5655f931ab
Somehow these GPUs manage not to respond to a PCI bus reset, removing our primary mechanism for resetting graphics cards. The result is that these devices typically work well for a single VM boot. If the VM is rebooted or restarted, the guest driver is not able to init the card from the dirty state, resulting in a blue screen for Windows guests. The workaround is to use a device specific reset. This is not 100% reliable though since it depends on the incoming state of the device, but it substantially improves the usability of these devices in a VM. Credit to Alex Deucher <alexander.deucher@amd.com> for his guidance. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Read the documentation in qemu-doc.html or on http://wiki.qemu-project.org - QEMU team