Re: [PATCH v5 02/12] KVM: arm/arm64: Document KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION
From: Christoffer Dall
Date: Mon Apr 30 2018 - 05:31:47 EST
On Mon, Apr 30, 2018 at 11:07:34AM +0200, Eric Auger wrote:
> We introduce a new KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION attribute in
> KVM_DEV_ARM_VGIC_GRP_ADDR group. It allows userspace to provide the
> base address and size of a redistributor region
> Compared to KVM_VGIC_V3_ADDR_TYPE_REDIST, this new attribute allows
> to declare several separate redistributor regions.
> So the whole redist space does not need to be contiguous anymore.
> Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx>
Acked-by: Christoffer Dall <christoffer.dall@xxxxxxx>
> v4 -> v5:
> - Document read access
> - removed Peter's R-b
> v3 -> v4:
> - Added Peter's R-b
> Documentation/virtual/kvm/devices/arm-vgic-v3.txt | 30 +++++++++++++++++++++--
> 1 file changed, 28 insertions(+), 2 deletions(-)
> diff --git a/Documentation/virtual/kvm/devices/arm-vgic-v3.txt b/Documentation/virtual/kvm/devices/arm-vgic-v3.txt
> index 9293b45..dcb7504 100644
> --- a/Documentation/virtual/kvm/devices/arm-vgic-v3.txt
> +++ b/Documentation/virtual/kvm/devices/arm-vgic-v3.txt
> @@ -27,16 +27,42 @@ Groups:
> VCPU and all of the redistributor pages are contiguous.
> Only valid for KVM_DEV_TYPE_ARM_VGIC_V3.
> This address needs to be 64K aligned.
> + KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION (rw, 64-bit)
> + The attribute data pointed by kvm_device_attr.addr is a __u64 value:
> + bits: | 63 .... 52 | 51 .... 16 | 15 - 12 |11 - 0
> + values: | count | base | flags | index
> + - index encodes the unique redistributor region index
> + - flags: reserved for future use, currently 0
> + - base field encodes bits [51:16] of the guest physical base address
> + of the first redistributor in the region.
> + - count encodes the number of redistributors in the region. Must be
> + greater than 0.
> + There are two 64K pages for each redistributor in the region and
> + redistributors are laid out contiguously within the region. Regions
> + are filled with redistributors in the index order. The sum of all
> + region count fields must be greater than or equal to the number of
> + VCPUs. Redistributor regions must be registered in the incremental
> + index order, starting from index 0.
> + The characteristics of a specific redistributor region can be read
> + by presetting the index field in the attr data.
> + Only valid for KVM_DEV_TYPE_ARM_VGIC_V3.
> + It is invalid to mix calls with KVM_VGIC_V3_ADDR_TYPE_REDIST and
> + KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION attributes.
> -E2BIG: Address outside of addressable IPA range
> - -EINVAL: Incorrectly aligned address
> + -EINVAL: Incorrectly aligned address, bad redistributor region
> + count/index, mixed redistributor region attribute usage
> -EEXIST: Address already configured
> + -ENOENT: Attempt to read the characteristics of a non existing
> + redistributor region
> -ENXIO: The group or attribute is unknown/unsupported for this device
> or hardware support is missing.
> -EFAULT: Invalid user pointer for attr->addr.
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