Re: [PATCH v1 0/2] Upgrade ACPI SPCR table to support SPCR table version 4 format

[Peter Maydell]

On Thu, 2 May 2024 at 06:12, Sia Jee Heng <jeeheng.sia@starfivetech.com> wrote:
>
> Update the SPCR table to accommodate the SPCR Table version 4 [1].
> The SPCR table has been modified to adhere to the version 4 format [2].
>
> Meanwhile, the virt SPCR golden reference files have been updated to
> accommodate the SPCR Table version 4.
>
> [1]: 
> https://learn.microsoft.com/en-us/windows-hardware/drivers/serports/serial-port-console-redirection-table
> [2]: https://github.com/acpica/acpica/pull/931
>
> Sia Jee Heng (2):
>   tests/qtest/bios-tables-test: Update virt SPCR golden references
>   hw/acpi: Upgrade ACPI SPCR table to support SPCR table version 4
>     format

This isn't the right way to make a change that requires
updates to the bios-tables-test reference files, because
"make check" will fail after patch 1 but before patch 2.

You need a three-patch approach. How to do that is documented
in the comment at the top of bios-tables-test.c. The resulting
three patches should look like:
 * patch 1 updates bios-tables-test-allowed-diff.h to
   mark the affected test or tests as "OK to fail"
 * patch 2 makes the changes to QEMU that alter the
   required table output
 * patch 3 updates the reference files and removes the
   tests from the allowed-diff file

See for instance commits 6c1c2e912fcf9, 1ec896fe7ca938,
ea2fde5bccc514 as an example.

Side note: if riscv virt has APCI tables now, maybe we
should add testing of them to the bios-tables-test ?

thanks
-- PMM