Re: [kvm-unit-tests PATCH v1 3/3] s390x: add pgm spec interrupt loop test

[Thomas Huth <thuth@redhat.com>]

On 30/06/2022 13.30, Nico Boehr wrote:
> An invalid PSW causes a program interrupt. When an invalid PSW is
> introduced in the pgm_new_psw, an interrupt loop occurs as soon as a
> program interrupt is caused.
> 
> QEMU should detect that and panick the guest, hence add a test for it.
> 
> Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
> ---
....
> +int main(void)
> +{
> +	report_prefix_push("pgmint-loop");
> +
> +	lowcore.pgm_new_psw.addr = (uint64_t) pgm_int_handler;
> +	/* bit 12 set is invalid */
> +	lowcore.pgm_new_psw.mask = extract_psw_mask() | BIT(63 - 12);

Basically patch looks fine to me ... just an idea for an extension (but that 
could also be done later):

Looking at the is_valid_psw() function in the Linux kernel sources, there 
are a couple of additional condition that could cause a PGM interrupt loop 
... you could maybe check them here, too, e.g. by adding a "extra_params = 
-append '...'" in the unittests.cfg file to select the indiviual tests via 
argv[] ?

  Thomas