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KVM: arm/arm64: PMU: remove request-less vcpu kick

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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 <drjones@redhat.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
This commit is contained in:
Andrew Jones 2017-06-04 14:44:00 +02:00 committed by Christoffer Dall
parent 325f9c649c
commit b7484931e4
1 changed files with 19 additions and 21 deletions
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40
virt/kvm/arm/pmu.c
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@ -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)