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

[JeeHeng Sia]

> -----Original Message-----
> From: Peter Maydell <peter.maydell@linaro.org>
> Sent: Thursday, May 2, 2024 5:19 PM
> To: JeeHeng Sia <jeeheng.sia@starfivetech.com>
> Cc: qemu-arm@nongnu.org; qemu-devel@nongnu.org; qemu-riscv@nongnu.org; 
> mst@redhat.com; imammedo@redhat.com;
> anisinha@redhat.com; shannon.zhaosl@gmail.com; sunilvl@ventanamicro.com; 
> palmer@dabbelt.com; alistair.francis@wdc.com;
> bin.meng@windriver.com; liwei1518@gmail.com; dbarboza@ventanamicro.com; 
> zhiwei_liu@linux.alibaba.com
> Subject: Re: [PATCH v1 0/2] Upgrade ACPI SPCR table to support SPCR table 
> version 4 format
> 
> 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.
Thank you for the guidance. I will improve the patch by referring to the 
example provided.
> 
> Side note: if riscv virt has APCI tables now, maybe we
> should add testing of them to the bios-tables-test ?
Sure. I will make modifications based on the RISC-V test.
> 
> thanks
> -- PMM