Marc Zyngier f4e23cf947 KVM: arm64: pmu: Fix cycle counter truncation ... When a counter is disabled, its value is sampled before the event is being disabled, and the value written back in the shadow register. In that process, the value gets truncated to 32bit, which is adequate for any counter but the cycle counter (defined as a 64bit counter). This obviously results in a corrupted counter, and things like "perf record -e cycles" not working at all when run in a guest... A similar, but less critical bug exists in kvm_pmu_get_counter_value. Make the truncation conditional on the counter not being the cycle counter, which results in a minor code reorganisation. Fixes: 80f393a23b ("KVM: arm/arm64: Support chained PMU counters") Reviewed-by: Andrew Murray <andrew.murray@arm.com> Reported-by: Julien Thierry <julien.thierry.kdev@gmail.com> Signed-off-by: Marc Zyngier <maz@kernel.org>		2019-10-20 10:47:07 +01:00
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kvm	KVM: arm64: pmu: Fix cycle counter truncation	2019-10-20 10:47:07 +01:00
lib	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500	2019-06-19 17:09:55 +02:00
Makefile	treewide: Add SPDX license identifier - Makefile/Kconfig	2019-05-21 10:50:46 +02:00