backends/igvm: Add IGVM loader and configuration

Adds an IGVM loader to QEMU which processes a given IGVM file and
applies the directives within the file to the current guest
configuration.

The IGVM loader can be used to configure both confidential and
non-confidential guests. For confidential guests, the
ConfidentialGuestSupport object for the system is used to encrypt
memory, apply the initial CPU state and perform other confidential guest
operations.

The loader is configured via a new IgvmCfg QOM object which allows the
user to provide a path to the IGVM file to process.

Signed-off-by: Roy Hopkins <roy.hopkins@randomman.co.uk>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Gerd Hoffman <kraxel@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://lore.kernel.org/r/ae3a07d8f514d93845a9c16bb155c847cb567b0d.1751554099.git.roy.hopkins@randomman.co.uk
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 51 insertions, 0 deletions

diff --git a/backends/igvm-cfg.c b/backends/igvm-cfg.c
new file mode 100644
index 0000000000..45df63e06c
--- /dev/null
+++ b/backends/igvm-cfg.c
@@ -0,0 +1,51 @@
+/*
+ * QEMU IGVM interface
+ *
+ * Copyright (C) 2023-2024 SUSE
+ *
+ * Authors:
+ *  Roy Hopkins <roy.hopkins@randomman.co.uk>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+
+#include "system/igvm-cfg.h"
+#include "igvm.h"
+#include "qom/object_interfaces.h"
+
+static char *get_igvm(Object *obj, Error **errp)
+{
+    IgvmCfg *igvm = IGVM_CFG(obj);
+    return g_strdup(igvm->filename);
+}
+
+static void set_igvm(Object *obj, const char *value, Error **errp)
+{
+    IgvmCfg *igvm = IGVM_CFG(obj);
+    g_free(igvm->filename);
+    igvm->filename = g_strdup(value);
+}
+
+OBJECT_DEFINE_TYPE_WITH_INTERFACES(IgvmCfg, igvm_cfg, IGVM_CFG, OBJECT,
+                                   { TYPE_USER_CREATABLE }, { NULL })
+
+static void igvm_cfg_class_init(ObjectClass *oc, const void *data)
+{
+    IgvmCfgClass *igvmc = IGVM_CFG_CLASS(oc);
+
+    object_class_property_add_str(oc, "file", get_igvm, set_igvm);
+    object_class_property_set_description(oc, "file",
+                                          "Set the IGVM filename to use");
+
+    igvmc->process = qigvm_process_file;
+}
+
+static void igvm_cfg_init(Object *obj)
+{
+}
+
+static void igvm_cfg_finalize(Object *obj)
+{
+}