On Tue, May 16, 2017 at 04:20:29AM +0200, Andrew Jones wrote: > The current use of KVM_REQ_VCPU_EXIT for pause is fine. Even the > requester clearing the request is OK, as this is the special case > where the sole requesting thread and receiving VCPU are executing > synchronously (see "Clearing Requests" in > Documentation/virtual/kvm/vcpu-requests.rst) However, that's about > to change, so let's ensure only the receiving VCPU clears the > request. Additionally, by guaranteeing KVM_REQ_VCPU_EXIT is always > set when pause is, we can avoid checking pause directly in VCPU RUN. > > Signed-off-by: Andrew Jones <[email protected]>
Reviewed-by: Christoffer Dall <[email protected]> > --- > virt/kvm/arm/arm.c | 20 +++++++++++++++++--- > 1 file changed, 17 insertions(+), 3 deletions(-) > > diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c > index 138212605ad9..21a4db90073f 100644 > --- a/virt/kvm/arm/arm.c > +++ b/virt/kvm/arm/arm.c > @@ -546,7 +546,6 @@ void kvm_arm_resume_guest(struct kvm *kvm) > > kvm_for_each_vcpu(i, vcpu, kvm) { > vcpu->arch.pause = false; > - kvm_clear_request(KVM_REQ_VCPU_EXIT, vcpu); > swake_up(kvm_arch_vcpu_wq(vcpu)); > } > } > @@ -557,6 +556,11 @@ static void vcpu_sleep(struct kvm_vcpu *vcpu) > > swait_event_interruptible(*wq, ((!vcpu->arch.power_off) && > (!vcpu->arch.pause))); > + > + if (vcpu->arch.pause) { > + /* Awaken to handle a signal, request we sleep again later. */ > + kvm_make_request(KVM_REQ_VCPU_EXIT, vcpu); > + } > } > > static int kvm_vcpu_initialized(struct kvm_vcpu *vcpu) > @@ -564,6 +568,14 @@ static int kvm_vcpu_initialized(struct kvm_vcpu *vcpu) > return vcpu->arch.target >= 0; > } > > +static void check_vcpu_requests(struct kvm_vcpu *vcpu) > +{ > + if (kvm_request_pending(vcpu)) { > + if (kvm_check_request(KVM_REQ_VCPU_EXIT, vcpu)) > + vcpu_sleep(vcpu); > + } > +} > + > /** > * kvm_arch_vcpu_ioctl_run - the main VCPU run function to execute guest code > * @vcpu: The VCPU pointer > @@ -609,7 +621,9 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct > kvm_run *run) > > update_vttbr(vcpu->kvm); > > - if (vcpu->arch.power_off || vcpu->arch.pause) > + check_vcpu_requests(vcpu); > + > + if (vcpu->arch.power_off) > vcpu_sleep(vcpu); > > /* > @@ -649,7 +663,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct > kvm_run *run) > > if (ret <= 0 || need_new_vmid_gen(vcpu->kvm) || > kvm_request_pending(vcpu) || > - vcpu->arch.power_off || vcpu->arch.pause) { > + vcpu->arch.power_off) { > vcpu->mode = OUTSIDE_GUEST_MODE; > local_irq_enable(); > kvm_pmu_sync_hwstate(vcpu); > -- > 2.9.3 > _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
