[libvirt] [question]Why libvirt bind all devices with same vendor id and device id to vfio-pci driver, and only unbind devices used by VMs to original driver?

Alex Williamson alex.williamson at redhat.com
Mon Oct 9 14:57:36 UTC 2017

On Mon, 9 Oct 2017 09:28:27 +0000
"Wuzongyong (Euler Dept)" <cordius.wu at huawei.com> wrote:

> Hi,
> As the title says, I thought that it's a bit unreasonable and inconsistent  to unbind devices assigned to VMs to original driver
> and leave other devices binding to vfio-pci driver.
> Why not to bind devices we need to vfio-pci driver instead of bind all devices with same type to vfio-pci driver?
> Or, we may can rebind devices unused with same type to original driver.

Because that's the way the kernel's new_id interface works, any
matching device without a driver will probe the new_id driver.  For a
new enough kernel and libvirt, the driver_override interface should be
used instead, which will only bind the target device.  Thanks,


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