[PATCH] qemu_migration: Unregister close callback only if connection still exists

[Michal Privoznik]

When doing a peer-to-peer migration it may happen that the
connection to the destination disappears. If that happens,
there's no point in trying to unregister the close callback
because the connection is closed already. It results only in
polluting logs with this message:

  error : virNetSocketReadWire:1814 : End of file while reading data: : Input/output error

and the reason for that is unregistering a connection callback
results in RPC (among other things).

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1918211
Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
---
 src/qemu/qemu_migration.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
index a4f44b465d..4d651aeb1a 100644
--- a/src/qemu/qemu_migration.c
+++ b/src/qemu/qemu_migration.c
@@ -5214,9 +5214,11 @@ qemuMigrationSrcPerformPeer2Peer(virQEMUDriver *driver,
 
  cleanup:
     virErrorPreserveLast(&orig_err);
-    qemuDomainObjEnterRemote(vm);
-    virConnectUnregisterCloseCallback(dconn, qemuMigrationSrcConnectionClosed);
-    ignore_value(qemuDomainObjExitRemote(vm, false));
+    if (dconn && virConnectIsAlive(dconn) == 1) {
+        qemuDomainObjEnterRemote(vm);
+        virConnectUnregisterCloseCallback(dconn, qemuMigrationSrcConnectionClosed);
+        ignore_value(qemuDomainObjExitRemote(vm, false));
+    }
     virErrorRestore(&orig_err);
     return ret;
 }
-- 
2.31.1