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

[Michael Tokarev]

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