arm64: KVM: PMU: Inject UNDEF exception on illegal register access

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@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 036efc9..750c129 100644 (file)
--- 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;
 }