On Wed, 22 Jul 2026 20:26:58 +0000, Congkai Tan wrote:
> Today when the perf tool runs in a guest on cores with PMUv3p4, it fails
> to parse the default metrics with "Failure to read '#slots'", since perf
> can only read 0 from sysfs caps/slots, which is backed by PMMIR_EL1.SLOTS
> that KVM traps as RAZ/WI.
>
> Taking into account backward compatibility and heterogeneous systems, the
> exposure of PMMIR_EL1.SLOTS is gated behind a new vCPU feature flag:
>
> [...]
Applied to next, thanks!
[1/4] KVM: arm64: Expose PMMIR_EL1.SLOTS under strict PMUv3 UAPI
https://git.kernel.org/kvmarm/kvmarm/c/453f6ff04b8d
[2/4] KVM: arm64: Advertise STALL_SLOT* in PMCEID1 under strict PMUv3 UAPI
https://git.kernel.org/kvmarm/kvmarm/c/203b22f76dc3
[3/4] KVM: arm64: Ignore writes to PMCR_EL0.N when using strict UAPI
https://git.kernel.org/kvmarm/kvmarm/c/bbef6317f97b
[4/4] KVM: arm64: Add KVM_ARM_VCPU_PMU_V3_STRICT vCPU feature
https://git.kernel.org/kvmarm/kvmarm/c/ad220e275c39
--
Best,
Oliver
