[vfio-users] [Qemu-discuss] vfio pass through only works once after reboot

[Lucas Neves]

I'm very interested in the solution to this problem as well. I pass through
a Radeon r9 285 (Tonga) to Windows.

On my previous setup, with QEMU from the git emulating a Q35 chipset on
SeaBIOS and a Windows 8.1 guest, the guest would work only once per boot of
the host. If I soft-reset the guest or shut it down and tried to run QEMU
again, the guest monitor would stay blank (although QEMU would continue
running, with no error messages). I have noticed that this problem only
occurs when using the proprietary AMD driver in the guest: running on the
native Windows 8.1 video driver, the guest could reboot without problems.

This week, I decided to change the whole system, hoping that something
would fix this problem. So now I'm emulating a i440fx chipset, using OVMF,
with a fresh install of Windows 10 as guest. Things have improved: now the
guest system can withstand soft reboots without problems. But whenever I
shut down the guest machine, it is still not possible to turn it on again
without rebooting the host.

Sorry I don't have my start script here, I can post it later if necessary.
But I inkove QEMU as a super user (sudo qemu-system-x86_64). And my host OS
is Ubuntu 15.04.

Thanks,
Lucas

On Thu, Sep 3, 2015 at 3:39 PM Blank Field <ihatethisfield at gmail.com> wrote:

> There is a special mailing list for all the vfio questions. It aims to
> replace the arch forum thread.
>
> http://lists.nongnu.org/archive/html/qemu-discuss/2015-09/msg00003.html
> I couldn't manage to not screw up the formatting with G-Mail, so there you
> have it as a link to archives.
>
> Regarding the problem - i don't remember exactly, but running qemu as a
> regular user requires some more steps than just chown.
> _______________________________________________
> vfio-users mailing list
> vfio-users at redhat.com
> https://www.redhat.com/mailman/listinfo/vfio-users
>
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