tree 25a142770f34cb0b7ba27e691d02509902a1974d
parent d768bd892fc8f066cd3aa000eb1867bcf32db0ee
author Martin Schwidefsky <schwidefsky@de.ibm.com> 1516084606 +0100
committer Martin Schwidefsky <schwidefsky@de.ibm.com> 1517838530 +0100

s390: run user space and KVM guests with modified branch prediction

Define TIF_ISOLATE_BP and TIF_ISOLATE_BP_GUEST and add the necessary
plumbing in entry.S to be able to run user space and KVM guests with
limited branch prediction.

To switch a user space process to limited branch prediction the
s390_isolate_bp() function has to be call, and to run a vCPU of a KVM
guest associated with the current task with limited branch prediction
call s390_isolate_bp_guest().

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>