KVM: arm-vgic: Set base addr through device API

Support setting the distributor and cpu interface base addresses in the
VM physical address space through the KVM_{SET,GET}_DEVICE_ATTR API
in addition to the ARM specific API.

This has the added benefit of being able to share more code in user
space and do things in a uniform manner.

Also deprecate the older API at the same time, but backwards
compatibility will be maintained.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

Documentation/virtual/kvm/devices/arm-vgic.txt

@@ -8,3 +8,14 @@ Only one VGIC instance may be instantiated through either this API or the
 legacy KVM_CREATE_IRQCHIP api.  The created VGIC will act as the VM interrupt
 controller, requiring emulated user-space devices to inject interrupts to the
 VGIC instead of directly to CPUs.
+
+Groups:
+  KVM_DEV_ARM_VGIC_GRP_ADDR
+  Attributes:
+    KVM_VGIC_V2_ADDR_TYPE_DIST (rw, 64-bit)
+      Base address in the guest physical address space of the GIC distributor
+      register mappings.
+
+    KVM_VGIC_V2_ADDR_TYPE_CPU (rw, 64-bit)
+      Base address in the guest physical address space of the GIC virtual cpu
+      interface register mappings.