On Tue, Feb 15, 2022 at 11:36 PM Like Xu <like.xu.linux@xxxxxxxxx> wrote: > Hardware resources will always be limited (the good news is that > the number of counters will increase in the future), and when we have > a common need for the same hardware, we should prioritize overall > fairness over a GUEST-first strategy. The bad news about the new counters on Intel is that they are less capable than the existing counters. SInce there is no bitmask for GP counters in CPUID.0AH, if you give 4 counters to the guest, then the host is stuck using the less capable counters. Overall fairness is definitely not what we want. See the other thread, which has a proposal for a more configurable perf subsystem that should meet your needs as well as ours. Can we move all of this discussion to the other thread, BTW?
