Re: [Qemu-devel] [PATCH 2/3] vfio: vfio-pci device assignment driver

[Stefan Hajnoczi]

On Tue, Jul 31, 2012 at 11:18:15PM -0600, Alex Williamson wrote:
> This adds the core of the QEMU VFIO-based PCI device assignment driver.
> To make use of this driver, enable CONFIG_VFIO, CONFIG_VFIO_IOMMU_TYPE1,
> and CONFIG_VFIO_PCI in your host Linux kernel config.  Load the vfio-pci
> module.  To assign device 0000:05:00.0 to a guest, do the following:
> 
> for dev in $(ls /sys/bus/pci/devices/0000:05:00.0/iommu_group/devices); do
>     vendor=$(cat /sys/bus/pci/devices/$dev/vendor)
>     device=$(cat /sys/bus/pci/devices/$dev/device)
>     if [ -e /sys/bus/pci/devices/$dev/driver ]; then
>         echo $dev > /sys/bus/pci/devices/$dev/driver/unbind
>     fi
>     echo $vendor $device > /sys/bus/pci/drivers/vfio-pci/new_id
> done

Both vfio-pci and the old driver successfully match the $vendor:$device.
What happens when another $vendor:$device PCI adapter is hotplugged into
the host?

Is there a way to bind vfio-pci on a per-adapter basis instead of a
per-$vendor:$device?

Stefan