Re: [kvm-unit-tests PATCH v3 6/9] s390x: css: stsch, enumeration test

Pierre Morel
2019-12-10T08:56:42Z

On 2019-12-09 17:49, Cornelia Huck wrote:
> On Fri, 6 Dec 2019 17:26:25 +0100
> Pierre Morel <pmorel@linux.ibm.com> wrote:
>
>> First step for testing the channel subsystem is to enumerate the css and
>> retrieve the css devices.
>>
>> This tests the success of STSCH I/O instruction.
>>
>> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
>> ---
>> lib/s390x/css.h | 1 +
>> s390x/Makefile | 2 ++
>> s390x/css.c | 82 +++++++++++++++++++++++++++++++++++++++++++++
>> s390x/unittests.cfg | 4 +++
>> 4 files changed, 89 insertions(+)
>> create mode 100644 s390x/css.c
>>
>
>> +static void test_enumerate(void)
>> +{
>> + struct pmcw *pmcw = &schib.pmcw;
>> + int scn;
>> + int cc, i;
>> + int found = 0;
>> +
>> + for (scn = 0; scn < 0xffff; scn++) {
>> + cc = stsch(scn|SID_ONE, &schib);
>> + if (!cc && (pmcw->flags & PMCW_DNV)) {
>
> Not sure when dnv is actually applicable... it is used for I/O
> subchannels; chsc subchannels don't have a device; message subchannels
> use a different bit IIRC; not sure about EADM subchannels.
>
> [Not very relevant as long as we run under KVM, but should be
> considered if you plan to run this test under z/VM or LPAR as well.]

Hum, interresting, I will check and modify accordingly.

>
>> + report_info("SID %04x Type %s PIM %x", scn,
>> + Channel_type[PMCW_CHANNEL_TYPE(pmcw)],
>> + pmcw->pim);
>> + for (i = 0; i < 8; i++) {
>> + if ((pmcw->pim << i) & 0x80) {
>> + report_info("CHPID[%d]: %02x", i,
>> + pmcw->chpid[i]);
>> + break;
>
> That 'break;' seems odd -- won't you end up printing the first chpid in
> the pim only?
yes
>
> Maybe modify this loop to print the chpid if the path is in the pim,
> and 'n/a' or so if not?

OK

>
>> + }
>> + }
>> + found++;
>> + }
>> + if (cc == 3) /* cc = 3 means no more channel in CSS */
>
> s/channel/subchannels/

thanks

>
>> + break;
>> + if (found && !test_device_sid)
>> + test_device_sid = scn|SID_ONE;
>> + }
>> + if (!found) {
>> + report("Tested %d devices, none found", 0, scn);
>> + return;
>> + }
>> + report("Tested %d devices, %d found", 1, scn, found);
>> +}
>

Thanks for the reviewing,
Regards,

Pierre

--
Pierre Morel
IBM Lab Boeblingen