[libvirt] [RFC PATCH 6/6] qemu: Format pseries.cap-hpt-mps on the command line

[Andrea Bolognani]

On Mon, 2018-06-04 at 11:33 +1000, David Gibson wrote:
> On Thu, May 24, 2018 at 07:34:25AM +0200, Peter Krempa wrote:
> > On Wed, May 23, 2018 at 19:09:59 +0200, Andrea Bolognani wrote:
> > > To be fair, it would perhaps make sense to perform the conversion
> > > directly inside QEMU, in order to make it more convenient not only
> > > for libvirt but for for people driving it directly as well.
> > 
> > If strictly only powers of two make sense for this knob then this gives
> > you input validation for free. On the other hand, specifying a big
> > number can overflow internally if it is ever used in the non-exponent
> > form. I think the format does not matter much, since libvirt's job is to
> > shield users from such weirdness.
> 
> Yeah, the above is basically my reasoning for using the exponent, not
> the final page size.

As Peter mentioned, what format is used doesn't matter much from
libvirt's point of view, and in fact this RFC already implements
the necessary format conversion; however, it might be convenient
for people spawning QEMU directly to be able to specify the page
size in a more human-friendly format.

How do you feel about that? If that's off the table, we'll just
go ahead with the current implementation.

-- 
Andrea Bolognani / Red Hat / Virtualization