RE: [PATCH v8 02/18] hw/usb/hcd-xhci: Add an auto-hub property and leave it off

[Jamin Lin <jamin_lin@xxxxxxxxxxxxxx>]

> Subject: RE: [PATCH v8 02/18] hw/usb/hcd-xhci: Add an auto-hub property and
> leave it off
> 
> > Subject: Re: [PATCH v8 02/18] hw/usb/hcd-xhci: Add an auto-hub
> > property and leave it off
> >
> > Hi Jamin,
> >
> > On Mon, Nov 02, 2026 at 09:22:05AM +0000, Jamin Lin wrote:
> > > Add auto-hub and leave it off. hw_compat_11_1 turns it on, so an
> > > older machine type keeps the hub it has today and a guest saved by
> > > an older QEMU still loads.
> >
> > Reran the migration check from v7: with pc-q35-11.1, a guest saved
> > without the series loads on v8 with the hub in place, for qemu-xhci
> > with four HID devices and for q35 -usb with six.
> >
> > But this missed the 11.2 soft freeze, so in 12.0 pc-q35-11.2 is an old
> > machine type too, and hw_compat_11_1 (my suggestion on v7) doesn't
> > cover it. Saved with pc-q35-11.2 on master, both cases fail on v8:
> >
> >   Unknown section or instance '0000:00:01.0/4/usb-hub' 0
> >   Unknown section or instance '0000:00:1d.7/6/usb-hub' 0
> >
> > The entries from 02-05 want hw_compat_11_2 once the 12.0 machine types
> > are in.
> >
> > Junjie
> 
> Hi Junjie, Marc-André, and Gerd,
> 
> Due to the QEMU code freeze and the planned 11.2 release in December,


I am not sure about the correct release version. I expect it to be v11.2.
If the version is wrong, please correct me.

Thanks,
Jamin


> disabling automatic hub creation while keeping migration compatibility with
> older QEMU versions requires adding the property to hw_compat_11_2.
> We need to wait until after the QEMU 11.2 release for the maintainers to add
> hw_compat_11_2 to each machine type.
> 
> The USB redirection server is my original upstream goal, and I think this 
> task is
> independent of the automatic hub task.
> So, I want to split the auto-hub changes into a separate prerequisite patch
> series and send v9 after the QEMU 11.2 release.
> 
> The USB redirection server common protocol series still needs rework on the
> device announcement and control transfer patches.
> I will send v9 next week and mention that it requires the patch series that
> disables automatic hub creation.
> 
> This way, we can continue testing and reviewing the USB redirection server
> common protocol this month.(November)
> 
> "If you agree, I will send v9 next week. Otherwise, I will wait until after 
> the
> QEMU 11.2 release and then resend the full patch series as v9."
> 
> Thanks,
> Jamin