Re: [PATCH kvm-unit-tests v1 2/6] s390x: smp: Test SIGP RESTART against stopped CPU

Eric Farman
2022-03-04T14:20:36Z

On Fri, 2022-03-04 at 11:43 +0100, Janosch Frank wrote:
> On 3/3/22 22:04, Eric Farman wrote:
> > test_restart() makes two smp_cpu_restart() calls against CPU 1.
> > It claims to perform both of them against running (operating) CPUs,
> > but the first invocation tries to achieve this by calling
> > smp_cpu_stop() to CPU 0. This will be rejected by the library.
>
> I played myself there :)

:)

>
> > Let's fix this by making the first restart operate on a stopped
> > CPU,
> > to ensure it gets test coverage instead of relying on other
> > callers.
> >
> > Fixes: 166da884d ("s390x: smp: Add restart when running test")
> > Signed-off-by: Eric Farman <farman@linux.ibm.com>
>
> If you want to you can add a report_pass() after the first wait flag.

I did in patch 5. I can move that here, but that patch has some
additional prefix changes for those reports, so didn't want to move TOO
much of that to this fix.

>
> Reviewed-by: Janosch Frank <frankja@linux.ibm.com>

Thank you!

>
> > ---
> > s390x/smp.c | 8 ++------
> > 1 file changed, 2 insertions(+), 6 deletions(-)
> >
> > diff --git a/s390x/smp.c b/s390x/smp.c
> > index 068ac74d..2f4af820 100644
> > --- a/s390x/smp.c
> > +++ b/s390x/smp.c
> > @@ -50,10 +50,6 @@ static void test_start(void)
> > report_pass("start");
> > }
> >
> > -/*
> > - * Does only test restart when the target is running.
> > - * The other tests do restarts when stopped multiple times
> > already.
> > - */
> > static void test_restart(void)
> > {
> > struct cpu *cpu = smp_cpu_from_idx(1);
> > @@ -62,8 +58,8 @@ static void test_restart(void)
> > lc->restart_new_psw.mask = extract_psw_mask();
> > lc->restart_new_psw.addr = (unsigned long)test_func;
> >
> > - /* Make sure cpu is running */
> > - smp_cpu_stop(0);
> > + /* Make sure cpu is stopped */
> > + smp_cpu_stop(1);
> > set_flag(0);
> > smp_cpu_restart(1);
> > wait_for_flag();