Re: [RFC PATCH 21/45] KVM: arm/arm64: vgic-new: Add SGIR register handler

Christoffer Dall
2016-03-31T11:35:53Z

On Fri, Mar 25, 2016 at 02:04:44AM +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 cde153f..a49726f 100644
> --- a/virt/kvm/arm/vgic/vgic_mmio.c
> +++ b/virt/kvm/arm/vgic/vgic_mmio.c
> @@ -512,6 +512,50 @@ static int vgic_mmio_write_target(struct kvm_vcpu *vcpu,
> return 0;
> }
>
> +static int vgic_mmio_write_sgir(struct kvm_vcpu *source_vcpu,
> + struct kvm_io_device *this,
> + gpa_t addr, int len, const void *val)
> +{
> + int nr_vcpus = atomic_read(&source_vcpu->kvm->online_vcpus);
> + u32 value = *(u32 *)val;
> + int intid = value & 0xf;
> + int targets = (value >> 16) & 0xff;
> + int mode = (value >> 24) & 0x03;
> + int c;
> + struct kvm_vcpu *vcpu;
> +
> + switch (mode) {
> + case 0x0: /* as specified by targets */
> + break;
> + case 0x1:
> + targets = (1U << nr_vcpus) - 1; /* all, ... */
> + targets &= ~(1U << source_vcpu->vcpu_id); /* but self */
> + break;
> + case 0x2: /* this very vCPU only */
> + targets = (1U << source_vcpu->vcpu_id);
> + break;
> + case 0x3: /* reserved */

should we not avoid generating any SGIs in this case?

> + break;
> + }
> +
> + kvm_for_each_vcpu(c, vcpu, source_vcpu->kvm) {
> + struct vgic_irq *irq;
> +
> + if (!(targets & (1U << c)))
> + continue;
> +
> + irq = vgic_get_irq(source_vcpu->kvm, vcpu, intid);
> +
> + spin_lock(&irq->irq_lock);
> + irq->pending = true;
> + irq->source |= 1U << source_vcpu->vcpu_id;
> +
> + vgic_queue_irq(source_vcpu->kvm, irq);
> + }
> +
> + 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),
> @@ -536,7 +580,7 @@ struct vgic_register_region vgic_v2_dist_registers[] = {
> REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_CONFIG,
> vgic_mmio_read_config, vgic_mmio_write_config, 2),
> REGISTER_DESC_WITH_LENGTH(GIC_DIST_SOFTINT,
> - vgic_mmio_read_nyi, vgic_mmio_write_nyi, 4),
> + vgic_mmio_read_raz, vgic_mmio_write_sgir, 4),
> REGISTER_DESC_WITH_LENGTH(GIC_DIST_SGI_PENDING_CLEAR,
> vgic_mmio_read_nyi, vgic_mmio_write_nyi, 16),
> REGISTER_DESC_WITH_LENGTH(GIC_DIST_SGI_PENDING_SET,
> --
> 2.7.3
>