On Mon, 28 Oct 2024 20:24:17 +0000,
Mark Brown <broonie@xxxxxxxxxx> wrote:
>
> ID_AA64ISAR3_EL1 is currently marked as unallocated in KVM but does have a
> number of bitfields defined in it. Expose FPRCVT and FAMINMAX, two simple
> instruction only extensions to guests.
>
> Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
> ---
> arch/arm64/kvm/sys_regs.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
> index dad88e31f9537fe02e28b117d6a740f15572e0ba..ab348c314d7963437e1876d441169f3ef4eff095 100644
> --- a/arch/arm64/kvm/sys_regs.c
> +++ b/arch/arm64/kvm/sys_regs.c
> @@ -2409,7 +2409,8 @@ static const struct sys_reg_desc sys_reg_descs[] = {
> ID_WRITABLE(ID_AA64ISAR2_EL1, ~(ID_AA64ISAR2_EL1_RES0 |
> ID_AA64ISAR2_EL1_APA3 |
> ID_AA64ISAR2_EL1_GPA3)),
> - ID_UNALLOCATED(6,3),
> + ID_WRITABLE(ID_AA64ISAR3_EL1, (ID_AA64ISAR3_EL1_FPRCVT |
> + ID_AA64ISAR3_EL1_FAMINMAX)),
Please add the required sanitisation of the register so that we do not
get any surprise exposure of unhandled features when someone changes
ftr_id_aa64isar3[].
M.
--
Without deviation from the norm, progress is not possible.
