Re: [PULL v4 46/83] acpi: pc/q35: drop ad-hoc PCI-ISA bridge AML routines and let bus ennumeration generate AML

[Igor Mammedov]

On Sat, 19 Nov 2022 09:49:39 +0100
Volker Rümelin <vr_qemu@t-online.de> wrote:

> Am 18.11.22 um 15:55 schrieb Igor Mammedov:
> > On Fri, 18 Nov 2022 14:08:36 +0100
> > Igor Mammedov <imammedo@redhat.com> wrote:
> >  
> >> On Thu, 17 Nov 2022 22:51:46 +0100
> >> Volker Rümelin <vr_qemu@t-online.de> wrote:  
> > [...]  
> >>> since this patch SeaBIOS no longer detects the PS/2 keyboard. This means
> >>> there's no keyboard in SeaBIOS, GRUB or FreeDOS. OVMF and Linux detect
> >>> the PS/2 keyboard without issues.
> >>>
> >>> Here are a few lines from the SeaBIOS debug log.
> >>>
> >>> table(50434146)=0x007e1971 (via rsdt)
> >>> ACPI: parse DSDT at 0x007e0040 (len 6449)
> >>> parse_termlist: parse error, skip from 92/465
> >>> Scan for VGA option rom
> >>> Running option rom at c000:0003
> >>> Start SeaVGABIOS (version rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org)
> >>>
> >>> and later
> >>>
> >>> SeaBIOS (version rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org)
> >>> ACPI: no PS/2 keyboard present  
> > it was a bug on SeaBIOS side, we need it to parse Alias term in AML
> > instead of choking on it
> >
> > proposed patch:
> >   
> > https://mail.coreboot.org/hyperkitty/list/seabios@seabios.org/thread/RGPL7HESH5U5JRLEO6FP77CZVHZK5J65/
> >
> > PS:
> > it's probably too late for it to make into 7.2
> >  
> 
> The proposed patch works.
> 
> It may still be an option to revert the commit 47a373faa6 (acpi: pc/q35: 
> drop ad-hoc PCI-ISA bridge AML routines and let bus ennumeration 
> generate AML). If an older QEMU version is migrated to QEMU 7.2.0 and 
> later and the guest reboots afterwards, it may end up without a working 
> keyboard because the migrated SeaBIOS is an older version.

ACPI blobs generated on old QEMU should be migrated as well,
so I'd expect it should be fine.
Problem will manifest itself only after VM was shut down and started anew.

Anyways lets see if a QEMU workaround is possible.

> With best regards,
> Volker
>