From: christoffer.dall@linaro.org (Christoffer Dall)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 02/10] arm/arm64: KVM: Move vgic handling to a non-preemptible section
Date: Tue, 30 Jun 2015 22:19:19 +0200 [thread overview]
Message-ID: <20150630201919.GZ11332@cbox> (raw)
In-Reply-To: <1433783045-8002-3-git-send-email-marc.zyngier@arm.com>
On Mon, Jun 08, 2015 at 06:03:57PM +0100, Marc Zyngier wrote:
> As we're about to introduce some serious GIC-poking to the vgic code,
> it is important to make sure that we're going to poke the part of
> the GIC that belongs to the CPU we're about to run on (otherwise,
> we'd end up with some unexpected interrupts firing)...
>
> Introducing a non-preemptible section in kvm_arch_vcpu_ioctl_run
> prevents the problem from occuring.
>
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
> arch/arm/kvm/arm.c | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
> diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
> index 46db690..4986300 100644
> --- a/arch/arm/kvm/arm.c
> +++ b/arch/arm/kvm/arm.c
> @@ -529,8 +529,18 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
> if (vcpu->arch.pause)
> vcpu_pause(vcpu);
>
> + /*
> + * Disarming the timer must be done with in a
s/with //
> + * 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_vgic_flush_hwstate(vcpu);
>
> local_irq_disable();
> @@ -546,6 +556,7 @@ 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_vgic_sync_hwstate(vcpu);
> + preempt_enable();
> kvm_timer_sync_hwstate(vcpu);
> continue;
> }
> @@ -580,6 +591,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
>
> kvm_vgic_sync_hwstate(vcpu);
>
> + preempt_enable();
> +
> kvm_timer_sync_hwstate(vcpu);
>
> ret = handle_exit(vcpu, run, ret);
> --
> 2.1.4
>
This should get more simple when rebased on cpu time accounting patch,
but otherwise looks good.
-Christoffer
WARNING: multiple messages have this Message-ID (diff)
From: Christoffer Dall <christoffer.dall@linaro.org>
To: Marc Zyngier <marc.zyngier@arm.com>
Cc: kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org,
"Eric Auger" <eric.auger@linaro.org>,
"Alex Bennée" <alex.bennee@linaro.org>,
"Andre Przywara" <andre.przywara@arm.com>
Subject: Re: [PATCH 02/10] arm/arm64: KVM: Move vgic handling to a non-preemptible section
Date: Tue, 30 Jun 2015 22:19:19 +0200 [thread overview]
Message-ID: <20150630201919.GZ11332@cbox> (raw)
In-Reply-To: <1433783045-8002-3-git-send-email-marc.zyngier@arm.com>
On Mon, Jun 08, 2015 at 06:03:57PM +0100, Marc Zyngier wrote:
> As we're about to introduce some serious GIC-poking to the vgic code,
> it is important to make sure that we're going to poke the part of
> the GIC that belongs to the CPU we're about to run on (otherwise,
> we'd end up with some unexpected interrupts firing)...
>
> Introducing a non-preemptible section in kvm_arch_vcpu_ioctl_run
> prevents the problem from occuring.
>
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
> arch/arm/kvm/arm.c | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
> diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
> index 46db690..4986300 100644
> --- a/arch/arm/kvm/arm.c
> +++ b/arch/arm/kvm/arm.c
> @@ -529,8 +529,18 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
> if (vcpu->arch.pause)
> vcpu_pause(vcpu);
>
> + /*
> + * Disarming the timer must be done with in a
s/with //
> + * 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_vgic_flush_hwstate(vcpu);
>
> local_irq_disable();
> @@ -546,6 +556,7 @@ 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_vgic_sync_hwstate(vcpu);
> + preempt_enable();
> kvm_timer_sync_hwstate(vcpu);
> continue;
> }
> @@ -580,6 +591,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
>
> kvm_vgic_sync_hwstate(vcpu);
>
> + preempt_enable();
> +
> kvm_timer_sync_hwstate(vcpu);
>
> ret = handle_exit(vcpu, run, ret);
> --
> 2.1.4
>
This should get more simple when rebased on cpu time accounting patch,
but otherwise looks good.
-Christoffer
next prev parent reply other threads:[~2015-06-30 20:19 UTC|newest]
Thread overview: 118+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-08 17:03 [PATCH 00/10] arm/arm64: KVM: Active interrupt state switching for shared devices Marc Zyngier
2015-06-08 17:03 ` Marc Zyngier
2015-06-08 17:03 ` [PATCH 01/10] arm/arm64: KVM: Fix ordering of timer/GIC on guest entry Marc Zyngier
2015-06-08 17:03 ` Marc Zyngier
2015-06-09 11:29 ` Alex Bennée
2015-06-09 11:29 ` Alex Bennée
2015-06-30 20:19 ` Christoffer Dall
2015-06-30 20:19 ` Christoffer Dall
2015-06-08 17:03 ` [PATCH 02/10] arm/arm64: KVM: Move vgic handling to a non-preemptible section Marc Zyngier
2015-06-08 17:03 ` Marc Zyngier
2015-06-09 11:38 ` Alex Bennée
2015-06-09 11:38 ` Alex Bennée
2015-06-30 20:19 ` Christoffer Dall [this message]
2015-06-30 20:19 ` Christoffer Dall
2015-06-08 17:03 ` [PATCH 03/10] KVM: arm/arm64: vgic: Convert struct vgic_lr to use bitfields Marc Zyngier
2015-06-08 17:03 ` Marc Zyngier
2015-06-09 13:12 ` Alex Bennée
2015-06-09 13:12 ` Alex Bennée
2015-06-10 17:23 ` Andre Przywara
2015-06-10 17:23 ` Andre Przywara
2015-06-10 18:04 ` Marc Zyngier
2015-06-10 18:04 ` Marc Zyngier
2015-06-08 17:03 ` [PATCH 04/10] KVM: arm/arm64: vgic: Allow HW irq to be encoded in LR Marc Zyngier
2015-06-08 17:03 ` Marc Zyngier
2015-06-09 13:21 ` Alex Bennée
2015-06-09 13:21 ` Alex Bennée
2015-06-09 14:03 ` Marc Zyngier
2015-06-09 14:03 ` Marc Zyngier
2015-06-17 11:53 ` Eric Auger
2015-06-17 11:53 ` Eric Auger
2015-06-17 12:39 ` Marc Zyngier
2015-06-17 12:39 ` Marc Zyngier
2015-06-17 13:21 ` Peter Maydell
2015-06-17 13:21 ` Peter Maydell
2015-06-17 13:34 ` Marc Zyngier
2015-06-17 13:34 ` Marc Zyngier
2015-06-08 17:04 ` [PATCH 05/10] KVM: arm/arm64: vgic: Relax vgic_can_sample_irq for edge IRQs Marc Zyngier
2015-06-08 17:04 ` Marc Zyngier
2015-06-30 20:19 ` Christoffer Dall
2015-06-30 20:19 ` Christoffer Dall
2015-07-01 9:17 ` Marc Zyngier
2015-07-01 9:17 ` Marc Zyngier
2015-07-01 11:58 ` Christoffer Dall
2015-07-01 11:58 ` Christoffer Dall
2015-07-01 18:18 ` Marc Zyngier
2015-07-01 18:18 ` Marc Zyngier
2015-07-02 16:23 ` Christoffer Dall
2015-07-02 16:23 ` Christoffer Dall
2015-07-03 9:50 ` Marc Zyngier
2015-07-03 9:50 ` Marc Zyngier
2015-07-03 9:57 ` Peter Maydell
2015-07-03 9:57 ` Peter Maydell
2015-06-08 17:04 ` [PATCH 06/10] KVM: arm/arm64: vgic: Allow dynamic mapping of physical/virtual interrupts Marc Zyngier
2015-06-08 17:04 ` Marc Zyngier
2015-06-11 8:43 ` Andre Przywara
2015-06-11 8:43 ` Andre Przywara
2015-06-11 8:56 ` Marc Zyngier
2015-06-11 8:56 ` Marc Zyngier
2015-06-15 15:44 ` Eric Auger
2015-06-15 15:44 ` Eric Auger
2015-06-16 8:28 ` Marc Zyngier
2015-06-16 8:28 ` Marc Zyngier
2015-06-16 9:10 ` Eric Auger
2015-06-16 9:10 ` Eric Auger
2015-06-30 20:19 ` Christoffer Dall
2015-06-30 20:19 ` Christoffer Dall
2015-07-01 10:20 ` Marc Zyngier
2015-07-01 10:20 ` Marc Zyngier
2015-07-01 11:45 ` Christoffer Dall
2015-07-01 11:45 ` Christoffer Dall
2015-06-08 17:04 ` [PATCH 07/10] KVM: arm/arm64: vgic: Allow HW interrupts to be queued to a guest Marc Zyngier
2015-06-08 17:04 ` Marc Zyngier
2015-06-11 8:44 ` Andre Przywara
2015-06-11 8:44 ` Andre Przywara
2015-06-11 9:15 ` Marc Zyngier
2015-06-11 9:15 ` Marc Zyngier
2015-06-11 9:44 ` Andre Przywara
2015-06-11 9:44 ` Andre Przywara
2015-06-11 10:02 ` Marc Zyngier
2015-06-11 10:02 ` Marc Zyngier
2015-06-15 16:11 ` Eric Auger
2015-06-15 16:11 ` Eric Auger
2015-06-17 11:51 ` Eric Auger
2015-06-17 11:51 ` Eric Auger
2015-06-17 12:23 ` Marc Zyngier
2015-06-17 12:23 ` Marc Zyngier
2015-06-08 17:04 ` [PATCH 08/10] KVM: arm/arm64: vgic: Add vgic_{get, set}_phys_irq_active Marc Zyngier
2015-06-08 17:04 ` [PATCH 08/10] KVM: arm/arm64: vgic: Add vgic_{get,set}_phys_irq_active Marc Zyngier
2015-06-17 15:11 ` [PATCH 08/10] KVM: arm/arm64: vgic: Add vgic_{get, set}_phys_irq_active Eric Auger
2015-06-17 15:11 ` [PATCH 08/10] KVM: arm/arm64: vgic: Add vgic_{get,set}_phys_irq_active Eric Auger
2015-06-08 17:04 ` [PATCH 09/10] KVM: arm/arm64: timer: Allow the timer to control the active state Marc Zyngier
2015-06-08 17:04 ` Marc Zyngier
2015-06-08 17:04 ` [PATCH 10/10] KVM: arm/arm64: vgic: Allow non-shared device HW interrupts Marc Zyngier
2015-06-08 17:04 ` Marc Zyngier
2015-06-17 15:11 ` Eric Auger
2015-06-17 15:11 ` Eric Auger
2015-06-17 15:37 ` Marc Zyngier
2015-06-17 15:37 ` Marc Zyngier
2015-06-17 15:50 ` Eric Auger
2015-06-17 15:50 ` Eric Auger
2015-06-18 8:37 ` Marc Zyngier
2015-06-18 8:37 ` Marc Zyngier
2015-06-18 17:51 ` Eric Auger
2015-06-18 17:51 ` Eric Auger
2015-06-30 20:19 ` Christoffer Dall
2015-06-30 20:19 ` Christoffer Dall
2015-07-01 8:26 ` Marc Zyngier
2015-07-01 8:26 ` Marc Zyngier
2015-07-01 8:57 ` Christoffer Dall
2015-07-01 8:57 ` Christoffer Dall
2015-06-10 8:33 ` [PATCH 00/10] arm/arm64: KVM: Active interrupt state switching for shared devices Eric Auger
2015-06-10 8:33 ` Eric Auger
2015-06-10 9:03 ` Marc Zyngier
2015-06-10 9:03 ` Marc Zyngier
2015-06-10 11:13 ` Eric Auger
2015-06-10 11:13 ` Eric Auger
2015-06-18 6:51 ` Eric Auger
2015-06-18 6:51 ` Eric Auger
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