trace: [tcg] Delay changes to dynamic state when translating

This keeps consistency across all decisions taken during translation
when the dynamic state of a vCPU is changed in the middle of translating
some guest code.

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-id: 149915750615.6295.3713699402253529487.stgit@frigg.lan
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Lluís Vilanova 2017-07-04 10:38:26 +02:00 committed by Stefan Hajnoczi
parent d01c05c955
commit d43811165d
2 changed files with 19 additions and 2 deletions

View File

@ -302,6 +302,8 @@ struct qemu_work_item;
* @kvm_fd: vCPU file descriptor for KVM.
* @work_mutex: Lock to prevent multiple access to queued_work_*.
* @queued_work_first: First asynchronous work pending.
* @trace_dstate_delayed: Delayed changes to trace_dstate (includes all changes
* to @trace_dstate).
* @trace_dstate: Dynamic tracing state of events for this vCPU (bitmask).
*
* State of one CPU core or thread.
@ -372,6 +374,7 @@ struct CPUState {
struct kvm_run *kvm_run;
/* Used for events with 'vcpu' and *without* the 'disabled' properties */
DECLARE_BITMAP(trace_dstate_delayed, CPU_TRACE_DSTATE_MAX_EVENTS);
DECLARE_BITMAP(trace_dstate, CPU_TRACE_DSTATE_MAX_EVENTS);
/* TODO Move common fields from CPUArchState here. */

View File

@ -61,6 +61,13 @@ void trace_event_set_state_dynamic(TraceEvent *ev, bool state)
}
}
static void trace_event_synchronize_vcpu_state_dynamic(
CPUState *vcpu, run_on_cpu_data ignored)
{
bitmap_copy(vcpu->trace_dstate, vcpu->trace_dstate_delayed,
CPU_TRACE_DSTATE_MAX_EVENTS);
}
void trace_event_set_vcpu_state_dynamic(CPUState *vcpu,
TraceEvent *ev, bool state)
{
@ -73,13 +80,20 @@ void trace_event_set_vcpu_state_dynamic(CPUState *vcpu,
if (state_pre != state) {
if (state) {
trace_events_enabled_count++;
set_bit(vcpu_id, vcpu->trace_dstate);
set_bit(vcpu_id, vcpu->trace_dstate_delayed);
(*ev->dstate)++;
} else {
trace_events_enabled_count--;
clear_bit(vcpu_id, vcpu->trace_dstate);
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);
}
}