| Message ID | 20170923004207.22356-11-cdall@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 23/09/17 01:41, Christoffer Dall wrote: > As we are about to play tricks with the timer to be more lazy in saving > and restoring state, we need to move the timer sync and flush functions > under a disabled irq section and since we have to flush the vgic state > after the timer and PMU state, we do the whole flush/sync sequence with > disabled irqs. > > The only downside is a slightly longer delay before being able to > process hardware interrupts and run softirqs. > > Signed-off-by: Christoffer Dall <cdall@linaro.org> > --- > virt/kvm/arm/arm.c | 26 +++++++++++++------------- > 1 file changed, 13 insertions(+), 13 deletions(-) > > diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c > index b9f68e4..27db222 100644 > --- a/virt/kvm/arm/arm.c > +++ b/virt/kvm/arm/arm.c > @@ -654,11 +654,11 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) > > kvm_pmu_flush_hwstate(vcpu); > > + local_irq_disable(); > + > kvm_timer_flush_hwstate(vcpu); > kvm_vgic_flush_hwstate(vcpu); > > - local_irq_disable(); > - > /* > * If we have a singal pending, or need to notify a userspace > * irqchip about timer or PMU level changes, then we exit (and > @@ -683,10 +683,10 @@ 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->mode = OUTSIDE_GUEST_MODE; > - local_irq_enable(); > kvm_pmu_sync_hwstate(vcpu); > kvm_timer_sync_hwstate(vcpu); > kvm_vgic_sync_hwstate(vcpu); > + local_irq_enable(); > preempt_enable(); > continue; > } > @@ -710,6 +710,16 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) > kvm_arm_clear_debug(vcpu); > > /* > + * We must sync the PMU and timer state before the vgic state so > + * that the vgic can properly sample the updated state of the > + * interrupt line. > + */ > + kvm_pmu_sync_hwstate(vcpu); > + kvm_timer_sync_hwstate(vcpu); > + > + kvm_vgic_sync_hwstate(vcpu); > + > + /* > * We may have taken a host interrupt in HYP mode (ie > * while executing the guest). This interrupt is still > * pending, as we haven't serviced it yet! > @@ -732,16 +742,6 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) > guest_exit(); > trace_kvm_exit(ret, kvm_vcpu_trap_get_class(vcpu), *vcpu_pc(vcpu)); > > - /* > - * We must sync the PMU and timer state before the vgic state so > - * that the vgic can properly sample the updated state of the > - * interrupt line. > - */ > - kvm_pmu_sync_hwstate(vcpu); > - kvm_timer_sync_hwstate(vcpu); > - > - kvm_vgic_sync_hwstate(vcpu); > - > preempt_enable(); > > ret = handle_exit(vcpu, run, ret); > Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> M.
diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c index b9f68e4..27db222 100644 --- a/virt/kvm/arm/arm.c +++ b/virt/kvm/arm/arm.c @@ -654,11 +654,11 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) kvm_pmu_flush_hwstate(vcpu); + local_irq_disable(); + kvm_timer_flush_hwstate(vcpu); kvm_vgic_flush_hwstate(vcpu); - local_irq_disable(); - /* * If we have a singal pending, or need to notify a userspace * irqchip about timer or PMU level changes, then we exit (and @@ -683,10 +683,10 @@ 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->mode = OUTSIDE_GUEST_MODE; - local_irq_enable(); kvm_pmu_sync_hwstate(vcpu); kvm_timer_sync_hwstate(vcpu); kvm_vgic_sync_hwstate(vcpu); + local_irq_enable(); preempt_enable(); continue; } @@ -710,6 +710,16 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) kvm_arm_clear_debug(vcpu); /* + * We must sync the PMU and timer state before the vgic state so + * that the vgic can properly sample the updated state of the + * interrupt line. + */ + kvm_pmu_sync_hwstate(vcpu); + kvm_timer_sync_hwstate(vcpu); + + kvm_vgic_sync_hwstate(vcpu); + + /* * We may have taken a host interrupt in HYP mode (ie * while executing the guest). This interrupt is still * pending, as we haven't serviced it yet! @@ -732,16 +742,6 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) guest_exit(); trace_kvm_exit(ret, kvm_vcpu_trap_get_class(vcpu), *vcpu_pc(vcpu)); - /* - * We must sync the PMU and timer state before the vgic state so - * that the vgic can properly sample the updated state of the - * interrupt line. - */ - kvm_pmu_sync_hwstate(vcpu); - kvm_timer_sync_hwstate(vcpu); - - kvm_vgic_sync_hwstate(vcpu); - preempt_enable(); ret = handle_exit(vcpu, run, ret);
As we are about to play tricks with the timer to be more lazy in saving and restoring state, we need to move the timer sync and flush functions under a disabled irq section and since we have to flush the vgic state after the timer and PMU state, we do the whole flush/sync sequence with disabled irqs. The only downside is a slightly longer delay before being able to process hardware interrupts and run softirqs. Signed-off-by: Christoffer Dall <cdall@linaro.org> --- virt/kvm/arm/arm.c | 26 +++++++++++++------------- 1 file changed, 13 insertions(+), 13 deletions(-)