On 11/02/2016 11:11 PM, cov@xxxxxxxxxxxxxx wrote: > Hi Wei, > > On 2016-11-02 14:55, Wei Huang wrote: >> KVM calls kvm_pmu_set_counter_event_type() when PMCCFILTR is configured. >> But this function can't deals with PMCCFILTR correctly because the >> evtCount >> bit of PMCCFILTR, which is reserved 0, conflits with the SW_INCR event >> type of other PMXEVTYPER<n> registers. To fix it, when eventsel == 0, KVM >> shouldn't return immediately, but instead it needs to check further if >> select_idx is ARMV8_PMU_CYCLE_IDX. >> >> Another issue is that KVM shouldn't copy the eventsel bits of PMCCFILTER >> directly to attr.config. Istead it shoudl convert the request to >> perf_event of type 0x11 (i.e. the "cpu cycle" event type). >> >> Signed-off-by: Wei Huang <wei@xxxxxxxxxx> >> --- >> virt/kvm/arm/pmu.c | 5 +++-- >> 1 file changed, 3 insertions(+), 2 deletions(-) >> >> diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c >> index 6e9c40e..13cc812 100644 >> --- a/virt/kvm/arm/pmu.c >> +++ b/virt/kvm/arm/pmu.c >> @@ -379,7 +379,8 @@ void kvm_pmu_set_counter_event_type(struct >> kvm_vcpu *vcpu, u64 data, >> eventsel = data & ARMV8_PMU_EVTYPE_EVENT; >> >> /* Software increment event does't need to be backed by a perf >> event */ >> - if (eventsel == ARMV8_PMU_EVTYPE_EVENT_SW_INCR) >> + if (eventsel == ARMV8_PMU_EVTYPE_EVENT_SW_INCR && >> + select_idx != ARMV8_PMU_CYCLE_IDX) >> return; >> >> memset(&attr, 0, sizeof(struct perf_event_attr)); >> @@ -391,7 +392,7 @@ void kvm_pmu_set_counter_event_type(struct >> kvm_vcpu *vcpu, u64 data, >> attr.exclude_kernel = data & ARMV8_PMU_EXCLUDE_EL1 ? 1 : 0; >> attr.exclude_hv = 1; /* Don't count EL2 events */ >> attr.exclude_host = 1; /* Don't count host events */ >> - attr.config = eventsel; >> + attr.config = (select_idx == ARMV8_PMU_CYCLE_IDX) ? 0x011 : >> eventsel; > > Nit: Is there some way you could use ARMV8_PMUV3_PERFCTR_CPU_CYCLES > currently > defined in arch/arm64/kernel/perf_event.c? The event definitions in perf_event.c are local to this file. To use them, I have to re-factor them out to a header file, which is bigger than this patch intended. How about adding the following line to arch/arm64/include/asm/perf_event.h (i.e. the same file of ARMV8_PMU_EVTYPE_EVENT_SW_INCR)? #define ARMV8_PMU_EVTYPE_EVENT_CPU_CYCLES 0x11 > > Thanks, > Cov -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
