Re: [PATCH v7 0/4] hw/acpi: add indication for i8042 in IA-PC boot flags of the FADT table

[Michael S. Tsirkin]

On Fri, Mar 04, 2022 at 09:10:28PM +0530, Ani Sinha 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.
> 
> To allow "flexible" indication, I don't hardcode the bit at location 1
> as on in the IA-PC boot flags, but try to search for i8042 on the ISA
> bus to verify it exists in the system.
> 
> Why this is useful you might ask - this patch allows the guest OS to
> probe and use the i8042 controller without decoding the ACPI AML blob
> at all. For example, as a developer of the SerenityOS kernel, I might
> want to allow people to not try to decode the ACPI AML namespace (for
> now, we still don't support ACPI AML as it's a work in progress), but
> still to not probe for the i8042 but just use it after looking in the
> IA-PC boot flags in the ACPI FADT table.

I wonder how will such a guest work on an existing qemu release then.

> Changelog:
> v7:
> fixed a compilation issue. the fix was not committed when running "make check"
> v6:
> addressed comments from v5. added microvm changes too as a part of this 
> series.
> v5:
> Addressed review comments from v4. Also got rid of microvm changes. Will send
> them in a separate patch.
> 
> 
> 
> Ani Sinha (1):
>   hw/acpi/microvm: turn on 8042 bit in FADT boot architecture flags if
>     present
> 
> Liav Albani (3):
>   tests/acpi: i386: allow FACP acpi table changes
>   hw/acpi: add indication for i8042 in IA-PC boot flags of the FADT
>     table
>   tests/acpi: i386: update FACP table differences
> 
>  hw/acpi/aml-build.c            |   8 +++++++-
>  hw/i386/acpi-build.c           |   8 ++++++++
>  hw/i386/acpi-microvm.c         |   6 ++++++
>  include/hw/acpi/acpi-defs.h    |   1 +
>  include/hw/input/i8042.h       |  15 +++++++++++++++
>  tests/data/acpi/q35/FACP       | Bin 244 -> 244 bytes
>  tests/data/acpi/q35/FACP.nosmm | Bin 244 -> 244 bytes
>  tests/data/acpi/q35/FACP.slic  | Bin 244 -> 244 bytes
>  tests/data/acpi/q35/FACP.xapic | Bin 244 -> 244 bytes
>  9 files changed, 37 insertions(+), 1 deletion(-)
> 
> -- 
> 2.25.1