arm/arm64: KVM: Fix ordering of timer/GIC on guest entry (9a99d050) · Commits · 戴 / test

As we now inject the timer interrupt when we're about to enter the guest, it makes a lot more sense to make sure this happens before the vgic code queues the pending interrupts. Otherwise, we get the interrupt on the following exit, which is not great for latency (and leads to all kind of bizarre issues when using with active interrupts at the HW level). Signed-off-by:

Marc Zyngier <marc.zyngier@arm.com> Reviewed-by:

Alex Bennée <alex.bennee@linaro.org> Reviewed-by:

Christoffer Dall <christoffer.dall@linaro.org>

arch/arm/kvm/arm.c

+3 −4

Original line number	Diff line number	Diff line
		@@ -523,8 +523,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu vcpu, struct kvm_run run)
		if (vcpu->arch.pause)
		vcpu_pause(vcpu);

		kvm_vgic_flush_hwstate(vcpu);
		kvm_timer_flush_hwstate(vcpu);
		kvm_vgic_flush_hwstate(vcpu);

		preempt_disable();
		local_irq_disable();
		@@ -540,8 +540,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu vcpu, struct kvm_run run)
		if (ret <= 0 \|\| need_new_vmid_gen(vcpu->kvm)) {
		local_irq_enable();
		preempt_enable();
		kvm_timer_sync_hwstate(vcpu);
		kvm_vgic_sync_hwstate(vcpu);
		kvm_timer_sync_hwstate(vcpu);
		continue;
		}

		@@ -587,9 +587,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu vcpu, struct kvm_run run)
		trace_kvm_exit(kvm_vcpu_trap_get_class(vcpu), *vcpu_pc(vcpu));
		preempt_enable();


		kvm_timer_sync_hwstate(vcpu);
		kvm_vgic_sync_hwstate(vcpu);
		kvm_timer_sync_hwstate(vcpu);

		ret = handle_exit(vcpu, run, ret);
		}

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