From mboxrd@z Thu Jan 1 00:00:00 1970 From: marc.zyngier@arm.com (Marc Zyngier) Date: Fri, 7 Aug 2015 16:45:37 +0100 Subject: [PATCH v4 01/11] arm/arm64: KVM: Fix ordering of timer/GIC on guest entry In-Reply-To: <1438962347-17541-1-git-send-email-marc.zyngier@arm.com> References: <1438962347-17541-1-git-send-email-marc.zyngier@arm.com> Message-ID: <1438962347-17541-2-git-send-email-marc.zyngier@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 Reviewed-by: Alex Benn?e Reviewed-by: Christoffer Dall --- arch/arm/kvm/arm.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index 9ce5cf0..1141d21 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -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); } -- 2.1.4