Re: [PATCH 4/6] s390: add system call to run tasks with modified branch prediction

Paolo Bonzini
2018-01-17T10:05:30Z

On 17/01/2018 11:03, Florian Weimer wrote:
> On 01/17/2018 10:48 AM, Martin Schwidefsky wrote:
>>          rc = syscall(__NR_s390_modify_bp);
>>          if (rc) {
>>                  perror("s390_modify_bp");
>>                  exit(EXIT_FAILURE);
>>          }
>
> Isn't this traditionally done through personality or prctl?
>
> This looks like something other architectures may want as well.

Yes, Intel would want to have a prctl or similar to enable STIBP
(single-thread indirect branch predictor).

Paolo