Re: [PATCH] pci: account for sysfs-disabled reset in pci_{slot,bus}_resettable
From: Nishanth Aravamudan
Date: Wed Jan 22 2025 - 13:15:13 EST
On Mon, Jan 13, 2025 at 05:25:40PM -0600, Bjorn Helgaas wrote:
> Please update subject line to match historical capitalization
> convention.
Thank you, I will fix in v2.
>
> On Mon, Jan 06, 2025 at 03:52:31PM -0600, Nishanth Aravamudan wrote:
> > vfio_pci_ioctl_get_pci_hot_reset_info checks if either the vdev's slot
> > or bus is not resettable by calling pci_probe_reset_{slot,bus}. Those
> > functions in turn call pci_{slot,bus}_resettable() to see if the PCI
> > device supports reset.
> >
> > However, commit d88f521da3ef ("PCI: Allow userspace to query and set
> > device reset mechanism") added support for userspace to disable reset of
> > specific PCI devices (by echo'ing "" into reset_method) and
> > pci_{slot,bus}_resettable methods do not check pci_reset_supported() to
> > see if userspace has disabled reset. Therefore, if an administrator
> > disables PCI reset of a specific device, but then uses vfio-pci with
> > that device (e.g. with qemu), vfio-pci will happily end up issuing a
> > reset to that device.
>
> Please consistently add "()" after function names.
Will fix in v2, as well.
-Nish