KVM: arm64: vgic-its: KVM_DEV_ARM_ITS_SAVE/RESTORE_TABLES

Introduce new attributes in KVM_DEV_ARM_VGIC_GRP_CTRL group:
- KVM_DEV_ARM_ITS_SAVE_TABLES: saves the ITS tables into guest RAM
- KVM_DEV_ARM_ITS_RESTORE_TABLES: restores them into VGIC internal
  structures.

We hold the vcpus lock during the save and restore to make
sure no vcpu is running.

At this stage the functionality is not yet implemented. Only
the skeleton is put in place.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
[Given we will move the iodev register until setting the base addr]
Reviewed-by: Christoffer Dall <cdall@linaro.org>
diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index ee4a0ad..5dd7be04 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -221,7 +221,9 @@ struct kvm_arch_memory_slot {
 #define KVM_DEV_ARM_VGIC_LINE_LEVEL_INTID_MASK	0x3ff
 #define VGIC_LEVEL_INFO_LINE_LEVEL	0
 
-#define   KVM_DEV_ARM_VGIC_CTRL_INIT	0
+#define   KVM_DEV_ARM_VGIC_CTRL_INIT		0
+#define   KVM_DEV_ARM_ITS_SAVE_TABLES           1
+#define   KVM_DEV_ARM_ITS_RESTORE_TABLES        2
 
 /* Device Control API on vcpu fd */
 #define KVM_ARM_VCPU_PMU_V3_CTRL	0