From 001d85bd6c039d3662a4f33a5d212ef3e0438b27 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Sun, 13 Nov 2022 16:38:21 +0000 Subject: [PATCH] KVM: arm64: PMU: Narrow the overflow checking when required For 64bit counters that overflow on a 32bit boundary, make sure we only check the bottom 32bit to generate a CHAIN event. Signed-off-by: Marc Zyngier Reviewed-by: Reiji Watanabe Link: https://lore.kernel.org/r/20221113163832.3154370-6-maz@kernel.org --- arch/arm64/kvm/pmu-emul.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c index d050143326b58..9e6bc7edc4de0 100644 --- a/arch/arm64/kvm/pmu-emul.c +++ b/arch/arm64/kvm/pmu-emul.c @@ -417,7 +417,8 @@ static void kvm_pmu_counter_increment(struct kvm_vcpu *vcpu, reg = lower_32_bits(reg); __vcpu_sys_reg(vcpu, PMEVCNTR0_EL0 + i) = reg; - if (reg) /* No overflow? move on */ + /* No overflow? move on */ + if (kvm_pmu_idx_has_64bit_overflow(vcpu, i) ? reg : lower_32_bits(reg)) continue; /* Mark overflow */ -- 2.30.2