Subject: [PATCH v2 0/2] KVM: PPC: Book3S PR: Fixes for AIL and SCV

From: Nicholas Piggin <[email-masked]>
Date: Sat, 29 Jan 2022 17:25:09 +1000

The first patch in this series fixes a KVM PR host crash due to a
guest executing the scv instruction or with a pseries SMP host, the
host CPUs executing the scv instruction while a PR guest is running.

The second patch fixes unimplemented H_SET_MODE AIL modes by returning
failure from the hcall rather than succeeding but not implementing
the required behaviour. This works around missing host scv support for
scv-capable Linux guests by causing them to disable the facility.

Still looking at doing a proper capability for QEMU/KVM so we can get
consistency between HV, PR, and TCG. That shouldn't change these
patches though.

Thanks,
Nick

Nicholas Piggin (2):
  KVM: PPC: Book3S PR: Disable SCV when AIL could be disabled
  KVM: PPC: Book3S PR: Disallow AIL != 0

 arch/powerpc/kernel/exceptions-64s.S |  4 ++++
 arch/powerpc/kernel/setup_64.c       | 28 ++++++++++++++++++++++++++++
 arch/powerpc/kvm/Kconfig             |  9 +++++++++
 arch/powerpc/kvm/book3s_pr.c         | 20 ++++++++++++++------
 arch/powerpc/kvm/book3s_pr_papr.c    | 20 ++++++++++++++++++++
 5 files changed, 75 insertions(+), 6 deletions(-)

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2.23.0