qemu: Refactor the code to build -incoming command line

Move the code from qemuBuildCommandLine into dedicated functions.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

src/qemu/qemu_command.c

@@ -9088,6 +9088,45 @@ qemuBuildTPMCommandLine(virDomainDefPtr def,
     return 0;
 }
 
+static int
+qemuBuildIncomingCheckProtocol(virQEMUCapsPtr qemuCaps,
+                               const char *migrateFrom)
+{
+    if (STRPREFIX(migrateFrom, "rdma")) {
+        if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_MIGRATE_RDMA)) {
+            virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
+                           _("incoming RDMA migration is not supported "
+                             "with this QEMU binary"));
+            return -1;
+        }
+    } else if (!STRPREFIX(migrateFrom, "tcp") &&
+               !STRPREFIX(migrateFrom, "exec") &&
+               !STRPREFIX(migrateFrom, "fd") &&
+               !STRPREFIX(migrateFrom, "unix") &&
+               STRNEQ(migrateFrom, "stdio")) {
+        virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
+                       _("unknown migration protocol"));
+        return -1;
+    }
+
+    return 0;
+}
+
+
+static char *
+qemuBuildIncomingURI(const char *migrateFrom,
+                     int migrateFd)
+{
+    char *uri = NULL;
+
+    if (STREQ(migrateFrom, "stdio"))
+        ignore_value(virAsprintf(&uri, "fd:%d", migrateFd));
+    else
+        ignore_value(VIR_STRDUP(uri, migrateFrom));
+
+    return uri;
+}
+
 
 qemuBuildCommandLineCallbacks buildCommandLineCallbacks = {
     .qemuGetSCSIDeviceSgName = virSCSIDeviceGetSgName,
@@ -10937,32 +10976,20 @@ qemuBuildCommandLine(virConnectPtr conn,
     }
 
     if (migrateFrom) {
-        virCommandAddArg(cmd, "-incoming");
-        if (STRPREFIX(migrateFrom, "tcp")) {
-            virCommandAddArg(cmd, migrateFrom);
-        } else if (STRPREFIX(migrateFrom, "rdma")) {
-            if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_MIGRATE_RDMA)) {
-                virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
-                               _("incoming RDMA migration is not supported "
-                                 "with this QEMU binary"));
-                goto error;
-            }
-            virCommandAddArg(cmd, migrateFrom);
-        } else if (STREQ(migrateFrom, "stdio")) {
-            virCommandAddArgFormat(cmd, "fd:%d", migrateFd);
-            virCommandPassFD(cmd, migrateFd, 0);
-        } else if (STRPREFIX(migrateFrom, "exec")) {
-            virCommandAddArg(cmd, migrateFrom);
-        } else if (STRPREFIX(migrateFrom, "fd")) {
-            virCommandAddArg(cmd, migrateFrom);
+        char *migrateURI;
+
+        if (qemuBuildIncomingCheckProtocol(qemuCaps, migrateFrom) < 0)
+            goto error;
+
+        if (STREQ(migrateFrom, "stdio") ||
+            STRPREFIX(migrateFrom, "fd"))
             virCommandPassFD(cmd, migrateFd, 0);
-        } else if (STRPREFIX(migrateFrom, "unix")) {
-            virCommandAddArg(cmd, migrateFrom);
-        } else {
-            virReportError(VIR_ERR_INTERNAL_ERROR,
-                           "%s", _("unknown migration protocol"));
+
+        migrateURI = qemuBuildIncomingURI(migrateFrom, migrateFd);
+        if (!migrateURI)
             goto error;
-        }
+        virCommandAddArgList(cmd, "-incoming", migrateURI, NULL);
+        VIR_FREE(migrateURI);
     }
 
     /* QEMU changed its default behavior to not include the virtio balloon