Re: [kvm-unit-tests PATCH v4 3/4] s390x: topology: Check the Perform Topology Function

Nico Boehr
2022-02-09T12:03:36Z

On Tue, 2022-02-08 at 14:27 +0100, Pierre Morel wrote:
> We check the PTF instruction.

You could test some very basic things as well:

- you get a privileged pgm int in problem state,
- reserved bits in first operand cause specification pgm int,
- reserved FC values result in a specification pgm int,
- second operand is ignored.

>
> - We do not expect to support vertical polarization.
>
> - We do not expect the Modified Topology Change Report to be
[...]

Forgive me if I'm missing something, but why _Modified_ Topology Change
Report?

> diff --git a/s390x/topology.c b/s390x/topology.c
> new file mode 100644
> index 00000000..a1f9ce51
> --- /dev/null
> +++ b/s390x/topology.c

[...]

> +static int ptf(unsigned long fc, unsigned long *rc)
> +{
> +       int cc;
> +
> +       asm volatile(
> +               "       .insn   rre,0xb9a20000,%1,0\n"
> +               "       ipm     %0\n"
> +               "       srl     %0,28\n"
> +               : "=d" (cc), "+d" (fc)
> +               : "d" (fc)

Why list fc here again?