Re: [PATCH v15 16/17] hvf: arm: disable SME when nested virt is active

[Peter Maydell]

On Fri, 6 Mar 2026 at 13:02, Mohamed Mediouni <moha...@unpredictable.fr> wrote:
>
> Currently, Apple doesn't support the nested virtualisation + SME combination.
>
> Signed-off-by: Mohamed Mediouni <moha...@unpredictable.fr>
> ---
>  target/arm/hvf/hvf.c | 3 +++
>  target/arm/hvf_arm.h | 5 +++++
>  2 files changed, 8 insertions(+)
>
> diff --git a/target/arm/hvf/hvf.c b/target/arm/hvf/hvf.c
> index 0183dd8a60..61ba5acce4 100644
> --- a/target/arm/hvf/hvf.c
> +++ b/target/arm/hvf/hvf.c
> @@ -1181,6 +1181,9 @@ static bool 
> hvf_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf)
>
>      if (hvf_nested_virt_enabled()) {
>          FIELD_DP64_IDREG(&host_isar, ID_AA64DFR0, PMUVER, 0x1);
> +        /* SME is not implemented with nested virt on the Apple side */
> +        SET_IDREG(&host_isar, ID_AA64PFR1,
> +              GET_IDREG(&host_isar, ID_AA64PFR1) & ~R_ID_AA64PFR1_SME_MASK);

This is
  FIELD_DP64_IDREG(&host_isar, ID_AA64PFR1, SME, 0);

isn't it?


thanks
-- PMM