virsh: Add comp-methods completion to migrate command

Signed-off-by: Lin Ma <lma@suse.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>

tools/virsh-completer-domain.c

@@ -959,3 +959,20 @@ virshDomainCoreDumpFormatCompleter(vshControl *ctl G_GNUC_UNUSED,
 
     return ret;
 }
+
+
+char **
+virshDomainMigrateCompMethodsCompleter(vshControl *ctl,
+                                       const vshCmd *cmd,
+                                       unsigned int flags)
+{
+    const char *methods[] = {"xbzrle", "mt",  NULL};
+    const char *method = NULL;
+
+    virCheckFlags(0, NULL);
+
+    if (vshCommandOptStringQuiet(ctl, cmd, "comp-methods", &method) < 0)
+        return NULL;
+
+    return virshCommaStringListComplete(method, methods);
+}

tools/virsh-completer-domain.h

@@ -127,3 +127,8 @@ char **
 virshDomainCoreDumpFormatCompleter(vshControl *ctl,
                                    const vshCmd *cmd,
                                    unsigned int flags);
+
+char **
+virshDomainMigrateCompMethodsCompleter(vshControl *ctl,
+                                       const vshCmd *cmd,
+                                       unsigned int flags);

tools/virsh-domain.c

@@ -10619,6 +10619,7 @@ static const vshCmdOptDef opts_migrate[] = {
     },
     {.name = "comp-methods",
      .type = VSH_OT_STRING,
+     .completer = virshDomainMigrateCompMethodsCompleter,
      .help = N_("comma separated list of compression methods to be used")
     },
     {.name = "comp-mt-level",