From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:47182 "EHLO mx0b-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725848AbfLCIoJ (ORCPT ); Tue, 3 Dec 2019 03:44:09 -0500 Received: from pps.filterd (m0127361.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id xB38bQU0059651 for ; Tue, 3 Dec 2019 03:44:07 -0500 Received: from e06smtp07.uk.ibm.com (e06smtp07.uk.ibm.com [195.75.94.103]) by mx0a-001b2d01.pphosted.com with ESMTP id 2wkm47k8xp-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 03 Dec 2019 03:44:05 -0500 Received: from localhost by e06smtp07.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 3 Dec 2019 08:43:59 -0000 Subject: Re: [kvm-unit-tests PATCH v2 6/9] s390x: css: stsch, enumeration test References: <1574945167-29677-1-git-send-email-pmorel@linux.ibm.com> <1574945167-29677-7-git-send-email-pmorel@linux.ibm.com> <20191202152246.4d627b0e.cohuck@redhat.com> <20191202191541.1ffd987e.cohuck@redhat.com> <20191202204922.508d389f.cohuck@redhat.com> From: Pierre Morel Date: Tue, 3 Dec 2019 09:43:55 +0100 MIME-Version: 1.0 In-Reply-To: <20191202204922.508d389f.cohuck@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Message-Id: <6bc09e13-69f9-78de-9ee1-94f65798f747@linux.ibm.com> Sender: linux-s390-owner@vger.kernel.org List-ID: To: Cornelia Huck Cc: kvm@vger.kernel.org, linux-s390@vger.kernel.org, frankja@linux.ibm.com, david@redhat.com, thuth@redhat.com On 2019-12-02 20:49, Cornelia Huck wrote: > On Mon, 2 Dec 2019 19:33:59 +0100 > Pierre Morel wrote: > >> On 2019-12-02 19:15, Cornelia Huck wrote: >>> On Mon, 2 Dec 2019 18:53:16 +0100 >>> Pierre Morel wrote: >>> >>>> On 2019-12-02 15:22, Cornelia Huck wrote: >>>>> On Thu, 28 Nov 2019 13:46:04 +0100 >>>>> Pierre Morel 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. > Thanks for the explanation, I will change the code accordingly. Regards, Pierre -- Pierre Morel IBM Lab Boeblingen