When using VHE, EL1 is unused by the host and EL2 is unused by the guest - therefore we can filter out these events with the PMU as per the 'exclude_host' and 'exclude_guest' attributes.
With both VHE and non-VHE we switch the counters between host/guest at EL2. With non-VHE when using 'exclude_host' we filter out EL2. These changes eliminate counters counting host events on the boundaries of guest entry/exit when using :G. However when using :H unless exclude_hv is set on non-VHE then there is a small blackout window at the guest entry/exit where host events are not captured. Signed-off-by: Andrew Murray <[email protected]> --- arch/arm64/kernel/perf_event.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c index 89d444f..c079c1f 100644 --- a/arch/arm64/kernel/perf_event.c +++ b/arch/arm64/kernel/perf_event.c @@ -971,12 +971,14 @@ static int armv8pmu_set_event_filter(struct hw_perf_event *event, * with other architectures (x86 and Power). */ if (is_kernel_in_hyp_mode()) { - if (!attr->exclude_kernel) + if (!attr->exclude_kernel && !attr->exclude_host) config_base |= ARMV8_PMU_INCLUDE_EL2; + if (attr->exclude_guest) + config_base |= ARMV8_PMU_EXCLUDE_EL1; } else { if (attr->exclude_kernel) config_base |= ARMV8_PMU_EXCLUDE_EL1; - if (!attr->exclude_hv) + if (!attr->exclude_hv && !attr->exclude_host) config_base |= ARMV8_PMU_INCLUDE_EL2; } if (attr->exclude_user) -- 2.7.4 _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
