We always expose the HW view of PMU in ID_AA64FDR0_EL1.PMUver,
even when the PMU feature is disabled, while the architecture
says that FEAT_PMUv3 not being implemented should result in this
field being zero.
Let's follow the architecture's guidance.
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
---
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 d2e1d745f067..6629cfde2838 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1070,10 +1070,15 @@ static u64 read_id_reg(const struct kvm_vcpu *vcpu,
(0xfUL << ID_AA64ISAR1_GPA_SHIFT) |
(0xfUL << ID_AA64ISAR1_GPI_SHIFT));
} else if (id == SYS_ID_AA64DFR0_EL1) {
+ u64 cap = 0;
+
/* Limit guests to PMUv3 for ARMv8.1 */
+ if (kvm_vcpu_has_pmu(vcpu))
+ cap = ID_AA64DFR0_PMUVER_8_1;
+
val = cpuid_feature_cap_perfmon_field(val,
ID_AA64DFR0_PMUVER_SHIFT,
- ID_AA64DFR0_PMUVER_8_1);
+ cap);
} else if (id == SYS_ID_DFR0_EL1) {
/* Limit guests to PMUv3 for ARMv8.1 */
val = cpuid_feature_cap_perfmon_field(val,
--
2.28.0
