[PATCH 2/9] backends/confidential-guest-support: Add IGVM file parameter

[Roy Hopkins <roy.hopkins@suse.com>]

In order to add support for parsing IGVM files for secure virtual
machines, a the path to an IGVM file needs to be specified as
part of the guest configuration. It makes sense to add this to
the ConfidentialGuestSupport object as this is common to all secure
virtual machines that potentially could support IGVM based
configuration.

This patch allows the filename to be configured via the QEMU
object model in preparation for subsequent patches that will read and
parse the IGVM file.

Signed-off-by: Roy Hopkins <roy.hopkins@suse.com>
---
 backends/confidential-guest-support.c     | 21 +++++++++++++++++++++
 include/exec/confidential-guest-support.h |  9 +++++++++
 qapi/qom.json                             | 13 +++++++++++++
 qemu-options.hx                           |  8 +++++++-
 4 files changed, 50 insertions(+), 1 deletion(-)

diff --git a/backends/confidential-guest-support.c b/backends/confidential-guest-support.c
index 052fde8db0..da436fb736 100644
--- a/backends/confidential-guest-support.c
+++ b/backends/confidential-guest-support.c
@@ -20,8 +20,29 @@ OBJECT_DEFINE_ABSTRACT_TYPE(ConfidentialGuestSupport,
                             CONFIDENTIAL_GUEST_SUPPORT,
                             OBJECT)
 
+#if defined(CONFIG_IGVM)
+static char *get_igvm(Object *obj, Error **errp)
+{
+    ConfidentialGuestSupport *cgs = CONFIDENTIAL_GUEST_SUPPORT(obj);
+    return g_strdup(cgs->igvm_filename);
+}
+
+static void set_igvm(Object *obj, const char *value, Error **errp)
+{
+    ConfidentialGuestSupport *cgs = CONFIDENTIAL_GUEST_SUPPORT(obj);
+    g_free(cgs->igvm_filename);
+    cgs->igvm_filename = g_strdup(value);
+}
+#endif
+
 static void confidential_guest_support_class_init(ObjectClass *oc, void *data)
 {
+#if defined(CONFIG_IGVM)
+    object_class_property_add_str(oc, "igvm-file",
+        get_igvm, set_igvm);
+    object_class_property_set_description(oc, "igvm-file",
+        "Set the IGVM filename to use");
+#endif
 }
 
 static void confidential_guest_support_init(Object *obj)
diff --git a/include/exec/confidential-guest-support.h b/include/exec/confidential-guest-support.h
index ba2dd4b5df..b08ad8de4d 100644
--- a/include/exec/confidential-guest-support.h
+++ b/include/exec/confidential-guest-support.h
@@ -51,6 +51,15 @@ struct ConfidentialGuestSupport {
      * so 'ready' is not set, we'll abort.
      */
     bool ready;
+
+#if defined(CONFIG_IGVM)
+    /*
+     * igvm_filename: Optional filename that specifies a file that contains
+     *                the configuration of the guest in Isolated Guest
+     *                Virtual Machine (IGVM) format.
+     */
+    char *igvm_filename;
+#endif
 };
 
 typedef struct ConfidentialGuestSupportClass {
diff --git a/qapi/qom.json b/qapi/qom.json
index 2a6e49365a..570bdd7d55 100644
--- a/qapi/qom.json
+++ b/qapi/qom.json
@@ -859,6 +859,18 @@
   'base': 'RngProperties',
   'data': { '*filename': 'str' } }
 
+##
+# @ConfidentialGuestProperties:
+#
+# Properties common to objects that are derivatives of confidential-guest-support.
+#
+# @igvm-file: IGVM file to use to configure guest (default: none)
+#
+# Since: 8.2
+##
+{ 'struct': 'ConfidentialGuestProperties',
+  'data': { '*igvm-file': 'str' } }
+
 ##
 # @SevGuestProperties:
 #
@@ -886,6 +898,7 @@
 # Since: 2.12
 ##
 { 'struct': 'SevGuestProperties',
+  'base': 'ConfidentialGuestProperties',
   'data': { '*sev-device': 'str',
             '*dh-cert-file': 'str',
             '*session-file': 'str',
diff --git a/qemu-options.hx b/qemu-options.hx
index 9be1e5817c..49d9226e35 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -5640,7 +5640,7 @@ SRST
                  -object secret,id=sec0,keyid=secmaster0,format=base64,\\
                      data=$SECRET,iv=$(<iv.b64)
 
-    ``-object sev-guest,id=id,cbitpos=cbitpos,reduced-phys-bits=val,[sev-device=string,policy=policy,handle=handle,dh-cert-file=file,session-file=file,kernel-hashes=on|off]``
+    ``-object sev-guest,id=id,cbitpos=cbitpos,reduced-phys-bits=val,[sev-device=string,policy=policy,handle=handle,dh-cert-file=file,session-file=file,kernel-hashes=on|off,igvm-file=file]``
         Create a Secure Encrypted Virtualization (SEV) guest object,
         which can be used to provide the guest memory encryption support
         on AMD processors.
@@ -5684,6 +5684,12 @@ SRST
         cmdline to a designated guest firmware page for measured Linux
         boot with -kernel. The default is off. (Since 6.2)
 
+        The ``igvm-file`` is an optional parameter that, when specified,
+        allows an Independent Guest Virtual Machine (IGVM) file to be
+        specified that configures the secure virtual machine and can
+        include, for example, an SVSM module, system firmware, initial
+        boot state, etc.
+
         e.g to launch a SEV guest
 
         .. parsed-literal::
-- 
2.43.0