[PATCH 18/20] KVM: arm64: Remove all traces of HCR_EL2.MIOCNCE

[Fuad Tabba]

On Mon, 26 Jan 2026 at 12:17, Marc Zyngier <maz at kernel.org> wrote:
>
> MIOCNCE had the potential to eat your data, and also was never
> implemented by anyone. It's been retrospectively removed from
> the architecture, and we're happy to follow that lead.
>
> Signed-off-by: Marc Zyngier <maz at kernel.org>

The field HCR_EL2.MIOCNCE is deprecated and made RES0.

Reviewed-by: Fuad Tabba <tabba at google.com>

Cheers,
/fuad






> ---
>  arch/arm64/kvm/config.c | 1 -
>  arch/arm64/tools/sysreg | 3 +--
>  2 files changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/arch/arm64/kvm/config.c b/arch/arm64/kvm/config.c
> index f892098b70c0b..eebafb90bcf62 100644
> --- a/arch/arm64/kvm/config.c
> +++ b/arch/arm64/kvm/config.c
> @@ -944,7 +944,6 @@ static const struct reg_bits_to_feat_map hcr_feat_map[] = {
>                    HCR_EL2_FMO          |
>                    HCR_EL2_ID           |
>                    HCR_EL2_IMO          |
> -                  HCR_EL2_MIOCNCE      |
>                    HCR_EL2_PTW          |
>                    HCR_EL2_SWIO         |
>                    HCR_EL2_TACR         |
> diff --git a/arch/arm64/tools/sysreg b/arch/arm64/tools/sysreg
> index 650d7d477087e..724e6ad966c20 100644
> --- a/arch/arm64/tools/sysreg
> +++ b/arch/arm64/tools/sysreg
> @@ -3834,8 +3834,7 @@ Field     43      NV1
>  Field  42      NV
>  Field  41      API
>  Field  40      APK
> -Res0   39
> -Field  38      MIOCNCE
> +Res0   39:38
>  Field  37      TEA
>  Field  36      TERR
>  Field  35      TLOR
> --
> 2.47.3
>