Commit b7484931 authored by Andrew Jones's avatar Andrew Jones Committed by Christoffer Dall
Browse files

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: default avatarAndrew Jones <drjones@redhat.com>
Reviewed-by: default avatarChristoffer Dall <cdall@linaro.org>
Signed-off-by: default avatarChristoffer Dall <cdall@linaro.org>
parent 325f9c64

virt/kvm/arm/pmu.c

+19 −21
Original line number Diff line number Diff line
@@ -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)

CRA Git | Maintained and supported by SUSTech CRA and CCSE