main_loop: do not set nonblocking if xen_enabled()

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
CC: qemu-stable@nongnu.org
diff --git a/vl.c b/vl.c
index 510d2c2..47ab45d 100644
--- a/vl.c
+++ b/vl.c
@@ -2022,7 +2022,7 @@
     int64_t ti;
 #endif
     do {
-        nonblocking = !kvm_enabled() && last_io > 0;
+        nonblocking = !kvm_enabled() && !xen_enabled() && last_io > 0;
 #ifdef CONFIG_PROFILER
         ti = profile_getclock();
 #endif