On Wed, Mar 10, 2021, Peter Zijlstra wrote: > On Tue, Mar 09, 2021 at 09:10:19AM -0800, Sean Christopherson wrote: > > > @@ -2024,9 +2021,6 @@ static int __init init_hw_perf_events(void) > > if (!x86_pmu.read) > > x86_pmu.read = _x86_pmu_read; > > > > - if (!x86_pmu.guest_get_msrs) > > - x86_pmu.guest_get_msrs = perf_guest_get_msrs_nop; > > I suspect I might've been over eager here and we're now in trouble when > *_pmu_init() clears x86_pmu.guest_get_msrs (like for instance on AMD). > > When that happens we need to restore __static_call_return0, otherwise > the following static_call_update() will patch in a NOP and RAX will be > garbage again. > > So I've taken the liberty to update the patch as below. Doh, I managed to forget about that between v1 and v2, too. Thanks much!
