From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Zyngier Subject: [PATCH 01/10] arm/arm64: KVM: Fix ordering of timer/GIC on guest entry Date: Mon, 8 Jun 2015 18:03:56 +0100 Message-ID: <1433783045-8002-2-git-send-email-marc.zyngier@arm.com> References: <1433783045-8002-1-git-send-email-marc.zyngier@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Andre Przywara To: kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org Return-path: In-Reply-To: <1433783045-8002-1-git-send-email-marc.zyngier@arm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu List-Id: kvm.vger.kernel.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 --- arch/arm/kvm/arm.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index d9631ec..46db690 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -529,9 +529,10 @@ 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); + local_irq_disable(); /* @@ -544,8 +545,8 @@ 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(); - kvm_timer_sync_hwstate(vcpu); kvm_vgic_sync_hwstate(vcpu); + kvm_timer_sync_hwstate(vcpu); continue; } @@ -577,9 +578,10 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) * Back from guest *************************************************************/ - kvm_timer_sync_hwstate(vcpu); kvm_vgic_sync_hwstate(vcpu); + kvm_timer_sync_hwstate(vcpu); + ret = handle_exit(vcpu, run, ret); } -- 2.1.4 From mboxrd@z Thu Jan 1 00:00:00 1970 From: marc.zyngier@arm.com (Marc Zyngier) Date: Mon, 8 Jun 2015 18:03:56 +0100 Subject: [PATCH 01/10] arm/arm64: KVM: Fix ordering of timer/GIC on guest entry In-Reply-To: <1433783045-8002-1-git-send-email-marc.zyngier@arm.com> References: <1433783045-8002-1-git-send-email-marc.zyngier@arm.com> Message-ID: <1433783045-8002-2-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 --- arch/arm/kvm/arm.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index d9631ec..46db690 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -529,9 +529,10 @@ 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); + local_irq_disable(); /* @@ -544,8 +545,8 @@ 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(); - kvm_timer_sync_hwstate(vcpu); kvm_vgic_sync_hwstate(vcpu); + kvm_timer_sync_hwstate(vcpu); continue; } @@ -577,9 +578,10 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) * Back from guest *************************************************************/ - kvm_timer_sync_hwstate(vcpu); kvm_vgic_sync_hwstate(vcpu); + kvm_timer_sync_hwstate(vcpu); + ret = handle_exit(vcpu, run, ret); } -- 2.1.4