diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 4fbc577470..c74931d577 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -83,7 +83,7 @@ GlobalProperty pc_compat_9_0[] = {
     { TYPE_X86_CPU, "x-amd-topoext-features-only", "false" },
     { TYPE_X86_CPU, "x-l1-cache-per-thread", "false" },
     { TYPE_X86_CPU, "guest-phys-bits", "0" },
-    { "sev-guest", "legacy-vm-type", "true" },
+    { "sev-guest", "legacy-vm-type", "on" },
     { TYPE_X86_CPU, "legacy-multi-node", "on" },
 };
 const size_t pc_compat_9_0_len = G_N_ELEMENTS(pc_compat_9_0);
diff --git a/qapi/qom.json b/qapi/qom.json
index 8e75a419c3..7eccd2e14e 100644
--- a/qapi/qom.json
+++ b/qapi/qom.json
@@ -924,12 +924,16 @@
 # @handle: SEV firmware handle (default: 0)
 #
 # @legacy-vm-type: Use legacy KVM_SEV_INIT KVM interface for creating the VM.
-#                  The newer KVM_SEV_INIT2 interface syncs additional vCPU
-#                  state when initializing the VMSA structures, which will
-#                  result in a different guest measurement. Set this to
-#                  maintain compatibility with older QEMU or kernel versions
-#                  that rely on legacy KVM_SEV_INIT behavior.
-#                  (default: false) (since 9.1)
+#                  The newer KVM_SEV_INIT2 interface, from Linux >= 6.10, syncs
+#                  additional vCPU state when initializing the VMSA structures,
+#                  which will result in a different guest measurement. Set
+#                  this to 'on' to force compatibility with older QEMU or kernel
+#                  versions that rely on legacy KVM_SEV_INIT behavior. 'auto'
+#                  will behave identically to 'on', but will automatically
+#                  switch to using KVM_SEV_INIT2 if the user specifies any
+#                  additional options that require it. If set to 'off', QEMU
+#                  will require KVM_SEV_INIT2 unconditionally.
+#                  (default: off) (since 9.1)
 #
 # Since: 2.12
 ##
@@ -939,7 +943,7 @@
             '*session-file': 'str',
             '*policy': 'uint32',
             '*handle': 'uint32',
-            '*legacy-vm-type': 'bool' } }
+            '*legacy-vm-type': 'OnOffAuto' } }
 
 ##
 # @SevSnpGuestProperties:
diff --git a/target/i386/sev.c b/target/i386/sev.c
index 2ba5f51722..a1157c0ede 100644
--- a/target/i386/sev.c
+++ b/target/i386/sev.c
@@ -144,7 +144,7 @@ struct SevGuestState {
     uint32_t policy;
     char *dh_cert_file;
     char *session_file;
-    bool legacy_vm_type;
+    OnOffAuto legacy_vm_type;
 };
 
 struct SevSnpGuestState {
@@ -1369,6 +1369,17 @@ sev_vm_state_change(void *opaque, bool running, RunState state)
     }
 }
 
+/*
+ * This helper is to examine sev-guest properties and determine if any options
+ * have been set which rely on the newer KVM_SEV_INIT2 interface and associated
+ * KVM VM types.
+ */
+static bool sev_init2_required(SevGuestState *sev_guest)
+{
+    /* Currently no KVM_SEV_INIT2-specific options are exposed via QEMU */
+    return false;
+}
+
 static int sev_kvm_type(X86ConfidentialGuest *cg)
 {
     SevCommonState *sev_common = SEV_COMMON(cg);
@@ -1379,14 +1390,39 @@ static int sev_kvm_type(X86ConfidentialGuest *cg)
         goto out;
     }
 
+    /* These are the only cases where legacy VM types can be used. */
+    if (sev_guest->legacy_vm_type == ON_OFF_AUTO_ON ||
+        (sev_guest->legacy_vm_type == ON_OFF_AUTO_AUTO &&
+         !sev_init2_required(sev_guest))) {
+        sev_common->kvm_type = KVM_X86_DEFAULT_VM;
+        goto out;
+    }
+
+    /*
+     * Newer VM types are required, either explicitly via legacy-vm-type=on, or
+     * implicitly via legacy-vm-type=auto along with additional sev-guest
+     * properties that require the newer VM types.
+     */
     kvm_type = (sev_guest->policy & SEV_POLICY_ES) ?
                 KVM_X86_SEV_ES_VM : KVM_X86_SEV_VM;
-    if (kvm_is_vm_type_supported(kvm_type) && !sev_guest->legacy_vm_type) {
-        sev_common->kvm_type = kvm_type;
-    } else {
-        sev_common->kvm_type = KVM_X86_DEFAULT_VM;
+    if (!kvm_is_vm_type_supported(kvm_type)) {
+        if (sev_guest->legacy_vm_type == ON_OFF_AUTO_AUTO) {
+            error_report("SEV: host kernel does not support requested %s VM type, which is required "
+                         "for the set of options specified. To allow use of the legacy "
+                         "KVM_X86_DEFAULT_VM VM type, please disable any options that are not "
+                         "compatible with the legacy VM type, or upgrade your kernel.",
+                         kvm_type == KVM_X86_SEV_VM ? "KVM_X86_SEV_VM" : "KVM_X86_SEV_ES_VM");
+        } else {
+            error_report("SEV: host kernel does not support requested %s VM type. To allow use of "
+                         "the legacy KVM_X86_DEFAULT_VM VM type, the 'legacy-vm-type' argument "
+                         "must be set to 'on' or 'auto' for the sev-guest object.",
+                         kvm_type == KVM_X86_SEV_VM ? "KVM_X86_SEV_VM" : "KVM_X86_SEV_ES_VM");
+        }
+
+        return -1;
     }
 
+    sev_common->kvm_type = kvm_type;
 out:
     return sev_common->kvm_type;
 }
@@ -1477,14 +1513,24 @@ static int sev_common_kvm_init(ConfidentialGuestSupport *cgs, Error **errp)
     }
 
     trace_kvm_sev_init();
-    if (x86_klass->kvm_type(X86_CONFIDENTIAL_GUEST(sev_common)) == KVM_X86_DEFAULT_VM) {
+    switch (x86_klass->kvm_type(X86_CONFIDENTIAL_GUEST(sev_common))) {
+    case KVM_X86_DEFAULT_VM:
         cmd = sev_es_enabled() ? KVM_SEV_ES_INIT : KVM_SEV_INIT;
 
         ret = sev_ioctl(sev_common->sev_fd, cmd, NULL, &fw_error);
-    } else {
+        break;
+    case KVM_X86_SEV_VM:
+    case KVM_X86_SEV_ES_VM:
+    case KVM_X86_SNP_VM: {
         struct kvm_sev_init args = { 0 };
 
         ret = sev_ioctl(sev_common->sev_fd, KVM_SEV_INIT2, &args, &fw_error);
+        break;
+    }
+    default:
+        error_setg(errp, "%s: host kernel does not support the requested SEV configuration.",
+                   __func__);
+        return -1;
     }
 
     if (ret) {
@@ -2074,14 +2120,23 @@ sev_guest_set_session_file(Object *obj, const char *value, Error **errp)
     SEV_GUEST(obj)->session_file = g_strdup(value);
 }
 
-static bool sev_guest_get_legacy_vm_type(Object *obj, Error **errp)
+static void sev_guest_get_legacy_vm_type(Object *obj, Visitor *v,
+                                         const char *name, void *opaque,
+                                         Error **errp)
 {
-    return SEV_GUEST(obj)->legacy_vm_type;
+    SevGuestState *sev_guest = SEV_GUEST(obj);
+    OnOffAuto legacy_vm_type = sev_guest->legacy_vm_type;
+
+    visit_type_OnOffAuto(v, name, &legacy_vm_type, errp);
 }
 
-static void sev_guest_set_legacy_vm_type(Object *obj, bool value, Error **errp)
+static void sev_guest_set_legacy_vm_type(Object *obj, Visitor *v,
+                                         const char *name, void *opaque,
+                                         Error **errp)
 {
-    SEV_GUEST(obj)->legacy_vm_type = value;
+    SevGuestState *sev_guest = SEV_GUEST(obj);
+
+    visit_type_OnOffAuto(v, name, &sev_guest->legacy_vm_type, errp);
 }
 
 static void
@@ -2107,9 +2162,9 @@ sev_guest_class_init(ObjectClass *oc, void *data)
                                   sev_guest_set_session_file);
     object_class_property_set_description(oc, "session-file",
             "guest owners session parameters (encoded with base64)");
-    object_class_property_add_bool(oc, "legacy-vm-type",
-                                   sev_guest_get_legacy_vm_type,
-                                   sev_guest_set_legacy_vm_type);
+    object_class_property_add(oc, "legacy-vm-type", "OnOffAuto",
+                              sev_guest_get_legacy_vm_type,
+                              sev_guest_set_legacy_vm_type, NULL, NULL);
     object_class_property_set_description(oc, "legacy-vm-type",
             "use legacy VM type to maintain measurement compatibility with older QEMU or kernel versions.");
 }
@@ -2125,6 +2180,8 @@ sev_guest_instance_init(Object *obj)
     object_property_add_uint32_ptr(obj, "policy", &sev_guest->policy,
                                    OBJ_PROP_FLAG_READWRITE);
     object_apply_compat_props(obj);
+
+    sev_guest->legacy_vm_type = ON_OFF_AUTO_AUTO;
 }
 
 /* guest info specific sev/sev-es */
