Re: Xen 4.18 pvshim console issue (with patch)

[Manuel Bouyer <bouyer@xxxxxxxxxxxxxxx>]

On Wed, Oct 18, 2023 at 03:29:08PM +0200, Jan Beulich wrote:
> On 18.10.2023 12:38, Manuel Bouyer wrote:
> > Hello,
> > With Xen 4.18, a PV domain running under pvshim doesn't get console input.
> > This is because the domain id in pvshim isn't 0 (and on x86 max_init_domid 
> > is
> > hardwired to 0), so console_input_domain() will never select that domain
> > as input.
> > 
> > The attached patch fixes it by translating 0 to the real domain id for
> > pvshim, but there may be a better way to do this.
> 
> My primary observation with the patch is that it presumably won't build for
> other than x86.

It's possible, I don't have other platform to test

> There are also indentation and other style issues, no S-o-b,
> and no description.

I'll let whoever commit it deal with this

> But I wonder whether a different approach doesn't want
> taking: Wouldn't it help if max_init_domid was 1 in the shim case, with no
> need for any other changes?

max_init_domid=1 won't help, because we're using the real domid from the
real hypervisor here. So it can be arbitrary large (in my tests I did a
printk here, and the domid was matching the id from 'xl list')

-- 
Manuel Bouyer <bouyer@xxxxxxxxxxxxxxx>
     NetBSD: 26 ans d'experience feront toujours la difference
--