[PATCH 0/2] KVM: arm64: Fix for probing default PMU

[Oliver Upton <oliver.upton@linux.dev>]

Follow-up to the discussion in [1].

KVM uses a junk perf event to probe for a default PMU instance to use
for the guest, which depends on perf finding the right PMU instance
to use for the event. Looks like perf is going to rely strictly on
the specified PMU type, breaking the entire scheme.

KVM now maintains a list of valid PMU instances that can be selected by
userspace, we can simply walk that to probe for a default PMU.

Applies to 6.4-rc3 and tested on -next.

[1] https://lore.kernel.org/all/20230524214133.GA2359762@dev-arch.thelio-3990X/

Oliver Upton (2):
  KVM: arm64: Iterate arm_pmus list to probe for default PMU
  KVM: arm64: Document default vPMU behavior on heterogeneous systems

 arch/arm64/kvm/pmu-emul.c | 58 ++++++++++++++++-----------------------
 1 file changed, 23 insertions(+), 35 deletions(-)


base-commit: 44c026a73be8038f03dbdeef028b642880cf1511
-- 
2.41.0.rc0.172.g3f132b7071-goog