The PEBS-PDIR facility on Ice Lake server is supported on IA31_FIXED0 only. If the guest configures counter 32 and PEBS is enabled, the PEBS-PDIR facility is supposed to be used, in which case KVM adjusts attr.precise_ip to 3 and request host perf to assign the exactly requested counter or fail. The cpu model check is also required since some platforms may place the PEBS-PDIR facility in another counter index. Signed-off-by: Like Xu <like.xu@xxxxxxxxxxxxxxx> --- arch/x86/kvm/pmu.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c index c6208234e007..f8aa4724d67b 100644 --- a/arch/x86/kvm/pmu.c +++ b/arch/x86/kvm/pmu.c @@ -143,6 +143,8 @@ static void pmc_reprogram_counter(struct kvm_pmc *pmc, u32 type, * in the PEBS record is calibrated on the guest side. */ attr.precise_ip = 1; + if (x86_match_cpu(vmx_icl_pebs_cpu) && pmc->idx == 32) + attr.precise_ip = 3; } event = perf_event_create_kernel_counter(&attr, -1, current, -- 2.21.3
