Re: [Qemu-devel] [PATCH v2] trace: Immediately apply per-vCPU state changes if a vCPU is being created

[Stefan Hajnoczi]

On Wed, Sep 13, 2017 at 01:50:25AM +0300, Lluís Vilanova wrote:
> Right now, function trace_event_set_vcpu_state_dynamic() asynchronously 
> enables
> events in the case a vCPU is executing TCG code. If the vCPU is being created
> this makes some events like "guest_cpu_enter" to not be traced.
> 
> Signed-off-by: Lluís Vilanova 
> Reviewed-by: Emilio G. Cota 
> ---
> 
> Changes in v2
> =
> 
> * Use RUN_ON_CPU_NULL [Emilio G. Cota].
> * Rebase on fcea73709b.
> ---
>  trace/control-target.c |   18 +++---
>  1 file changed, 11 insertions(+), 7 deletions(-)

Thanks, applied to my tracing tree:
https://github.com/stefanha/qemu/commits/tracing

Stefan

[Qemu-devel] [PATCH v2] trace: Immediately apply per-vCPU state changes if a vCPU is being created

[Lluís Vilanova]

Right now, function trace_event_set_vcpu_state_dynamic() asynchronously enables
events in the case a vCPU is executing TCG code. If the vCPU is being created
this makes some events like "guest_cpu_enter" to not be traced.

Signed-off-by: Lluís Vilanova 
Reviewed-by: Emilio G. Cota 
---

Changes in v2
=

* Use RUN_ON_CPU_NULL [Emilio G. Cota].
* Rebase on fcea73709b.
---
 trace/control-target.c |   18 +++---
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/trace/control-target.c b/trace/control-target.c
index 4e36101997..706b2cee9d 100644
--- a/trace/control-target.c
+++ b/trace/control-target.c
@@ -88,13 +88,17 @@ void trace_event_set_vcpu_state_dynamic(CPUState *vcpu,
 clear_bit(vcpu_id, vcpu->trace_dstate_delayed);
 (*ev->dstate)--;
 }
-/*
- * Delay changes until next TB; we want all TBs to be built from a
- * single set of dstate values to ensure consistency of generated
- * tracing code.
- */
-async_run_on_cpu(vcpu, trace_event_synchronize_vcpu_state_dynamic,
- RUN_ON_CPU_NULL);
+if (vcpu->created) {
+/*
+ * Delay changes until next TB; we want all TBs to be built from a
+ * single set of dstate values to ensure consistency of generated
+ * tracing code.
+ */
+async_run_on_cpu(vcpu, trace_event_synchronize_vcpu_state_dynamic,
+ RUN_ON_CPU_NULL);
+} else {
+trace_event_synchronize_vcpu_state_dynamic(vcpu, RUN_ON_CPU_NULL);
+}
 }
 }
 

[Qemu-devel] [PATCH v2] trace: Immediately apply per-vCPU state changes if a vCPU is being created

[Lluís Vilanova]

Right now, function trace_event_set_vcpu_state_dynamic() asynchronously enables
events in the case a vCPU is executing TCG code. If the vCPU is being created
this makes some events like "guest_cpu_enter" to not be traced.

Signed-off-by: Lluís Vilanova 
Reviewed-by: Emilio G. Cora 
---

Changes in v2
=

* Use RUN_ON_CPU_NULL [Emilio G. Cota].
* Rebase on fcea73709b.
---
 trace/control-target.c |   18 +++---
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/trace/control-target.c b/trace/control-target.c
index 4e36101997..706b2cee9d 100644
--- a/trace/control-target.c
+++ b/trace/control-target.c
@@ -88,13 +88,17 @@ void trace_event_set_vcpu_state_dynamic(CPUState *vcpu,
 clear_bit(vcpu_id, vcpu->trace_dstate_delayed);
 (*ev->dstate)--;
 }
-/*
- * Delay changes until next TB; we want all TBs to be built from a
- * single set of dstate values to ensure consistency of generated
- * tracing code.
- */
-async_run_on_cpu(vcpu, trace_event_synchronize_vcpu_state_dynamic,
- RUN_ON_CPU_NULL);
+if (vcpu->created) {
+/*
+ * Delay changes until next TB; we want all TBs to be built from a
+ * single set of dstate values to ensure consistency of generated
+ * tracing code.
+ */
+async_run_on_cpu(vcpu, trace_event_synchronize_vcpu_state_dynamic,
+ RUN_ON_CPU_NULL);
+} else {
+trace_event_synchronize_vcpu_state_dynamic(vcpu, RUN_ON_CPU_NULL);
+}
 }
 }