Re: missing boot rom: is it really a fatal error?

["Michael S. Tsirkin" <mst@redhat.com>]

On Mon, May 08, 2023 at 01:42:04PM +0300, Michael Tokarev wrote:
> 08.05.2023 13:28, Michael S. Tsirkin wrote:
> > On Sun, May 07, 2023 at 08:56:23PM +0300, Michael Tokarev wrote:
> ..
> 
> > > I'm about to revert that old change on debian, to make it just a warning instead
> > > of an error (the code is different now, but the same principle applies), - because
> > > I dislike dependencies which are useless 99.9% of the time and are trivial to
> > > install when actually needed.
> ..
> > I advise against it.
> > If you boot guest on a system with boot rom not installed you will not
> > be able to migrate to a system with boot rom installed.
> > why not? because we don't know how big to make the rom BAR.
> > And users will not discover until much much later after they have
> > painted themselves into a corner.
> 
> Yes, I know about the migration. Actually there's an old bug report open
> against debian qemu package, - the context is similar to the old bios128
> vs bios256 thing in qemu upstream, - boot roms might change in size too.
> 
> In this context though, the talk is not about migration at all. The missing
> dep is in Xen HVM qemu package, a xen-only build of qemu-system-i386. And
> this one fails to start unless the boot roms are provided. It is not even
> capable of migration to begin with :)
> 
> Thank you for the reminder, - very useful.
> 
> /mjt

I guess we decided we'd rather not handle reports from users about net
boot not working. It's true most users don't need net boot but then
that's true for most qemu functionality - 99% of users
probably need 1% of the functionality. It's just a different 1% for each
user...

-- 
MST