arm64: KVM: PMU: Inject UNDEF on read access to PMSWINC_EL0
PMSWINC_EL0 is a WO register, so let's UNDEF when reading from it
(in the highly hypothetical case where this doesn't UNDEF at EL1).
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 20f90c0..3fef01d 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -772,16 +772,15 @@
if (!kvm_arm_pmu_v3_ready(vcpu))
return trap_raz_wi(vcpu, p, r);
+ if (!p->is_write)
+ return read_from_write_only(vcpu, p);
+
if (pmu_write_swinc_el0_disabled(vcpu))
return false;
- if (p->is_write) {
- mask = kvm_pmu_valid_counter_mask(vcpu);
- kvm_pmu_software_increment(vcpu, p->regval & mask);
- return true;
- }
-
- return false;
+ mask = kvm_pmu_valid_counter_mask(vcpu);
+ kvm_pmu_software_increment(vcpu, p->regval & mask);
+ return true;
}
static bool access_pmuserenr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,