Re: [Xen-devel] testing of Xen PCIbackend support for slot and bus reset

[Martin Ãhrling <martin@xxxxxxxxxxxxxxxxx>]

Use the 'do_flr' SysFS instead of the 'reset'. Once an PCI device
is 'owned' by PCIback the 'reset' is no longer routed to the GPU driver.

Got a bit confused by the conditional check for the presence of reset file in pcistub_try_create_reset_file(). You are absolutely correct in that these devices are owned by pciback and not another driver. Can an alternate reset file (with another reset function) be created at an earlier stage or is this a guard to prevent the reset file (calling pcistub_reset_store())Â from being created multiple times?

Still a bit confused. I may be missing something, but the sysfs file name used for pcistub_reset_pci_dev() seems to be "reset". The function shall do FLR and, if possible, D3/bus/slot reset as fallback but only if it has no side effects for other functions on the device (equivalent to a real FLR). Shouldn't this function be registered as en emulated "do_flr" file instead of "reset"?

And the 'reset' does not do a bus-reset (whcih is what you need for
most GPUs).

Â

The reset function in this branch looks similar to the one in devel/xen-pciback.slot_and_bus.v0. I have tested the latter and I can verify that it works well. I had to do some additional changes to avoid infinite wait after a couple of reboots but the reset function worked well.

/Martin

Â

>
> /Martin
>
> 2014-08-17 3:52 GMT+02:00 Richie <listmail@xxxxxxxxxxxx>:
>
> >Â @Konrad
> >
> > I'm interesting in testing your latest iteration of bus reset support.
> > Actually I cloned your devel/xen-pciback.slot_and_bus.v2.1
> > <http://git.kernel.org/cgit/linux/kernel/git/konrad/xen.git/log/?h=devel/xen-pciback.slot_and_bus.v2.1>

> > branch and tested that but did not seem to reset the vga card. I did
> > capture dmesg output which was nice and clean regarding resetting the
> > device but don't have it handy.
> >
> > _______________________________________________
> > Xen-devel mailing list
> > Xen-devel@xxxxxxxxxxxxx
> > http://lists.xen.org/xen-devel
> >
> >

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