Re: Hard and silent lock up since linux 3.14 with PCIe pass through (vfio)

[Andreas Hartmann <andihartmann@freenet.de>]

Hello Alex,

Alex Williamson wrote:
> Hi Andreas,
[...]
> Sorry for the breakage.  Is it possible to run lspci on the device in a
> loop from the host and capture whether we're failing to restore some of
> the VC bits to their previous state? 

> Does the problem also occur if you
> unbind from host driver,

The machine is booted w/ blacklisted ath9k. Then, the device is bound to
vfio:

echo "168c 0030" > /sys/bus/pci/drivers/vfio-pci/new_id
echo 0000:03:00.0 > /sys/bus/pci/devices/0000:03:00.0/driver/unbind
echo 0000:03:00.0 > /sys/bus/pci/drivers/vfio-pci/bind

afterwards the VM is started -> hang.

W/o starting th VM, I can bind it to vfio and unbind it from vfio w/o
any problem.

> echo 1 > reset in pci-sysfs,

echo 1 > /sys/bus/pci/devices/0000:03:00.0 works w/o any problem while
bound to vfio. Even after unbinding from vfio and rebinding to vfio
again ... .

> and re-bind to the

Do you mean loading ath9k in host system after unbinding from vfio? If
yes: Works w/o any problem. It's even possible to reset it or do a
ifconfig wlan0 up, ifconfig wlan0 down, rmmod ath9k, bind it to vfio
again and reset it, ....

Looks like the hang only is triggered by qemu-system_x86_64 on startup
the VM.

> host?  I'll also try to reproduce on my 990fx system, but I won't be
> able to do that until next week due to travel.  Thanks,


Regards,
Andreas