[PATCH v1] KVM: arm64: selftests: Handle feature fields with nonzero minimum value correctly

[Jing Zhang]

Hi Zenghui,

On Sun, Jan 14, 2024 at 11:41 PM Zenghui Yu <yuzenghui at huawei.com> wrote:
>
> Hi Jing,
>
> On 2024/1/10 0:56, Jing Zhang wrote:
> > There are some feature fields with nonzero minimum valid value. Make
> > sure get_safe_value() won't return invalid field values for them.
> > Also fix a bug that wrongly uses the feature bits type as the feature
> > bits sign causing all fields as signed in the get_safe_value() and
> > get_invalid_value().
> >
> > Fixes: 54a9ea73527d ("KVM: arm64: selftests: Test for setting ID register from usersapce")
> > Reported-by: Zenghui Yu <yuzenghui at huawei.com>
> > Reported-by: Itaru Kitayama <itaru.kitayama at linux.dev>
> > Signed-off-by: Jing Zhang <jingzhangos at google.com>
> > ---
> >  .../selftests/kvm/aarch64/set_id_regs.c       | 20 +++++++++++++++----
> >  1 file changed, 16 insertions(+), 4 deletions(-)
> >
> > diff --git a/tools/testing/selftests/kvm/aarch64/set_id_regs.c b/tools/testing/selftests/kvm/aarch64/set_id_regs.c
> > index bac05210b539..f17454dc6d9e 100644
> > --- a/tools/testing/selftests/kvm/aarch64/set_id_regs.c
> > +++ b/tools/testing/selftests/kvm/aarch64/set_id_regs.c
> > @@ -224,13 +224,20 @@ uint64_t get_safe_value(const struct reg_ftr_bits *ftr_bits, uint64_t ftr)
> >  {
> >       uint64_t ftr_max = GENMASK_ULL(ARM64_FEATURE_FIELD_BITS - 1, 0);
> >
> > -     if (ftr_bits->type == FTR_UNSIGNED) {
> > +     if (ftr_bits->sign == FTR_UNSIGNED) {
> >               switch (ftr_bits->type) {
> >               case FTR_EXACT:
> >                       ftr = ftr_bits->safe_val;
> >                       break;
> >               case FTR_LOWER_SAFE:
> > -                     if (ftr > 0)
> > +                     uint64_t min_safe = 0;
> > +
> > +                     if (!strcmp(ftr_bits->name, "ID_AA64DFR0_EL1_DebugVer"))
> > +                             min_safe = ID_AA64DFR0_EL1_DebugVer_IMP;
> > +                     else if (!strcmp(ftr_bits->name, "ID_DFR0_EL1_CopDbg"))
> > +                             min_safe = ID_DFR0_EL1_CopDbg_Armv8;
> > +
> > +                     if (ftr > min_safe)
>
> As I mentioned in my previous reply, there is a compilation error with
> gcc-10.3.1.
>
> | aarch64/set_id_regs.c: In function 'get_safe_value':
> | aarch64/set_id_regs.c:233:4: error: a label can only be part of a
> statement and a declaration is not a statement
> |   233 |    uint64_t min_safe = 0;
> |       |    ^~~~~~~~
> | aarch64/set_id_regs.c:262:4: error: a label can only be part of a
> statement and a declaration is not a statement
> |   262 |    uint64_t min_safe = 0;
> |       |    ^~~~~~~~
>
> Please fix it.

Will fix it.
>
> Zenghui

Thanks,
Jing