Re: [PATCH] KVM: selftest: Add family and model check for zen4 in PMU filter test

[Manali Shukla <manali.shukla@amd.com>]

On 5/1/2024 9:02 PM, Sean Christopherson wrote:
> On Wed, May 01, 2024, Manali Shukla wrote:
>> PMU event filter test fails on zen4 architecture because of
>> unavailability of family and model check for zen4 in use_amd_pmu().
>> So, add family and model check for zen4 architecture in use_amd_pmu().
> 
> Is there a less ugly way to detect that 0xc2,0 == "branch instructions retired"?
> E.g. can we instead check for v2 PMU support, or are there no guarantees going
> forward?  Pivoting on FMS is so painful :-(

We have confirmed with the hardware team that 0xc2,0 == "branch instructions retired"
is always true going forward, we intend to maintain backward compatibility for branch
instruction retired. Since event 0xc2 is supported on all currently released F17h+ 
processors as branch instructions retired, we can check for "family >= 0x17" for all
Zen and its successors instead of checking them individually in pmu_event_filter_test.c.

- Manali