[vfio-users] Win 10 VM often freezes Linux when shutting down

[Alex Williamson]

On Thu, 18 Feb 2016 06:00:59 -0800
Nick Sukharev <nicksukharev at gmail.com> wrote:

> So, if I am not using virsh, would it be sufficient to just remove audio
> devices from my shell script that starts qemu? I am also not using them and
> just thought I need to pass them to make AMD drivers happy. I am happy with
> virtual audio provided by QEMU (and have multiple cards so wiring their
> audio output to some speakers would be a project just by itself)

In the case of the GPU audio function, you can't simply ignore it
because it's part of the same IOMMU group as the GPU itself.  It needs
to be bound to vfio-pci or pci-stub or else you can't use the group
with the GPU at all.  You don't necessarily need to assign it to the
guest though.  The problem suspected here would occur when the devices
are bound back to the host drivers.  You can easily just not do that if
you're using a script, that's effectively what the libvirt instructions
do.  If you really just don't want to deal with a device at all, you
can do a software hot unplug (echo 1> /sys/bus/pci/devices/.../remove).