2 * emulator main execution loop
4 * Copyright (c) 2003-2005 Fabrice Bellard
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
19 #include "qemu/osdep.h"
22 #include "disas/disas.h"
23 #include "exec/exec-all.h"
25 #include "qemu/atomic.h"
26 #include "sysemu/qtest.h"
27 #include "qemu/timer.h"
29 #include "exec/tb-hash.h"
30 #include "exec/tb-lookup.h"
32 #include "qemu/main-loop.h"
33 #if defined(TARGET_I386) && !defined(CONFIG_USER_ONLY)
34 #include "hw/i386/apic.h"
36 #include "sysemu/cpus.h"
37 #include "sysemu/replay.h"
39 /* -icount align implementation. */
41 typedef struct SyncClocks
{
43 int64_t last_cpu_icount
;
44 int64_t realtime_clock
;
47 #if !defined(CONFIG_USER_ONLY)
48 /* Allow the guest to have a max 3ms advance.
49 * The difference between the 2 clocks could therefore
52 #define VM_CLOCK_ADVANCE 3000000
53 #define THRESHOLD_REDUCE 1.5
54 #define MAX_DELAY_PRINT_RATE 2000000000LL
55 #define MAX_NB_PRINTS 100
57 static void align_clocks(SyncClocks
*sc
, const CPUState
*cpu
)
61 if (!icount_align_option
) {
65 cpu_icount
= cpu
->icount_extra
+ cpu
->icount_decr
.u16
.low
;
66 sc
->diff_clk
+= cpu_icount_to_ns(sc
->last_cpu_icount
- cpu_icount
);
67 sc
->last_cpu_icount
= cpu_icount
;
69 if (sc
->diff_clk
> VM_CLOCK_ADVANCE
) {
71 struct timespec sleep_delay
, rem_delay
;
72 sleep_delay
.tv_sec
= sc
->diff_clk
/ 1000000000LL;
73 sleep_delay
.tv_nsec
= sc
->diff_clk
% 1000000000LL;
74 if (nanosleep(&sleep_delay
, &rem_delay
) < 0) {
75 sc
->diff_clk
= rem_delay
.tv_sec
* 1000000000LL + rem_delay
.tv_nsec
;
80 Sleep(sc
->diff_clk
/ SCALE_MS
);
86 static void print_delay(const SyncClocks
*sc
)
88 static float threshold_delay
;
89 static int64_t last_realtime_clock
;
92 if (icount_align_option
&&
93 sc
->realtime_clock
- last_realtime_clock
>= MAX_DELAY_PRINT_RATE
&&
94 nb_prints
< MAX_NB_PRINTS
) {
95 if ((-sc
->diff_clk
/ (float)1000000000LL > threshold_delay
) ||
96 (-sc
->diff_clk
/ (float)1000000000LL <
97 (threshold_delay
- THRESHOLD_REDUCE
))) {
98 threshold_delay
= (-sc
->diff_clk
/ 1000000000LL) + 1;
99 printf("Warning: The guest is now late by %.1f to %.1f seconds\n",
103 last_realtime_clock
= sc
->realtime_clock
;
108 static void init_delay_params(SyncClocks
*sc
,
111 if (!icount_align_option
) {
114 sc
->realtime_clock
= qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL_RT
);
115 sc
->diff_clk
= qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL
) - sc
->realtime_clock
;
116 sc
->last_cpu_icount
= cpu
->icount_extra
+ cpu
->icount_decr
.u16
.low
;
117 if (sc
->diff_clk
< max_delay
) {
118 max_delay
= sc
->diff_clk
;
120 if (sc
->diff_clk
> max_advance
) {
121 max_advance
= sc
->diff_clk
;
124 /* Print every 2s max if the guest is late. We limit the number
125 of printed messages to NB_PRINT_MAX(currently 100) */
129 static void align_clocks(SyncClocks
*sc
, const CPUState
*cpu
)
133 static void init_delay_params(SyncClocks
*sc
, const CPUState
*cpu
)
136 #endif /* CONFIG USER ONLY */
138 /* Execute a TB, and fix up the CPU state afterwards if necessary */
139 static inline tcg_target_ulong
cpu_tb_exec(CPUState
*cpu
, TranslationBlock
*itb
)
141 CPUArchState
*env
= cpu
->env_ptr
;
143 TranslationBlock
*last_tb
;
145 uint8_t *tb_ptr
= itb
->tc
.ptr
;
147 qemu_log_mask_and_addr(CPU_LOG_EXEC
, itb
->pc
,
149 TARGET_FMT_lx
"/" TARGET_FMT_lx
"/%#x] %s\n",
150 cpu
->cpu_index
, itb
->tc
.ptr
,
151 itb
->cs_base
, itb
->pc
, itb
->flags
,
152 lookup_symbol(itb
->pc
));
154 #if defined(DEBUG_DISAS)
155 if (qemu_loglevel_mask(CPU_LOG_TB_CPU
)
156 && qemu_log_in_addr_range(itb
->pc
)) {
159 if (qemu_loglevel_mask(CPU_LOG_TB_FPU
)) {
160 flags
|= CPU_DUMP_FPU
;
162 #if defined(TARGET_I386)
163 flags
|= CPU_DUMP_CCOP
;
165 log_cpu_state(cpu
, flags
);
168 #endif /* DEBUG_DISAS */
170 cpu
->can_do_io
= !use_icount
;
171 ret
= tcg_qemu_tb_exec(env
, tb_ptr
);
173 last_tb
= (TranslationBlock
*)(ret
& ~TB_EXIT_MASK
);
174 tb_exit
= ret
& TB_EXIT_MASK
;
175 trace_exec_tb_exit(last_tb
, tb_exit
);
177 if (tb_exit
> TB_EXIT_IDX1
) {
178 /* We didn't start executing this TB (eg because the instruction
179 * counter hit zero); we must restore the guest PC to the address
180 * of the start of the TB.
182 CPUClass
*cc
= CPU_GET_CLASS(cpu
);
183 qemu_log_mask_and_addr(CPU_LOG_EXEC
, last_tb
->pc
,
184 "Stopped execution of TB chain before %p ["
185 TARGET_FMT_lx
"] %s\n",
186 last_tb
->tc
.ptr
, last_tb
->pc
,
187 lookup_symbol(last_tb
->pc
));
188 if (cc
->synchronize_from_tb
) {
189 cc
->synchronize_from_tb(cpu
, last_tb
);
192 cc
->set_pc(cpu
, last_tb
->pc
);
198 #ifndef CONFIG_USER_ONLY
199 /* Execute the code without caching the generated code. An interpreter
200 could be used if available. */
201 static void cpu_exec_nocache(CPUState
*cpu
, int max_cycles
,
202 TranslationBlock
*orig_tb
, bool ignore_icount
)
204 TranslationBlock
*tb
;
205 uint32_t cflags
= curr_cflags() | CF_NOCACHE
;
208 cflags
&= ~CF_USE_ICOUNT
;
211 /* Should never happen.
212 We only end up here when an existing TB is too long. */
213 cflags
|= MIN(max_cycles
, CF_COUNT_MASK
);
216 tb
= tb_gen_code(cpu
, orig_tb
->pc
, orig_tb
->cs_base
,
217 orig_tb
->flags
, cflags
);
218 tb
->orig_tb
= orig_tb
;
221 /* execute the generated code */
222 trace_exec_tb_nocache(tb
, tb
->pc
);
223 cpu_tb_exec(cpu
, tb
);
226 tb_phys_invalidate(tb
, -1);
232 void cpu_exec_step_atomic(CPUState
*cpu
)
234 CPUClass
*cc
= CPU_GET_CLASS(cpu
);
235 TranslationBlock
*tb
;
236 target_ulong cs_base
, pc
;
239 uint32_t cf_mask
= cflags
& CF_HASH_MASK
;
240 /* volatile because we modify it between setjmp and longjmp */
241 volatile bool in_exclusive_region
= false;
243 if (sigsetjmp(cpu
->jmp_env
, 0) == 0) {
244 tb
= tb_lookup__cpu_state(cpu
, &pc
, &cs_base
, &flags
, cf_mask
);
247 tb
= tb_gen_code(cpu
, pc
, cs_base
, flags
, cflags
);
253 /* Since we got here, we know that parallel_cpus must be true. */
254 parallel_cpus
= false;
255 in_exclusive_region
= true;
256 cc
->cpu_exec_enter(cpu
);
257 /* execute the generated code */
258 trace_exec_tb(tb
, pc
);
259 cpu_tb_exec(cpu
, tb
);
260 cc
->cpu_exec_exit(cpu
);
263 * The mmap_lock is dropped by tb_gen_code if it runs out of
266 #ifndef CONFIG_SOFTMMU
267 tcg_debug_assert(!have_mmap_lock());
269 assert_no_pages_locked();
272 if (in_exclusive_region
) {
273 /* We might longjump out of either the codegen or the
274 * execution, so must make sure we only end the exclusive
275 * region if we started it.
277 parallel_cpus
= true;
284 target_ulong cs_base
;
286 tb_page_addr_t phys_page1
;
289 uint32_t trace_vcpu_dstate
;
292 static bool tb_lookup_cmp(const void *p
, const void *d
)
294 const TranslationBlock
*tb
= p
;
295 const struct tb_desc
*desc
= d
;
297 if (tb
->pc
== desc
->pc
&&
298 tb
->page_addr
[0] == desc
->phys_page1
&&
299 tb
->cs_base
== desc
->cs_base
&&
300 tb
->flags
== desc
->flags
&&
301 tb
->trace_vcpu_dstate
== desc
->trace_vcpu_dstate
&&
302 (tb_cflags(tb
) & (CF_HASH_MASK
| CF_INVALID
)) == desc
->cf_mask
) {
303 /* check next page if needed */
304 if (tb
->page_addr
[1] == -1) {
307 tb_page_addr_t phys_page2
;
308 target_ulong virt_page2
;
310 virt_page2
= (desc
->pc
& TARGET_PAGE_MASK
) + TARGET_PAGE_SIZE
;
311 phys_page2
= get_page_addr_code(desc
->env
, virt_page2
);
312 if (tb
->page_addr
[1] == phys_page2
) {
320 TranslationBlock
*tb_htable_lookup(CPUState
*cpu
, target_ulong pc
,
321 target_ulong cs_base
, uint32_t flags
,
324 tb_page_addr_t phys_pc
;
328 desc
.env
= (CPUArchState
*)cpu
->env_ptr
;
329 desc
.cs_base
= cs_base
;
331 desc
.cf_mask
= cf_mask
;
332 desc
.trace_vcpu_dstate
= *cpu
->trace_dstate
;
334 phys_pc
= get_page_addr_code(desc
.env
, pc
);
335 desc
.phys_page1
= phys_pc
& TARGET_PAGE_MASK
;
336 h
= tb_hash_func(phys_pc
, pc
, flags
, cf_mask
, *cpu
->trace_dstate
);
337 return qht_lookup_custom(&tb_ctx
.htable
, &desc
, h
, tb_lookup_cmp
);
340 void tb_set_jmp_target(TranslationBlock
*tb
, int n
, uintptr_t addr
)
342 if (TCG_TARGET_HAS_direct_jump
) {
343 uintptr_t offset
= tb
->jmp_target_arg
[n
];
344 uintptr_t tc_ptr
= (uintptr_t)tb
->tc
.ptr
;
345 tb_target_set_jmp_target(tc_ptr
, tc_ptr
+ offset
, addr
);
347 tb
->jmp_target_arg
[n
] = addr
;
351 static inline void tb_add_jump(TranslationBlock
*tb
, int n
,
352 TranslationBlock
*tb_next
)
356 assert(n
< ARRAY_SIZE(tb
->jmp_list_next
));
357 qemu_spin_lock(&tb_next
->jmp_lock
);
359 /* make sure the destination TB is valid */
360 if (tb_next
->cflags
& CF_INVALID
) {
361 goto out_unlock_next
;
363 /* Atomically claim the jump destination slot only if it was NULL */
364 old
= atomic_cmpxchg(&tb
->jmp_dest
[n
], (uintptr_t)NULL
, (uintptr_t)tb_next
);
366 goto out_unlock_next
;
369 /* patch the native jump address */
370 tb_set_jmp_target(tb
, n
, (uintptr_t)tb_next
->tc
.ptr
);
372 /* add in TB jmp list */
373 tb
->jmp_list_next
[n
] = tb_next
->jmp_list_head
;
374 tb_next
->jmp_list_head
= (uintptr_t)tb
| n
;
376 qemu_spin_unlock(&tb_next
->jmp_lock
);
378 qemu_log_mask_and_addr(CPU_LOG_EXEC
, tb
->pc
,
379 "Linking TBs %p [" TARGET_FMT_lx
380 "] index %d -> %p [" TARGET_FMT_lx
"]\n",
381 tb
->tc
.ptr
, tb
->pc
, n
,
382 tb_next
->tc
.ptr
, tb_next
->pc
);
386 qemu_spin_unlock(&tb_next
->jmp_lock
);
390 static inline TranslationBlock
*tb_find(CPUState
*cpu
,
391 TranslationBlock
*last_tb
,
392 int tb_exit
, uint32_t cf_mask
)
394 TranslationBlock
*tb
;
395 target_ulong cs_base
, pc
;
398 tb
= tb_lookup__cpu_state(cpu
, &pc
, &cs_base
, &flags
, cf_mask
);
401 tb
= tb_gen_code(cpu
, pc
, cs_base
, flags
, cf_mask
);
403 /* We add the TB in the virtual pc hash table for the fast lookup */
404 atomic_set(&cpu
->tb_jmp_cache
[tb_jmp_cache_hash_func(pc
)], tb
);
406 #ifndef CONFIG_USER_ONLY
407 /* We don't take care of direct jumps when address mapping changes in
408 * system emulation. So it's not safe to make a direct jump to a TB
409 * spanning two pages because the mapping for the second page can change.
411 if (tb
->page_addr
[1] != -1) {
415 /* See if we can patch the calling TB. */
416 if (last_tb
&& !qemu_loglevel_mask(CPU_LOG_TB_NOCHAIN
)) {
417 tb_add_jump(last_tb
, tb_exit
, tb
);
422 static inline bool cpu_handle_halt(CPUState
*cpu
)
425 #if defined(TARGET_I386) && !defined(CONFIG_USER_ONLY)
426 if ((cpu
->interrupt_request
& CPU_INTERRUPT_POLL
)
427 && replay_interrupt()) {
428 X86CPU
*x86_cpu
= X86_CPU(cpu
);
429 qemu_mutex_lock_iothread();
430 apic_poll_irq(x86_cpu
->apic_state
);
431 cpu_reset_interrupt(cpu
, CPU_INTERRUPT_POLL
);
432 qemu_mutex_unlock_iothread();
435 if (!cpu_has_work(cpu
)) {
445 static inline void cpu_handle_debug_exception(CPUState
*cpu
)
447 CPUClass
*cc
= CPU_GET_CLASS(cpu
);
450 if (!cpu
->watchpoint_hit
) {
451 QTAILQ_FOREACH(wp
, &cpu
->watchpoints
, entry
) {
452 wp
->flags
&= ~BP_WATCHPOINT_HIT
;
456 cc
->debug_excp_handler(cpu
);
459 static inline bool cpu_handle_exception(CPUState
*cpu
, int *ret
)
461 if (cpu
->exception_index
< 0) {
462 #ifndef CONFIG_USER_ONLY
463 if (replay_has_exception()
464 && cpu
->icount_decr
.u16
.low
+ cpu
->icount_extra
== 0) {
465 /* try to cause an exception pending in the log */
466 cpu_exec_nocache(cpu
, 1, tb_find(cpu
, NULL
, 0, curr_cflags()), true);
469 if (cpu
->exception_index
< 0) {
474 if (cpu
->exception_index
>= EXCP_INTERRUPT
) {
475 /* exit request from the cpu execution loop */
476 *ret
= cpu
->exception_index
;
477 if (*ret
== EXCP_DEBUG
) {
478 cpu_handle_debug_exception(cpu
);
480 cpu
->exception_index
= -1;
483 #if defined(CONFIG_USER_ONLY)
484 /* if user mode only, we simulate a fake exception
485 which will be handled outside the cpu execution
487 #if defined(TARGET_I386)
488 CPUClass
*cc
= CPU_GET_CLASS(cpu
);
489 cc
->do_interrupt(cpu
);
491 *ret
= cpu
->exception_index
;
492 cpu
->exception_index
= -1;
495 if (replay_exception()) {
496 CPUClass
*cc
= CPU_GET_CLASS(cpu
);
497 qemu_mutex_lock_iothread();
498 cc
->do_interrupt(cpu
);
499 qemu_mutex_unlock_iothread();
500 cpu
->exception_index
= -1;
501 } else if (!replay_has_interrupt()) {
502 /* give a chance to iothread in replay mode */
503 *ret
= EXCP_INTERRUPT
;
512 static inline bool cpu_handle_interrupt(CPUState
*cpu
,
513 TranslationBlock
**last_tb
)
515 CPUClass
*cc
= CPU_GET_CLASS(cpu
);
517 /* Clear the interrupt flag now since we're processing
518 * cpu->interrupt_request and cpu->exit_request.
519 * Ensure zeroing happens before reading cpu->exit_request or
520 * cpu->interrupt_request (see also smp_wmb in cpu_exit())
522 atomic_mb_set(&cpu
->icount_decr
.u16
.high
, 0);
524 if (unlikely(atomic_read(&cpu
->interrupt_request
))) {
525 int interrupt_request
;
526 qemu_mutex_lock_iothread();
527 interrupt_request
= cpu
->interrupt_request
;
528 if (unlikely(cpu
->singlestep_enabled
& SSTEP_NOIRQ
)) {
529 /* Mask out external interrupts for this step. */
530 interrupt_request
&= ~CPU_INTERRUPT_SSTEP_MASK
;
532 if (interrupt_request
& CPU_INTERRUPT_DEBUG
) {
533 cpu
->interrupt_request
&= ~CPU_INTERRUPT_DEBUG
;
534 cpu
->exception_index
= EXCP_DEBUG
;
535 qemu_mutex_unlock_iothread();
538 if (replay_mode
== REPLAY_MODE_PLAY
&& !replay_has_interrupt()) {
540 } else if (interrupt_request
& CPU_INTERRUPT_HALT
) {
542 cpu
->interrupt_request
&= ~CPU_INTERRUPT_HALT
;
544 cpu
->exception_index
= EXCP_HLT
;
545 qemu_mutex_unlock_iothread();
548 #if defined(TARGET_I386)
549 else if (interrupt_request
& CPU_INTERRUPT_INIT
) {
550 X86CPU
*x86_cpu
= X86_CPU(cpu
);
551 CPUArchState
*env
= &x86_cpu
->env
;
553 cpu_svm_check_intercept_param(env
, SVM_EXIT_INIT
, 0, 0);
554 do_cpu_init(x86_cpu
);
555 cpu
->exception_index
= EXCP_HALTED
;
556 qemu_mutex_unlock_iothread();
560 else if (interrupt_request
& CPU_INTERRUPT_RESET
) {
563 qemu_mutex_unlock_iothread();
567 /* The target hook has 3 exit conditions:
568 False when the interrupt isn't processed,
569 True when it is, and we should restart on a new TB,
570 and via longjmp via cpu_loop_exit. */
572 if (cc
->cpu_exec_interrupt(cpu
, interrupt_request
)) {
574 cpu
->exception_index
= -1;
577 /* The target hook may have updated the 'cpu->interrupt_request';
578 * reload the 'interrupt_request' value */
579 interrupt_request
= cpu
->interrupt_request
;
581 if (interrupt_request
& CPU_INTERRUPT_EXITTB
) {
582 cpu
->interrupt_request
&= ~CPU_INTERRUPT_EXITTB
;
583 /* ensure that no TB jump will be modified as
584 the program flow was changed */
588 /* If we exit via cpu_loop_exit/longjmp it is reset in cpu_exec */
589 qemu_mutex_unlock_iothread();
592 /* Finally, check if we need to exit to the main loop. */
593 if (unlikely(atomic_read(&cpu
->exit_request
)
594 || (use_icount
&& cpu
->icount_decr
.u16
.low
+ cpu
->icount_extra
== 0))) {
595 atomic_set(&cpu
->exit_request
, 0);
596 if (cpu
->exception_index
== -1) {
597 cpu
->exception_index
= EXCP_INTERRUPT
;
605 static inline void cpu_loop_exec_tb(CPUState
*cpu
, TranslationBlock
*tb
,
606 TranslationBlock
**last_tb
, int *tb_exit
)
611 trace_exec_tb(tb
, tb
->pc
);
612 ret
= cpu_tb_exec(cpu
, tb
);
613 tb
= (TranslationBlock
*)(ret
& ~TB_EXIT_MASK
);
614 *tb_exit
= ret
& TB_EXIT_MASK
;
615 if (*tb_exit
!= TB_EXIT_REQUESTED
) {
621 insns_left
= atomic_read(&cpu
->icount_decr
.u32
);
622 if (insns_left
< 0) {
623 /* Something asked us to stop executing chained TBs; just
624 * continue round the main loop. Whatever requested the exit
625 * will also have set something else (eg exit_request or
626 * interrupt_request) which will be handled by
627 * cpu_handle_interrupt. cpu_handle_interrupt will also
628 * clear cpu->icount_decr.u16.high.
633 /* Instruction counter expired. */
635 #ifndef CONFIG_USER_ONLY
636 /* Ensure global icount has gone forward */
637 cpu_update_icount(cpu
);
638 /* Refill decrementer and continue execution. */
639 insns_left
= MIN(0xffff, cpu
->icount_budget
);
640 cpu
->icount_decr
.u16
.low
= insns_left
;
641 cpu
->icount_extra
= cpu
->icount_budget
- insns_left
;
642 if (!cpu
->icount_extra
) {
643 /* Execute any remaining instructions, then let the main loop
644 * handle the next event.
646 if (insns_left
> 0) {
647 cpu_exec_nocache(cpu
, insns_left
, tb
, false);
653 /* main execution loop */
655 int cpu_exec(CPUState
*cpu
)
657 CPUClass
*cc
= CPU_GET_CLASS(cpu
);
659 SyncClocks sc
= { 0 };
661 /* replay_interrupt may need current_cpu */
664 if (cpu_handle_halt(cpu
)) {
670 cc
->cpu_exec_enter(cpu
);
672 /* Calculate difference between guest clock and host clock.
673 * This delay includes the delay of the last cycle, so
674 * what we have to do is sleep until it is 0. As for the
675 * advance/delay we gain here, we try to fix it next time.
677 init_delay_params(&sc
, cpu
);
679 /* prepare setjmp context for exception handling */
680 if (sigsetjmp(cpu
->jmp_env
, 0) != 0) {
681 #if defined(__clang__) || !QEMU_GNUC_PREREQ(4, 6)
682 /* Some compilers wrongly smash all local variables after
683 * siglongjmp. There were bug reports for gcc 4.5.0 and clang.
684 * Reload essential local variables here for those compilers.
685 * Newer versions of gcc would complain about this code (-Wclobbered). */
687 cc
= CPU_GET_CLASS(cpu
);
688 #else /* buggy compiler */
689 /* Assert that the compiler does not smash local variables. */
690 g_assert(cpu
== current_cpu
);
691 g_assert(cc
== CPU_GET_CLASS(cpu
));
692 #endif /* buggy compiler */
693 #ifndef CONFIG_SOFTMMU
694 tcg_debug_assert(!have_mmap_lock());
696 if (qemu_mutex_iothread_locked()) {
697 qemu_mutex_unlock_iothread();
701 /* if an exception is pending, we execute it here */
702 while (!cpu_handle_exception(cpu
, &ret
)) {
703 TranslationBlock
*last_tb
= NULL
;
706 while (!cpu_handle_interrupt(cpu
, &last_tb
)) {
707 uint32_t cflags
= cpu
->cflags_next_tb
;
708 TranslationBlock
*tb
;
710 /* When requested, use an exact setting for cflags for the next
711 execution. This is used for icount, precise smc, and stop-
712 after-access watchpoints. Since this request should never
713 have CF_INVALID set, -1 is a convenient invalid value that
714 does not require tcg headers for cpu_common_reset. */
716 cflags
= curr_cflags();
718 cpu
->cflags_next_tb
= -1;
721 tb
= tb_find(cpu
, last_tb
, tb_exit
, cflags
);
722 cpu_loop_exec_tb(cpu
, tb
, &last_tb
, &tb_exit
);
723 /* Try to align the host and virtual clocks
724 if the guest is in advance */
725 align_clocks(&sc
, cpu
);
729 cc
->cpu_exec_exit(cpu
);