Re: [Xen-devel] [PATCH V3 2/2] Xen/PCIback: Implement PCI flr/slot/bus reset with 'reset' SysFS attribute

[Govinda Tatti]

On 12/12/2017 9:01 AM, Jan Beulich wrote:
> > > > On 12.12.17 at 15:48, <Govinda.Tatti@xxxxxxxxxx> wrote:
> > Thanks Jan for your review comments. Please see below for my comments.
> First of all - can you please do something about your reply style?
> HTML mail should be avoided. You'll see that the (plain text) reply
> as a result is rather hard to follow, too.
Sorry about it. I had an issue with my Thunderbird setting.
> > --- a/Documentation/ABI/testing/sysfs-driver-pciback
> > +++ b/Documentation/ABI/testing/sysfs-driver-pciback
> > @@ -11,3 +11,18 @@ 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/reset
> > +Date:           Dec 2017
> > +KernelVersion:  4.15
> > +Contact:        xen-devel@xxxxxxxxxxxxxxxxxxxx
> > +Description:
> > +                An option to perform a flr/slot/bus reset when a PCI device
> > + is owned by Xen PCI backend. Writing a string of DDDD:BB:DD.F
> > SSSS:BB:DD.F (or else the D-s are ambiguous, the more that "domain"
> > in Xen code is ambiguous anyway - I continue to be mislead by struct
> > pcistub_device_id's domain field)  Thanks for catching this issue. I will
> > fix it.
> >
> >
> > Also I assume the SSSS part is optional (default zero), which
> > probably can and should be expressed in some way.  SSSS can be 0 or
> > non-zero, subject to system configuration.
> The question isn't system configuration, but whether the field can
> be omitted on input, with zero being assumed in such a case. That's
> a common shorthand, considering that the vast majority of x86
> (and maybe other) systems aren't using segments other than zero
Yes, it can be omitted if SSSS is zero.I will add this information
to above documentation file.

Cheers
GOVINDA