Re: [PATCH v4 31/42] hw/pci-host/gpex-acpi: Add support for dsdt construction for pxb-cxl

[Alex Bennée]

Jonathan Cameron <Jonathan.Cameron@huawei.com> writes:

> On Tue, 25 Jan 2022 17:15:58 +0000
> Alex Bennée <alex.bennee@linaro.org> wrote:
>
>> Jonathan Cameron <Jonathan.Cameron@huawei.com> writes:
>> 
>> > This adds code to instantiate the slightly extended ACPI root port
>> > description in DSDT as per the CXL 2.0 specification.
>> >
>> > Basically a cut and paste job from the i386/pc code.  
>> 
>> This fails to build on all machines:
>> 
>>   FAILED: qemu-system-mips64el 
>>   c++ -m64 -mcx16 -o qemu-system-mips64el
<snip>
>> /usr/lib/x86_64-linux-gnu/libssh.so -lstdc++ -Wl,--end-group
>>   /usr/bin/ld: /lib/x86_64-linux-gnu/libtirpc.so.3: warning: common of 
>> `rpc_createerr@@GLIBC_2.2.5' overridden by definition from 
>> /lib/x86_64-linux-gnu/libc.so.6
>>   /usr/bin/ld: libcommon.fa.p/hw_pci-host_gpex-acpi.c.o: in function 
>> `acpi_dsdt_add_gpex':
>>   /home/alex/lsrc/qemu.git/builds/all/../../hw/pci-host/gpex-acpi.c:191: 
>> undefined reference to `build_cxl_osc_method'
>>   collect2: error: ld returned 1 exit status
>>   [1600/2203] Linking target qemu-system-or1k
<snip>
>> > @@ -175,7 +187,11 @@ void acpi_dsdt_add_gpex(Aml *scope, struct GPEXConfig 
>> > *cfg)
>> >                              cfg->pio.base, 0, 0, 0);
>> >              aml_append(dev, aml_name_decl("_CRS", crs));
>> >  
>> > -            acpi_dsdt_add_pci_osc(dev);
>> > +            if (is_cxl) {
>> > +                build_cxl_osc_method(dev);  
>> 
>> Either we need an #ifdef gate on CONFIG_ACPI_CXL
>
>  error: attempt to use poisoned "CONFIG_ACPI_CXL"

Hmm I'm not sure why that happened. We generally poison symbols to stop
making configuration changes objects that are shared between binaries. I
guess softmmu_ss must be shared then. Paolo?

>
>> or possibly a stub
>> implementation (with a g_assert_not_reached()).
> That works.
>
> Turns out I was too lazy thinking riscv was enough to exercise the
> not CXL support case.
>
> Lesson learned - mips64el now in my standard config :)
> I'd not realized there were ACPI supporting MIPS machines...

It's worth making sure your gitlab account is setup to run the CI loop
because it's the first thing I do when I review a series ;-)

  https://gitlab.com/stsquad/qemu/-/pipelines/456700583

-- 
Alex Bennée