From: Pavel Dovgalyuk <pavel.dovgalyuk@ispras.ru>

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.Dovgalyuk@ispras.ru>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <163542168516.2127597.8781375223437124644.stgit@pasha-ThinkPad-X280>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 softmmu/physmem.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/softmmu/physmem.c b/softmmu/physmem.c
index 555c907f67..d58752678d 100644
--- a/softmmu/physmem.c
+++ b/softmmu/physmem.c
@@ -938,18 +938,16 @@ void cpu_check_watchpoint(CPUState *cpu, vaddr addr, vaddr len,
                 cpu->watchpoint_hit = wp;
 
                 mmap_lock();
+                /* This call also restores vCPU state */
                 tb_check_watchpoint(cpu, ra);
                 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);
                 }
             }
-- 
2.25.1