From b7484931e4a8b06fe734ac2b5134f09204bad11a Mon Sep 17 00:00:00 2001 From: Andrew Jones Date: Sun, 4 Jun 2017 14:44:00 +0200 Subject: [PATCH] KVM: arm/arm64: PMU: remove request-less vcpu kick Refactor PMU overflow handling in order to remove the request-less vcpu kick. Now, since kvm_vgic_inject_irq() uses vcpu requests, there should be no chance that a kick sent at just the wrong time (between the VCPU's call to kvm_pmu_flush_hwstate() and before it enters guest mode) results in a failure for the guest to see updated GIC state until its next exit some time later for some other reason. Signed-off-by: Andrew Jones Reviewed-by: Christoffer Dall Signed-off-by: Christoffer Dall --- virt/kvm/arm/pmu.c | 40 +++++++++++++++++++--------------------- 1 file changed, 19 insertions(+), 21 deletions(-) diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c index 4b43e7f3b158..2451607dc25e 100644 --- a/virt/kvm/arm/pmu.c +++ b/virt/kvm/arm/pmu.c @@ -203,6 +203,23 @@ static u64 kvm_pmu_overflow_status(struct kvm_vcpu *vcpu) return reg; } +static void kvm_pmu_check_overflow(struct kvm_vcpu *vcpu) +{ + struct kvm_pmu *pmu = &vcpu->arch.pmu; + bool overflow = !!kvm_pmu_overflow_status(vcpu); + + if (pmu->irq_level == overflow) + return; + + pmu->irq_level = overflow; + + if (likely(irqchip_in_kernel(vcpu->kvm))) { + int ret = kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id, + pmu->irq_num, overflow); + WARN_ON(ret); + } +} + /** * kvm_pmu_overflow_set - set PMU overflow interrupt * @vcpu: The vcpu pointer @@ -210,37 +227,18 @@ static u64 kvm_pmu_overflow_status(struct kvm_vcpu *vcpu) */ void kvm_pmu_overflow_set(struct kvm_vcpu *vcpu, u64 val) { - u64 reg; - if (val == 0) return; vcpu_sys_reg(vcpu, PMOVSSET_EL0) |= val; - reg = kvm_pmu_overflow_status(vcpu); - if (reg != 0) - kvm_vcpu_kick(vcpu); + kvm_pmu_check_overflow(vcpu); } static void kvm_pmu_update_state(struct kvm_vcpu *vcpu) { - struct kvm_pmu *pmu = &vcpu->arch.pmu; - bool overflow; - if (!kvm_arm_pmu_v3_ready(vcpu)) return; - - overflow = !!kvm_pmu_overflow_status(vcpu); - if (pmu->irq_level == overflow) - return; - - pmu->irq_level = overflow; - - if (likely(irqchip_in_kernel(vcpu->kvm))) { - int ret; - ret = kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id, - pmu->irq_num, overflow); - WARN_ON(ret); - } + kvm_pmu_check_overflow(vcpu); } bool kvm_pmu_should_notify_user(struct kvm_vcpu *vcpu) -- 2.20.1