Re: [PATCH V8 00/18] KVM: x86/pmu: Add *basic* support to enable guest PEBS via DS

From: Liang, Kan
Date: Thu Jul 22 2021 - 09:08:23 EST




On 7/22/2021 8:53 AM, Liuxiangdong wrote:
Hi,like and lingshan.

We can use pebs on the Icelake by using "perf record -e $event:pp", but how can we get all the supported $event for the Icelake?
Because it seems like that all the hardware event/software event/kernel pmu event listed by "perf list" can use ":pp" without error.


By quering events list for Icelake("https://perfmon-events.intel.com/), we can use "perf record -e cpu/event=0xXX,unask=0xXX/pp"
to enable sampling. There are some events with "PEBS: [PreciseEventingIP]" in "Additional Info" column. Are they the only supported
precise events? Do those events which have "PEBS:[NonPreciseEventingIP]" in last column support PEBS?


Starts from Ice Lake, the extended PEBS feature is supported, which extend the PEBS for all counters and all performance monitoring events (both precise event and non-precise). You can sample any events with PEBS.
For details, please refer to the 18.9.1 extended PEBS in the latest SDM vol3.

Thanks,
Kan