[RFC PATCH v2 0/2] s390x: Improvements to SIGP handling [QEMU]

[Eric Farman <farman@linux.ibm.com>]

Here is an update to the SIGP handling I brought up a few
weeks ago [1]. It doesn't share anything with v1, as one of
the patches has already been pulled to master [2] and the
other is now dropped in favor of this direction.

Here, we take advantage of a new KVM ioctl [3] to indicate
when userspace has completed processing a particular SIGP
order, based on David's suggestion [4]. This code resets
the "busy" situation for every order, regardless of whether
the Principles of Operation dictates whether the order
would mark the vcpu busy.

It's not as graceful as I'd like, but it does what I expect
it to. Maybe some more refactoring on this side would help
matters. Thoughts?

[1] https://lore.kernel.org/r/20211008203811.1980478-1-farman@linux.ibm.com/
[2] https://lore.kernel.org/r/20211015091622.1302433-1-thuth@redhat.com/
[3] https://lore.kernel.org/r/20211102194652.2685098-1-farman@linux.ibm.com/
[4] https://lore.kernel.org/r/3e3b38d1-b338-0211-04ab-91f913c1f557@redhat.com/

Eric Farman (2):
  Temporary linux-headers update
  s390x: Implement the USER_SIGP_BUSY capability

 linux-headers/linux/kvm.h    |  4 ++++
 target/s390x/cpu-sysemu.c    |  7 +++++++
 target/s390x/cpu.h           |  4 ++++
 target/s390x/kvm/kvm.c       |  9 ++++++++
 target/s390x/kvm/kvm_s390x.h |  1 +
 target/s390x/sigp.c          | 40 ++++++++++++++++++++++++++++++++++++
 6 files changed, 65 insertions(+)

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2.25.1