On Fri, May 06, 2016 at 11:45:36AM +0100, Andre Przywara wrote:
> From: Marc Zyngier <marc.zyngier@xxxxxxx>
>
> Those three registers are v2 emulation specific, so their implementation
> lives entirely in vgic-mmio-v2.c. Also they are handled in one function,
> as their implementation is pretty simple.
> When the guest enables the distributor, we kick all VCPUs to get
> potentially pending interrupts serviced.
>
> Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
> Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
> ---
> Changelog RFC..v1:
> - kick VCPUs is the distributor gets enabled
> - improve comment
>
> Changelog v1 .. v2:
> - adapt to new MMIO framework
> - use switch() statements to improve readability
>
> Changelog v2 .. v3:
> - add vgic_kick_vcpus() implementation
>
> include/linux/irqchip/arm-gic.h | 1 +
> virt/kvm/arm/vgic/vgic-mmio-v2.c | 48 +++++++++++++++++++++++++++++++++++++++-
> virt/kvm/arm/vgic/vgic.c | 15 +++++++++++++
> virt/kvm/arm/vgic/vgic.h | 4 ++++
> 4 files changed, 67 insertions(+), 1 deletion(-)
>
> diff --git a/include/linux/irqchip/arm-gic.h b/include/linux/irqchip/arm-gic.h
> index be0d26f..fd05185 100644
> --- a/include/linux/irqchip/arm-gic.h
> +++ b/include/linux/irqchip/arm-gic.h
> @@ -33,6 +33,7 @@
>
> #define GIC_DIST_CTRL 0x000
> #define GIC_DIST_CTR 0x004
> +#define GIC_DIST_IIDR 0x008
> #define GIC_DIST_IGROUP 0x080
> #define GIC_DIST_ENABLE_SET 0x100
> #define GIC_DIST_ENABLE_CLEAR 0x180
> diff --git a/virt/kvm/arm/vgic/vgic-mmio-v2.c b/virt/kvm/arm/vgic/vgic-mmio-v2.c
> index 2729a22..69e96f7 100644
> --- a/virt/kvm/arm/vgic/vgic-mmio-v2.c
> +++ b/virt/kvm/arm/vgic/vgic-mmio-v2.c
> @@ -20,9 +20,55 @@
> #include "vgic.h"
> #include "vgic-mmio.h"
>
> +static unsigned long vgic_mmio_read_v2_misc(struct kvm_vcpu *vcpu,
> + gpa_t addr, unsigned int len)
> +{
> + u32 value;
> +
> + switch (addr & 0x0c) {
> + case GIC_DIST_CTRL:
> + value = vcpu->kvm->arch.vgic.enabled ? GICD_ENABLE : 0;
> + break;
> + case GIC_DIST_CTR:
> + value = vcpu->kvm->arch.vgic.nr_spis + VGIC_NR_PRIVATE_IRQS;
> + value = (value >> 5) - 1;
> + value |= (atomic_read(&vcpu->kvm->online_vcpus) - 1) << 5;
> + break;
> + case GIC_DIST_IIDR:
> + value = (PRODUCT_ID_KVM << 24) | (IMPLEMENTER_ARM << 0);
> + break;
> + default:
> + return 0;
> + }
> +
> + return extract_bytes(value, addr & 3, len);
> +}
> +
> +static void vgic_mmio_write_v2_misc(struct kvm_vcpu *vcpu,
> + gpa_t addr, unsigned int len,
> + unsigned long val)
> +{
> + switch (addr & 0x0c) {
> + case GIC_DIST_CTRL:
> + if (!(addr & 1)) {
what is this !(addr & 1) check?
> + struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
> + bool was_enabled = dist->enabled;
> +
> + dist->enabled = val & GICD_ENABLE;
> + if (!was_enabled && dist->enabled)
> + vgic_kick_vcpus(vcpu->kvm);
> + }
> + break;
> + case GIC_DIST_CTR:
> + case GIC_DIST_IIDR:
> + /* Nothing to do */
> + return;
> + }
> +}
> +
> static const struct vgic_register_region vgic_v2_dist_registers[] = {
> REGISTER_DESC_WITH_LENGTH(GIC_DIST_CTRL,
> - vgic_mmio_read_raz, vgic_mmio_write_wi, 12),
> + vgic_mmio_read_v2_misc, vgic_mmio_write_v2_misc, 12),
> REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_IGROUP,
> vgic_mmio_read_rao, vgic_mmio_write_wi, 1),
> REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ENABLE_SET,
> diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c
> index c3dbcf3..5355de6 100644
> --- a/virt/kvm/arm/vgic/vgic.c
> +++ b/virt/kvm/arm/vgic/vgic.c
> @@ -544,3 +544,18 @@ int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu)
>
> return pending;
> }
> +
> +void vgic_kick_vcpus(struct kvm *kvm)
> +{
> + struct kvm_vcpu *vcpu;
> + int c;
> +
> + /*
> + * We've injected an interrupt, time to find out who deserves
> + * a good kick...
> + */
> + kvm_for_each_vcpu(c, vcpu, kvm) {
> + if (kvm_vgic_vcpu_pending_irq(vcpu))
> + kvm_vcpu_kick(vcpu);
> + }
> +}
> diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
> index fd9acaa..cf62015 100644
> --- a/virt/kvm/arm/vgic/vgic.h
> +++ b/virt/kvm/arm/vgic/vgic.h
> @@ -16,11 +16,15 @@
> #ifndef __KVM_ARM_VGIC_NEW_H__
> #define __KVM_ARM_VGIC_NEW_H__
>
> +#define PRODUCT_ID_KVM 0x4b /* ASCII code K */
> +#define IMPLEMENTER_ARM 0x43b
> +
> #define vgic_irq_is_sgi(intid) ((intid) < VGIC_NR_SGIS)
>
> struct vgic_irq *vgic_get_irq(struct kvm *kvm, struct kvm_vcpu *vcpu,
> u32 intid);
> bool vgic_queue_irq_unlock(struct kvm *kvm, struct vgic_irq *irq);
> +void vgic_kick_vcpus(struct kvm *kvm);
>
> void vgic_v2_process_maintenance(struct kvm_vcpu *vcpu);
> void vgic_v2_fold_lr_state(struct kvm_vcpu *vcpu);
> --
> 2.7.3
>
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