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From: Christoffer Dall <christoffer.dall@linaro.org>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: kvmarm@lists.cs.columbia.edu,
	linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org
Subject: [PULL 4/8] KVM: arm/arm64: Fix preemptible timer active state crazyness
Date: Tue, 24 Nov 2015 18:35:32 +0100	[thread overview]
Message-ID: <1448386536-30118-5-git-send-email-christoffer.dall@linaro.org> (raw)
In-Reply-To: <1448386536-30118-1-git-send-email-christoffer.dall@linaro.org>

We were setting the physical active state on the GIC distributor in a
preemptible section, which could cause us to set the active state on
different physical CPU from the one we were actually going to run on,
hacoc ensues.

Since we are no longer descheduling/scheduling soft timers in the
flush/sync timer functions, simply moving the timer flush into a
non-preemptible section.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
---
 arch/arm/kvm/arm.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index eab83b2..e06fd29 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -564,17 +564,12 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 			vcpu_sleep(vcpu);
 
 		/*
-		 * Disarming the background timer must be done in a
-		 * preemptible context, as this call may sleep.
-		 */
-		kvm_timer_flush_hwstate(vcpu);
-
-		/*
 		 * Preparing the interrupts to be injected also
 		 * involves poking the GIC, which must be done in a
 		 * non-preemptible context.
 		 */
 		preempt_disable();
+		kvm_timer_flush_hwstate(vcpu);
 		kvm_vgic_flush_hwstate(vcpu);
 
 		local_irq_disable();
-- 
2.1.2.330.g565301e.dirty

WARNING: multiple messages have this Message-ID (diff)
From: christoffer.dall@linaro.org (Christoffer Dall)
To: linux-arm-kernel@lists.infradead.org
Subject: [PULL 4/8] KVM: arm/arm64: Fix preemptible timer active state crazyness
Date: Tue, 24 Nov 2015 18:35:32 +0100	[thread overview]
Message-ID: <1448386536-30118-5-git-send-email-christoffer.dall@linaro.org> (raw)
In-Reply-To: <1448386536-30118-1-git-send-email-christoffer.dall@linaro.org>

We were setting the physical active state on the GIC distributor in a
preemptible section, which could cause us to set the active state on
different physical CPU from the one we were actually going to run on,
hacoc ensues.

Since we are no longer descheduling/scheduling soft timers in the
flush/sync timer functions, simply moving the timer flush into a
non-preemptible section.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
---
 arch/arm/kvm/arm.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index eab83b2..e06fd29 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -564,17 +564,12 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 			vcpu_sleep(vcpu);
 
 		/*
-		 * Disarming the background timer must be done in a
-		 * preemptible context, as this call may sleep.
-		 */
-		kvm_timer_flush_hwstate(vcpu);
-
-		/*
 		 * Preparing the interrupts to be injected also
 		 * involves poking the GIC, which must be done in a
 		 * non-preemptible context.
 		 */
 		preempt_disable();
+		kvm_timer_flush_hwstate(vcpu);
 		kvm_vgic_flush_hwstate(vcpu);
 
 		local_irq_disable();
-- 
2.1.2.330.g565301e.dirty

  parent reply	other threads:[~2015-11-24 17:35 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-11-24 17:35 [PULL 0/8] KVM/ARM Fixes for v4.4-rc3 Christoffer Dall
2015-11-24 17:35 ` Christoffer Dall
2015-11-24 17:35 ` [PULL 1/8] ARM/arm64: KVM: test properly for a PTE's uncachedness Christoffer Dall
2015-11-24 17:35   ` Christoffer Dall
2015-11-24 17:35   ` Christoffer Dall
2015-11-24 17:35 ` [PULL 2/8] arm64: KVM: Fix AArch32 to AArch64 register mapping Christoffer Dall
2015-11-24 17:35   ` Christoffer Dall
2015-11-24 17:35   ` Christoffer Dall
2015-11-24 17:35 ` [PULL 3/8] arm64: KVM: Add workaround for Cortex-A57 erratum 834220 Christoffer Dall
2015-11-24 17:35   ` Christoffer Dall
2015-11-24 17:35   ` Christoffer Dall
2015-11-24 17:35 ` Christoffer Dall [this message]
2015-11-24 17:35   ` [PULL 4/8] KVM: arm/arm64: Fix preemptible timer active state crazyness Christoffer Dall
2015-11-24 17:35 ` [PULL 5/8] KVM: arm/arm64: arch_timer: Preserve physical dist. active state on LR.active Christoffer Dall
2015-11-24 17:35   ` Christoffer Dall
2015-11-24 17:35 ` [PULL 6/8] KVM: arm/arm64: vgic: Trust the LR state for HW IRQs Christoffer Dall
2015-11-24 17:35   ` Christoffer Dall
2015-11-24 17:35 ` [PULL 7/8] arm64: kvm: avoid %p in __kvm_hyp_panic Christoffer Dall
2015-11-24 17:35   ` Christoffer Dall
2015-11-24 17:35 ` [PULL 8/8] arm64: kvm: report original PAR_EL1 upon panic Christoffer Dall
2015-11-24 17:35   ` Christoffer Dall
2015-11-24 18:36 ` [PULL 0/8] KVM/ARM Fixes for v4.4-rc3 Paolo Bonzini
2015-11-24 18:36   ` Paolo Bonzini

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