Subject: [PATCH v3 33/55] KVM: arm/arm64: vgic-new: Add GICv3 CTLR, IIDR, TYPER handlers

From: [email-masked] (Christoffer Dall)
Date: Thu, 12 May 2016 13:47:03 +0200

On Fri, May 06, 2016 at 11:45:46AM +0100, Andre Przywara wrote:
> As in the GICv2 emulation we handle those three registers in one
> function.
> 
> Signed-off-by: Andre Przywara <[email-masked]>
> ---
> Changelog RFC..v1:
> - kick VCPUs if distributor gets enabled
> 
> Changelog v1 .. v2:
> - rewrite write handler to use switch statement
> 
>  virt/kvm/arm/vgic/vgic-mmio-v3.c | 50 +++++++++++++++++++++++++++++++++++++++-
>  virt/kvm/arm/vgic/vgic.h         |  2 ++
>  2 files changed, 51 insertions(+), 1 deletion(-)
> 
> diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
> index 06c7ec5..5f4558c 100644
> --- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
> +++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
> @@ -22,6 +22,54 @@
>  #include "vgic.h"
>  #include "vgic-mmio.h"
>  
> +static unsigned long vgic_mmio_read_v3_misc(struct kvm_vcpu *vcpu,
> +					    gpa_t addr, unsigned int len)
> +{
> +	u32 value = 0;
> +
> +	switch (addr & 0x0c) {
> +	case GICD_CTLR:
> +		if (vcpu->kvm->arch.vgic.enabled)
> +			value |= GICD_CTLR_ENABLE_SS_G1;
> +		value |= GICD_CTLR_ARE_NS | GICD_CTLR_DS;
> +		break;
> +	case GICD_TYPER:
> +		value = vcpu->kvm->arch.vgic.nr_spis + VGIC_NR_PRIVATE_IRQS;
> +		value = (value >> 5) - 1;
> +		value |= (INTERRUPT_ID_BITS_SPIS - 1) << 19;
> +		break;
> +	case GICD_IIDR:
> +		value = (PRODUCT_ID_KVM << 24) | (IMPLEMENTER_ARM << 0);
> +		break;
> +	default:
> +		return 0;
> +	}
> +
> +	return extract_bytes(value, addr & 3, len);

why do we return extract_bytes here?  This register can only be accessed
in full with a 32-bit aligned access, right?

> +}
> +
> +static void vgic_mmio_write_v3_misc(struct kvm_vcpu *vcpu,
> +				    gpa_t addr, unsigned int len,
> +				    unsigned long val)
> +{
> +	switch (addr & 0x0c) {
> +	case GICD_CTLR:
> +		if (!(addr & 1)) {

obviously same question as on the v2 counterpart

> +			struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
> +			bool was_enabled = dist->enabled;
> +
> +			dist->enabled = val & GICD_CTLR_ENABLE_SS_G1;
> +
> +			if (!was_enabled && dist->enabled)
> +				vgic_kick_vcpus(vcpu->kvm);
> +		}
> +		break;
> +	case GICD_TYPER:
> +	case GICD_IIDR:
> +		return;
> +	}
> +}
> +
>  /*
>   * The GICv3 per-IRQ registers are split to control PPIs and SGIs in the
>   * redistributors, while SPIs are covered by registers in the distributor
> @@ -46,7 +94,7 @@
>  
>  static const struct vgic_register_region vgic_v3_dist_registers[] = {
>  	REGISTER_DESC_WITH_LENGTH(GICD_CTLR,
> -		vgic_mmio_read_raz, vgic_mmio_write_wi, 16),
> +		vgic_mmio_read_v3_misc, vgic_mmio_write_v3_misc, 16),
>  	REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(GICD_IGROUPR,
>  		vgic_mmio_read_rao, vgic_mmio_write_wi, 1),
>  	REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(GICD_ISENABLER,
> diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
> index 39a8a65..635e2e2 100644
> --- a/virt/kvm/arm/vgic/vgic.h
> +++ b/virt/kvm/arm/vgic/vgic.h
> @@ -19,6 +19,8 @@
>  #define PRODUCT_ID_KVM		0x4b	/* ASCII code K */
>  #define IMPLEMENTER_ARM		0x43b
>  
> +#define INTERRUPT_ID_BITS_SPIS	10
> +
>  #define vgic_irq_is_sgi(intid) ((intid) < VGIC_NR_SGIS)
>  
>  struct vgic_irq *vgic_get_irq(struct kvm *kvm, struct kvm_vcpu *vcpu,
> -- 
> 2.7.3
>