From: Cornelia Huck <cohuck@redhat.com>
To: Pierre Morel <pmorel@linux.ibm.com>
Cc: kvm@vger.kernel.org, linux-s390@vger.kernel.org,
frankja@linux.ibm.com, david@redhat.com, thuth@redhat.com
Subject: Re: [kvm-unit-tests PATCH v3 7/9] s390x: css: msch, enable test
Date: Tue, 10 Dec 2019 10:09:50 +0100 [thread overview]
Message-ID: <20191210100950.466e6211.cohuck@redhat.com> (raw)
In-Reply-To: <a19d7e91-4048-3eaa-a819-51e95dd922de@linux.ibm.com>
On Tue, 10 Dec 2019 10:01:46 +0100
Pierre Morel <pmorel@linux.ibm.com> wrote:
> On 2019-12-09 17:54, Cornelia Huck wrote:
> > On Fri, 6 Dec 2019 17:26:26 +0100
> > Pierre Morel <pmorel@linux.ibm.com> wrote:
> >
> >> A second step when testing the channel subsystem is to prepare a channel
> >> for use.
> >> This includes:
> >> - Get the current SubCHannel Information Block (SCHIB) using STSCH
> >> - Update it in memory to set the ENABLE bit
> >> - Tell the CSS that the SCHIB has been modified using MSCH
> >> - Get the SCHIB from the CSS again to verify that the subchannel is
> >> enabled.
> >>
> >> This tests the success of the MSCH instruction by enabling a channel.
> >>
> >> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
> >> ---
> >> s390x/css.c | 39 +++++++++++++++++++++++++++++++++++++++
> >> 1 file changed, 39 insertions(+)
> >>
> >> diff --git a/s390x/css.c b/s390x/css.c
> >> index 3d4a986..4c0031c 100644
> >> --- a/s390x/css.c
> >> +++ b/s390x/css.c
> >> @@ -58,11 +58,50 @@ static void test_enumerate(void)
> >> report("Tested %d devices, %d found", 1, scn, found);
> >> }
> >>
> >> +static void test_enable(void)
> >> +{
> >> + struct pmcw *pmcw = &schib.pmcw;
> >> + int cc;
> >> +
> >> + if (!test_device_sid) {
> >> + report_skip("No device");
> >> + return;
> >> + }
> >> + /* Read the SCIB for this subchannel */
> >
> > s/SCIB/SCHIB/
>
> yes
>
> >
> >> + cc = stsch(test_device_sid, &schib);
> >> + if (cc) {
> >> + report("stsch cc=%d", 0, cc);
> >> + return;
> >> + }
> >> + /* Update the SCHIB to enable the channel */
> >> + pmcw->flags |= PMCW_ENABLE;
> >> +
> >> + /* Tell the CSS we want to modify the subchannel */
> >> + cc = msch(test_device_sid, &schib);
> >> + if (cc) {
> >> + report("msch cc=%d", 0, cc);
> >
> > So you expect the subchannel to be idle? Probably true, especially as
> > QEMU has no reason to post an unsolicited interrupt for a test device.
> >
> >> + return;
> >> + }
> >> +
> >> + /* Read the SCHIB again to verify the enablement */
> >> + cc = stsch(test_device_sid, &schib);
> >> + if (cc) {
> >> + report("stsch cc=%d", 0, cc);
> >> + return;
> >> + }
> >> + if (!(pmcw->flags & PMCW_ENABLE)) {
> >> + report("Enable failed. pmcw: %x", 0, pmcw->flags);
> >
> > This check is fine when running under KVM. If this test is modified to
> > run under z/VM in the future, you probably should retry here: I've seen
> > the enable bit 'stick' only after the second msch() there.
>
> Oh. Thanks, may be I can loop with a delay and count.
FWIW, the Linux kernel code is trying 5 times.
> If I need to do this may be I need to create dedicated sub-functions to
> include the sanity tests.
I'm not sure how worthwhile investing time here is, actually: If you
don't plan to run under anything but KVM, you won't need it. I'm not
sure if current versions of z/VM still display the same behaviour (it
has been some time...); on the other hand, it is compliant with the
architecture...
>
> >
> >> + return;
> >> + }
> >> + report("Tested", 1);
> >> +}
> >> +
> >> static struct {
> >> const char *name;
> >> void (*func)(void);
> >> } tests[] = {
> >> { "enumerate (stsch)", test_enumerate },
> >> + { "enable (msch)", test_enable },
> >> { NULL, NULL }
> >> };
> >>
> >
>
next prev parent reply other threads:[~2019-12-10 9:10 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-06 16:26 [kvm-unit-tests PATCH v3 0/9] s390x: Testing the Channel Subsystem I/O Pierre Morel
2019-12-06 16:26 ` [kvm-unit-tests PATCH v3 1/9] s390x: saving regs for interrupts Pierre Morel
2019-12-06 16:26 ` [kvm-unit-tests PATCH v3 2/9] s390x: Define the PSW bits Pierre Morel
2019-12-06 16:29 ` Thomas Huth
2019-12-09 8:53 ` Pierre Morel
2019-12-06 16:26 ` [kvm-unit-tests PATCH v3 3/9] s390: interrupt registration Pierre Morel
2019-12-09 11:40 ` Thomas Huth
2019-12-09 16:44 ` Pierre Morel
2019-12-09 11:48 ` David Hildenbrand
2019-12-09 16:44 ` Pierre Morel
2019-12-06 16:26 ` [kvm-unit-tests PATCH v3 4/9] s390x: export the clock get_clock_ms() utility Pierre Morel
2019-12-09 11:42 ` Thomas Huth
2019-12-09 11:49 ` David Hildenbrand
2019-12-09 16:43 ` Pierre Morel
2019-12-09 16:44 ` Pierre Morel
2019-12-06 16:26 ` [kvm-unit-tests PATCH v3 5/9] s390x: Library resources for CSS tests Pierre Morel
2019-12-09 11:49 ` Thomas Huth
2019-12-09 16:43 ` Pierre Morel
2019-12-10 10:07 ` Pierre Morel
2019-12-10 10:28 ` Thomas Huth
2019-12-10 11:22 ` Pierre Morel
2019-12-10 11:27 ` Thomas Huth
2019-12-10 11:28 ` Pierre Morel
2019-12-06 16:26 ` [kvm-unit-tests PATCH v3 6/9] s390x: css: stsch, enumeration test Pierre Morel
2019-12-09 11:52 ` Thomas Huth
2019-12-09 16:42 ` Pierre Morel
2019-12-09 16:49 ` Cornelia Huck
2019-12-10 8:56 ` Pierre Morel
2019-12-10 11:37 ` Pierre Morel
2019-12-06 16:26 ` [kvm-unit-tests PATCH v3 7/9] s390x: css: msch, enable test Pierre Morel
2019-12-09 16:54 ` Cornelia Huck
2019-12-10 9:01 ` Pierre Morel
2019-12-10 9:09 ` Cornelia Huck [this message]
2019-12-10 17:35 ` Pierre Morel
2019-12-06 16:26 ` [kvm-unit-tests PATCH v3 8/9] s390x: css: ssch/tsch with sense and interrupt Pierre Morel
2019-12-09 17:22 ` Cornelia Huck
2019-12-10 9:12 ` Pierre Morel
2019-12-06 16:26 ` [kvm-unit-tests PATCH v3 9/9] s390x: css: ping pong Pierre Morel
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