[PATCH v3 02/12] KVM: arm/arm64: Document KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION

Eric Auger
2018-04-13T08:20:48Z

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@redhat.com>
---
Documentation/virtual/kvm/devices/arm-vgic-v3.txt | 25 ++++++++++++++++++++++-
1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/Documentation/virtual/kvm/devices/arm-vgic-v3.txt b/Documentation/virtual/kvm/devices/arm-vgic-v3.txt
index 9293b45..cbc4328 100644
--- a/Documentation/virtual/kvm/devices/arm-vgic-v3.txt
+++ b/Documentation/virtual/kvm/devices/arm-vgic-v3.txt
@@ -27,9 +27,32 @@ 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 attr field of kvm_device_attr encodes 3 values:
+ 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.
+ 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.
+
Errors:
-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
-ENXIO: The group or attribute is unknown/unsupported for this device
or hardware support is missing.
--
2.5.5