[PATCH 13/20] KVM: arm64: Move RESx into individual register descriptors

[Fuad Tabba]

>
> Actually, this interacts badly with check_feat_map(), which tries to
> find whether we have fully populated the registers, excluding the RESx
> bits. But since we consider E2H to be a reserved but, we end-up with:
>
> [    0.141317] kvm [1]: Undefined HCR_EL2 behaviour, bits 0000000400000000
>
> With my approach, it was possible to distinguish the architecturally
> RESx bits (defined as RES0 or RES1), as they were the only ones with
> the FORCE_RESx attribute.
>
> I can work around it with
>
> diff --git a/arch/arm64/kvm/config.c b/arch/arm64/kvm/config.c
> index 364bdd1e5be51..398458f4a6b7b 100644
> --- a/arch/arm64/kvm/config.c
> +++ b/arch/arm64/kvm/config.c
> @@ -1283,7 +1283,7 @@ static void __init check_feat_map(const struct reg_bits_to_feat_map *map,
>         u64 mask = 0;
>
>         for (int i = 0; i < map_size; i++)
> -               if (!(map[i].flags & FORCE_RESx))
> +               if (!(map[i].flags & FORCE_RESx) || !(map[i].bits & resx))
>                         mask |= map[i].bits;
>
>         if (mask != ~resx)
>
> but it becomes a bit awkward...

If it becomes more complicated than the original, then what's the
point. Up to you whether you want to try to pursue this or not. From
my part:

Reviewed-by: Fuad Tabba <tabba at google.com>

Thanks,
/fuad




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