Re: [PATCH V6 11/11] nvme: pci: support nested EH

Johannes Thumshirn
2018-05-17T14:23:45Z

On Thu, May 17, 2018 at 08:20:51AM -0600, Keith Busch wrote:
> > Heh. But yes, this test and the PCI "enable" interface in sysfs look
> > horribly wrong. pci_disable_device/pci_enable_device aren't something we
> > can just do underneath the driver. Even if injecting the lowlevel
> > config space manipulations done by it might be useful and a good test
> > the Linux state ones are just killing the driver.
>
> Yes, I'm totally fine with injecting errors into the config space, but
> for goodness sakes, don't fuck with the internal kernel structures out
> from under drivers using them.
>
> My suggestion is to use 'setpci' to disable the device if you want to
> inject this scenario. That way you get the desired broken device
> scenario you want to test, but struct pci_dev hasn't been altered.
>
> > The enable attribute appears to have been added by Arjan for the
> > Xorg driver. I think if we have a driver bound to the device we
> > should not allow it.
>
> Agreed. Alternatively possibly call the driver's reset_preparei/done
> callbacks.

Exactly, but as long as we can issue the reset via sysfs the test-case
is still valid.

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