Re: [RFC PATCH 17/45] KVM: arm/arm64: vgic-new: Add PRIORITY registers handlers

Christoffer Dall
2016-03-31T09:50:22Z

On Fri, Mar 25, 2016 at 02:04:40AM +0000, Andre Przywara wrote:
> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> ---
> virt/kvm/arm/vgic/vgic_mmio.c | 46 ++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 45 insertions(+), 1 deletion(-)
>
> diff --git a/virt/kvm/arm/vgic/vgic_mmio.c b/virt/kvm/arm/vgic/vgic_mmio.c
> index 8514f92..788e186 100644
> --- a/virt/kvm/arm/vgic/vgic_mmio.c
> +++ b/virt/kvm/arm/vgic/vgic_mmio.c
> @@ -289,6 +289,50 @@ static int vgic_mmio_write_cpending(struct kvm_vcpu *vcpu,
> return 0;
> }
>
> +static int vgic_mmio_read_priority(struct kvm_vcpu *vcpu,
> + struct kvm_io_device *this,
> + gpa_t addr, int len, void *val)
> +{
> + struct vgic_io_device *iodev = container_of(this,
> + struct vgic_io_device, dev);
> + u32 intid = (addr - iodev->base_addr);
> + int i;
> +
> + if (iodev->redist_vcpu)
> + vcpu = iodev->redist_vcpu;
> +
> + for (i = 0; i < len; i++) {
> + struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
> +
> + ((u8 *)val)[i] = irq->priority;
> + }
> +
> + return 0;
> +}
> +
> +static int vgic_mmio_write_priority(struct kvm_vcpu *vcpu,
> + struct kvm_io_device *this,
> + gpa_t addr, int len, const void *val)
> +{
> + struct vgic_io_device *iodev = container_of(this,
> + struct vgic_io_device, dev);
> + u32 intid = (addr - iodev->base_addr);
> + int i;
> +
> + if (iodev->redist_vcpu)
> + vcpu = iodev->redist_vcpu;
> +
> + for (i = 0; i < len; i++) {
> + struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
> +
> + spin_lock(&irq->irq_lock);
> + irq->priority = ((u8 *)val)[i];
> + spin_unlock(&irq->irq_lock);

if we add the priority check in PATCH 11 you have to kick the vcpu here
irq->vcpu is set. (and possibly even without a change to PATCH 11 in
case the VCPU is running with a bund of now lower-priority interrupts in
the LRs).

> + }
> +
> + return 0;
> +}
> +
> struct vgic_register_region vgic_v2_dist_registers[] = {
> REGISTER_DESC_WITH_LENGTH(GIC_DIST_CTRL,
> vgic_mmio_read_v2_misc, vgic_mmio_write_v2_misc, 12),
> @@ -307,7 +351,7 @@ struct vgic_register_region vgic_v2_dist_registers[] = {
> REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ACTIVE_CLEAR,
> vgic_mmio_read_nyi, vgic_mmio_write_nyi, 1),
> REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_PRI,
> - vgic_mmio_read_nyi, vgic_mmio_write_nyi, 8),
> + vgic_mmio_read_priority, vgic_mmio_write_priority, 8),
> REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_TARGET,
> vgic_mmio_read_nyi, vgic_mmio_write_nyi, 8),
> REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_CONFIG,
> --
> 2.7.3
>