[PATCH v4 04/12] KVM: arm64: handle ITS related GICv3 redistributor registers

[Christoffer Dall]

On Sat, Mar 26, 2016 at 02:14:02AM +0000, Andre Przywara wrote:
> In the GICv3 redistributor there are the PENDBASER and PROPBASER
> registers which we did not emulate so far, as they only make sense
> when having an ITS. In preparation for that emulate those MMIO
> accesses by storing the 64-bit data written into it into a variable
> which we later read in the ITS emulation.
> 
> Signed-off-by: Andre Przywara <andre.przywara at arm.com>
> ---
>  include/kvm/vgic/vgic.h       |  8 ++++++++
>  virt/kvm/arm/vgic/vgic_mmio.c | 26 ++++++++++++++++++++++----
>  2 files changed, 30 insertions(+), 4 deletions(-)
> 
> diff --git a/include/kvm/vgic/vgic.h b/include/kvm/vgic/vgic.h
> index 11344e6..8ea5dd7 100644
> --- a/include/kvm/vgic/vgic.h
> +++ b/include/kvm/vgic/vgic.h
> @@ -145,6 +145,14 @@ struct vgic_dist {
>  
>  	struct vgic_io_device	*dist_iodevs;
>  	struct vgic_io_device	*redist_iodevs;
> +
> +	/* Address of LPI configuration table shared by all redistributors */
> +	u64			propbaser;

is this an architectural requirement or an implementation decision?

> +
> +	/* Addresses of LPI pending tables per redistributor */
> +	u64			*pendbaser;

have we considered having an array of redistributors and putting the
field in each one of those instead?

> +
> +	bool			lpis_enabled;
>  };
>  
>  struct vgic_v2_cpu_if {
> diff --git a/virt/kvm/arm/vgic/vgic_mmio.c b/virt/kvm/arm/vgic/vgic_mmio.c
> index 7d5d630..252b9aff 100644
> --- a/virt/kvm/arm/vgic/vgic_mmio.c
> +++ b/virt/kvm/arm/vgic/vgic_mmio.c
> @@ -771,7 +771,9 @@ static int vgic_mmio_read_v3r_propbase(struct kvm_vcpu *vcpu,
>  				       struct kvm_io_device *this,
>  				       gpa_t addr, int len, void *val)
>  {
> -	/* TODO: implement */
> +	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
> +
> +	write_mask64(dist->propbaser, addr & 7, len, val);
>  	return 0;
>  }
>  
> @@ -779,7 +781,11 @@ static int vgic_mmio_write_v3r_propbase(struct kvm_vcpu *vcpu,
>  				        struct kvm_io_device *this,
>  				        gpa_t addr, int len, const void *val)
>  {
> -	/* TODO: implement */
> +	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
> +
> +	/* Storing a value with LPIs already enabled is undefined */
> +	if (!dist->lpis_enabled)
> +		dist->propbaser = mask64(dist->propbaser, addr & 7, len, val);
>  	return 0;
>  }
>  
> @@ -787,7 +793,12 @@ static int vgic_mmio_read_v3r_pendbase(struct kvm_vcpu *vcpu,
>  				       struct kvm_io_device *this,
>  				       gpa_t addr, int len, void *val)
>  {
> -	/* TODO: implement */
> +	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
> +	struct vgic_io_device *iodev = container_of(this,
> +						    struct vgic_io_device, dev);
> +	u64 pendbaser = dist->pendbaser[iodev->redist_vcpu->vcpu_id];
> +
> +	write_mask64(pendbaser, addr & 7, len, val);
>  	return 0;
>  }
>  
> @@ -795,7 +806,14 @@ static int vgic_mmio_write_v3r_pendbase(struct kvm_vcpu *vcpu,
>  				        struct kvm_io_device *this,
>  				        gpa_t addr, int len, const void *val)
>  {
> -	/* TODO: implement */
> +	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
> +	struct vgic_io_device *iodev = container_of(this,
> +						    struct vgic_io_device, dev);
> +	u64 *pendbaser = &dist->pendbaser[iodev->redist_vcpu->vcpu_id];
> +
> +	/* Storing a value with LPIs already enabled is undefined */
> +	if (!dist->lpis_enabled)
> +		*pendbaser = mask64(*pendbaser, addr & 7, len, val);
>  	return 0;
>  }
>  
> -- 
> 2.7.3
>