Commit d4381116 authored by Lluís Vilanova's avatar Lluís Vilanova Committed by Stefan Hajnoczi
Browse files

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: default avatarLluís Vilanova <vilanova@ac.upc.edu>
Reviewed-by: default avatarRichard Henderson <rth@twiddle.net>
Reviewed-by: default avatarEmilio G. Cota <cota@braap.org>
Signed-off-by: default avatarEmilio G. Cota <cota@braap.org>
Message-id: 149915750615.6295.3713699402253529487.stgit@frigg.lan
Signed-off-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
parent d01c05c9

include/qom/cpu.h

+3 −0
Original line number Diff line number Diff line
@@ -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. */

trace/control-target.c

+16 −2
Original line number Diff line number Diff line
@@ -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);

    }

}