[PATCH v4 19/43] KVM: arm64: Restrict ACCDATA_EL1 undef to FEAT_LS64_ACCDATA being disabled

Marc Zyngier maz at kernel.org
Tue May 6 09:43:24 PDT 2025


We currently unconditionally make ACCDATA_EL1 accesses UNDEF.

As we are about to support it, restrict the UNDEF behaviour to cases
where FEAT_LS64_ACCDATA is not exposed to the guest.

Signed-off-by: Marc Zyngier <maz at kernel.org>
---
 arch/arm64/kvm/sys_regs.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 6e01b06bedcae..ce347ddb6fae0 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -5150,10 +5150,12 @@ void kvm_calculate_traps(struct kvm_vcpu *vcpu)
 	kvm->arch.fgu[HFGRTR_GROUP] = (HFGRTR_EL2_nAMAIR2_EL1		|
 				       HFGRTR_EL2_nMAIR2_EL1		|
 				       HFGRTR_EL2_nS2POR_EL1		|
-				       HFGRTR_EL2_nACCDATA_EL1		|
 				       HFGRTR_EL2_nSMPRI_EL1_MASK	|
 				       HFGRTR_EL2_nTPIDR2_EL0_MASK);
 
+	if (!kvm_has_feat(kvm, ID_AA64ISAR1_EL1, LS64, LS64_ACCDATA))
+		kvm->arch.fgu[HFGRTR_GROUP] |= HFGRTR_EL2_nACCDATA_EL1;
+
 	if (!kvm_has_feat(kvm, ID_AA64ISAR0_EL1, TLB, OS))
 		kvm->arch.fgu[HFGITR_GROUP] |= (HFGITR_EL2_TLBIRVAALE1OS|
 						HFGITR_EL2_TLBIRVALE1OS	|
-- 
2.39.2




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