[PATCH 23/25] KVM: arm64: Make AMU sysreg UNDEF if FEAT_AMU is not advertised to the guest

[Marc Zyngier]

No AMU? No AMU! IF we see an AMU-related trap, let's turn it into
an UNDEF!

Signed-off-by: Marc Zyngier <maz at kernel.org>
---
 arch/arm64/kvm/sys_regs.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index bcde43b81755..afe6975fcf5c 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -3994,6 +3994,10 @@ void kvm_init_sysreg(struct kvm_vcpu *vcpu)
 		kvm->arch.fgu[HFGxTR_GROUP] |= (HFGxTR_EL2_nPIRE0_EL1 |
 						HFGxTR_EL2_nPIR_EL1);
 
+	if (!kvm_has_feat(kvm, ID_AA64PFR0_EL1, AMU, IMP))
+		kvm->arch.fgu[HAFGRTR_GROUP] |= ~(HAFGRTR_EL2_RES0 |
+						  HAFGRTR_EL2_RES1);
+
 	set_bit(KVM_ARCH_FLAG_FGU_INITIALIZED, &kvm->arch.flags);
 out:
 	mutex_unlock(&kvm->arch.config_lock);
-- 
2.39.2