[PATCH v3 23/55] KVM: arm/arm64: vgic-new: Add CTLR, TYPER and IIDR handlers

[christoffer.dall@linaro.org (Christoffer Dall)]

On Fri, May 06, 2016 at 11:45:36AM +0100, Andre Przywara wrote:
> From: Marc Zyngier <marc.zyngier@arm.com>
> 
> 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@arm.com>
> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> ---
> 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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