                page_addr);
1192 #endif
1193     }
1194 #else
1195     /* if some code is already present, then the pages are already
1196        protected. So we handle the case where only the first TB is
1197        allocated in a physical page */
1198     if (!page_already_protected) {
1199         tlb_protect_code(page_addr);
1200     }
1201 #endif
1202 }
1203 
1204 /* add a new TB and link it to the physical page tables. phys_page2 is
1205  * (-1) to indicate that only one page contains the TB.
1206  *
1207  * Called with mmap_lock held for user-mode emulation.
1208  */
1209 static void tb_link_page(TranslationBlock *tb, tb_page_addr_t phys_pc,
1210                          tb_page_addr_t phys_page2)
1211 {
1212     uint32_t h;
1213 
1214     assert_memory_lock();
1215 
1216     /* add in the page list */
1217     tb_alloc_page(tb, 0, phys_pc & TARGET_PAGE_MASK);
1218     if (phys_page2 != -1) {
1219         tb_alloc_page(tb, 1, phys_page2);
1220     } else {
1221         tb->page_addr[1] = -1;
1222     }
1223 
1224     /* add in the hash table */
1225     h = tb_hash_func(phys_pc, tb->pc, tb->flags, tb->trace_vcpu_dstate);
1226     qht_insert(&tcg_ctx.tb_ctx.htable, tb, h);
1227 
1228 #ifdef DEBUG_TB_CHECK
1229     tb_page_check();
1230 #endif
1231 }
1232 
1233 /* Called with mmap_lock held for user mode emulation.  */
1234 TranslationBlock *tb_gen_code(CPUState *cpu,
1235                               target_ulong pc, target_ulong cs_base,
1236                               uint32_t flags, int cflags)
1237 {
1238     CPUArchState *env = cpu->env_ptr;
1239     TranslationBlock *tb;
1240     tb_page_addr_t phys_pc, phys_page2;
1241     target_ulong virt_page2;
1242     tcg_insn_unit *gen_code_buf;
1243     int gen_code_size, search_size;
1244 #ifdef CONFIG_PROFILER
1245     int64_t ti;
1246 #endif
1247     assert_memory_lock();
1248 
1249     phys_pc = get_page_addr_code(env, pc);
1250     if (use_icount && !(cflags & CF_IGNORE_ICOUNT)) {
1251         cflags |= CF_USE_ICOUNT;
1252     }
1253 
1254     tb = tb_alloc(pc);
1255     if (unlikely(!tb)) {
1256  buffer_overflow:
1257         /* flush must be done */
1258         tb_flush(cpu);
1259         mmap_unlock();
1260         /* Make the execution loop process the flush as soon as possible.  */
1261         cpu->exception_index = EXCP_INTERRUPT;
1262         cpu_loop_exit(cpu);
1263     }
1264 
1265     gen_code_buf = tcg_ctx.code_gen_ptr;
1266     tb->tc_ptr = gen_code_buf;
1267     tb->pc = pc;
1268     tb->cs_base = cs_base;
1269     tb->flags = flags;
1270     tb->cflags = cflags;
1271     tb->trace_vcpu_dstate = *cpu->trace_dstate;
1272 
1273 #ifdef CONFIG_PROFILER
1274     tcg_ctx.tb_count1++; /* includes aborted translations because of
1275                        exceptions */
1276     ti = profile_getclock();
1277 #endif
1278 
1279     tcg_func_start(&tcg_ctx);
1280 
1281     tcg_ctx.cpu = ENV_GET_CPU(env);
1282     gen_intermediate_code(cpu, tb);
1283     tcg_ctx.cpu = NULL;
1284 
1285     trace_translate_block(tb, tb->pc, tb->tc_ptr);
1286 
1287     /* generate machine code */
1288     tb->jmp_reset_offset[0] = TB_JMP_RESET_OFFSET_INVALID;
1289     tb->jmp_reset_offset[1] = TB_JMP_RESET_OFFSET_INVALID;
1290     tcg_ctx.tb_jmp_reset_offset = tb->jmp_reset_offset;
1291     if (TCG_TARGET_HAS_direct_jump) {
1292         tcg_ctx.tb_jmp_insn_offset = tb->jmp_target_arg;
1293         tcg_ctx.tb_jmp_target_addr = NULL;
1294     } else {
1295         tcg_ctx.tb_jmp_insn_offset = NULL;
1296         tcg_ctx.tb_jmp_target_addr = tb->jmp_target_arg;
1297     }
1298 
1299 #ifdef CONFIG_PROFILER
1300     tcg_ctx.tb_count++;
1301     tcg_ctx.interm_time += profile_getclock() - ti;
1302     ti = profile_getclock();
1303 #endif
1304 
1305     /* ??? Overflow could be handled better here.  In particular, we
1306        don't need to re-do gen_intermediate_code, nor should we re-do
1307        the tcg optimization currently hidden inside tcg_gen_code.  All
1308        that should be required is to flush the TBs, allocate a new TB,
1309        re-initialize it per above, and re-do the actual code generation.  */
1310     gen_code_size = tcg_gen_code(&tcg_ctx, tb);
1311     if (unlikely(gen_code_size < 0)) {
1312         goto buffer_overflow;
1313     }
1314     search_size = encode_search(tb, (void *)gen_code_buf + gen_code_size);
1315     if (unlikely(search_size < 0)) {
1316         goto buffer_overflow;
1317     }
1318 
1319 #ifdef CONFIG_PROFILER
1320     tcg_ctx.code_time += profile_getclock() - ti;
1321     tcg_ctx.code_in_len += tb->size;
1322     tcg_ctx.code_out_len += gen_code_size;
1323     tcg_ctx.search_out_len += search_size;
1324 #endif
1325 
1326 #ifdef DEBUG_DISAS
1327     if (qemu_loglevel_mask(CPU_LOG_TB_OUT_ASM) &&
1328         qemu_log_in_addr_range(tb->pc)) {
1329         qemu_log_lock();
1330         qemu_log("OUT: [size=%d]\n", gen_code_size);
1331         if (tcg_ctx.data_gen_ptr) {
1332             size_t code_size = tcg_ctx.data_gen_ptr - tb->tc_ptr;
1333             size_t data_size = gen_code_size - code_size;
1334             size_t i;
1335 
1336             log_disas(tb->tc_ptr, code_size);
1337 
1338             for (i = 0; i < data_size; i += sizeof(tcg_target_ulong)) {
1339                 if (sizeof(tcg_target_ulong) == 8) {
1340                     qemu_log("0x%08" PRIxPTR ":  .quad  0x%016" PRIx64 "\n",
1341                              (uintptr_t)tcg_ctx.data_gen_ptr + i,
1342                              *(uint64_t *)(tcg_ctx.data_gen_ptr + i));
1343                 } else {
1344                     qemu_log("0x%08" PRIxPTR ":  .long  0x%08x\n",
1345                              (uintptr_t)tcg_ctx.data_gen_ptr + i,
1346                              *(uint32_t *)(tcg_ctx.data_gen_ptr + i));
1347                 }
1348             }
1349         } else {
1350             log_disas(tb->tc_ptr, gen_code_size);
1351         }
1352         qemu_log("\n");
1353         qemu_log_flush();
1354         qemu_log_unlock();
1355     }
1356 #endif
1357 
1358     tcg_ctx.code_gen_ptr = (void *)
1359         ROUND_UP((uintptr_t)gen_code_buf + gen_code_size + search_size,
1360                  CODE_GEN_ALIGN);
1361 
1362     /* init jump list */
1363     assert(((uintptr_t)tb & 3) == 0);
1364     tb->jmp_list_first = (uintptr_t)tb | 2;
1365     tb->jmp_list_next[0] = (uintptr_t)NULL;
1366     tb->jmp_list_next[1] = (uintptr_t)NULL;
1367 
1368     /* init original jump addresses wich has been set during tcg_gen_code() */
1369     if (tb->jmp_reset_offset[0] != TB_JMP_RESET_OFFSET_INVALID) {
1370         tb_reset_jump(tb, 0);
1371     }
1372     if (tb->jmp_reset_offset[1] != TB_JMP_RESET_OFFSET_INVALID) {
1373         tb_reset_jump(tb, 1);
1374     }
1375 
1376     /* check next page if needed */
1377     virt_page2 = (pc + tb->size - 1) & TARGET_PAGE_MASK;
1378     phys_page2 = -1;
1379     if ((pc & TARGET_PAGE_MASK) != virt_page2) {
1380         phys_page2 = get_page_addr_code(env, virt_page2);
1381     }
1382     /* As long as consistency of the TB stuff is provided by tb_lock in user
1383      * mode and is implicit in single-threaded softmmu emulation, no explicit
1384      * memory barrier is required before tb_link_page() makes the TB visible
1385      * through the physical hash table and physical page list.
1386      */
1387     tb_link_page(tb, phys_pc, phys_page2);
1388     return tb;
1389 }
1390 
1391 /*
1392  * Invalidate all TBs which intersect with the target physical address range
1393  * [start;end[. NOTE: start and end may refer to *different* physical pages.
1394  * 'is_cpu_write_access' should be true if called from a real cpu write
1395  * access: the virtual CPU will exit the current TB if code is modified inside
1396  * this TB.
1397  *
1398  * Called with mmap_lock held for user-mode emulation, grabs tb_lock
1399  * Called with tb_lock held for system-mode emulation
1400  */
1401 static void tb_invalidate_phys_range_1(tb_page_addr_t start, tb_page_addr_t end)
1402 {
1403     while (start < end) {
1404         tb_invalidate_phys_page_range(start, end, 0);
1405         start &= TARGET_PAGE_MASK;
1406         start += TARGET_PAGE_SIZE;
1407     }
1408 }
1409 
1410 #ifdef CONFIG_SOFTMMU
1411 void tb_invalidate_phys_range(tb_page_addr_t start, tb_page_addr_t end)
1412 {
1413     assert_tb_locked();
1414     tb_invalidate_phys_range_1(start, end);
1415 }
1416 #else
1417 void tb_invalidate_phys_range(tb_page_addr_t start, tb_page_addr_t end)
1418 {
1419     assert_memory_lock();
1420     tb_lock();
1421     tb_invalidate_phys_range_1(start, end);
1422     tb_unlock();
1423 }
1424 #endif
1425 /*
1426  * Invalidate all TBs which intersect with the target physical address range
1427  * [start;end[. NOTE: start and end must refer to the *same* physical page.
1428  * 'is_cpu_write_access' should be true if called from a real cpu write
1429  * access: the virtual CPU will exit the current TB if code is modified inside
1430  * this TB.
1431  *
1432  * Called with tb_lock/mmap_lock held for user-mode emulation
1433  * Called with tb_lock held for system-mode emulation
1434  */
1435 void tb_invalidate_phys_page_range(tb_page_addr_t start, tb_page_addr_t end,
1436                                    int is_cpu_write_access)
1437 {
1438     TranslationBlock *tb, *tb_next;
1439 #if defined(TARGET_HAS_PRECISE_SMC)
1440     CPUState *cpu = current_cpu;
1441     CPUArchState *env = NULL;
1442 #endif
1443     tb_page_addr_t tb_start, tb_end;
1444     PageDesc *p;
1445     int n;
1446 #ifdef TARGET_HAS_PRECISE_SMC
1447     int current_tb_not_found = is_cpu_write_access;
1448     TranslationBlock *current_tb = NULL;
1449     int current_tb_modified = 0;
1450     target_ulong current_pc = 0;
1451     target_ulong current_cs_base = 0;
1452     uint32_t current_flags = 0;
1453 #endif /* TARGET_HAS_PRECISE_SMC */
1454 
1455     assert_memory_lock();
1456     assert_tb_locked();
1457 
1458     p = page_find(start >> TARGET_PAGE_BITS);
1459     if (!p) {
1460         return;
1461     }
1462 #if defined(TARGET_HAS_PRECISE_SMC)
1463     if (cpu != NULL) {
1464         env = cpu->env_ptr;
1465     }
1466 #endif
1467 
1468     /* we remove all the TBs in the range [start, end[ */
1469     /* XXX: see if in some cases it could be faster to invalidate all
1470        the code */
1471     tb = p->first_tb;
1472     while (tb != NULL) {
1473         n = (uintptr_t)tb & 3;
1474         tb = (TranslationBlock *)((uintptr_t)tb & ~3);
1475         tb_next = tb->page_next[n];
1476         /* NOTE: this is subtle as a TB may span two physical pages */
1477         if (n == 0) {
1478             /* NOTE: tb_end may be after the end of the page, but
1479                it is not a problem */
1480             tb_start = tb->page_addr[0] + (tb->pc & ~TARGET_PAGE_MASK);
1481             tb_end = tb_start + tb->size;
1482         } else {
1483             tb_start = tb->page_addr[1];
1484             tb_end = tb_start + ((tb->pc + tb->size) & ~TARGET_PAGE_MASK);
1485         }
1486         if (!(tb_end <= start || tb_start >= end)) {
1487 #ifdef TARGET_HAS_PRECISE_SMC
1488             if (current_tb_not_found) {
1489                 current_tb_not_found = 0;
1490                 current_tb = NULL;
1491                 if (cpu->mem_io_pc) {
1492                     /* now we have a real cpu fault */
1493                     current_tb = tb_find_pc(cpu->mem_io_pc);
1494                 }
1495             }
1496             if (current_tb == tb &&
1497                 (current_tb->cflags & CF_COUNT_MASK) != 1) {
1498                 /* If we are modifying the current TB, we must stop
1499                 its execution. We could be more precise by checking
1500                 that the modification is after the current PC, but it
1501                 would require a specialized function to partially
1502                 restore the CPU state */
1503 
1504                 current_tb_modified = 1;
1505                 cpu_restore_state_from_tb(cpu, current_tb, cpu->mem_io_pc);
1506                 cpu_get_tb_cpu_state(env, &current_pc, &current_cs_base,
1507                                      &current_flags);
1508             }
1509 #endif /* TARGET_HAS_PRECISE_SMC */
1510             tb_phys_invalidate(tb, -1);
1511         }
1512         tb = tb_next;
1513     }
1514 #if !defined(CONFIG_USER_ONLY)
1515     /* if no code remaining, no need to continue to use slow writes */
1516     if (!p->first_tb) {
1517         invalidate_page_bitmap(p);
1518         tlb_unprotect_code(start);
1519     }
1520 #endif
1521 #ifdef TARGET_HAS_PRECISE_SMC
1522     if (current_tb_modified) {
1523         /* we generate a block containing just the instruction
1524            modifying the memory. It will ensure that it cannot modify
1525            itself */
1526         tb_gen_code(cpu, current_pc, current_cs_base, current_flags, 1);
1527         cpu_loop_exit_noexc(cpu);
1528     }
1529 #endif
1530 }
1531 
1532 #ifdef CONFIG_SOFTMMU
1533 /* len must be <= 8 and start must be a multiple of len.
1534  * Called via softmmu_template.h when code areas are written to with
1535  * iothread mutex not held.
1536  */
1537 void tb_invalidate_phys_page_fast(tb_page_addr_t start, int len)
1538 {
1539     PageDesc *p;
1540 
1541 #if 0
1542     if (1) {
1543         qemu_log("modifying code at 0x%x size=%d EIP=%x PC=%08x\n",
1544                   cpu_single_env->mem_io_vaddr, len,
1545                   cpu_single_env->eip,
1546                   cpu_single_env->eip +
1547                   (intptr_t)cpu_single_env->segs[R_CS].base);
1548     }
1549 #endif
1550     assert_memory_lock();
1551 
1552     p = page_find(start >> TARGET_PAGE_BITS);
1553     if (!p) {
1554         return;
1555     }
1556     if (!p->code_bitmap &&
1557         ++p->code_write_count >= SMC_BITMAP_USE_THRESHOLD) {
1558         /* build code bitmap.  FIXME: writes should be protected by
1559          * tb_lock, reads by tb_lock or RCU.
1560          */
1561         build_page_bitmap(p);
1562     }
1563     if (p->code_bitmap) {
1564         unsigned int nr;
1565         unsigned long b;
1566 
1567         nr = start & ~TARGET_PAGE_MASK;
1568         b = p->code_bitmap[BIT_WORD(nr)] >> (nr & (BITS_PER_LONG - 1));
1569         if (b & ((1 << len) - 1)) {
1570             goto do_invalidate;
1571         }
1572     } else {
1573     do_invalidate:
1574         tb_invalidate_phys_page_range(start, start + len, 1);
1575     }
1576 }
1577 #else
1578 /* Called with mmap_lock held. If pc is not 0 then it indicates the
1579  * host PC of the faulting store instruction that caused this invalidate.
1580  * Returns true if the caller needs to abort execution of the current
1581  * TB (because it was modified by this store and the guest CPU has
1582  * precise-SMC semantics).
1583  */
1584 static bool tb_invalidate_phys_page(tb_page_addr_t addr, uintptr_t pc)
1585 {
1586     TranslationBlock *tb;
1587     PageDesc *p;
1588     int n;
1589 #ifdef TARGET_HAS_PRECISE_SMC
1590     TranslationBlock *current_tb = NULL;
1591     CPUState *cpu = current_cpu;
1592     CPUArchState *env = NULL;
1593     int current_tb_modified = 0;
1594     target_ulong current_pc = 0;
1595     target_ulong current_cs_base = 0;
1596     uint32_t current_flags = 0;
1597 #endif
1598 
1599     assert_memory_lock();
1600 
1601     addr &= TARGET_PAGE_MASK;
1602     p = page_find(addr >> TARGET_PAGE_BITS);
1603     if (!p) {
1604         return false;
1605     }
1606 
1607     tb_lock();
1608     tb = p->first_tb;
1609 #ifdef TARGET_HAS_PRECISE_SMC
1610     if (tb && pc != 0) {
1611         current_tb = tb_find_pc(pc);
1612     }
1613     if (cpu != NULL) {
1614         env = cpu->env_ptr;
1615     }
1616 #endif
1617     while (tb != NULL) {
1618         n = (uintptr_t)tb & 3;
1619         tb = (TranslationBlock *)((uintptr_t)tb & ~3);
1620 #ifdef TARGET_HAS_PRECISE_SMC
1621         if (current_tb == tb &&
1622             (current_tb->cflags & CF_COUNT_MASK) != 1) {
1623                 /* If we are modifying the current TB, we must stop
1624                    its execution. We could be more precise by checking
1625                    that the modification is after the current PC, but it
1626                    would require a specialized function to partially
1627                    restore the CPU state */
1628 
1629             current_tb_modified = 1;
1630             cpu_restore_state_from_tb(cpu, current_tb, pc);
1631             cpu_get_tb_cpu_state(env, &current_pc, &current_cs_base,
1632                                  &current_flags);
1633         }
1634 #endif /* TARGET_HAS_PRECISE_SMC */
1635         tb_phys_invalidate(tb, addr);
1636         tb = tb->page_next[n];
1637     }
1638     p->first_tb = NULL;
1639 #ifdef TARGET_HAS_PRECISE_SMC
1640     if (current_tb_modified) {
1641         /* we generate a block containing just the instruction
1642            modifying the memory. It will ensure that it cannot modify
1643            itself */
1644         tb_gen_code(cpu, current_pc, current_cs_base, current_flags, 1);
1645         /* tb_lock will be reset after cpu_loop_exit_noexc longjmps
1646          * back into the cpu_exec loop. */
1647         return true;
1648     }
1649 #endif
1650     tb_unlock();
1651 
1652     return false;
1653 }
1654 #endif
1655 
1656 /* find the TB 'tb' such that tb[0].tc_ptr <= tc_ptr <
1657    tb[1].tc_ptr. Return NULL if not found */
1658 static TranslationBlock *tb_find_pc(uintptr_t tc_ptr)
1659 {
1660     int m_min, m_max, m;
1661     uintptr_t v;
1662     TranslationBlock *tb;
1663 
1664     if (tcg_ctx.tb_ctx.nb_tbs <= 0) {
1665         return NULL;
1666     }
1667     if (tc_ptr < (uintptr_t)tcg_ctx.code_gen_buffer ||
1668         tc_ptr >= (uintptr_t)tcg_ctx.code_gen_ptr) {
1669         return NULL;
1670     }
1671     /* binary search (cf Knuth) */
1672     m_min = 0;
1673     m_max = tcg_ctx.tb_ctx.nb_tbs - 1;
1674     while (m_min <= m_max) {
1675         m = (m_min + m_max) >> 1;
1676         tb = tcg_ctx.tb_ctx.tbs[m];
1677         v = (uintptr_t)tb->tc_ptr;
1678         if (v == tc_ptr) {
1679             return tb;
1680         } else if (tc_ptr < v) {
1681             m_max = m - 1;
1682         } else {
1683             m_min = m + 1;
1684         }
1685     }
1686     return tcg_ctx.tb_ctx.tbs[m_max];
1687 }
1688 
1689 #if !defined(CONFIG_USER_ONLY)
1690 void tb_invalidate_phys_addr(AddressSpace *as, hwaddr addr)
1691 {
1692     ram_addr_t ram_addr;
1693     MemoryRegion *mr;
1694     hwaddr l = 1;
1695 
1696     rcu_read_lock();
1697     mr = address_space_translate(as, addr, &addr, &l, false);
1698     if (!(memory_region_is_ram(mr)
1699           || memory_region_is_romd(mr))) {
1700         rcu_read_unlock();
1701         return;
1702     }
1703     ram_addr = memory_region_get_ram_addr(mr) + addr;
1704     tb_lock();
1705     tb_invalidate_phys_page_range(ram_addr, ram_addr + 1, 0);
1706     tb_unlock();
1707     rcu_read_unlock();
1708 }
1709 #endif /* !defined(CONFIG_USER_ONLY) */
1710 
1711 /* Called with tb_lock held.  */
1712 void tb_check_watchpoint(CPUState *cpu)
1713 {
1714     TranslationBlock *tb;
1715 
1716     tb = tb_find_pc(cpu->mem_io_pc);
1717     if (tb) {
1718         /* We can use retranslation to find the PC.  */
1719         cpu_restore_state_from_tb(cpu, tb, cpu->mem_io_pc);
1720         tb_phys_invalidate(tb, -1);
1721     } else {
1722         /* The exception probably happened in a helper.  The CPU state should
1723            have been saved before calling it. Fetch the PC from there.  */
1724         CPUArchState *env = cpu->env_ptr;
1725         target_ulong pc, cs_base;
1726         tb_page_addr_t addr;
1727         uint32_t flags;
1728 
1729         cpu_get_tb_cpu_state(env, &pc, &cs_base, &flags);
1730         addr = get_page_addr_code(env, pc);
1731         tb_invalidate_phys_range(addr, addr + 1);
1732     }
1733 }
1734 
1735 #ifndef CONFIG_USER_ONLY
1736 /* in deterministic execution mode, instructions doing device I/Os
1737  * must be at the end of the TB.
1738  *
1739  * Called by softmmu_template.h, with iothread mutex not held.
1740  */
1741 void cpu_io_recompile(CPUState *cpu, uintptr_t retaddr)
1742 {
1743 #if defined(TARGET_MIPS) || defined(TARGET_SH4)
1744     CPUArchState *env = cpu->env_ptr;
1745 #endif
1746     TranslationBlock *tb;
1747     uint32_t n, cflags;
1748     target_ulong pc, cs_base;
1749     uint32_t flags;
1750 
1751     tb_lock();
1752     tb = tb_find_pc(retaddr);
1753     if (!tb) {
1754         cpu_abort(cpu, "cpu_io_recompile: could not find TB for pc=%p",
1755                   (void *)retaddr);
1756     }
1757     n = cpu->icount_decr.u16.low + tb->icount;
1758     cpu_restore_state_from_tb(cpu, tb, retaddr);
1759     /* Calculate how many instructions had been executed before the fault
1760        occurred.  */
1761     n = n - cpu->icount_decr.u16.low;
1762     /* Generate a new TB ending on the I/O insn.  */
1763     n++;
1764     /* On MIPS and SH, delay slot instructions can only be restarted if
1765        they were already the first instruction in the TB.  If this is not
1766        the first instruction in a TB then re-execute the preceding
1767        branch.  */
1768 #if defined(TARGET_MIPS)
1769     if ((env->hflags & MIPS_HFLAG_BMASK) != 0 && n > 1) {
1770         env->active_tc.PC -= (env->hflags & MIPS_HFLAG_B16 ? 2 : 4);
1771         cpu->icount_decr.u16.low++;
1772         env->hflags &= ~MIPS_HFLAG_BMASK;
1773     }
1774 #elif defined(TARGET_SH4)
1775     if ((env->flags & ((DELAY_SLOT | DELAY_SLOT_CONDITIONAL))) != 0
1776             && n > 1) {
1777         env->pc -= 2;
1778         cpu->icount_decr.u16.low++;
1779         env->flags &= ~(DELAY_SLOT | DELAY_SLOT_CONDITIONAL);
1780     }
1781 #endif
1782     /* This should never happen.  */
1783     if (n > CF_COUNT_MASK) {
1784         cpu_abort(cpu, "TB too big during recompile");
1785     }
1786 
1787     cflags = n | CF_LAST_IO;
1788     pc = tb->pc;
1789     cs_base = tb->cs_base;
1790     flags = tb->flags;
1791     tb_phys_invalidate(tb, -1);
1792     if (tb->cflags & CF_NOCACHE) {
1793         if (tb->orig_tb) {
1794             /* Invalidate original TB if this TB was generated in
1795              * cpu_exec_nocache() */
1796             tb_phys_invalidate(tb->orig_tb, -1);
1797         }
1798         tb_free(tb);
1799     }
1800     /* FIXME: In theory this could raise an exception.  In practice
1801        we have already translated the block once so it's probably ok.  */
1802     tb_gen_code(cpu, pc, cs_base, flags, cflags);
1803 
1804     /* TODO: If env->pc != tb->pc (i.e. the faulting instruction was not
1805      * the first in the TB) then we end up generating a whole new TB and
1806      *  repeating the fault, which is horribly inefficient.
1807      *  Better would be to execute just this insn uncached, or generate a
1808      *  second new TB.
1809      *
1810      * cpu_loop_exit_noexc will longjmp back to cpu_exec where the
1811      * tb_lock gets reset.
1812      */
1813     cpu_loop_exit_noexc(cpu);
1814 }
1815 
1816 static void tb_jmp_cache_clear_page(CPUState *cpu, target_ulong page_addr)
1817 {
1818     unsigned int i, i0 = tb_jmp_cache_hash_page(page_addr);
1819 
1820     for (i = 0; i < TB_JMP_PAGE_SIZE; i++) {
1821         atomic_set(&cpu->tb_jmp_cache[i0 + i], NULL);
1822     }
1823 }
1824 
1825 void tb_flush_jmp_cache(CPUState *cpu, target_ulong addr)
1826 {
1827     /* Discard jump cache entries for any tb which might potentially
1828        overlap the flushed page.  */
1829     tb_jmp_cache_clear_page(cpu, addr - TARGET_PAGE_SIZE);
1830     tb_jmp_cache_clear_page(cpu, addr);
1831 }
1832 
1833 static void print_qht_statistics(FILE *f, fprintf_function cpu_fprintf,
1834                                  struct qht_stats hst)
1835 {
1836     uint32_t hgram_opts;
1837     size_t hgram_bins;
1838     char *hgram;
1839 
1840     if (!hst.head_buckets) {
1841         return;
1842     }
1843     cpu_fprintf(f, "TB hash buckets     %zu/%zu (%0.2f%% head buckets used)\n",
1844                 hst.used_head_buckets, hst.head_buckets,
1845                 (double)hst.used_head_buckets / hst.head_buckets * 100);
1846 
1847     hgram_opts =  QDIST_PR_BORDER | QDIST_PR_LABELS;
1848     hgram_opts |= QDIST_PR_100X   | QDIST_PR_PERCENT;
1849     if (qdist_xmax(&hst.occupancy) - qdist_xmin(&hst.occupancy) == 1) {
1850         hgram_opts |= QDIST_PR_NODECIMAL;
1851     }
1852     hgram = qdist_pr(&hst.occupancy, 10, hgram_opts);
1853     cpu_fprintf(f, "TB hash occupancy   %0.2f%% avg chain occ. Histogram: %s\n",
1854                 qdist_avg(&hst.occupancy) * 100, hgram);
1855     g_free(hgram);
1856 
1857     hgram_opts = QDIST_PR_BORDER | QDIST_PR_LABELS;
1858     hgram_bins = qdist_xmax(&hst.chain) - qdist_xmin(&hst.chain);
1859     if (hgram_bins > 10) {
1860         hgram_bins = 10;
1861     } else {
1862         hgram_bins = 0;
1863         hgram_opts |= QDIST_PR_NODECIMAL | QDIST_PR_NOBINRANGE;
1864     }
1865     hgram = qdist_pr(&hst.chain, hgram_bins, hgram_opts);
1866     cpu_fprintf(f, "TB hash avg chain   %0.3f buckets. Histogram: %s\n",
1867                 qdist_avg(&hst.chain), hgram);
1868     g_free(hgram);
1869 }
1870 
1871 void dump_exec_info(FILE *f, fprintf_function cpu_fprintf)
1872 {
1873     int i, target_code_size, max_target_code_size;
1874     int direct_jmp_count, direct_jmp2_count, cross_page;
1875     TranslationBlock *tb;
1876     struct qht_stats hst;
1877 
1878     tb_lock();
1879 
1880     target_code_size = 0;
1881     max_target_code_size = 0;
1882     cross_page = 0;
1883     direct_jmp_count = 0;
1884     direct_jmp2_count = 0;
1885     for (i = 0; i < tcg_ctx.tb_ctx.nb_tbs; i++) {
1886         tb = tcg_ctx.tb_ctx.tbs[i];
1887         target_code_size += tb->size;
1888         if (tb->size > max_target_code_size) {
1889             max_target_code_size = tb->size;
1890         }
1891         if (tb->page_addr[1] != -1) {
1892             cross_page++;
1893         }
1894         if (tb->jmp_reset_offset[0] != TB_JMP_RESET_OFFSET_INVALID) {
1895             direct_jmp_count++;
1896             if (tb->jmp_reset_offset[1] != TB_JMP_RESET_OFFSET_INVALID) {
1897                 direct_jmp2_count++;
1898             }
1899         }
1900     }
1901     /* XXX: avoid using doubles ? */
1902     cpu_fprintf(f, "Translation buffer state:\n");
1903     cpu_fprintf(f, "gen code size       %td/%zd\n",
1904                 tcg_ctx.code_gen_ptr - tcg_ctx.code_gen_buffer,
1905                 tcg_ctx.code_gen_highwater - tcg_ctx.code_gen_buffer);
1906     cpu_fprintf(f, "TB count            %d\n", tcg_ctx.tb_ctx.nb_tbs);
1907     cpu_fprintf(f, "TB avg target size  %d max=%d bytes\n",
1908             tcg_ctx.tb_ctx.nb_tbs ? target_code_size /
1909                     tcg_ctx.tb_ctx.nb_tbs : 0,
1910             max_target_code_size);
1911     cpu_fprintf(f, "TB avg host size    %td bytes (expansion ratio: %0.1f)\n",
1912             tcg_ctx.tb_ctx.nb_tbs ? (tcg_ctx.code_gen_ptr -
1913                                      tcg_ctx.code_gen_buffer) /
1914                                      tcg_ctx.tb_ctx.nb_tbs : 0,
1915                 target_code_size ? (double) (tcg_ctx.code_gen_ptr -
1916                                              tcg_ctx.code_gen_buffer) /
1917                                              target_code_size : 0);
1918     cpu_fprintf(f, "cross page TB count %d (%d%%)\n", cross_page,
1919             tcg_ctx.tb_ctx.nb_tbs ? (cross_page * 100) /
1920                                     tcg_ctx.tb_ctx.nb_tbs : 0);
1921     cpu_fprintf(f, "direct jump count   %d (%d%%) (2 jumps=%d %d%%)\n",
1922                 direct_jmp_count,
1923                 tcg_ctx.tb_ctx.nb_tbs ? (direct_jmp_count * 100) /
1924                         tcg_ctx.tb_ctx.nb_tbs : 0,
1925                 direct_jmp2_count,
1926                 tcg_ctx.tb_ctx.nb_tbs ? (direct_jmp2_count * 100) /
1927                         tcg_ctx.tb_ctx.nb_tbs : 0);
1928 
1929     qht_statistics_init(&tcg_ctx.tb_ctx.htable, &hst);
1930     print_qht_statistics(f, cpu_fprintf, hst);
1931     qht_statistics_destroy(&hst);
1932 
1933     cpu_fprintf(f, "\nStatistics:\n");
1934     cpu_fprintf(f, "TB flush count      %u\n",
1935             atomic_read(&tcg_ctx.tb_ctx.tb_flush_count));
1936     cpu_fprintf(f, "TB invalidate count %d\n",
1937             tcg_ctx.tb_ctx.tb_phys_invalidate_count);
1938     cpu_fprintf(f, "TLB flush count     %zu\n", tlb_flush_count());
1939     tcg_dump_info(f, cpu_fprintf);
1940 
1941     tb_unlock();
1942 }
1943 
1944 void dump_opcount_info(FILE *f, fprintf_function cpu_fprintf)
1945 {
1946     tcg_dump_op_count(f, cpu_fprintf);
1947 }
1948 
1949 #else /* CONFIG_USER_ONLY */
1950 
1951 void cpu_interrupt(CPUState *cpu, int mask)
1952 {
1953     g_assert(qemu_mutex_iothread_locked());
1954     cpu->interrupt_request |= mask;
1955     cpu->icount_decr.u16.high = -1;
1956 }
1957 
1958 /*
1959  * Walks guest process memory "regions" one by one
1960  * and calls callback function 'fn' for each region.
1961  */
1962 struct walk_memory_regions_data {
1963     walk_memory_regions_fn fn;
1964     void *priv;
1965     target_ulong start;
1966     int prot;
1967 };
1968 
1969 static int walk_memory_regions_end(struct walk_memory_regions_data *data,
1970                                    target_ulong end, int new_prot)
1971 {
1972     if (data->start != -1u) {
1973         int rc = data->fn(data->priv, data->start, end, data->prot);
1974         if (rc != 0) {
1975             return rc;
1976         }
1977     }
1978 
1979     data->start = (new_prot ? end : -1u);
1980     data->prot = new_prot;
1981 
1982     return 0;
1983 }
1984 
1985 static int walk_memory_regions_1(struct walk_memory_regions_data *data,
1986                                  target_ulong base, int level, void **lp)
1987 {
1988     target_ulong pa;
1989     int i, rc;
1990 
1991     if (*lp == NULL) {
1992         return walk_memory_regions_end(data, base, 0);
1993     }
1994 
1995     if (level == 0) {
1996         PageDesc *pd = *lp;
1997 
1998         for (i = 0; i < V_L2_SIZE; ++i) {
1999             int prot = pd[i].flags;
2000 
2001             pa = base | (i << TARGET_PAGE_BITS);
2002             if (prot != data->prot) {
2003                 rc = walk_memory_regions_end(data, pa, prot);
2004                 if (rc != 0) {
2005                     return rc;
2006                 }
2007             }
2008         }
2009     } else {
2010         void **pp = *lp;
2011 
2012         for (i = 0; i < V_L2_SIZE; ++i) {
2013             pa = base | ((target_ulong)i <<
2014                 (TARGET_PAGE_BITS + V_L2_BITS * level));
2015             rc = walk_memory_regions_1(data, pa, level - 1, pp + i);
2016             if (rc != 0) {
2017                 return rc;
2018             }
2019         }
2020     }
2021 
2022     return 0;
2023 }
2024 
2025 int walk_memory_regions(void *priv, walk_memory_regions_fn fn)
2026 {
2027     struct walk_memory_regions_data data;
2028     uintptr_t i, l1_sz = v_l1_size;
2029 
2030     data.fn = fn;
2031     data.priv = priv;
2032     data.start = -1u;
2033     data.prot = 0;
2034 
2035     for (i = 0; i < l1_sz; i++) {
2036         target_ulong base = i << (v_l1_shift + TARGET_PAGE_BITS);
2037         int rc = walk_memory_regions_1(&data, base, v_l2_levels, l1_map + i);
2038         if (rc != 0) {
2039             return rc;
2040         }
2041     }
2042 
2043     return walk_memory_regions_end(&data, 0, 0);
2044 }
2045 
2046 static int dump_region(void *priv, target_ulong start,
2047     target_ulong end, unsigned long prot)
2048 {
2049     FILE *f = (FILE *)priv;
2050 
2051     (void) fprintf(f, TARGET_FMT_lx"-"TARGET_FMT_lx
2052         " "TARGET_FMT_lx" %c%c%c\n",
2053         start, end, end - start,
2054         ((prot & PAGE_READ) ? 'r' : '-'),
2055         ((prot & PAGE_WRITE) ? 'w' : '-'),
2056         ((prot & PAGE_EXEC) ? 'x' : '-'));
2057 
2058     return 0;
2059 }
2060 
2061 /* dump memory mappings */
2062 void page_dump(FILE *f)
2063 {
2064     const int length = sizeof(target_ulong) * 2;
2065     (void) fprintf(f, "%-*s %-*s %-*s %s\n",
2066             length, "start", length, "end", length, "size", "prot");
2067     walk_memory_regions(f, dump_region);
2068 }
2069 
2070 int page_get_flags(target_ulong address)
2071 {
2072     PageDesc *p;
2073 
2074     p = page_find(address >> TARGET_PAGE_BITS);
2075     if (!p) {
2076         return 0;
2077     }
2078     return p->flags;
2079 }
2080 
2081 /* Modify the flags of a page and invalidate the code if necessary.
2082    The flag PAGE_WRITE_ORG is positioned automatically depending
2083    on PAGE_WRITE.  The mmap_lock should already be held.  */
2084 void page_set_flags(target_ulong start, target_ulong end, int flags)
2085 {
2086     target_ulong addr, len;
2087 
2088     /* This function should never be called with addresses outside the
2089        guest address space.  If this assert fires, it probably indicates
2090        a missing call to h2g_valid.  */
2091 #if TARGET_ABI_BITS > L1_MAP_ADDR_SPACE_BITS
2092     assert(end < ((target_ulong)1 << L1_MAP_ADDR_SPACE_BITS));
2093 #endif
2094     assert(start < end);
2095     assert_memory_lock();
2096 
2097     start = start & TARGET_PAGE_MASK;
2098     end = TARGET_PAGE_ALIGN(end);
2099 
2100     if (flags & PAGE_WRITE) {
2101         flags |= PAGE_WRITE_ORG;
2102     }
2103 
2104     for (addr = start, len = end - start;
2105          len != 0;
2106          len -= TARGET_PAGE_SIZE, addr += TARGET_PAGE_SIZE) {
2107         PageDesc *p = page_find_alloc(addr >> TARGET_PAGE_BITS, 1);
2108 
2109         /* If the write protection bit is set, then we invalidate
2110            the code inside.  */
2111         if (!(p->flags & PAGE_WRITE) &&
2112             (flags & PAGE_WRITE) &&
2113             p->first_tb) {
2114             tb_invalidate_phys_page(addr, 0);
2115         }
2116         p->flags = flags;
2117     }
2118 }
2119 
2120 int page_check_range(target_ulong start, target_ulong len, int flags)
2121 {
2122     PageDesc *p;
2123     target_ulong end;
2124     target_ulong addr;
2125 
2126     /* This function should never be called with addresses outside the
2127        guest address space.  If this assert fires, it probably indicates
2128        a missing call to h2g_valid.  */
2129 #if TARGET_ABI_BITS > L1_MAP_ADDR_SPACE_BITS
2130     assert(start < ((target_ulong)1 << L1_MAP_ADDR_SPACE_BITS));
2131 #endif
2132 
2133     if (len == 0) {
2134         return 0;
2135     }
2136     if (start + len - 1 < start) {
2137         /* We've wrapped around.  */
2138         return -1;
2139     }
2140 
2141     /* must do before we loose bits in the next step */
2142     end = TARGET_PAGE_ALIGN(start + len);
2143     start = start & TARGET_PAGE_MASK;
2144 
2145     for (addr = start, len = end - start;
2146          len != 0;
2147          len -= TARGET_PAGE_SIZE, addr += TARGET_PAGE_SIZE) {
2148         p = page_find(addr >> TARGET_PAGE_BITS);
2149         if (!p) {
2150             return -1;
2151         }
2152         if (!(p->flags & PAGE_VALID)) {
2153             return -1;
2154         }
2155 
2156         if ((flags & PAGE_READ) && !(p->flags & PAGE_READ)) {
2157             return -1;
2158         }
2159         if (flags & PAGE_WRITE) {
2160             if (!(p->flags & PAGE_WRITE_ORG)) {
2161                 return -1;
2162             }
2163             /* unprotect the page if it was put read-only because it
2164                contains translated code */
2165             if (!(p->flags & PAGE_WRITE)) {
2166                 if (!page_unprotect(addr, 0)) {
2167                     return -1;
2168                 }
2169             }
2170         }
2171     }
2172     return 0;
2173 }
2174 
2175 /* called from signal handler: invalidate the code and unprotect the
2176  * page. Return 0 if the fault was not handled, 1 if it was handled,
2177  * and 2 if it was handled but the caller must cause the TB to be
2178  * immediately exited. (We can only return 2 if the 'pc' argument is
2179  * non-zero.)
2180  */
2181 int page_unprotect(target_ulong address, uintptr_t pc)
2182 {
2183     unsigned int prot;
2184     bool current_tb_invalidated;
2185     PageDesc *p;
2186     target_ulong host_start, host_end, addr;
2187 
2188     /* Technically this isn't safe inside a signal handler.  However we
2189        know this only ever happens in a synchronous SEGV handler, so in
2190        practice it seems to be ok.  */
2191     mmap_lock();
2192 
2193     p = page_find(address >> TARGET_PAGE_BITS);
2194     if (!p) {
2195         mmap_unlock();
2196         return 0;
2197     }
2198 
2199     /* if the page was really writable, then we change its
2200        protection back to writable */
2201     if ((p->flags & PAGE_WRITE_ORG) && !(p->flags & PAGE_WRITE)) {
2202         host_start = address & qemu_host_page_mask;
2203         host_end = host_start + qemu_host_page_size;
2204 
2205         prot = 0;
2206         current_tb_invalidated = false;
2207         for (addr = host_start ; addr < host_end ; addr += TARGET_PAGE_SIZE) {
2208             p = page_find(addr >> TARGET_PAGE_BITS);
2209             p->flags |= PAGE_WRITE;
2210             prot |= p->flags;
2211 
2212             /* and since the content will be modified, we must invalidate
2213                the corresponding translated code. */
2214             current_tb_invalidated |= tb_invalidate_phys_page(addr, pc);
2215 #ifdef DEBUG_TB_CHECK
2216             tb_invalidate_check(addr);
2217 #endif
2218         }
2219         mprotect((void *)g2h(host_start), qemu_host_page_size,
2220                  prot & PAGE_BITS);
2221 
2222         mmap_unlock();
2223         /* If current TB was invalidated return to main loop */
2224         return current_tb_invalidated ? 2 : 1;
2225     }
2226     mmap_unlock();
2227     return 0;
2228 }
2229 #endif /* CONFIG_USER_ONLY */
2230 
2231 /* This is a wrapper for common code that can not use CONFIG_SOFTMMU */
2232 void tcg_flush_softmmu_tlb(CPUState *cs)
2233 {
2234 #ifdef CONFIG_SOFTMMU
2235     tlb_flush(cs);
2236 #endif
2237 }
2238