1 files changed, 54 insertions, 9 deletions

diff --git a/hw/core/machine.c b/hw/core/machine.c
index 5d6163ab70..970046f438 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -32,6 +32,9 @@
 #include "hw/mem/nvdimm.h"
 #include "migration/global_state.h"
 #include "migration/vmstate.h"
+#include "exec/confidential-guest-support.h"
+#include "hw/virtio/virtio.h"
+#include "hw/virtio/virtio-pci.h"
 
 GlobalProperty hw_compat_5_2[] = {};
 const size_t hw_compat_5_2_len = G_N_ELEMENTS(hw_compat_5_2);
@@ -427,24 +430,37 @@ static char *machine_get_memory_encryption(Object *obj, Error **errp)
 {
     MachineState *ms = MACHINE(obj);
 
-    return g_strdup(ms->memory_encryption);
+    if (ms->cgs) {
+        return g_strdup(object_get_canonical_path_component(OBJECT(ms->cgs)));
+    }
+
+    return NULL;
 }
 
 static void machine_set_memory_encryption(Object *obj, const char *value,
                                         Error **errp)
 {
-    MachineState *ms = MACHINE(obj);
+    Object *cgs =
+        object_resolve_path_component(object_get_objects_root(), value);
+
+    if (!cgs) {
+        error_setg(errp, "No such memory encryption object '%s'", value);
+        return;
+    }
 
-    g_free(ms->memory_encryption);
-    ms->memory_encryption = g_strdup(value);
+    object_property_set_link(obj, "confidential-guest-support", cgs, errp);
+}
 
+static void machine_check_confidential_guest_support(const Object *obj,
+                                                     const char *name,
+                                                     Object *new_target,
+                                                     Error **errp)
+{
     /*
-     * With memory encryption, the host can't see the real contents of RAM,
-     * so there's no point in it trying to merge areas.
+     * So far the only constraint is that the target has the
+     * TYPE_CONFIDENTIAL_GUEST_SUPPORT interface, and that's checked
+     * by the QOM core
      */
-    if (value) {
-        machine_set_mem_merge(obj, false, errp);
-    }
 }
 
 static bool machine_get_nvdimm(Object *obj, Error **errp)
@@ -844,6 +860,15 @@ static void machine_class_init(ObjectClass *oc, void *data)
     object_class_property_set_description(oc, "suppress-vmdesc",
         "Set on to disable self-describing migration");
 
+    object_class_property_add_link(oc, "confidential-guest-support",
+                                   TYPE_CONFIDENTIAL_GUEST_SUPPORT,
+                                   offsetof(MachineState, cgs),
+                                   machine_check_confidential_guest_support,
+                                   OBJ_PROP_LINK_STRONG);
+    object_class_property_set_description(oc, "confidential-guest-support",
+                                          "Set confidential guest scheme to support");
+
+    /* For compatibility */
     object_class_property_add_str(oc, "memory-encryption",
         machine_get_memory_encryption, machine_set_memory_encryption);
     object_class_property_set_description(oc, "memory-encryption",
@@ -1166,6 +1191,26 @@ void machine_run_board_init(MachineState *machine)
                     cc->deprecation_note);
     }
 
+    if (machine->cgs) {
+        /*
+         * With confidential guests, the host can't see the real
+         * contents of RAM, so there's no point in it trying to merge
+         * areas.
+         */
+        machine_set_mem_merge(OBJECT(machine), false, &error_abort);
+
+        /*
+         * Virtio devices can't count on directly accessing guest
+         * memory, so they need iommu_platform=on to use normal DMA
+         * mechanisms.  That requires also disabling legacy virtio
+         * support for those virtio pci devices which allow it.
+         */
+        object_register_sugar_prop(TYPE_VIRTIO_PCI, "disable-legacy",
+                                   "on", true);
+        object_register_sugar_prop(TYPE_VIRTIO_DEVICE, "iommu_platform",
+                                   "on", false);
+    }
+
     machine_class->init(machine);
     phase_advance(PHASE_MACHINE_INITIALIZED);
 }