Re: [PATCH v3 7/9] KVM: arm/arm64: Check if irq lines to the GIC are already used

Marc Zyngier
2017-06-08T14:08:40Z

On Thu, Jun 08 2017 at 3:34:44 pm BST, Christoffer Dall <cdall@linaro.org> wrote:
> We check if other in-kernel devices have already been connected to the
> GIC for a particular interrupt line when possible.
>
> For the PMU, we can do this whenever setting the PMU interrupt number
> from userspace.
>
> For the timers, we have to wait until we try to enable the timer,
> because we have a concept of default IRQ numbers that userspace
> shouldn't have to work around in the initialization phase.
>
> Signed-off-by: Christoffer Dall <cdall@linaro.org>
> ---
> virt/kvm/arm/arch_timer.c | 18 ++++++++++--------
> virt/kvm/arm/pmu.c | 7 +++++++
> 2 files changed, 17 insertions(+), 8 deletions(-)
>
> diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c
> index e03da1a..07f6f9b 100644
> --- a/virt/kvm/arm/arch_timer.c
> +++ b/virt/kvm/arm/arch_timer.c
> @@ -618,20 +618,22 @@ void kvm_timer_vcpu_terminate(struct kvm_vcpu *vcpu)
> kvm_vgic_unmap_phys_irq(vcpu, vtimer->irq.irq);
> }
>
> -static bool timer_irqs_are_valid(struct kvm *kvm)
> +static bool timer_irqs_are_valid(struct kvm_vcpu *vcpu)
> {
> - struct kvm_vcpu *vcpu;
> int vtimer_irq, ptimer_irq;
> - int i;
> + int i, ret;
>
> - vcpu = kvm_get_vcpu(kvm, 0);
> vtimer_irq = vcpu_vtimer(vcpu)->irq.irq;
> - ptimer_irq = vcpu_ptimer(vcpu)->irq.irq;
> + ret = kvm_vgic_set_owner(vcpu, vtimer_irq, vcpu_vtimer(vcpu));
> + if (ret)
> + return false;
>
> - if (vtimer_irq == ptimer_irq)
> + ptimer_irq = vcpu_ptimer(vcpu)->irq.irq;
> + ret = kvm_vgic_set_owner(vcpu, ptimer_irq, vcpu_ptimer(vcpu));
> + if (ret)
> return false;
>
> - kvm_for_each_vcpu(i, vcpu, kvm) {
> + kvm_for_each_vcpu(i, vcpu, vcpu->kvm) {
> if (vcpu_vtimer(vcpu)->irq.irq != vtimer_irq ||
> vcpu_ptimer(vcpu)->irq.irq != ptimer_irq)
> return false;
> @@ -659,7 +661,7 @@ int kvm_timer_enable(struct kvm_vcpu *vcpu)
> if (!vgic_initialized(vcpu->kvm))
> return -ENODEV;
>
> - if (!timer_irqs_are_valid(vcpu->kvm)) {
> + if (!timer_irqs_are_valid(vcpu)) {
> kvm_debug("incorrectly configured timer irqs\n");
> return -EINVAL;
> }
> diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c
> index 574feff..3f08669 100644
> --- a/virt/kvm/arm/pmu.c
> +++ b/virt/kvm/arm/pmu.c
> @@ -480,6 +480,8 @@ static int kvm_arm_pmu_v3_init(struct kvm_vcpu *vcpu)
> return -EBUSY;
>
> if (irqchip_in_kernel(vcpu->kvm)) {
> + int ret;
> +
> /*
> * If using the PMU with an in-kernel virtual GIC
> * implementation, we require the GIC to be already
> @@ -490,6 +492,11 @@ static int kvm_arm_pmu_v3_init(struct kvm_vcpu *vcpu)
>
> if (!kvm_arm_pmu_irq_initialized(vcpu))
> return -ENXIO;
> +
> + ret = kvm_vgic_set_owner(vcpu, vcpu->arch.pmu.irq_num,
> + &vcpu->arch.pmu);
> + if (ret)
> + return ret;
> }
>
> vcpu->arch.pmu.created = true;

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>

M.
--
Jazz is not dead, it just smell funny.