KVM: PPC: Book3S HV: Nested support in H_RPT_INVALIDATE

Enable support for process-scoped invalidations from nested
guests and partition-scoped invalidations for nested guests.

Process-scoped invalidations for any level of nested guests
are handled by implementing H_RPT_INVALIDATE handler in the
nested guest exit path in L0.

Partition-scoped invalidation requests are forwarded to the
right nested guest, handled there and passed down to L0
for eventual handling.

Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
[aneesh: Nested guest partition-scoped invalidation changes]
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
[mpe: Squash in fixup patch]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210621085003.904767-5-bharata@linux.ibm.com
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index b32b968..279eae8 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -923,6 +923,34 @@ static int kvmppc_get_yield_count(struct kvm_vcpu *vcpu)
 	return yield_count;
 }
 
+/*
+ * H_RPT_INVALIDATE hcall handler for nested guests.
+ *
+ * Handles only nested process-scoped invalidation requests in L0.
+ */
+static int kvmppc_nested_h_rpt_invalidate(struct kvm_vcpu *vcpu)
+{
+	unsigned long type = kvmppc_get_gpr(vcpu, 6);
+	unsigned long pid, pg_sizes, start, end;
+
+	/*
+	 * The partition-scoped invalidations aren't handled here in L0.
+	 */
+	if (type & H_RPTI_TYPE_NESTED)
+		return RESUME_HOST;
+
+	pid = kvmppc_get_gpr(vcpu, 4);
+	pg_sizes = kvmppc_get_gpr(vcpu, 7);
+	start = kvmppc_get_gpr(vcpu, 8);
+	end = kvmppc_get_gpr(vcpu, 9);
+
+	do_h_rpt_invalidate_prt(pid, vcpu->arch.nested->shadow_lpid,
+				type, pg_sizes, start, end);
+
+	kvmppc_set_gpr(vcpu, 3, H_SUCCESS);
+	return RESUME_GUEST;
+}
+
 static long kvmppc_h_rpt_invalidate(struct kvm_vcpu *vcpu,
 				    unsigned long id, unsigned long target,
 				    unsigned long type, unsigned long pg_sizes,
@@ -936,10 +964,18 @@ static long kvmppc_h_rpt_invalidate(struct kvm_vcpu *vcpu,
 
 	/*
 	 * Partition-scoped invalidation for nested guests.
-	 * Not yet supported
 	 */
-	if (type & H_RPTI_TYPE_NESTED)
-		return H_P3;
+	if (type & H_RPTI_TYPE_NESTED) {
+		if (!nesting_enabled(vcpu->kvm))
+			return H_FUNCTION;
+
+		/* Support only cores as target */
+		if (target != H_RPTI_TARGET_CMMU)
+			return H_P2;
+
+		return do_h_rpt_invalidate_pat(vcpu, id, type, pg_sizes,
+					       start, end);
+	}
 
 	/*
 	 * Process-scoped invalidation for L1 guests.
@@ -1784,6 +1820,23 @@ static int kvmppc_handle_nested_exit(struct kvm_vcpu *vcpu)
 		if (!xics_on_xive())
 			kvmppc_xics_rm_complete(vcpu, 0);
 		break;
+	case BOOK3S_INTERRUPT_SYSCALL:
+	{
+		unsigned long req = kvmppc_get_gpr(vcpu, 3);
+
+		/*
+		 * The H_RPT_INVALIDATE hcalls issued by nested
+		 * guests for process-scoped invalidations when
+		 * GTSE=0, are handled here in L0.
+		 */
+		if (req == H_RPT_INVALIDATE) {
+			r = kvmppc_nested_h_rpt_invalidate(vcpu);
+			break;
+		}
+
+		r = RESUME_HOST;
+		break;
+	}
 	default:
 		r = RESUME_HOST;
 		break;