Bug 742836 - Setting multifunction=on breaks SPICE/QXL multihead support in Windows
Setting multifunction=on breaks SPICE/QXL multihead support in Windows
Product: Fedora
Classification: Fedora
Component: libvirt (Show other bugs)
Unspecified Unspecified
unspecified Severity unspecified
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Assigned To: Laine Stump
Fedora Extras Quality Assurance
: Regression
Depends On:
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Reported: 2011-10-02 23:44 EDT by Laine Stump
Modified: 2011-10-09 15:50 EDT (History)
9 users (show)

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Fixed In Version: libvirt-0.9.6-2.fc16
Doc Type: Bug Fix
Doc Text:
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Last Closed: 2011-10-09 15:50:53 EDT
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RHEL 7.3 requirements from Atomic Host:
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Description Laine Stump 2011-10-02 23:44:32 EDT
Description of problem:
Since libvirt started adding multifunction=on to PCI devices, SPICE/QXL multihead support in Windows no longer works.

Version-Release number of selected component (if applicable):


Steps to Reproduce:
1. Create a Windows XP guest with SPICE graphics + QXL display adapter
2. Install QXL graphics device driver in Windows
3. Stop the guest
4. Add a second <video> element to the guest for QXL display adapter
5. Start the guest again
6. Configure the QXL device driver for the second display

Actual results:
Windows fails to start the QXL device driver with an error 'Code 10'

Expected results:
The second device is initialized.


In response to a suggestion by Dan Berrange on libvir-list:


I pushed the following patch to upstream libvirt, which removes the automatic setting of the multifunction bit, in favor of an XML attribute to turn it on as desired:

commit c329db7180d77c8077b9f9cd167a71d7f347227a
Author: Laine Stump <laine@laine.org>
Date:   Thu Sep 29 13:00:32 2011 -0400

    qemu: make PCI multifunction support more manual
This allows exact control of when the multifunction bit should be turned on/off for each slot/function on the guest's PCI bus, eliminating the issue with the QXL driver's (and possibly/probably other drivers') lack of multifunction support.
Comment 1 Fedora Update System 2011-10-03 12:06:55 EDT
libvirt-0.9.6-2.fc16 has been submitted as an update for Fedora 16.
Comment 2 Fedora Update System 2011-10-03 13:45:17 EDT
Package libvirt-0.9.6-2.fc16:
* should fix your issue,
* was pushed to the Fedora 16 testing repository,
* should be available at your local mirror within two days.
Update it with:
# su -c 'yum update --enablerepo=updates-testing libvirt-0.9.6-2.fc16'
as soon as you are able to.
Please go to the following url:
then log in and leave karma (feedback).
Comment 3 Fedora Update System 2011-10-09 15:50:53 EDT
libvirt-0.9.6-2.fc16 has been pushed to the Fedora 16 stable repository.  If problems still persist, please make note of it in this bug report.

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