Re: [PATCH v5 03/41] KVM: arm64: Make MPAMSM_EL1 accesses UNDEF

Marc Zyngier
2026-03-02T17:54:04Z

On Tue, 24 Feb 2026 17:56:42 +0000,
Ben Horgan <ben.horgan@arm.com> wrote:
>
> The MPAMSM_EL1 controls the MPAM labeling for an SMCU, Streaming Mode

nit: The MPAMSM_EL1 *register* controls...

> Compute Unit. As there is on MPAM support in kvm, make sure MPAMSM_EL1

s/on/no/, s/kvm/KVM/.

> accesses trigger an UNDEF.
>
> Tested-by: Gavin Shan <gshan@redhat.com>
> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
> Tested-by: Peter Newman <peternewman@google.com>
> Tested-by: Zeng Heng <zengheng4@huawei.com>
> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
> Reviewed-by: Gavin Shan <gshan@redhat.com>
> Signed-off-by: Ben Horgan <ben.horgan@arm.com>
> ---
> Changes since v2:
> Remove paragraph from commit on allowed range of values
> ---
> arch/arm64/kvm/sys_regs.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
> index a7cd0badc20c..2c9a52e66fe0 100644
> --- a/arch/arm64/kvm/sys_regs.c
> +++ b/arch/arm64/kvm/sys_regs.c
> @@ -3373,6 +3373,8 @@ static const struct sys_reg_desc sys_reg_descs[] = {
>
> { SYS_DESC(SYS_MPAM1_EL1), undef_access },
> { SYS_DESC(SYS_MPAM0_EL1), undef_access },
> + { SYS_DESC(SYS_MPAMSM_EL1), undef_access },
> +
> { SYS_DESC(SYS_VBAR_EL1), access_rw, reset_val, VBAR_EL1, 0 },
> { SYS_DESC(SYS_DISR_EL1), NULL, reset_val, DISR_EL1, 0 },
>

Acked-by: Marc Zyngier <maz@kernel.org>

M.

--
Without deviation from the norm, progress is not possible.