Re: [PATCH v4 2/3] hw/acpi: add indication for i8042 in IA-PC boot flags of the FADT table

[Ani Sinha]

On Wed, Mar 2, 2022 at 12:50 AM Liav Albani <liavalb@gmail.com> wrote:
>
>
> On 3/1/22 11:52, Ani Sinha wrote:
> >
> > On Tue, 1 Mar 2022, Igor Mammedov wrote:
> >
> >> On Mon, 28 Feb 2022 22:17:32 +0200
> >> Liav Albani <liavalb@gmail.com> wrote:
> >>
> >>> This can allow the guest OS to determine more easily if i8042 controller
> >>> is present in the system or not, so it doesn't need to do probing of the
> >>> controller, but just initialize it immediately, before enumerating the
> >>> ACPI AML namespace.
> >>>
> >>> This change only applies to the x86/q35 machine type, as it uses FACP
> >>> ACPI table with revision higher than 1, which should implement at least
> >>> ACPI 2.0 features within the table, hence it can also set the IA-PC boot
> >>> flags register according to the ACPI 2.0 specification.
> >>>
> >>> Signed-off-by: Liav Albani <liavalb@gmail.com>
> >>> ---
> >>>   hw/acpi/aml-build.c         | 11 ++++++++++-
> >>>   hw/i386/acpi-build.c        |  9 +++++++++
> >>>   hw/i386/acpi-microvm.c      |  9 +++++++++
> >> commit message says it's q35 specific, so wy it touched microvm anc piix4?
> > Igor is correct. Although I see that currently there are no 8042 devices
> > for microvms, maybe we should be conservative and add the code to detect
> > the device anyway. In that case, the change could affect microvms too when
> > such devices get added in the future.
> >
> >
> > echo -e "info qtree\r\nquit\r\n" | ./qemu-system-x86_64 -machine microvm
> > -monitor stdio 2>/dev/null | grep 8042
> >
> > <empty>
>
> What about this?
>
> echo -e "info qtree\r\nquit\r\n" | qemu-system-x86_64 -machine microvm
> -device i8042 -monitor stdio 2>/dev/null | grep 8042
>
> Or this?
>
> echo -e "info mtree\r\nquit\r\n" | qemu-system-x86_64 -machine microvm
> -device i8042 -monitor stdio 2>/dev/null | grep 8042

On both occasions you are explicitly adding the device.