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authorWei Huang2016-11-16 09:20:57 +0000
committerMarc Zyngier2016-11-18 09:02:04 +0000
commit9e3f7a29694049edd728e2400ab57ad7553e5aa9 (patch)
tree1afa6545f2e297504d5b260ab1f107f2da2fcea0
parentd42c79701a3ee5c38fbbc82f98a140420bd40134 (diff)
arm64: KVM: pmu: Fix AArch32 cycle counter access
We're missing the handling code for the cycle counter accessed from a 32bit guest, leading to unexpected results. Cc: stable@vger.kernel.org # 4.6+ Signed-off-by: Wei Huang <wei@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
-rw-r--r--arch/arm64/kvm/sys_regs.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index f302fdb3a030..87e7e6608cd8 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -597,8 +597,14 @@ 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))
@@ -606,7 +612,7 @@ 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))