On 07.09.21 13:30, Pavel Dovgalyuk wrote:
Watchpoint processing code restores vCPU state twice:
in tb_check_watchpoint and in cpu_loop_exit_restore/cpu_restore_state.
Normally it does not affect anything, but in icount mode instruction
counter is incremented twice and becomes incorrect.
This patch eliminates unneeded CPU state restore.
Signed-off-by: Pavel Dovgalyuk <pavel.dovgal...@ispras.ru>
---
softmmu/physmem.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/softmmu/physmem.c b/softmmu/physmem.c
index 23e77cb771..4025dfab11 100644
--- a/softmmu/physmem.c
+++ b/softmmu/physmem.c
@@ -941,14 +941,11 @@ void cpu_check_watchpoint(CPUState *cpu, vaddr addr,
vaddr len,
if (wp->flags & BP_STOP_BEFORE_ACCESS) {
cpu->exception_index = EXCP_DEBUG;
mmap_unlock();
- cpu_loop_exit_restore(cpu, ra);
+ cpu_loop_exit(cpu);
} else {
/* Force execution of one insn next time. */
cpu->cflags_next_tb = 1 | curr_cflags(cpu);
mmap_unlock();
- if (ra) {
- cpu_restore_state(cpu, ra, true);
- }
cpu_loop_exit_noexc(cpu);
}
}
I'm not an expert on that code, but it looks good to me.
Maybe we could have added a comment above the tb_check_watchpoint() call
to highlight that the restore will happen in there.
Reviewed-by: David Hildenbrand <da...@redhat.com>
--
Thanks,
David / dhildenb
