On 01/10/19 13:32, Vitaly Kuznetsov wrote: > Jim Mattson <jmattson@xxxxxxxxxx> writes: > >> KVM can only virtualize as many PMCs as the host supports. >> >> Limit the number of generic counters and fixed counters to the number >> of corresponding counters supported on the host, rather than to >> INTEL_PMC_MAX_GENERIC and INTEL_PMC_MAX_FIXED, respectively. >> >> Note that INTEL_PMC_MAX_GENERIC is currently 32, which exceeds the 18 >> contiguous MSR indices reserved by Intel for event selectors. Since >> the existing code relies on a contiguous range of MSR indices for >> event selectors, it can't possibly work for more than 18 general >> purpose counters. > > Should we also trim msrs_to_save[] by removing impossible entries > (18-31) then? Yes, I'll send a patch in a second. Paolo
