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 v2 6/9] s390x: css: stsch, enumeration test
Date: Mon, 2 Dec 2019 20:49:22 +0100 [thread overview]
Message-ID: <20191202204922.508d389f.cohuck@redhat.com> (raw)
In-Reply-To: <bb189d95-ddfc-7031-d0dd-7de3e0dd5a7f@linux.ibm.com>
On Mon, 2 Dec 2019 19:33:59 +0100
Pierre Morel <pmorel@linux.ibm.com> wrote:
> On 2019-12-02 19:15, Cornelia Huck wrote:
> > On Mon, 2 Dec 2019 18:53:16 +0100
> > Pierre Morel <pmorel@linux.ibm.com> wrote:
> >
> >> On 2019-12-02 15:22, Cornelia Huck wrote:
> >>> On Thu, 28 Nov 2019 13:46:04 +0100
> >>> Pierre Morel <pmorel@linux.ibm.com> wrote:
> >
> >>>> +static int test_device_sid;
> >>>> +
> >>>> +static void test_enumerate(void)
> >>>> +{
> >>>> + struct pmcw *pmcw = &schib.pmcw;
> >>>> + int sid;
> >>>> + int ret, i;
> >>>> + int found = 0;
> >>>> +
> >>>> + for (sid = 0; sid < 0xffff; sid++) {
> >>>> + ret = stsch(sid|SID_ONE, &schib);
> >>>
> >>> This seems a bit odd. You are basically putting the subchannel number
> >>> into sid, OR in the one, and then use the resulting value as the sid
> >>> (subchannel identifier).
> >>>
> >>>> + if (!ret && (pmcw->flags & PMCW_DNV)) {
> >>>> + report_info("SID %04x Type %s PIM %x", sid,
> >>>
> >>> That's not a sid, but the subchannel number (see above).
> >>>
> >>>> + Channel_type[pmcw->st], pmcw->pim);
> >>>> + for (i = 0; i < 8; i++) {
> >>>> + if ((pmcw->pim << i) & 0x80) {
> >>>> + report_info("CHPID[%d]: %02x", i,
> >>>> + pmcw->chpid[i]);
> >>>> + break;
> >>>> + }
> >>>> + }
> >>>> + found++;
> >>>> +
> >>>> + }
> >>>
> >>> Here, you iterate over the 0-0xffff range, even if you got a condition
> >>> code 3 (indicating no more subchannels in that set). Is that
> >>> intentional?
> >>
> >> I thought there could be more subchannels.
> >> I need then a break in the loop when this happens.
> >> I will reread the PoP to see how to find that no more subchannel are in
> >> that set.
> >
> > The fact that cc 3 for stsch == no more subchannels is unfortunately a
> > bit scattered across the PoP :/ Dug it out some time ago, maybe it's
> > still in the archives somewhere...
>
> So the the subchannel are always one after the other?
While QEMU (and z/VM) usually do that, they can really be scattered
around. For the in-between I/O subchannels that don't lead to a device,
you'll still get cc 0, it's just the dnv bit that is 0. The cc 3
basically just tells you that you can stop looking.
next prev parent reply other threads:[~2019-12-02 19:49 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-28 12:45 [kvm-unit-tests PATCH v2 0/9] s390x: Testing the Channel Subsystem I/O Pierre Morel
2019-11-28 12:45 ` [kvm-unit-tests PATCH v2 1/9] s390x: saving regs for interrupts Pierre Morel
2019-11-28 12:46 ` [kvm-unit-tests PATCH v2 2/9] s390x: Define the PSW bits Pierre Morel
2019-11-28 14:36 ` David Hildenbrand
2019-11-28 19:16 ` Pierre Morel
2019-11-28 19:48 ` David Hildenbrand
2019-11-29 13:04 ` Pierre Morel
2019-12-02 11:11 ` Janosch Frank
2019-12-02 11:17 ` David Hildenbrand
2019-12-02 16:52 ` Pierre Morel
2019-11-28 12:46 ` [kvm-unit-tests PATCH v2 3/9] s390x: irq: make IRQ handler weak Pierre Morel
2019-11-29 12:01 ` David Hildenbrand
2019-12-02 10:41 ` Thomas Huth
2019-12-02 16:55 ` Pierre Morel
2019-11-28 12:46 ` [kvm-unit-tests PATCH v2 4/9] s390x: export the clock get_clock_ms() utility Pierre Morel
2019-11-29 12:03 ` David Hildenbrand
2019-11-29 13:04 ` Pierre Morel
2019-12-02 11:13 ` Janosch Frank
2019-12-02 17:03 ` Pierre Morel
2019-11-28 12:46 ` [kvm-unit-tests PATCH v2 5/9] s390x: Library resources for CSS tests Pierre Morel
2019-12-02 14:06 ` Cornelia Huck
2019-12-02 17:33 ` Pierre Morel
2019-11-28 12:46 ` [kvm-unit-tests PATCH v2 6/9] s390x: css: stsch, enumeration test Pierre Morel
2019-12-02 14:22 ` Cornelia Huck
2019-12-02 17:53 ` Pierre Morel
2019-12-02 18:15 ` Cornelia Huck
2019-12-02 18:33 ` Pierre Morel
2019-12-02 19:49 ` Cornelia Huck [this message]
2019-12-03 8:43 ` Pierre Morel
2019-11-28 12:46 ` [kvm-unit-tests PATCH v2 7/9] s390x: css: msch, enable test Pierre Morel
2019-12-02 14:30 ` Cornelia Huck
2019-12-02 17:55 ` Pierre Morel
2019-11-28 12:46 ` [kvm-unit-tests PATCH v2 8/9] s390x: css: ssch/tsch with sense and interrupt Pierre Morel
2019-12-02 14:55 ` Cornelia Huck
2019-12-02 18:18 ` Pierre Morel
2019-12-02 19:54 ` Cornelia Huck
2019-12-03 8:58 ` Pierre Morel
2019-11-28 12:46 ` [kvm-unit-tests PATCH v2 9/9] s390x: css: ping pong Pierre Morel
2019-12-02 15:03 ` Cornelia Huck
2019-12-02 18:25 ` Pierre Morel
2019-12-06 14:18 ` Pierre Morel
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