[vfio-users] VirtIO Drives and Network are causing issues with Windows

[Alex Williamson]

On Tue, 2016-01-12 at 19:57 +0000, Jonathan Scruggs wrote:
> Hi all,
> 
> On an earlier 4.1.4 (or .5 can't remember) kernel, I had a Windows
> guest using a VirtIO system drive and a VirtIO network adapter.
> Everything was fine and I was even able to upgrade to windows 10.
> This was when Windows 10 final was released. I removed the VM for a
> while because I got bored with Windows.
> 
> However, I have since moved on to the new 4.1.15 kernel and wanted to
> redo the windows guest. I saved my config files and reinstalled
> Windows 8.1. I noticed now that the VirtIO network card would just
> stop transfering data after a bit. I use the performance tab on Virt-
> Manager and all network traffic just stops. Also the Hard Drive would
> slow down sometimes.
> 
> It's even worse when trying to upgrade to Windows 10. Any form of
> upgrade would fail on the reboot phase. Also, the new 1511 build of
> the Windows 10 installation ISO would even fail to start up. You
> press the key to boot from the disk and you would get a blue screen
> about a thread exception. Changing to a SCSI_VirtIO controller would
> allow Windows 10 to at least boot to the install screen, then you add
> the driver to detect the disk, but the disk would freeze during the
> transfering files phase and never start again. It would freeze at
> roughly the 22% level point.
> 
> I had to change to a bog standard SATA drive to install Windows 10.
> Network with the VirtIO Network Card is still spotty.
> 
> Is there a serious bug in both Windows 8.1 and the new build of
> Windows 10 that fails on VirtIO devices or is it the implementation
> in the 4.1.15 kernel somehow causing issues? How do I test?

qemu-discuss might be a better place to ask this unless there's
specifically some interaction with vfio.  Thanks,

Alex