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

From: Christoffer Dall
Date: Mon Apr 30 2018 - 05:44:50 EST

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@xxxxxxxxxx>

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

>
> ---
> 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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