[kvm-unit-tests,v1,0/6] s390x: SIGP fixes

Message

Eric Farman March 3, 2022, 9:04 p.m. UTC

Hi all,

Some of you may remember the recent discussions to straighten out
some serialization issues with the SIGNAL PROCESSOR instruction,
and its interaction with userspace. This resulted in a few kernel
patches [1] that reliably solve the issues I was seeing.

The attached kvm-unit-tests series adapts the existing smp tests
such that it can reproduce the problems I saw when those patches
are reverted (typically by simultaneously doing a kernel compile),
and also demonstrate that those patches indeed fix the issue.

There's some cleanup in here too, based on my understanding of
the smp tests as I was walking through here. Thoughts?

[1] 812de04661c4 KVM: s390: Clarify SIGP orders versus STOP/RESTART
    67cf68b6a5cc KVM: s390: Add a routine for setting userspace CPU state
    8eeba194a32e KVM: s390: Simplify SIGP Set Arch handling

Eric Farman (6):
  lib: s390x: smp: Retry SIGP SENSE on CC2
  s390x: smp: Test SIGP RESTART against stopped CPU
  s390x: smp: Fix checks for SIGP STOP STORE STATUS
  s390x: smp: Create and use a non-waiting CPU stop
  s390x: smp: Create and use a non-waiting CPU restart
  lib: s390x: smp: Convert remaining smp_sigp to _retry

 lib/s390x/smp.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++---
 lib/s390x/smp.h |  2 ++
 s390x/smp.c     | 39 +++++++++++++++++++-----------------
 3 files changed, 73 insertions(+), 21 deletions(-)