# HG changeset patch
# User Keir Fraser <keir.fraser@citrix.com>
# Date 1267799474 0
# Node ID e9d4cb54c551efa06d05e03d3916995f1c0f4d07
# Parent  fd6946ad6816477039498b288c2a3023d1b63a73
vt-d: ensure x2apic is not enabled accidently if no DRHD at all.

Thanks to Jan Beulich for pointing this out.

Signed-off-by: Dexuan Cui <dexuan.cui@intel.com>

diff -r fd6946ad6816 -r e9d4cb54c551 xen/drivers/passthrough/vtd/intremap.c
--- a/xen/drivers/passthrough/vtd/intremap.c	Fri Mar 05 14:30:45 2010 +0000
+++ b/xen/drivers/passthrough/vtd/intremap.c	Fri Mar 05 14:31:14 2010 +0000
@@ -131,6 +131,9 @@ int iommu_supports_eim(void)
     if ( !iommu_enabled || !iommu_qinval || !iommu_intremap )
         return 0;
 
+    if ( list_empty(&acpi_drhd_units) )
+        return 0;
+
     for_each_drhd_unit ( drhd )
         if ( !ecap_queued_inval(drhd->ecap) ||
              !ecap_intr_remap(drhd->ecap) ||