Re: [Xen-devel] [PATCH v4 2/4] docs: Introduce xenstore paths for PV driver information

[Paul Durrant <Paul.Durrant@xxxxxxxxxx>]

> -----Original Message-----
> From: Ian Jackson [mailto:Ian.Jackson@xxxxxxxxxxxxx]
> Sent: 16 November 2015 17:36
> To: Paul Durrant
> Cc: xen-devel@xxxxxxxxxxxxxxxxxxxx; Ian Campbell; Jan Beulich; Keir (Xen.org);
> Tim (Xen.org)
> Subject: Re: [PATCH v4 2/4] docs: Introduce xenstore paths for PV driver
> information
> 
> Paul Durrant writes ("[PATCH v4 2/4] docs: Introduce xenstore paths for PV
> driver information"):
> > For domain management purposes it is convenient to be able to see
> > information about PV drivers in xenstore. The XAPI toolstack in
> > XenServer has always created a ~/drivers path for this purpose.
> >
> > This patch documents that path and also adds a specification of how
> > it should be used.
> ...
> > +* DISTRIBUTION -- information about a software distribution, comprised
> > +                  of 3 or 4 space separated fields as follows:
> 
> I think you should also specify an allowable character set, and
> expected matching rules (if any).
> 

I'm unclear about what's legal. In xenstore.txt there's a paragraph:

" While xenstore and most tools and APIs are capable of dealing with
arbitrary binary data as values, this should generally be avoided.
Data should generally be human-readable for ease of management and
debugging; xenstore is not a high-performance facility and should be
used only for small amounts of control plane data.  Therefore xenstore
values should normally be 7-bit ASCII text strings containing bytes
0x20..0x7f only, and should not contain a trailing nul byte.  (The
APIs used for accessing xenstore generally add a nul when reading, for
the caller's convenience.)"

So, should we allow anything other than 7-bit ASCII?

> > +                  VENDOR -- Commonly used vendor short name,
> > +                            e.g "Citrix" rather than "Citrix Systems
> > +                            Inc."
> > +
> > +                  PRODUCT -- Commonly used product (e.g. driver) name
> > +                             without version information.
> 
> "If a toolstack needs to match on these values it should support Unix
> glob style matching" ?
> 

Yes, I can add that.

> > +                  ATTRIBUTES -- Optional human readable text enclosed in
> > +                                parentheses to denote attributes of the
> > +                                software, e.g. "(debug)"
> 
> What are the parentheses for ?  How might a toolstack provide
> facilities to match this ?
> 

I was not expecting any matching on attributes, since it's optional anyway. I 
guess the parentheses are indeed redundant.

  Paul

> Ian.

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel