commit 57c95175e271ca63b3f1be44efef8997f20ffe13
Author: Jim Fehlig <jfehlig@suse.com>
Date:   Thu Sep 1 16:40:46 2011 -0600

    Increase size of buffer for xend response
    
    On systems with many pcpus, the sexpr returned by xend can be quite
    large for dom0 when it is configured to have #vcpus = #pcpus (default).
    E.g. on a 80 pcpu system, where dom0 had 80 vcpus, the sexpr details
    for dom0 was 73817 bytes!  Increase maximum buffer size to 256k.

diff --git a/src/xen/xend_internal.c b/src/xen/xend_internal.c
index 957cd17..0a7fb48 100644
--- a/src/xen/xend_internal.c
+++ b/src/xen/xend_internal.c
@@ -56,7 +56,7 @@
  * The number of Xen scheduler parameters
  */
 
-#define XEND_RCV_BUF_MAX_LEN 65536
+#define XEND_RCV_BUF_MAX_LEN (256 * 1024)
 
 static int
 virDomainXMLDevID(virDomainPtr domain,