[VTD] prevent dom0 from using vt-d hw

[VTD] prevent dom0 from using vt-d hw

[Kay, Allen M]

[-- Attachment #1: Type: text/plain, Size: 189 bytes --]

This patch ensures xen vmm has exclusive access of vt-d hw by zaping
vt-d "DMAR" ACPI table signature after xen has finished using it.

Signed-off-by: Allen Kay <allen.m.kay@intel.com>

[-- Attachment #2: dmar.patch --]
[-- Type: application/octet-stream, Size: 464 bytes --]

diff -r ca1085e8ab82 xen/arch/x86/hvm/vmx/vtd/dmar.c
--- a/xen/arch/x86/hvm/vmx/vtd/dmar.c	Wed Oct 03 16:33:23 2007 +0100
+++ b/xen/arch/x86/hvm/vmx/vtd/dmar.c	Wed Oct 03 11:26:40 2007 -0700
@@ -483,6 +483,10 @@ acpi_parse_dmar(unsigned long phys_addr,
 
         entry_header = ((void *)entry_header + entry_header->length);
     }
+
+    /* Zap APCI DMAR signature to prevent dom0 using vt-d HW. */
+    dmar->header.signature[0] = '\0';
+
     return ret;
 }
 

[-- Attachment #3: Type: text/plain, Size: 138 bytes --]

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel

Re: [VTD] prevent dom0 from using vt-d hw

[Andy Grover]

Kay, Allen M wrote:
> This patch ensures xen vmm has exclusive access of vt-d hw by zaping
> vt-d "DMAR" ACPI table signature after xen has finished using it.

+    /* Zap APCI DMAR signature to prevent dom0 using vt-d HW. */

"ACPI", I think you mean.

Regards -- Andy