Re: [PATCH] hw/acpi: refactor acpi hp modules so that targets can just use what they need

[Philippe Mathieu-Daudé]

On 8/12/21 3:22 PM, Ani Sinha wrote:
> On Thu, 12 Aug 2021, Ani Sinha wrote:
> 
>> Currently various acpi hotplug modules like cpu hotplug, memory hotplug, pci
>> hotplug, nvdimm hotplug are all pulled in when CONFIG_ACPI_X86 is turned on.
>> This brings in support for whole lot of subsystems that some targets like
>> mips does not need. They are added just to satisfy symbol dependencies. This
>> is ugly and should be avoided. Targets should be able to pull in just what 
>> they
>> need and no more. For example, mips only needs support for PIIX4 and does not
>> need acpi pci hotplug support or cpu hotplug support or memory hotplug 
>> support
>> etc. This change is an effort to clean this up.
>> In this change, new config variables are added for various acpi hotplug
>> subsystems. Targets like mips can only enable PIIX4 support and not the rest
>> of all the other modules which were being previously pulled in as a part of
>> CONFIG_ACPI_X86. Function stubs make sure that symbols which piix4 needs but
>> are not required by mips (for example, symbols specific to pci hotplug etc)
>> are available to satisfy the dependencies.
>>
>> Currently, this change only addresses issues with mips malta targets. In 
>> future
>> we might be able to clean up other targets which are similarly pulling in lot
>> of unnecessary hotplug modules by enabling ACPI_X86.
>>
>> This change should also address issues such as the following:
>> https://gitlab.com/qemu-project/qemu/-/issues/221
>> https://gitlab.com/qemu-project/qemu/-/issues/193
> 
> I do not have a cross compiled mips64 vmlinux handy, so can't verify that
> issue #193 was indeed resolved.

The functional tests use some pre-built:

$ git grep I6400 tests/acceptance/

> I have verified that #221 was indeed
> fixed.

Good news!