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From: Christoffer Dall <cdall@linaro.org>
To: kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org
Cc: kvm@vger.kernel.org, Marc Zyngier <marc.zyngier@arm.com>,
	Will Deacon <will.deacon@arm.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Christoffer Dall <cdall@linaro.org>
Subject: [PATCH v3 10/20] KVM: arm/arm64: Move timer/vgic flush/sync under disabled irq
Date: Sat, 23 Sep 2017 02:41:57 +0200	[thread overview]
Message-ID: <20170923004207.22356-11-cdall@linaro.org> (raw)
In-Reply-To: <20170923004207.22356-1-cdall@linaro.org>

As we are about to play tricks with the timer to be more lazy in saving
and restoring state, we need to move the timer sync and flush functions
under a disabled irq section and since we have to flush the vgic state
after the timer and PMU state, we do the whole flush/sync sequence with
disabled irqs.

The only downside is a slightly longer delay before being able to
process hardware interrupts and run softirqs.

Signed-off-by: Christoffer Dall <cdall@linaro.org>
---
 virt/kvm/arm/arm.c | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
index b9f68e4..27db222 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c
@@ -654,11 +654,11 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 
 		kvm_pmu_flush_hwstate(vcpu);
 
+		local_irq_disable();
+
 		kvm_timer_flush_hwstate(vcpu);
 		kvm_vgic_flush_hwstate(vcpu);
 
-		local_irq_disable();
-
 		/*
 		 * If we have a singal pending, or need to notify a userspace
 		 * irqchip about timer or PMU level changes, then we exit (and
@@ -683,10 +683,10 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 		if (ret <= 0 || need_new_vmid_gen(vcpu->kvm) ||
 		    kvm_request_pending(vcpu)) {
 			vcpu->mode = OUTSIDE_GUEST_MODE;
-			local_irq_enable();
 			kvm_pmu_sync_hwstate(vcpu);
 			kvm_timer_sync_hwstate(vcpu);
 			kvm_vgic_sync_hwstate(vcpu);
+			local_irq_enable();
 			preempt_enable();
 			continue;
 		}
@@ -710,6 +710,16 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 		kvm_arm_clear_debug(vcpu);
 
 		/*
+		 * We must sync the PMU and timer state before the vgic state so
+		 * that the vgic can properly sample the updated state of the
+		 * interrupt line.
+		 */
+		kvm_pmu_sync_hwstate(vcpu);
+		kvm_timer_sync_hwstate(vcpu);
+
+		kvm_vgic_sync_hwstate(vcpu);
+
+		/*
 		 * We may have taken a host interrupt in HYP mode (ie
 		 * while executing the guest). This interrupt is still
 		 * pending, as we haven't serviced it yet!
@@ -732,16 +742,6 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 		guest_exit();
 		trace_kvm_exit(ret, kvm_vcpu_trap_get_class(vcpu), *vcpu_pc(vcpu));
 
-		/*
-		 * We must sync the PMU and timer state before the vgic state so
-		 * that the vgic can properly sample the updated state of the
-		 * interrupt line.
-		 */
-		kvm_pmu_sync_hwstate(vcpu);
-		kvm_timer_sync_hwstate(vcpu);
-
-		kvm_vgic_sync_hwstate(vcpu);
-
 		preempt_enable();
 
 		ret = handle_exit(vcpu, run, ret);
-- 
2.9.0

WARNING: multiple messages have this Message-ID (diff)
From: cdall@linaro.org (Christoffer Dall)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v3 10/20] KVM: arm/arm64: Move timer/vgic flush/sync under disabled irq
Date: Sat, 23 Sep 2017 02:41:57 +0200	[thread overview]
Message-ID: <20170923004207.22356-11-cdall@linaro.org> (raw)
In-Reply-To: <20170923004207.22356-1-cdall@linaro.org>

As we are about to play tricks with the timer to be more lazy in saving
and restoring state, we need to move the timer sync and flush functions
under a disabled irq section and since we have to flush the vgic state
after the timer and PMU state, we do the whole flush/sync sequence with
disabled irqs.

The only downside is a slightly longer delay before being able to
process hardware interrupts and run softirqs.

Signed-off-by: Christoffer Dall <cdall@linaro.org>
---
 virt/kvm/arm/arm.c | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
index b9f68e4..27db222 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c
@@ -654,11 +654,11 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 
 		kvm_pmu_flush_hwstate(vcpu);
 
+		local_irq_disable();
+
 		kvm_timer_flush_hwstate(vcpu);
 		kvm_vgic_flush_hwstate(vcpu);
 
-		local_irq_disable();
-
 		/*
 		 * If we have a singal pending, or need to notify a userspace
 		 * irqchip about timer or PMU level changes, then we exit (and
@@ -683,10 +683,10 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 		if (ret <= 0 || need_new_vmid_gen(vcpu->kvm) ||
 		    kvm_request_pending(vcpu)) {
 			vcpu->mode = OUTSIDE_GUEST_MODE;
-			local_irq_enable();
 			kvm_pmu_sync_hwstate(vcpu);
 			kvm_timer_sync_hwstate(vcpu);
 			kvm_vgic_sync_hwstate(vcpu);
+			local_irq_enable();
 			preempt_enable();
 			continue;
 		}
@@ -710,6 +710,16 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 		kvm_arm_clear_debug(vcpu);
 
 		/*
+		 * We must sync the PMU and timer state before the vgic state so
+		 * that the vgic can properly sample the updated state of the
+		 * interrupt line.
+		 */
+		kvm_pmu_sync_hwstate(vcpu);
+		kvm_timer_sync_hwstate(vcpu);
+
+		kvm_vgic_sync_hwstate(vcpu);
+
+		/*
 		 * We may have taken a host interrupt in HYP mode (ie
 		 * while executing the guest). This interrupt is still
 		 * pending, as we haven't serviced it yet!
@@ -732,16 +742,6 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 		guest_exit();
 		trace_kvm_exit(ret, kvm_vcpu_trap_get_class(vcpu), *vcpu_pc(vcpu));
 
-		/*
-		 * We must sync the PMU and timer state before the vgic state so
-		 * that the vgic can properly sample the updated state of the
-		 * interrupt line.
-		 */
-		kvm_pmu_sync_hwstate(vcpu);
-		kvm_timer_sync_hwstate(vcpu);
-
-		kvm_vgic_sync_hwstate(vcpu);
-
 		preempt_enable();
 
 		ret = handle_exit(vcpu, run, ret);
-- 
2.9.0

  parent reply	other threads:[~2017-09-23  0:42 UTC|newest]

Thread overview: 110+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-09-23  0:41 [PATCH v3 00/20] KVM: arm/arm64: Optimize arch timer register handling Christoffer Dall
2017-09-23  0:41 ` Christoffer Dall
2017-09-23  0:41 ` [PATCH v3 01/20] irqchip/gic: Deal with broken firmware exposing only 4kB of GICv2 CPU interface Christoffer Dall
2017-09-23  0:41   ` Christoffer Dall
2017-09-23  0:41 ` [PATCH v3 02/20] arm64: Use physical counter for in-kernel reads Christoffer Dall
2017-09-23  0:41   ` Christoffer Dall
2017-10-09 16:10   ` Marc Zyngier
2017-10-09 16:10     ` Marc Zyngier
2017-10-17 15:33   ` Will Deacon
2017-10-17 15:33     ` Will Deacon
2017-10-18 10:00     ` Christoffer Dall
2017-10-18 10:00       ` Christoffer Dall
2017-09-23  0:41 ` [PATCH v3 03/20] arm64: Use the physical counter when available for read_cycles Christoffer Dall
2017-09-23  0:41   ` Christoffer Dall
2017-10-09 16:21   ` Marc Zyngier
2017-10-09 16:21     ` Marc Zyngier
2017-10-18 11:34     ` Christoffer Dall
2017-10-18 11:34       ` Christoffer Dall
2017-10-18 15:52       ` Marc Zyngier
2017-10-18 15:52         ` Marc Zyngier
2017-09-23  0:41 ` [PATCH v3 04/20] KVM: arm/arm64: Guard kvm_vgic_map_is_active against !vgic_initialized Christoffer Dall
2017-09-23  0:41   ` Christoffer Dall
2017-10-09 16:22   ` Marc Zyngier
2017-10-09 16:22     ` Marc Zyngier
2017-09-23  0:41 ` [PATCH v3 05/20] KVM: arm/arm64: Support calling vgic_update_irq_pending from irq context Christoffer Dall
2017-09-23  0:41   ` Christoffer Dall
2017-10-09 16:37   ` Marc Zyngier
2017-10-09 16:37     ` Marc Zyngier
2017-10-18 11:54     ` Christoffer Dall
2017-10-18 11:54       ` Christoffer Dall
2017-09-23  0:41 ` [PATCH v3 06/20] KVM: arm/arm64: Check that system supports split eoi/deactivate Christoffer Dall
2017-09-23  0:41   ` Christoffer Dall
2017-10-09 16:47   ` Marc Zyngier
2017-10-09 16:47     ` Marc Zyngier
2017-10-18 13:41     ` Christoffer Dall
2017-10-18 13:41       ` Christoffer Dall
2017-10-18 16:03       ` Marc Zyngier
2017-10-18 16:03         ` Marc Zyngier
2017-10-18 19:16         ` Christoffer Dall
2017-10-18 19:16           ` Christoffer Dall
2017-09-23  0:41 ` [PATCH v3 07/20] KVM: arm/arm64: Make timer_arm and timer_disarm helpers more generic Christoffer Dall
2017-09-23  0:41   ` Christoffer Dall
2017-10-09 17:05   ` Marc Zyngier
2017-10-09 17:05     ` Marc Zyngier
2017-10-18 16:47     ` Christoffer Dall
2017-10-18 16:47       ` Christoffer Dall
2017-10-18 16:53       ` Marc Zyngier
2017-10-18 16:53         ` Marc Zyngier
2017-09-23  0:41 ` [PATCH v3 08/20] KVM: arm/arm64: Rename soft timer to bg_timer Christoffer Dall
2017-09-23  0:41   ` Christoffer Dall
2017-10-09 17:06   ` Marc Zyngier
2017-10-09 17:06     ` Marc Zyngier
2017-09-23  0:41 ` [PATCH v3 09/20] KVM: arm/arm64: Use separate timer for phys timer emulation Christoffer Dall
2017-09-23  0:41   ` Christoffer Dall
2017-10-09 17:23   ` Marc Zyngier
2017-10-09 17:23     ` Marc Zyngier
2017-10-19  7:38     ` Christoffer Dall
2017-10-19  7:38       ` Christoffer Dall
2017-09-23  0:41 ` Christoffer Dall [this message]
2017-09-23  0:41   ` [PATCH v3 10/20] KVM: arm/arm64: Move timer/vgic flush/sync under disabled irq Christoffer Dall
2017-10-09 17:34   ` Marc Zyngier
2017-10-09 17:34     ` Marc Zyngier
2017-09-23  0:41 ` [PATCH v3 11/20] KVM: arm/arm64: Move timer save/restore out of the hyp code Christoffer Dall
2017-09-23  0:41   ` Christoffer Dall
2017-10-09 17:47   ` Marc Zyngier
2017-10-09 17:47     ` Marc Zyngier
2017-10-19  7:46     ` Christoffer Dall
2017-10-19  7:46       ` Christoffer Dall
2017-09-23  0:41 ` [PATCH v3 12/20] genirq: Document vcpu_info usage for percpu_devid interrupts Christoffer Dall
2017-09-23  0:41   ` Christoffer Dall
2017-10-09 17:48   ` Marc Zyngier
2017-10-09 17:48     ` Marc Zyngier
2017-09-23  0:42 ` [PATCH v3 13/20] KVM: arm/arm64: Set VCPU affinity for virt timer irq Christoffer Dall
2017-09-23  0:42   ` Christoffer Dall
2017-10-09 17:52   ` Marc Zyngier
2017-10-09 17:52     ` Marc Zyngier
2017-09-23  0:42 ` [PATCH v3 14/20] KVM: arm/arm64: Avoid timer save/restore in vcpu entry/exit Christoffer Dall
2017-09-23  0:42   ` Christoffer Dall
2017-10-10  8:47   ` Marc Zyngier
2017-10-10  8:47     ` Marc Zyngier
2017-10-19  8:15     ` Christoffer Dall
2017-10-19  8:15       ` Christoffer Dall
2017-09-23  0:42 ` [PATCH v3 15/20] KVM: arm/arm64: Support EL1 phys timer register access in set/get reg Christoffer Dall
2017-09-23  0:42   ` Christoffer Dall
2017-10-10  9:10   ` Marc Zyngier
2017-10-10  9:10     ` Marc Zyngier
2017-10-19  8:32     ` Christoffer Dall
2017-10-19  8:32       ` Christoffer Dall
2017-09-23  0:42 ` [PATCH v3 16/20] KVM: arm/arm64: Use kvm_arm_timer_set/get_reg for guest register traps Christoffer Dall
2017-09-23  0:42   ` Christoffer Dall
2017-10-10  9:12   ` Marc Zyngier
2017-10-10  9:12     ` Marc Zyngier
2017-09-23  0:42 ` [PATCH v3 17/20] KVM: arm/arm64: Move phys_timer_emulate function Christoffer Dall
2017-09-23  0:42   ` Christoffer Dall
2017-10-10  9:21   ` Marc Zyngier
2017-10-10  9:21     ` Marc Zyngier
2017-09-23  0:42 ` [PATCH v3 18/20] KVM: arm/arm64: Avoid phys timer emulation in vcpu entry/exit Christoffer Dall
2017-09-23  0:42   ` Christoffer Dall
2017-10-10  9:45   ` Marc Zyngier
2017-10-10  9:45     ` Marc Zyngier
2017-10-19  8:44     ` Christoffer Dall
2017-10-19  8:44       ` Christoffer Dall
2017-09-23  0:42 ` [PATCH v3 19/20] KVM: arm/arm64: Get rid of kvm_timer_flush_hwstate Christoffer Dall
2017-09-23  0:42   ` Christoffer Dall
2017-10-10  9:46   ` Marc Zyngier
2017-10-10  9:46     ` Marc Zyngier
2017-09-23  0:42 ` [PATCH v3 20/20] KVM: arm/arm64: Rework kvm_timer_should_fire Christoffer Dall
2017-09-23  0:42   ` Christoffer Dall
2017-10-10  9:59   ` Marc Zyngier
2017-10-10  9:59     ` Marc Zyngier

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