Re: [libvirt] [PATCH] Add PCI sysfs reset access
On Fri, 2011-03-18 at 10:18 +0000, Daniel P. Berrange wrote:
On Thu, Mar 17, 2011 at 02:26:36PM -0600, Alex Williamson wrote:
> I'm proposing we make use of $PCIDIR/reset in qemu-kvm to reset
> devices on VM reset. We need to add it to libvirt's list of
> files that get ownership for device assignment.
What does access to the 'reset' file allow you todo ? If we're
to allow access, it must only allow for Function Level Resets.
We don't want QEMU doing bus level resets, for example, since
that could impact other VMs.
Writing 1 to the reset file calls pci_reset_function(), which is the
same function kvm calls to clear the state of the device when it's first
assigned. This will try device specific resets, flr reset, pm reset,
and finally bus reset, but only if this device is the only device on the
bus. Thanks,
Alex