Hi Brendan,

On 8/21/2024 3:08 PM, Brendan Jackman wrote:
> Hi Shivank,
> 
> On Tue, 20 Aug 2024 at 11:52, Shivank Garg <shivankg@amd.com> wrote:
>>
>>  .pushsection .noinstr.text, "ax"
>>  SYM_CODE_START(fill_return_buffer)
>> +       UNWIND_HINT_FUNC
>>         __FILL_RETURN_BUFFER(%_ASM_AX,RSB_CLEAR_LOOPS)
>>         RET
>>  SYM_CODE_END(fill_return_buffer)
>> +__EXPORT_THUNK(fill_return_buffer)
>>  .popsection
> 
> Thanks a lot for the pointer! UNWIND_HINT_FUNC does indeed seem to be
> what I was missing with the objtool warning.
> 
> Regarding the build failure, could you share your config/toolchain
> info so I can try to reproduce? Would be handy for checking my next
> posting. Now I see your mail, it seems surprising that it compiles for
> me.
>
gcc --version
gcc (Ubuntu 11.4.0-1ubuntu1~22.04) 11.4.0

I have attached my config.

> Also while I'm replying to this thread I'll note this:
> 
>> +       if (!IS_ENABLED(CONFIG_RETPOLINE) ||
>> +           !cpu_feature_enabled(X86_FEATURE_RSB_VMEXIT))
> 
> It's called CONFIG_MITIGATION_RETPOLINE now.
> 
> And furthermore, kvm_get_running_vcpu needs to be noinstr, I'm getting
> an objtool warning about this that wasn't mentioned in my cover
> letter.
Strangely, I didn't see this warning.

Thanks,
Shivank