[PATCH v2 02/14] KVM: arm64: Hide ID_AA64MMFR2_EL1.NV from guest and userspace

Marc Zyngier maz at kernel.org
Thu Feb 20 05:48:55 PST 2025


Since our take on FEAT_NV is to only support FEAT_NV2, we should
never expose ID_AA64MMFR2_EL1.NV to a guest nor userspace.

Make sure we mask this field for good.

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

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 82430c1e1dd02..9f10dbd26e348 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1627,6 +1627,7 @@ static u64 __kvm_read_sanitised_id_reg(const struct kvm_vcpu *vcpu,
 		break;
 	case SYS_ID_AA64MMFR2_EL1:
 		val &= ~ID_AA64MMFR2_EL1_CCIDX_MASK;
+		val &= ~ID_AA64MMFR2_EL1_NV;
 		break;
 	case SYS_ID_AA64MMFR3_EL1:
 		val &= ID_AA64MMFR3_EL1_TCRX | ID_AA64MMFR3_EL1_S1POE |
-- 
2.39.2




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