Re: [Qemu-devel] [SeaBIOS] [PATCH v2] map 64-bit PCI BARs at location provided by emulator

[Kevin O'Connor]

On Sun, Oct 13, 2013 at 08:19:16PM +0200, Igor Mammedov wrote:
> On Sun, 13 Oct 2013 19:33:19 +0200
> Igor Mammedov <address@hidden> wrote:
> > On Sun, 13 Oct 2013 19:46:09 +0300
> > "Michael S. Tsirkin" <address@hidden> wrote:
> > > On Sun, Oct 13, 2013 at 06:23:28PM +0200, Igor Mammedov wrote:
> > > > On Sun, 13 Oct 2013 18:59:20 +0300
> > > > "Michael S. Tsirkin" <address@hidden> wrote:
> > > All we care about for a compatible bios is that it
> > > keep working in old hardware configurations.
> > > IMO there's no real need for old BIOS to work
> > > with e.g. memory hotplug - it's reasonable
> > > to ask users to update fitmware if they want
> > > to use this feature.
> > Fine with me if we don't care about strange hangs if something misused.
> > 
> > But RamSizeOver4G still doesn't allow correctly place PCI window if large
> > amount of memory present/reserved.
> BTW: I don't think it's good practice to change semantics of an old interface
> in general. It's less confusing to leave old interface as is (obsoleting it
> eventually) and use a new one.

I agree.  The RamSizeOver4G (as passed via three cmos bytes) is ugly -
lets not make it more complex.  Any new info can be passed via fw_cfg.
Indeed, I'd happily accept patches that migrated the existing cmos
parameters to new fw_cfg entries.

-Kevin