From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3036AC04AAD for ; Tue, 7 May 2019 09:10:12 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id EC315214AE for ; Tue, 7 May 2019 09:10:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EC315214AE Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([127.0.0.1]:42750 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hNw71-0000jf-7z for qemu-devel@archiver.kernel.org; Tue, 07 May 2019 05:10:11 -0400 Received: from eggs.gnu.org ([209.51.188.92]:40941) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hNw5O-0008Re-HD for qemu-devel@nongnu.org; Tue, 07 May 2019 05:08:31 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hNw5M-0005AR-MK for qemu-devel@nongnu.org; Tue, 07 May 2019 05:08:30 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:58366 helo=mx0a-001b2d01.pphosted.com) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hNw5K-00054Q-GR for qemu-devel@nongnu.org; Tue, 07 May 2019 05:08:28 -0400 Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x478wO3i047823 for ; Tue, 7 May 2019 05:08:20 -0400 Received: from e06smtp04.uk.ibm.com (e06smtp04.uk.ibm.com [195.75.94.100]) by mx0b-001b2d01.pphosted.com with ESMTP id 2sb62u32x1-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 07 May 2019 05:08:19 -0400 Received: from localhost by e06smtp04.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Tue, 7 May 2019 10:08:16 +0100 Received: from b06wcsmtp001.portsmouth.uk.ibm.com (b06wcsmtp001.portsmouth.uk.ibm.com [9.149.105.160]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x4798E1i28180542 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 7 May 2019 09:08:14 GMT Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 49C90A4676; Tue, 7 May 2019 09:08:14 +0000 (GMT) Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 0AC05A467B; Tue, 7 May 2019 09:08:14 +0000 (GMT) Received: from [9.152.222.136] (unknown [9.152.222.136]) by b06wcsmtp001.portsmouth.uk.ibm.com (Postfix) with ESMTP; Tue, 7 May 2019 09:08:13 +0000 (GMT) To: Cornelia Huck , Halil Pasic , Christian Borntraeger References: <20190507081251.24307-1-cohuck@redhat.com> From: Pierre Morel Date: Tue, 7 May 2019 11:08:13 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190507081251.24307-1-cohuck@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US X-TM-AS-GCONF: 00 x-cbid: 19050709-0016-0000-0000-000002791EB4 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19050709-0017-0000-0000-000032D5C75D Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-05-07_05:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1905070059 Content-Transfer-Encoding: quoted-printable X-MIME-Autoconverted: from 8bit to quoted-printable by mx0b-001b2d01.pphosted.com id x478wO3i047823 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [generic] X-Received-From: 148.163.158.5 Subject: Re: [Qemu-devel] [PATCH RFC v2] s390/css: handle CCW_FLAG_SKIP X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: pmorel@linux.ibm.com Cc: Eric Farman , qemu-s390x@nongnu.org, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 07/05/2019 10:12, Cornelia Huck wrote: > If a ccw has CCW_FLAG_SKIP set, and the command is of type > read, read backwards, or sense, no data should be written > to the guest for that command. >=20 > Signed-off-by: Cornelia Huck > --- >=20 > v1 -> v2: fixed checks for command type [Eric] >=20 > Still only lightly tested (it boots); I don't think I have a tool > generating channel programs with the skip flag handy. >=20 > --- > hw/s390x/css.c | 22 ++++++++++++++++++---- > include/hw/s390x/css.h | 1 + > 2 files changed, 19 insertions(+), 4 deletions(-) >=20 > diff --git a/hw/s390x/css.c b/hw/s390x/css.c > index 8fc9e35ba5d3..080ac7e5bc0b 100644 > --- a/hw/s390x/css.c > +++ b/hw/s390x/css.c > @@ -830,8 +830,12 @@ static int ccw_dstream_rw_noflags(CcwDataStream *c= ds, void *buff, int len, > if (op =3D=3D CDS_OP_A) { > goto incr; > } > - ret =3D address_space_rw(&address_space_memory, cds->cda, > - MEMTXATTRS_UNSPECIFIED, buff, len, op); > + if (!cds->do_skip) { > + ret =3D address_space_rw(&address_space_memory, cds->cda, > + MEMTXATTRS_UNSPECIFIED, buff, len, op); > + } else { > + ret =3D 0; > + } > if (ret !=3D MEMTX_OK) { > cds->flags |=3D CDS_F_STREAM_BROKEN; > return -EINVAL; > @@ -928,8 +932,13 @@ static int ccw_dstream_rw_ida(CcwDataStream *cds, = void *buff, int len, > do { > iter_len =3D MIN(len, cont_left); > if (op !=3D CDS_OP_A) { > - ret =3D address_space_rw(&address_space_memory, cds->cda, > - MEMTXATTRS_UNSPECIFIED, buff, iter_= len, op); > + if (!cds->do_skip) { > + ret =3D address_space_rw(&address_space_memory, cds->c= da, > + MEMTXATTRS_UNSPECIFIED, buff, i= ter_len, > + op); > + } else { > + ret =3D 0; > + } > if (ret !=3D MEMTX_OK) { > /* assume inaccessible address */ > ret =3D -EINVAL; /* channel program check */ > @@ -968,6 +977,11 @@ void ccw_dstream_init(CcwDataStream *cds, CCW1 con= st *ccw, ORB const *orb) > =20 > cds->count =3D ccw->count; > cds->cda_orig =3D ccw->cda; > + /* skip is only effective for read, read backwards, or sense comma= nds */ > + cds->do_skip =3D (ccw->flags & CCW_FLAG_SKIP) && > + ((ccw->cmd_code & CCW_CMD_BASIC_SENSE) =3D=3D CCW_CMD_BASIC_SE= NSE || > + (ccw->cmd_code & 0x02) =3D=3D 0x02 /* read */ || > + (ccw->cmd_code & 0x0c) =3D=3D 0x0c /* read backwards */); I think you should use masks like ((code & 0x3) =3D=3D 2) =3D> READ ((code & 0xf) =3D=3D 0xc) =3D> READ BACKWARD ((code & 0xf) =3D=3D 0x4) =3D> SENSE Regards, Pierre > ccw_dstream_rewind(cds); > if (!(cds->flags & CDS_F_IDA)) { > cds->op_handler =3D ccw_dstream_rw_noflags; > diff --git a/include/hw/s390x/css.h b/include/hw/s390x/css.h > index aae19c427229..7cc183ef4366 100644 > --- a/include/hw/s390x/css.h > +++ b/include/hw/s390x/css.h > @@ -97,6 +97,7 @@ typedef struct CcwDataStream { > int (*op_handler)(struct CcwDataStream *cds, void *buff, int len, > CcwDataStreamOp op); > hwaddr cda; > + bool do_skip; > } CcwDataStream; > =20 > /* >=20 --=20 Pierre Morel Linux/KVM/QEMU in B=C3=B6blingen - Germany