diff mbox series

[v5,01/15] replay: don't record interrupt poll

Message ID 160077694335.10249.16333420401245362506.stgit@pasha-ThinkPad-X280
State New
Headers show
Series Reverse debugging | expand

Commit Message

Pavel Dovgalyuk Sept. 22, 2020, 12:15 p.m. UTC 
Interrupt poll is not a real interrupt event. It is needed only for
thread safety. This interrupt is used for i386 and converted
to hardware interrupt by cpu_handle_interrupt function.
Therefore it is not needed to be recorded, because hardware
interrupt will be recorded after converting.

Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

--

v4 changes:
 - Condition check refactoring (suggested by Alex Bennée)
---
 accel/tcg/cpu-exec.c |   21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

Comments

Philippe Mathieu-Daudé Sept. 22, 2020, 12:57 p.m. UTC | #1 
On 9/22/20 2:15 PM, Pavel Dovgalyuk wrote:
> Interrupt poll is not a real interrupt event. It is needed only for
> thread safety. This interrupt is used for i386 and converted
> to hardware interrupt by cpu_handle_interrupt function.
> Therefore it is not needed to be recorded, because hardware
> interrupt will be recorded after converting.
> 
> Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
> Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
diff mbox series

Patch

diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c
index 66d38f9d85..c065b4cc77 100644
--- a/accel/tcg/cpu-exec.c
+++ b/accel/tcg/cpu-exec.c
@@ -429,8 +429,7 @@  static inline bool cpu_handle_halt(CPUState *cpu)
 {
     if (cpu->halted) {
 #if defined(TARGET_I386) && !defined(CONFIG_USER_ONLY)
-        if ((cpu->interrupt_request & CPU_INTERRUPT_POLL)
-            && replay_interrupt()) {
+        if (cpu->interrupt_request & CPU_INTERRUPT_POLL) {
             X86CPU *x86_cpu = X86_CPU(cpu);
             qemu_mutex_lock_iothread();
             apic_poll_irq(x86_cpu->apic_state);
@@ -526,6 +525,20 @@  static inline bool cpu_handle_exception(CPUState *cpu, int *ret)
     return false;
 }
 
+/*
+ * CPU_INTERRUPT_POLL is a virtual event which gets converted into a
+ * "real" interrupt event later. It does not need to be recorded for
+ * replay purposes.
+ */
+static inline bool need_replay_interrupt(int interrupt_request)
+{
+#if defined(TARGET_I386)
+    return !(interrupt_request & CPU_INTERRUPT_POLL);
+#else
+    return true;
+#endif
+}
+
 static inline bool cpu_handle_interrupt(CPUState *cpu,
                                         TranslationBlock **last_tb)
 {
@@ -587,7 +600,9 @@  static inline bool cpu_handle_interrupt(CPUState *cpu,
            and via longjmp via cpu_loop_exit.  */
         else {
             if (cc->cpu_exec_interrupt(cpu, interrupt_request)) {
-                replay_interrupt();
+                if (need_replay_interrupt(interrupt_request)) {
+                    replay_interrupt();
+                }
                 /*
                  * After processing the interrupt, ensure an EXCP_DEBUG is
                  * raised when single-stepping so that GDB doesn't miss the