[PATCH v3 5/6] KVM: arm64: Make ID_AA64PFR1_EL1.RAS_frac writable

[Cornelia Huck]

On Sun, Aug 17 2025, Marc Zyngier <maz at kernel.org> wrote:

> Allow userspace to write to RAS_frac, under the condition that
> the host supports RASv1p1 with RAS_frac==1. Other configurations
> will result in RAS_frac being exposed as 0, and therefore implicitly
> not writable.
>
> To avoid the clutter, the ID_AA64PFR1_EL1 sanitisation is moved to
> its own function.
>
> Signed-off-by: Marc Zyngier <maz at kernel.org>
> ---
>  arch/arm64/kvm/nested.c   |  3 ++-
>  arch/arm64/kvm/sys_regs.c | 41 ++++++++++++++++++++++++++-------------
>  2 files changed, 29 insertions(+), 15 deletions(-)

Reviewed-by: Cornelia Huck <cohuck at redhat.com>