[PATCH v2 0/3] KVM: arm64: make EL2 feature fields writable in ID_AA64MMFR1_EL1

[Oliver Upton]

On Tue, Sep 09, 2025 at 11:44:12AM +0800, Jinqian Yang wrote:
> Allow userspace to downgrade EL2 features (VH, TWED, HCX) to ensure VM live
> migration compatibility between hosts with varying feature support.
> 
> v1: https://lore.kernel.org/linux-arm-kernel/20250325121126.1380681-1-yangjinqian1@huawei.com/
> 
> Change Log:
> v1->v2:
>   -Added support for downgrading TWED and VH fields.
>   -Added corresponding test cases to the set_id_regs selftest.
> 
> Jinqian Yang (3):
>   KVM: arm64: Make ID_AA64MMFR1_EL1.HCX writable from userspace
>   KVM: arm64: Make ID_AA64MMFR1_EL1.TWED writable from userspace
>   KVM: arm64: Make ID_AA64MMFR1_EL1.VH writable from userspace
> 
>  arch/arm64/kvm/sys_regs.c                       | 3 ---
>  tools/testing/selftests/kvm/arm64/set_id_regs.c | 3 +++

General comment: please make do kernel and selftest changes in separate
patches.

Thanks,
Oliver