[PATCH v2 02/22] target/arm: Add confidential guest support

[Jean-Philippe Brucker <jean-philippe@linaro.org>]

Add a new RmeGuest object, inheriting from ConfidentialGuestSupport, to
support the Arm Realm Management Extension (RME). It is instantiated by
passing on the command-line:

  -M virt,confidential-guest-support=<id>
  -object guest-rme,id=<id>[,options...]

This is only the skeleton. Support will be added in following patches.

Cc: Eric Blake <eblake@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Cc: Daniel P. Berrangé <berrange@redhat.com>
Cc: Eduardo Habkost <eduardo@habkost.net>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
---
 docs/system/confidential-guest-support.rst |  1 +
 qapi/qom.json                              |  3 +-
 target/arm/kvm-rme.c                       | 46 ++++++++++++++++++++++
 target/arm/meson.build                     |  7 +++-
 4 files changed, 55 insertions(+), 2 deletions(-)
 create mode 100644 target/arm/kvm-rme.c

diff --git a/docs/system/confidential-guest-support.rst b/docs/system/confidential-guest-support.rst
index 0c490dbda2..acf46d8856 100644
--- a/docs/system/confidential-guest-support.rst
+++ b/docs/system/confidential-guest-support.rst
@@ -40,5 +40,6 @@ Currently supported confidential guest mechanisms are:
 * AMD Secure Encrypted Virtualization (SEV) (see :doc:`i386/amd-memory-encryption`)
 * POWER Protected Execution Facility (PEF) (see :ref:`power-papr-protected-execution-facility-pef`)
 * s390x Protected Virtualization (PV) (see :doc:`s390x/protvirt`)
+* Arm Realm Management Extension (RME)
 
 Other mechanisms may be supported in future.
diff --git a/qapi/qom.json b/qapi/qom.json
index 85e6b4f84a..623ec8071f 100644
--- a/qapi/qom.json
+++ b/qapi/qom.json
@@ -996,7 +996,8 @@
     'tls-creds-x509',
     'tls-cipher-suites',
     { 'name': 'x-remote-object', 'features': [ 'unstable' ] },
-    { 'name': 'x-vfio-user-server', 'features': [ 'unstable' ] }
+    { 'name': 'x-vfio-user-server', 'features': [ 'unstable' ] },
+    'rme-guest'
   ] }
 
 ##
diff --git a/target/arm/kvm-rme.c b/target/arm/kvm-rme.c
new file mode 100644
index 0000000000..960dd75608
--- /dev/null
+++ b/target/arm/kvm-rme.c
@@ -0,0 +1,46 @@
+/*
+ * QEMU Arm RME support
+ *
+ * Copyright Linaro 2024
+ */
+
+#include "qemu/osdep.h"
+
+#include "exec/confidential-guest-support.h"
+#include "hw/boards.h"
+#include "hw/core/cpu.h"
+#include "kvm_arm.h"
+#include "migration/blocker.h"
+#include "qapi/error.h"
+#include "qom/object_interfaces.h"
+#include "sysemu/kvm.h"
+#include "sysemu/runstate.h"
+
+#define TYPE_RME_GUEST "rme-guest"
+OBJECT_DECLARE_SIMPLE_TYPE(RmeGuest, RME_GUEST)
+
+struct RmeGuest {
+    ConfidentialGuestSupport parent_obj;
+};
+
+static void rme_guest_class_init(ObjectClass *oc, void *data)
+{
+}
+
+static const TypeInfo rme_guest_info = {
+    .parent = TYPE_CONFIDENTIAL_GUEST_SUPPORT,
+    .name = TYPE_RME_GUEST,
+    .instance_size = sizeof(struct RmeGuest),
+    .class_init = rme_guest_class_init,
+    .interfaces = (InterfaceInfo[]) {
+        { TYPE_USER_CREATABLE },
+        { }
+    }
+};
+
+static void rme_register_types(void)
+{
+    type_register_static(&rme_guest_info);
+}
+
+type_init(rme_register_types);
diff --git a/target/arm/meson.build b/target/arm/meson.build
index 2e10464dbb..c610c078f7 100644
--- a/target/arm/meson.build
+++ b/target/arm/meson.build
@@ -8,7 +8,12 @@ arm_ss.add(files(
 ))
 arm_ss.add(zlib)
 
-arm_ss.add(when: 'CONFIG_KVM', if_true: files('hyp_gdbstub.c', 'kvm.c'), if_false: files('kvm-stub.c'))
+arm_ss.add(when: 'CONFIG_KVM',
+  if_true: files(
+    'hyp_gdbstub.c',
+    'kvm.c',
+    'kvm-rme.c'),
+  if_false: files('kvm-stub.c'))
 arm_ss.add(when: 'CONFIG_HVF', if_true: files('hyp_gdbstub.c'))
 
 arm_ss.add(when: 'TARGET_AARCH64', if_true: files(
-- 
2.44.0