[PATCH 1/3] KVM: arm/arm64: Fix preemptible timer active state crazyness
marc.zyngier at arm.com
Tue Nov 24 07:51:14 PST 2015
On Tue, 24 Nov 2015 16:43:58 +0100
Christoffer Dall <christoffer.dall at linaro.org> wrote:
> 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.
> Signed-off-by: Christoffer Dall <christoffer.dall at 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)
> - * 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.
> + kvm_timer_flush_hwstate(vcpu);
Reviewed-by: Marc Zyngier <marc.zyngier at arm.com>
Jazz is not dead. It just smells funny.
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