vtd: Update vtd.txt

Add "iommu=1" option in grub, due to VT-d is not enabled by default.

In addition, describes how to enable MSI/MSI-x for assigned devices.

Signed-off-by: Weidong Han <weidong.han@intel.com>

diff --git a/docs/misc/vtd.txt b/docs/misc/vtd.txt
index 6264463fb0112eeca7a2e40e45d1d8d1110607d2..277321ba232b3ec1536b182d9eca9c390e148a6e 100644 (file)
--- a/docs/misc/vtd.txt
+++ b/docs/misc/vtd.txt
@@ -2,7 +2,7 @@ Title   : How to do PCI Passthrough with VT-d
 Authors : Allen Kay    <allen.m.kay@intel.com>
           Weidong Han  <weidong.han@intel.com>
 Created : October-24-2007
-Updated : May-07-2008
+Updated : August-06-2008
 
 How to turn on VT-d in Xen
 --------------------------
@@ -21,7 +21,7 @@ How to turn on VT-d in Xen
 
 title Xen-Fedora Core (2.6.18-xen)
         root (hd0,0)
-        kernel /boot/xen.gz com1=115200,8n1 console=com1
+        kernel /boot/xen.gz com1=115200,8n1 console=com1 iommu=1
         module /boot/vmlinuz-2.6.18.8-xen root=LABEL=/ ro xencons=ttyS console=tty0 console=ttyS0, pciback.hide=(01:00.0)(03:00.0)
         module /boot/initrd-2.6.18-xen.img
 
@@ -32,6 +32,11 @@ title Xen-Fedora Core (2.6.18-xen)
     "ifconfig" to see if IP address has been assigned to NIC devices.
 
 
+Enable MSI/MSI-x for assigned devices
+-------------------------------------
+Add "msi=1" option in kernel line of host grub.
+
+
 Caveat on Conventional PCI Device Passthrough
 ---------------------------------------------