From 5de41c06a4d4bc4222bf8477fd641a987d06be58 Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@redhat.com>
Date: Fri, 11 Dec 2009 10:06:05 +0100
Subject: [PATCH] retrieve paused/running state at migration start

This patch fixes the bug where paused/running state is not
transmitted during migration.  As a result, in the QEMU driver
for example the machine was always started on the destination
end.

In order to do so, just read the state and if it is appropriate and
set the VIR_MIGRATE_PAUSED flag.

* src/libvirt.c (virDomainMigrateVersion1, virDomainMigrateVersion2):
  Automatically add VIR_MIGRATE_PAUSED when appropriate.
* src/xen/xend_internal.c (xenDaemonDomainMigratePerform): Give a nicer
  error message when migration of paused domains is attempted.
---
 src/libvirt.c           | 14 +++++++++++++-
 src/xen/xend_internal.c |  9 +++++++++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/src/libvirt.c b/src/libvirt.c
index 2ced604828..008e322887 100644
--- a/src/libvirt.c
+++ b/src/libvirt.c
@@ -2963,7 +2963,13 @@ virDomainMigrateVersion1 (virDomainPtr domain,
     virDomainPtr ddomain = NULL;
     char *uri_out = NULL;
     char *cookie = NULL;
-    int cookielen = 0;
+    int cookielen = 0, ret;
+    virDomainInfo info;
+
+    ret = virDomainGetInfo (domain, &info);
+    if (ret == 0 && info.state == VIR_DOMAIN_PAUSED) {
+        flags |= VIR_MIGRATE_PAUSED;
+    }
 
     /* Prepare the migration.
      *
@@ -3028,6 +3034,7 @@ virDomainMigrateVersion2 (virDomainPtr domain,
     char *cookie = NULL;
     char *dom_xml = NULL;
     int cookielen = 0, ret;
+    virDomainInfo info;
 
     /* Prepare the migration.
      *
@@ -3054,6 +3061,11 @@ virDomainMigrateVersion2 (virDomainPtr domain,
     if (!dom_xml)
         return NULL;
 
+    ret = virDomainGetInfo (domain, &info);
+    if (ret == 0 && info.state == VIR_DOMAIN_PAUSED) {
+        flags |= VIR_MIGRATE_PAUSED;
+    }
+
     ret = dconn->driver->domainMigratePrepare2
         (dconn, &cookie, &cookielen, uri, &uri_out, flags, dname,
          bandwidth, dom_xml);
diff --git a/src/xen/xend_internal.c b/src/xen/xend_internal.c
index 241a102a9a..d782a87224 100644
--- a/src/xen/xend_internal.c
+++ b/src/xen/xend_internal.c
@@ -4444,6 +4444,15 @@ xenDaemonDomainMigratePerform (virDomainPtr domain,
     if (flags & VIR_MIGRATE_PERSIST_DEST)
         flags &= ~VIR_MIGRATE_PERSIST_DEST;
 
+    /* This is buggy in Xend, but could be supported in principle.  Give
+     * a nice error message.
+     */
+    if (flags & VIR_MIGRATE_PAUSED) {
+        virXendError (conn, VIR_ERR_NO_SUPPORT,
+                      "%s", _("xenDaemonDomainMigrate: xend cannot migrate paused domains"));
+        return -1;
+    }
+
     /* XXX we could easily do tunnelled & peer2peer migration too
        if we want to. support these... */
     if (flags != 0) {