From nobody Wed May 8 03:34:15 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1557163156; cv=none; d=zoho.com; s=zohoarc; b=X5/2tm46jHRE4Y7ou+aFX4x6ucDRNvbHz2E5OaM/EDY65X1fPa23zhp7S9XaoxcFfC6k5VL0S0KSw+pCVwB6iIhbYJ3Rvm4AFNBQDCzJulsxaDimWgny5DpItHfIBFC403NdZ8ZcXWAYVHvI1b5+5epa+KZ/aNx9F51j3Kw8qD4= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zoho.com; s=zohoarc; t=1557163156; h=Content-Transfer-Encoding:Cc:Date:From:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:Sender:Subject:To:ARC-Authentication-Results; bh=7ZjUL+W9oeXWu9QgmpqIRJMfgPcY5HDzrVxp1jsoGfQ=; b=Pry8RW/+A9Xfv/DWhk6wL/n/0N9bYZtD3e8h0/To3C+BtZOICH4TeBWlbOKooAZvogpNwtXvzSNy6rXwfb2vvJcs/JXtt9woIpxltEXnLLuibo8tgkw4MfZs+TnSTNOoOX+ikzwQkNOz7ioxLQeOuNR7bJShOGtiOYk2sHayDE8= ARC-Authentication-Results: i=1; mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1557163156765748.5742827851667; Mon, 6 May 2019 10:19:16 -0700 (PDT) Received: from localhost ([127.0.0.1]:59635 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hNhGi-0005kK-Ca for importer@patchew.org; Mon, 06 May 2019 13:19:12 -0400 Received: from eggs.gnu.org ([209.51.188.92]:33747) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hNhFB-0005BW-E3 for qemu-devel@nongnu.org; Mon, 06 May 2019 13:17:38 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hNhFA-0004Mg-HE for qemu-devel@nongnu.org; Mon, 06 May 2019 13:17:37 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53316) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hNhFA-0004M0-Bi; Mon, 06 May 2019 13:17:36 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 3CA173086227; Mon, 6 May 2019 17:17:35 +0000 (UTC) Received: from localhost (unknown [10.40.205.81]) by smtp.corp.redhat.com (Postfix) with ESMTPS id BB0DD60BEC; Mon, 6 May 2019 17:17:34 +0000 (UTC) From: Cornelia Huck To: Halil Pasic , Christian Borntraeger Date: Mon, 6 May 2019 19:17:30 +0200 Message-Id: <20190506171730.17556-1-cohuck@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.42]); Mon, 06 May 2019 17:17:35 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH RFC] 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: , Cc: Eric Farman , qemu-s390x@nongnu.org, Cornelia Huck , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="utf-8" 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. Signed-off-by: Cornelia Huck --- Only extremely lightly tested (i.e., can boot a guest.) --- hw/s390x/css.c | 22 ++++++++++++++++++---- include/hw/s390x/css.h | 1 + 2 files changed, 19 insertions(+), 4 deletions(-) diff --git a/hw/s390x/css.c b/hw/s390x/css.c index 8fc9e35ba5d3..6ee31cc2e08f 100644 --- a/hw/s390x/css.c +++ b/hw/s390x/css.c @@ -830,8 +830,12 @@ static int ccw_dstream_rw_noflags(CcwDataStream *cds, = 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->cda, + MEMTXATTRS_UNSPECIFIED, buff, iter_= 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 const *= 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 commands = */ + cds->do_skip =3D (ccw->flags & CCW_FLAG_SKIP) && + (ccw->cmd_code & CCW_CMD_BASIC_SENSE || + ccw->cmd_code & 0x02 /* read */ || + ccw->cmd_code & 0x0c /* read backwards */); 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 2.20.1