commit f493d83fbd3257453e63f2f32ee90a216fd531c1
Author: Daniel P. Berrange <berrange@redhat.com>
Date:   Thu May 9 13:53:39 2013 +0100

    Cope with missing swap cgroup controls
    
    It is possible to build a kernel without swap cgroup controls
    present. This causes a fatal error when querying memory
    parameters. Treat missing swap controls as meaning "unlimited".
    The fatal error remains if the user tries to actually change
    the limit.
    
    Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

Index: libvirt-1.0.5/src/qemu/qemu_driver.c
===================================================================
--- libvirt-1.0.5.orig/src/qemu/qemu_driver.c
+++ libvirt-1.0.5/src/qemu/qemu_driver.c
@@ -7351,9 +7351,12 @@ qemuDomainGetMemoryParameters(virDomainP
         case 2: /* fill swap hard limit here */
             rc = virCgroupGetMemSwapHardLimit(priv->cgroup, &val);
             if (rc != 0) {
-                virReportSystemError(-rc, "%s",
-                                     _("unable to get swap hard limit"));
-                goto cleanup;
+                if (rc != -ENOENT) {
+                    virReportSystemError(-rc, "%s",
+                                         _("unable to get swap hard limit"));
+                    goto cleanup;
+                }
+                val = VIR_DOMAIN_MEMORY_PARAM_UNLIMITED;
             }
             if (virTypedParameterAssign(param,
                                         VIR_DOMAIN_MEMORY_SWAP_HARD_LIMIT,