Re: [PATCH v2 2/2] pci: add romsize property

[Dr. David Alan Gilbert]

* Peter Xu (peterx@redhat.com) wrote:
> On Mon, Feb 01, 2021 at 08:56:32AM +0100, Gerd Hoffmann wrote:
> >   Hi,
> > 
> > > +    DEFINE_PROP_UINT32("romsize", PCIDevice, romsize, -1),
> > 
> > IIRC we have a DEFINE_PROP_SIZE() which can parse units and therefore
> > accepts -- for example -- "512k" or "1M".
> 
> Actually IMHO there's some fair point to make it uint32: even 1 byte would
> matter here or migration fails.  Hence, we don't need to worry about things
> like 512KB or 512KiB, for example.
> 
> Not to mention that I bet 99.99% qemu users won't really use this parameter,
> only if we'd migrate across distros.  That's rare, we'd copy the exact byte
> value of the source ROM size here (e.g. via "info ramblock", or "ls -l" the
> romfile then round to pow2 and specify on dest) or we simply copy this param
> over from another source VM.

Well, we should sometime, set it for the default upstream machine types,
so that distros get a better chance of getting their rom images right
and consistent.

Dave

> Thanks,
> 
> -- 
> Peter Xu
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK