[RFC v2 02/12] KVM: arm/arm64: Document KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION

From: Eric Auger
Date: Tue Mar 27 2018 - 10:04:38 EST


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>
---
Documentation/virtual/kvm/devices/arm-vgic-v3.txt | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)

diff --git a/Documentation/virtual/kvm/devices/arm-vgic-v3.txt b/Documentation/virtual/kvm/devices/arm-vgic-v3.txt
index 9293b45..0ded904 100644
--- a/Documentation/virtual/kvm/devices/arm-vgic-v3.txt
+++ b/Documentation/virtual/kvm/devices/arm-vgic-v3.txt
@@ -27,6 +27,24 @@ 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. There are two 64K pages
+ for each VCPU and all of the redistributor pages are contiguous
+ within the redistributor region.
+ - count encodes the number of redistributors in the region.
+ 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. When attempted an
+ -EINVAL error is returned.
+
Errors:
-E2BIG: Address outside of addressable IPA range
-EINVAL: Incorrectly aligned address
--
2.5.5