[PULL 28/79] arm64: KVM: PMU: Inject UNDEF exception on illegal register access

Christoffer Dall cdall at linaro.org
Sun Apr 23 10:08:38 PDT 2017


From: Marc Zyngier <marc.zyngier at arm.com>

Both pmu_*_el0_disabled() and pmu_counter_idx_valid() perform checks
on the validity of an access, but only return a boolean indicating
if the access is valid or not.

Let's allow these functions to also inject an UNDEF exception if
the access was illegal.

Reviewed-by: Christoffer Dall <cdall at linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
---
 arch/arm64/kvm/sys_regs.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 036efc97..750c129 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -465,6 +465,9 @@ static bool check_pmu_access_disabled(struct kvm_vcpu *vcpu, u64 flags)
 	u64 reg = vcpu_sys_reg(vcpu, PMUSERENR_EL0);
 	bool enabled = (reg & flags) || vcpu_mode_priv(vcpu);
 
+	if (!enabled)
+		kvm_inject_undefined(vcpu);
+
 	return !enabled;
 }
 
@@ -564,8 +567,10 @@ static bool pmu_counter_idx_valid(struct kvm_vcpu *vcpu, u64 idx)
 
 	pmcr = vcpu_sys_reg(vcpu, PMCR_EL0);
 	val = (pmcr >> ARMV8_PMU_PMCR_N_SHIFT) & ARMV8_PMU_PMCR_N_MASK;
-	if (idx >= val && idx != ARMV8_PMU_CYCLE_IDX)
+	if (idx >= val && idx != ARMV8_PMU_CYCLE_IDX) {
+		kvm_inject_undefined(vcpu);
 		return false;
+	}
 
 	return true;
 }
-- 
2.9.0




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