On Thu, Nov 01, 2018 at 06:04:01PM +0800, Wei Wang wrote: > Add x86_perf_mask_perf_counters to reserve counters from the host perf > subsystem. The masked counters will not be assigned to any host perf > events. This can be used by the hypervisor to reserve perf counters for > a guest to use. > > This function is currently supported on Intel CPUs only, but put in x86 > perf core because the counter assignment is implemented here and we need > to re-enable the pmu which is defined in the x86 perf core in the case > that a counter to be masked happens to be used by the host. > > Signed-off-by: Wei Wang <[email protected]> > Cc: Peter Zijlstra <[email protected]> > Cc: Andi Kleen <[email protected]> > Cc: Paolo Bonzini <[email protected]> > --- > arch/x86/events/core.c | 37 +++++++++++++++++++++++++++++++++++++ > arch/x86/include/asm/perf_event.h | 1 + > 2 files changed, 38 insertions(+) > > diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c > index 106911b..e73135a 100644 > --- a/arch/x86/events/core.c > +++ b/arch/x86/events/core.c > @@ -716,6 +716,7 @@ struct perf_sched { > static void perf_sched_init(struct perf_sched *sched, struct > event_constraint **constraints, > int num, int wmin, int wmax, int gpmax) > { > + struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); > int idx; > > memset(sched, 0, sizeof(*sched)); > @@ -723,6 +724,9 @@ static void perf_sched_init(struct perf_sched *sched, > struct event_constraint ** > sched->max_weight = wmax; > sched->max_gp = gpmax; > sched->constraints = constraints; > +#ifdef CONFIG_CPU_SUP_INTEL > + sched->state.used[0] = cpuc->intel_ctrl_guest_mask; > +#endif
NAK. This completely undermines the whole purpose of event scheduling.
