Messages in this thread | | | Date | Wed, 29 Nov 2017 14:26:30 -0500 | From | Konrad Rzeszutek Wilk <> | Subject | Re: [Xen-devel] [PATCH] Xen/pciback: Implement PCI slot or bus reset with 'do_flr' SysFS attribute |
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On Wed, Nov 29, 2017 at 09:40:20AM -0700, Jan Beulich wrote: > >>> On 29.11.17 at 17:29, <konrad.wilk@oracle.com> wrote: > > On Wed, Nov 29, 2017 at 08:35:33AM -0700, Jan Beulich wrote: > >> >>> On 29.11.17 at 16:08, <govinda.tatti@oracle.com> wrote: > >> > On 11/9/2017 2:28 AM, Jan Beulich wrote: > >> >>>>> On 08.11.17 at 16:44, <govinda.tatti@oracle.com> wrote: > >> >>> On 11/7/2017 8:40 AM, Jan Beulich wrote: > >> >>>>>>> On 06.11.17 at 18:48, <Govinda.Tatti@Oracle.COM> wrote: > >> >>>>> --- a/Documentation/ABI/testing/sysfs-driver-pciback > >> >>>>> +++ b/Documentation/ABI/testing/sysfs-driver-pciback > >> >>>>> @@ -11,3 +11,15 @@ Description: > >> >>>>> #echo 00:19.0-E0:2:FF > > > /sys/bus/pci/drivers/pciback/quirks > >> >>>>> will allow the guest to read and write to the > > configuration > >> >>>>> register 0x0E. > >> >>>>> + > >> >>>>> +What: /sys/bus/pci/drivers/pciback/do_flr > >> >>>>> +Date: Nov 2017 > >> >>>>> +KernelVersion: 4.15 > >> >>>>> +Contact: xen-devel@lists.xenproject.org > >> >>>>> +Description: > >> >>>>> + An option to perform a slot or bus reset when a PCI device > >> >>>>> + is owned by Xen PCI backend. Writing a string of DDDD:BB:DD.F > >> >>>>> + will cause the pciback driver to perform a slot or bus reset > >> >>>>> + if the device supports it. It also checks to make sure that > >> >>>>> + all of the devices under the bridge are owned by Xen PCI > >> >>>>> + backend. > >> >>>> Why do you name this "do_flr" when you don't even try FLR, but > >> >>>> go to slot or then bus reset right away. > >> >>> Yes, I agree but xen toolstack has already been modified to > >> >>> consume"do_flr" attribute. Hence, we are using the > >> >>> function that matches with sysfs attribute. > >> >> That's not a valid reason imo: Right now the driver doesn't expose > >> >> such an attribute, so if the tool stack was trying to use it, it would > >> >> not do what is intended at present anyway (i.e. the code could at > >> >> best be called dead). > >> > Sure, we can consider renaming "do_flr" attribute to "pci reset" or "bus > >> > reset". > >> > Please let me knowyour preference. > >> > >> Well, that's more a question to Konrad as the maintainer. > >> Personally I'd prefer just "reset", as "pci" is redundant and "bus" > > > > Can't do 'reset'. > > Why?
B/c I forgot that this attribute is not per device, but on the module sub-directory:
/sys/bus/pci/drivers/pciback/do_flr
It can be indeed called 'reset'.
> > >> doesn't cover the slot variant. > > > > 'bus_reset' sounds lovely? > > Lovely sounding or not, it may end up misleading, and even more so > if - like asked for - FLR would be tried first.
Fair enough. Reset should work then.
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