PCI Passthrough to Fully Virtual XEN Guest stops working after patch update

This document (7012337) is provided subject to the disclaimer at the end of this document.

Environment

SUSE Linux Enterprise Server 11 Service Pack 2
SUSE Linux Enterprise Server 11 Service Pack 1
XEN

Situation

After applying the XEN updates released in May 2013, PCI PassThrough to Fully Virtualized Guest VM stops working.

Resolution

Add the following boot parameter to the XEN hypervisor:

"iommu=no-intremap"

For example:


# cat /boot/grub/menu.lst

###Don't change this comment - YaST2 identifier: Original name: xen###
title Xen -- SUSE Linux Enterprise Desktop 11 SP2 - 3.0.58-0.6.6
root (hd0,5)
kernel /boot/xen.gz vga=mode-0x314 iommu=no-intremap
module /boot/vmlinuz-3.0.58-0.6.6-xen root=/dev/sda6 resume=/dev/sda5 splash=silent showopts vga=0x314
module /boot/initrd-3.0.58-0.6.6-xen

Cause

Issues identified with certain INTEL processor chipsets required iommu to be disabled by default in order for PCI PassThrough to work with PV Guests.

In order for both PV and FV Guests to work with PCI Passthrough the "no-intremap" must be used.

No change is needed if PCI devices are only passed through to PV guests.

Disclaimer

This Support Knowledgebase provides a valuable tool for SUSE customers and parties interested in our products and solutions to acquire information, ideas and learn from one another. Materials are provided for informational, personal or non-commercial use within your organization and are presented "AS IS" WITHOUT WARRANTY OF ANY KIND.