diff --git a/src/arch/aarch64/args.gni b/src/arch/aarch64/args.gni
new file mode 100644
index 0000000..1582b34
--- /dev/null
+++ b/src/arch/aarch64/args.gni
@@ -0,0 +1,18 @@
+# Copyright 2019 The Hafnium Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+declare_args() {
+  # SMC hooks to be used for the platform, specified as build target.
+  plat_smc = "//src/arch/aarch64/smc:absent"
+}
diff --git a/src/arch/aarch64/hypervisor/BUILD.gn b/src/arch/aarch64/hypervisor/BUILD.gn
index e72833a..8a057e9 100644
--- a/src/arch/aarch64/hypervisor/BUILD.gn
+++ b/src/arch/aarch64/hypervisor/BUILD.gn
@@ -13,6 +13,7 @@
 # limitations under the License.
 
 import("//build/toolchain/offset_size_header.gni")
+import("//src/arch/aarch64/args.gni")
 
 offset_size_header("offsets") {
   sources = [
@@ -46,5 +47,6 @@
     "//src/arch/aarch64:arch",
     "//src/arch/aarch64:entry",
     "//src/arch/aarch64:smc",
+    plat_smc,
   ]
 }
diff --git a/src/arch/aarch64/hypervisor/handler.c b/src/arch/aarch64/hypervisor/handler.c
index fd490ff..a2d0437 100644
--- a/src/arch/aarch64/hypervisor/handler.c
+++ b/src/arch/aarch64/hypervisor/handler.c
@@ -19,6 +19,7 @@
 #include "hf/arch/barriers.h"
 #include "hf/arch/init.h"
 #include "hf/arch/mm.h"
+#include "hf/arch/plat/smc.h"
 
 #include "hf/api.h"
 #include "hf/check.h"
@@ -286,6 +287,7 @@
  */
 static void smc_forwarder(const struct vm *vm, struct spci_value *args)
 {
+	struct spci_value ret;
 	uint32_t client_id = vm->id;
 	uintreg_t arg7 = args->arg7;
 
@@ -300,8 +302,8 @@
 	 * upper bits.
 	 */
 	args->arg7 = client_id | (arg7 & ~CLIENT_ID_MASK);
-	*args = smc_forward(args->func, args->arg1, args->arg2, args->arg3,
-			    args->arg4, args->arg5, args->arg6, args->arg7);
+	ret = smc_forward(args->func, args->arg1, args->arg2, args->arg3,
+			  args->arg4, args->arg5, args->arg6, args->arg7);
 
 	/*
 	 * Preserve the value passed by the caller, rather than the client_id we
@@ -309,7 +311,11 @@
 	 * may be in x7, but the SMCs that we are forwarding are legacy calls
 	 * from before SMCCC 1.2 so won't have more than 4 return values anyway.
 	 */
-	args->arg7 = arg7;
+	ret.arg7 = arg7;
+
+	plat_smc_post_forward(*args, &ret);
+
+	*args = ret;
 }
 
 static bool spci_handler(struct spci_value *args, struct vcpu **next)
@@ -425,12 +431,12 @@
 	switch (args.func & ~SMCCC_CONVENTION_MASK) {
 	case HF_DEBUG_LOG:
 		vcpu->regs.r[0] = api_debug_log(args.arg1, vcpu);
-		return next;
+		return NULL;
 	}
 
 	smc_forwarder(vcpu->vm, &args);
 	arch_regs_set_retval(&vcpu->regs, args);
-	return next;
+	return NULL;
 }
 
 struct vcpu *hvc_handler(struct vcpu *vcpu)
diff --git a/src/arch/aarch64/smc/BUILD.gn b/src/arch/aarch64/smc/BUILD.gn
new file mode 100644
index 0000000..00004f3
--- /dev/null
+++ b/src/arch/aarch64/smc/BUILD.gn
@@ -0,0 +1,19 @@
+# Copyright 2019 The Hafnium Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+source_set("absent") {
+  sources = [
+    "absent.c",
+  ]
+}
diff --git a/src/arch/aarch64/smc/absent.c b/src/arch/aarch64/smc/absent.c
new file mode 100644
index 0000000..6ea9b8d
--- /dev/null
+++ b/src/arch/aarch64/smc/absent.c
@@ -0,0 +1,23 @@
+/*
+ * Copyright 2019 The Hafnium Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "hf/arch/plat/smc.h"
+
+void plat_smc_post_forward(struct spci_value args, struct spci_value *ret)
+{
+	(void)args;
+	(void)ret;
+}