[PATCH 27/28] KVM: arm64: Expose FEAT_NV3 to guests

[Joey Gouly]

On Thu, Jul 02, 2026 at 05:02:47PM +0100, Marc Zyngier wrote:
> Further enable FEAT_NV3 by making it visible to NV guests.
> 
> Signed-off-by: Marc Zyngier <maz at kernel.org>

Reviewed-by: Joey Gouly <joey.gouly at arm.com>

> ---
>  arch/arm64/kvm/nested.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c
> index c9bf04944f9cb..64c8fb82fadf6 100644
> --- a/arch/arm64/kvm/nested.c
> +++ b/arch/arm64/kvm/nested.c
> @@ -1728,7 +1728,7 @@ u64 limit_nv_id_reg(struct kvm *kvm, u32 reg, u64 val)
>  		 * You get EITHER
>  		 *
>  		 * - FEAT_VHE without FEAT_E2H0
> -		 * - FEAT_NV limited to FEAT_NV2(p1)
> +		 * - FEAT_NV limited to FEAT_NV2(p1)/NV3
>  		 * - HCR_EL2.NV1 being RES0
>  		 *
>  		 * OR
> @@ -1740,7 +1740,9 @@ u64 limit_nv_id_reg(struct kvm *kvm, u32 reg, u64 val)
>  		if (test_bit(KVM_ARM_VCPU_HAS_EL2_E2H0, kvm->arch.vcpu_features)) {
>  			val = 0;
>  		} else {
> -			if (cpus_have_final_cap(ARM64_HAS_NV2P1))
> +			if (cpus_have_final_cap(ARM64_HAS_NV3))
> +				val = ID_REG_LIMIT_FIELD_ENUM(val, ID_AA64MMFR4_EL1, NV_frac, NV3);
> +			else if (cpus_have_final_cap(ARM64_HAS_NV2P1))
>  				val = ID_REG_LIMIT_FIELD_ENUM(val, ID_AA64MMFR4_EL1, NV_frac, NV2P1);
>  			else
>  				val = SYS_FIELD_PREP_ENUM(ID_AA64MMFR4_EL1, NV_frac, NV2_ONLY);
> -- 
> 2.47.3
>