[RFC PATCH 24/26] migration: Add start-migrate-incoming QMP command

[Dov Murik <dovmurik@linux.vnet.ibm.com>]

This command forces a running VM into a migrate-incoming state.  When
using guest-assisted migration (for confidential guests), the target
must be started so that its auxiliary vcpu is running the migration
helper; after it is ready we can start receiving the incoming migration
connection.

Signed-off-by: Dov Murik <dovmurik@linux.vnet.ibm.com>
---
 qapi/migration.json   | 26 ++++++++++++++++++++++++++
 migration/migration.c |  5 +++++
 2 files changed, 31 insertions(+)

diff --git a/qapi/migration.json b/qapi/migration.json
index 6e5943fbb4..c7361e0038 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -1569,6 +1569,32 @@
 ##
 { 'command': 'migrate-incoming', 'data': {'uri': 'str' } }
 
+##
+# @start-migrate-incoming:
+#
+# Force start an incoming migration even in a running VM.  This is used by the
+# target VM in guest-assisted migration of a confidential guest.
+#
+# @uri: The Uniform Resource Identifier identifying the source or
+#       address to listen on
+#
+# Returns: nothing on success
+#
+# Since: 6.0
+#
+# Notes:
+#
+# The uri format is the same as the -incoming command-line option.
+#
+# Example:
+#
+# -> { "execute": "start-migrate-incoming",
+#      "arguments": { "uri": "tcp::4446" } }
+# <- { "return": {} }
+#
+##
+{ 'command': 'start-migrate-incoming', 'data': {'uri': 'str' } }
+
 ##
 # @xen-save-devices-state:
 #
diff --git a/migration/migration.c b/migration/migration.c
index 7ec25bd006..4729b89bef 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -2098,6 +2098,11 @@ void qmp_migrate_incoming(const char *uri, Error **errp)
     once = false;
 }
 
+void qmp_start_migrate_incoming(const char *uri, Error **errp)
+{
+    qemu_start_incoming_migration(uri, errp);
+}
+
 void qmp_migrate_recover(const char *uri, Error **errp)
 {
     MigrationIncomingState *mis = migration_incoming_get_current();
-- 
2.20.1