Re: [PATCH v2] x86/entry/64: Do not use RDPID in paranoid entry to accomodate KVM

From: Thomas Gleixner
Date: Tue Aug 25 2020 - 06:44:38 EST


On Fri, Aug 21 2020 at 11:35, Brian Gerst wrote:
> On Fri, Aug 21, 2020 at 10:22 AM Sean Christopherson
>> > .macro GET_PERCPU_BASE reg:req
>> > - ALTERNATIVE \
>> > - "LOAD_CPU_AND_NODE_SEG_LIMIT \reg", \
>> > - "RDPID \reg", \
>>
>> This was the only user of the RDPID macro, I assume we want to yank that out
>> as well?
>
> No. That one should be kept until the minimum binutils version is
> raised to one that supports the RDPID opcode.

The macro is unused and nothing in the kernel can use RDPID as we just
established.

Thanks,

tglx