arm/arm64: KVM: add virtual GICv3 distributor emulation

With everything separated and prepared, we implement a model of a
GICv3 distributor and redistributors by using the existing framework
to provide handler functions for each register group.

Currently we limit the emulation to a model enforcing a single
security state, with SRE==1 (forcing system register access) and
ARE==1 (allowing more than 8 VCPUs).

We share some of the functions provided for GICv2 emulation, but take
the different ways of addressing (v)CPUs into account.
Save and restore is currently not implemented.

Similar to the split-off of the GICv2 specific code, the new emulation
code goes into a new file (vgic-v3-emul.c).

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
diff --git a/virt/kvm/arm/vgic.h b/virt/kvm/arm/vgic.h
index e363b93..1e83bdf 100644
--- a/virt/kvm/arm/vgic.h
+++ b/virt/kvm/arm/vgic.h
@@ -35,6 +35,8 @@
 #define ACCESS_WRITE_VALUE	(3 << 1)
 #define ACCESS_WRITE_MASK(x)	((x) & (3 << 1))
 
+#define VCPU_NOT_ALLOCATED	((u8)-1)
+
 unsigned long *vgic_bitmap_get_shared_map(struct vgic_bitmap *x);
 
 void vgic_update_state(struct kvm *kvm);
@@ -116,5 +118,6 @@
 
 int vgic_init(struct kvm *kvm);
 void vgic_v2_init_emulation(struct kvm *kvm);
+void vgic_v3_init_emulation(struct kvm *kvm);
 
 #endif