Re: [virtio-comment] comment on pci section

[Cornelia Huck <cornelia.huck@de.ibm.com>]

On Thu, 06 Feb 2014 11:11:37 +1030
Rusty Russell <rusty@au1.ibm.com> wrote:

> Cornelia Huck <cornelia.huck@de.ibm.com> writes:
> > On Wed, 05 Feb 2014 09:49:18 +1030
> > Rusty Russell <rusty@au1.ibm.com> wrote:
> >
> >> +Once the driver has set the DRIVER_OK status bit, all the configured virtqueue of the device are considered live.  All of a device's virtqueues are no longer live once the device has been reset.
> >
> > What about something similar to my earlier suggestions?
> >
> > "Once the driver has set the DRIVER_OK status bit, all of the
> > configured virtqueues of the device are considered live.  Any of the
> > virtqueues of a device are no longer live once the device has been
> > reset."
> 
> We're really getting down to subtleties of language at this point :)

:)

> I don't really mind, but:
> 
> "Any of" has suggestions that it means a subset of.  "All of" indicates
> the complete set.  Maybe it's better to reverse the sentence?
> 
>         None of the virtqueues of a device are live once the device has
>         been reset.

Yes, that's even better.

> 
> >> +A driver MUST NOT alter descriptor table entries which have been
> >> +exposed in the available ring (and not marked consumed by the device
> >> +in the used ring) of a live virtqueue.
> >> +
> >> +A driver MUST NOT decrement the available index on a live virtqueue (ie.
> >> +do not try to "unexpose" buffers).
> >
> > "(i.e. the driver MUST NOT try to "unexpose" buffers)."
> >
> > ?
> 
> It's parenthetical to explain motivation, rather than an additional
> requirement (the "MUST NOT decrement" is the requirement).  Perhaps it's
> clearer if we say:
> 
>    A driver MUST NOT decrement the available index on a live virtqueue (ie.
>    there is no way to "unexpose" buffers).
> 
> ?

Sounds good.

> 
> Cheers,
> Rusty.