On Fri, Dec 20, 2019 at 02:30:22PM +0000, Andrew Murray wrote: > A side effect of supporting the SPE in guests is that we prevent the > host from collecting data whilst inside a guest thus creating a black-out > window. This occurs because instead of emulating the SPE, we share it > with our guests.
We used to permit this; do we know if anyone is using it? Thanks, Mark. > Let's accurately describe our capabilities by using the perf exclude > flags to prevent !exclude_guest and exclude_host flags from being used. > > Signed-off-by: Andrew Murray <[email protected]> > --- > drivers/perf/arm_spe_pmu.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/perf/arm_spe_pmu.c b/drivers/perf/arm_spe_pmu.c > index 2d24af4cfcab..3703dbf459de 100644 > --- a/drivers/perf/arm_spe_pmu.c > +++ b/drivers/perf/arm_spe_pmu.c > @@ -679,6 +679,9 @@ static int arm_spe_pmu_event_init(struct perf_event > *event) > if (attr->exclude_idle) > return -EOPNOTSUPP; > > + if (!attr->exclude_guest || attr->exclude_host) > + return -EOPNOTSUPP; > + > /* > * Feedback-directed frequency throttling doesn't work when we > * have a buffer of samples. We'd need to manually count the > -- > 2.21.0 > _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
