From 8d8b37e242decffb789cd86f501100dd881ded10 Mon Sep 17 00:00:00 2001 From: Wei Huang Date: Wed, 16 Nov 2016 09:20:57 +0000 Subject: [PATCH] arm64: KVM: pmu: Fix AArch32 cycle counter access commit 9e3f7a29694049edd728e2400ab57ad7553e5aa9 upstream. We're missing the handling code for the cycle counter accessed from a 32bit guest, leading to unexpected results. Signed-off-by: Wei Huang Signed-off-by: Marc Zyngier Signed-off-by: Greg Kroah-Hartman --- arch/arm64/kvm/sys_regs.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index e51367d159d02..31c144f7339a0 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -602,8 +602,14 @@ static bool access_pmu_evcntr(struct kvm_vcpu *vcpu, idx = ARMV8_PMU_CYCLE_IDX; } else { - BUG(); + return false; } + } else if (r->CRn == 0 && r->CRm == 9) { + /* PMCCNTR */ + if (pmu_access_event_counter_el0_disabled(vcpu)) + return false; + + idx = ARMV8_PMU_CYCLE_IDX; } else if (r->CRn == 14 && (r->CRm & 12) == 8) { /* PMEVCNTRn_EL0 */ if (pmu_access_event_counter_el0_disabled(vcpu)) @@ -611,7 +617,7 @@ static bool access_pmu_evcntr(struct kvm_vcpu *vcpu, idx = ((r->CRm & 3) << 3) | (r->Op2 & 7); } else { - BUG(); + return false; } if (!pmu_counter_idx_valid(vcpu, idx)) -- 2.47.2