Re: [RFC PATCH 15/45] KVM: arm/arm64: vgic-new: Add ENABLE registers handlers

Christoffer Dall
2016-03-31T09:31:59Z

On Fri, Mar 25, 2016 at 02:04:38AM +0000, Andre Przywara wrote:
> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> ---
> virt/kvm/arm/vgic/vgic_mmio.c | 81 +++++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 79 insertions(+), 2 deletions(-)
>
> diff --git a/virt/kvm/arm/vgic/vgic_mmio.c b/virt/kvm/arm/vgic/vgic_mmio.c
> index e62366e..0688a69 100644
> --- a/virt/kvm/arm/vgic/vgic_mmio.c
> +++ b/virt/kvm/arm/vgic/vgic_mmio.c
> @@ -129,15 +129,92 @@ static int vgic_mmio_write_v2_misc(struct kvm_vcpu *vcpu,
> return 0;
> }
>
> +/*
> + * Read accesses to both GICD_ICENABLER and GICD_ISENABLER return the value
> + * of the enabled bit, so there is only one function for both here.
> + */
> +static int vgic_mmio_read_enable(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) * 8;
> + u32 value = 0;
> + int i;
> +
> + if (iodev->redist_vcpu)
> + vcpu = iodev->redist_vcpu;
> +
> + /* Loop over all IRQs affected by this read */
> + for (i = 0; i < len * 8; i++) {
> + struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
> +
> + if (irq->enabled)
> + value |= (1U << i);
> + }
> +
> + write_mask32(value, addr & 3, len, val);
> + return 0;
> +}
> +
> +static int vgic_mmio_write_senable(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) * 8;
> + int i;
> +
> + if (iodev->redist_vcpu)
> + vcpu = iodev->redist_vcpu;
> +
> + for_each_set_bit(i, val, len * 8) {
> + struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
> +
> + spin_lock(&irq->irq_lock);
> + irq->enabled = true;
> + vgic_queue_irq(vcpu->kvm, irq);

this makes me feel like we should rename this to vgic_queue_irq_unlock

> + }
> +
> + return 0;
> +}
> +
> +static int vgic_mmio_write_cenable(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) * 8;
> + int i;
> +
> + if (iodev->redist_vcpu)
> + vcpu = iodev->redist_vcpu;
> +
> + for_each_set_bit(i, val, len * 8) {
> + struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
> +
> + spin_lock(&irq->irq_lock);
> +
> + irq->enabled = false;
> + /* TODO: Does the exit/entry code take care of "unqueuing"? */

yes it does, the sync calls prune_ap_list, which calls the Oracle, which
returns null if the IRQ is no longer enabled, so the prune function
removes the IRQ from the list.

> +
> + spin_unlock(&irq->irq_lock);
> + }
> + 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),
> REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_IGROUP,
> vgic_mmio_read_raz, vgic_mmio_write_wi, 1),
> REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ENABLE_SET,
> - vgic_mmio_read_nyi, vgic_mmio_write_nyi, 1),
> + vgic_mmio_read_enable, vgic_mmio_write_senable, 1),
> REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ENABLE_CLEAR,
> - vgic_mmio_read_nyi, vgic_mmio_write_nyi, 1),
> + vgic_mmio_read_enable, vgic_mmio_write_cenable, 1),
> REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_PENDING_SET,
> vgic_mmio_read_nyi, vgic_mmio_write_nyi, 1),
> REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_PENDING_CLEAR,
> --
> 2.7.3
>