KVM: PPC: Book3S HV: Add KVM_CAP_PPC_RPT_INVALIDATE capability

Now that we have H_RPT_INVALIDATE fully implemented, enable
support for the same via KVM_CAP_PPC_RPT_INVALIDATE KVM capability

Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210621085003.904767-6-bharata@linux.ibm.com

Documentation/virt/kvm/api.rst

@@ -6362,6 +6362,24 @@ default.
 
 See Documentation/x86/sgx/2.Kernel-internals.rst for more details.
 
+7.26 KVM_CAP_PPC_RPT_INVALIDATE
+-------------------------------
+
+:Capability: KVM_CAP_PPC_RPT_INVALIDATE
+:Architectures: ppc
+:Type: vm
+
+This capability indicates that the kernel is capable of handling
+H_RPT_INVALIDATE hcall.
+
+In order to enable the use of H_RPT_INVALIDATE in the guest,
+user space might have to advertise it for the guest. For example,
+IBM pSeries (sPAPR) guest starts using it if "hcall-rpt-invalidate" is
+present in the "ibm,hypertas-functions" device-tree property.
+
+This capability is enabled for hypervisors on platforms like POWER9
+that support radix MMU.
+
 8. Other capabilities.
 ======================
 

arch/powerpc/kvm/powerpc.c

@@ -682,6 +682,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 		r = !!(hv_enabled && kvmppc_hv_ops->enable_dawr1 &&
 		       !kvmppc_hv_ops->enable_dawr1(NULL));
 		break;
+	case KVM_CAP_PPC_RPT_INVALIDATE:
+		r = 1;
+		break;
 #endif
 	default:
 		r = 0;

include/uapi/linux/kvm.h

@@ -1082,6 +1082,7 @@ struct kvm_ppc_resize_hpt {
 #define KVM_CAP_SGX_ATTRIBUTE 196
 #define KVM_CAP_VM_COPY_ENC_CONTEXT_FROM 197
 #define KVM_CAP_PTP_KVM 198
+#define KVM_CAP_PPC_RPT_INVALIDATE 199
 
 #ifdef KVM_CAP_IRQ_ROUTING