Re: [PATCH v5 11/12] KVM: arm/arm64: Implement KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION

[Christoffer Dall <christoffer.dall@arm.com>]

On Mon, Apr 30, 2018 at 11:07:43AM +0200, Eric Auger wrote:
> Now all the internals are ready to handle multiple redistributor
> regions, let's allow the userspace to register them.
> 
> Signed-off-by: Eric Auger <eric.auger@redhat.com>

Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>

> 
> ---
> v4 -> v5:
> - s/uint<n>_t/u<n>
> - fix KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION read
> - fix read path
> - return -ENOENT instead of -ENODEV when reading the
>   attributes of a region that does not exist
> 
> v3 -> v4:
> - vgic_v3_rdist_region_from_index is introduced in this patch
> 
> v2 -> v3:
> - early exit if vgic_v3_rdist_region_from_index() fails
> ---
>  virt/kvm/arm/vgic/vgic-kvm-device.c | 40 ++++++++++++++++++++++++++++++++++++-
>  virt/kvm/arm/vgic/vgic-mmio-v3.c    |  4 ++--
>  virt/kvm/arm/vgic/vgic-v3.c         | 14 +++++++++++++
>  virt/kvm/arm/vgic/vgic.h            | 13 +++++++++++-
>  4 files changed, 67 insertions(+), 4 deletions(-)
> 
> diff --git a/virt/kvm/arm/vgic/vgic-kvm-device.c b/virt/kvm/arm/vgic/vgic-kvm-device.c
> index 76ab369..6ada243 100644
> --- a/virt/kvm/arm/vgic/vgic-kvm-device.c
> +++ b/virt/kvm/arm/vgic/vgic-kvm-device.c
> @@ -92,7 +92,7 @@ int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write)
>  		if (r)
>  			break;
>  		if (write) {
> -			r = vgic_v3_set_redist_base(kvm, *addr);
> +			r = vgic_v3_set_redist_base(kvm, 0, *addr, 0);
>  			goto out;
>  		}
>  		rdreg = list_first_entry(&vgic->rd_regions,
> @@ -103,6 +103,43 @@ int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write)
>  			addr_ptr = &rdreg->base;
>  		break;
>  	}
> +	case KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION:
> +	{
> +		struct vgic_redist_region *rdreg;
> +		u8 index;
> +
> +		r = vgic_check_type(kvm, KVM_DEV_TYPE_ARM_VGIC_V3);
> +		if (r)
> +			break;
> +
> +		index = *addr & KVM_VGIC_V3_RDIST_INDEX_MASK;
> +
> +		if (write) {
> +			gpa_t base = *addr & KVM_VGIC_V3_RDIST_BASE_MASK;
> +			u32 count = (*addr & KVM_VGIC_V3_RDIST_COUNT_MASK)
> +					>> KVM_VGIC_V3_RDIST_COUNT_SHIFT;
> +			u8 flags = (*addr & KVM_VGIC_V3_RDIST_FLAGS_MASK)
> +					>> KVM_VGIC_V3_RDIST_FLAGS_SHIFT;
> +
> +			if (!count || flags)
> +				r = -EINVAL;
> +			else
> +				r = vgic_v3_set_redist_base(kvm, index,
> +							    base, count);
> +			goto out;
> +		}
> +
> +		rdreg = vgic_v3_rdist_region_from_index(kvm, index);
> +		if (!rdreg) {
> +			r = -ENOENT;
> +			goto out;
> +		}
> +
> +		*addr = index;
> +		*addr |= rdreg->base;
> +		*addr |= (u64)rdreg->count << KVM_VGIC_V3_RDIST_COUNT_SHIFT;
> +		goto out;
> +	}
>  	default:
>  		r = -ENODEV;
>  	}
> @@ -674,6 +711,7 @@ static int vgic_v3_has_attr(struct kvm_device *dev,
>  		switch (attr->attr) {
>  		case KVM_VGIC_V3_ADDR_TYPE_DIST:
>  		case KVM_VGIC_V3_ADDR_TYPE_REDIST:
> +		case KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION:
>  			return 0;
>  		}
>  		break;
> diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
> index 1b1e07f..fcebd42 100644
> --- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
> +++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
> @@ -764,11 +764,11 @@ static int vgic_v3_insert_redist_region(struct kvm *kvm, uint32_t index,
>  	return ret;
>  }
>  
> -int vgic_v3_set_redist_base(struct kvm *kvm, u64 addr)
> +int vgic_v3_set_redist_base(struct kvm *kvm, u32 index, u64 addr, u32 count)
>  {
>  	int ret;
>  
> -	ret = vgic_v3_insert_redist_region(kvm, 0, addr, 0);
> +	ret = vgic_v3_insert_redist_region(kvm, index, addr, count);
>  	if (ret)
>  		return ret;
>  
> diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
> index 5563671..70d5ba1 100644
> --- a/virt/kvm/arm/vgic/vgic-v3.c
> +++ b/virt/kvm/arm/vgic/vgic-v3.c
> @@ -482,6 +482,20 @@ struct vgic_redist_region *vgic_v3_rdist_free_slot(struct list_head *rd_regions)
>  	return NULL;
>  }
>  
> +struct vgic_redist_region *vgic_v3_rdist_region_from_index(struct kvm *kvm,
> +							   u32 index)
> +{
> +	struct list_head *rd_regions = &kvm->arch.vgic.rd_regions;
> +	struct vgic_redist_region *rdreg;
> +
> +	list_for_each_entry(rdreg, rd_regions, list) {
> +		if (rdreg->index == index)
> +			return rdreg;
> +	}
> +	return NULL;
> +}
> +
> +
>  int vgic_v3_map_resources(struct kvm *kvm)
>  {
>  	struct vgic_dist *dist = &kvm->arch.vgic;
> diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
> index 6af7d8a..375aa66 100644
> --- a/virt/kvm/arm/vgic/vgic.h
> +++ b/virt/kvm/arm/vgic/vgic.h
> @@ -96,6 +96,13 @@
>  /* we only support 64 kB translation table page size */
>  #define KVM_ITS_L1E_ADDR_MASK		GENMASK_ULL(51, 16)
>  
> +#define KVM_VGIC_V3_RDIST_INDEX_MASK	GENMASK_ULL(11, 0)
> +#define KVM_VGIC_V3_RDIST_FLAGS_MASK	GENMASK_ULL(15, 12)
> +#define KVM_VGIC_V3_RDIST_FLAGS_SHIFT	12
> +#define KVM_VGIC_V3_RDIST_BASE_MASK	GENMASK_ULL(51, 16)
> +#define KVM_VGIC_V3_RDIST_COUNT_MASK	GENMASK_ULL(63, 52)
> +#define KVM_VGIC_V3_RDIST_COUNT_SHIFT	52
> +
>  /* Requires the irq_lock to be held by the caller. */
>  static inline bool irq_is_pending(struct vgic_irq *irq)
>  {
> @@ -201,7 +208,7 @@ int vgic_v3_probe(const struct gic_kvm_info *info);
>  int vgic_v3_map_resources(struct kvm *kvm);
>  int vgic_v3_lpi_sync_pending_status(struct kvm *kvm, struct vgic_irq *irq);
>  int vgic_v3_save_pending_tables(struct kvm *kvm);
> -int vgic_v3_set_redist_base(struct kvm *kvm, u64 addr);
> +int vgic_v3_set_redist_base(struct kvm *kvm, u32 index, u64 addr, u32 count);
>  int vgic_register_redist_iodev(struct kvm_vcpu *vcpu);
>  bool vgic_v3_check_base(struct kvm *kvm);
>  
> @@ -270,6 +277,10 @@ vgic_v3_rd_region_size(struct kvm *kvm, struct vgic_redist_region *rdreg)
>  	else
>  		return rdreg->count * KVM_VGIC_V3_REDIST_SIZE;
>  }
> +
> +struct vgic_redist_region *vgic_v3_rdist_region_from_index(struct kvm *kvm,
> +							   u32 index);
> +
>  bool vgic_v3_rdist_overlap(struct kvm *kvm, gpa_t base, size_t size);
>  
>  static inline bool vgic_dist_overlap(struct kvm *kvm, gpa_t base, size_t size)
> -- 
> 2.5.5
> 
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