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authorPavel Dovgalyuk <dovgaluk@ispras.ru>2017-02-07 09:54:57 +0300
committerPaolo Bonzini <pbonzini@redhat.com>2017-02-24 15:51:19 +0100
commitcfb2d02be9413d45b30ed6d8e38800250b6b4b48 (patch)
tree20061573b26c877ddc37e96485102d1717fe33f3 /cpu-exec.c
parent1aab16c28a0232d898d6f56f5a56019472296ee7 (diff)
downloadqemu-arm-cfb2d02be9413d45b30ed6d8e38800250b6b4b48.tar.gz
replay: check icount in cpu exec loop
This patch adds check to break cpu loop when icount expires without setting the TB_EXIT_ICOUNT_EXPIRED flag. It happens when there is no available translated blocks and all instructions were executed. In icount replay mode unnecessary tb_find will be called (which may cause an exception) and execution will be non-deterministic. Because cpu_loop_exec_tb cannot longjmp anymore, we can remove the anticipated call to align_clocks in cpu_loop_exec_tb, as well as the SyncClocks *sc argument. Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru> Message-Id: <002801d2810f$18809c20$4981d460$@ru> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Pavel Dovgalyuk <dovgaluk@ispras.ru>
Diffstat (limited to 'cpu-exec.c')
-rw-r--r--cpu-exec.c15
1 files changed, 7 insertions, 8 deletions
diff --git a/cpu-exec.c b/cpu-exec.c
index 8f094c8e15..7ddf66cf23 100644
--- a/cpu-exec.c
+++ b/cpu-exec.c
@@ -517,7 +517,10 @@ static inline bool cpu_handle_interrupt(CPUState *cpu,
*last_tb = NULL;
}
}
- if (unlikely(atomic_read(&cpu->exit_request) || replay_has_interrupt())) {
+
+ /* Finally, check if we need to exit to the main loop. */
+ if (unlikely(atomic_read(&cpu->exit_request)
+ || (use_icount && cpu->icount_decr.u16.low + cpu->icount_extra == 0))) {
atomic_set(&cpu->exit_request, 0);
cpu->exception_index = EXCP_INTERRUPT;
return true;
@@ -527,8 +530,7 @@ static inline bool cpu_handle_interrupt(CPUState *cpu,
}
static inline void cpu_loop_exec_tb(CPUState *cpu, TranslationBlock *tb,
- TranslationBlock **last_tb, int *tb_exit,
- SyncClocks *sc)
+ TranslationBlock **last_tb, int *tb_exit)
{
uintptr_t ret;
int32_t insns_left;
@@ -579,10 +581,7 @@ static inline void cpu_loop_exec_tb(CPUState *cpu, TranslationBlock *tb,
*/
if (insns_left > 0) {
cpu_exec_nocache(cpu, insns_left, tb, false);
- align_clocks(sc, cpu);
}
- cpu->exception_index = EXCP_INTERRUPT;
- cpu_loop_exit(cpu);
}
#endif
}
@@ -593,7 +592,7 @@ int cpu_exec(CPUState *cpu)
{
CPUClass *cc = CPU_GET_CLASS(cpu);
int ret;
- SyncClocks sc;
+ SyncClocks sc = { 0 };
/* replay_interrupt may need current_cpu */
current_cpu = cpu;
@@ -643,7 +642,7 @@ int cpu_exec(CPUState *cpu)
while (!cpu_handle_interrupt(cpu, &last_tb)) {
TranslationBlock *tb = tb_find(cpu, last_tb, tb_exit);
- cpu_loop_exec_tb(cpu, tb, &last_tb, &tb_exit, &sc);
+ cpu_loop_exec_tb(cpu, tb, &last_tb, &tb_exit);
/* Try to align the host and virtual clocks
if the guest is in advance */
align_clocks(&sc, cpu);