From patchwork Thu May 16 13:33:27 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cornelia Huck X-Patchwork-Id: 1100566 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 454XSx2Zr0z9s3Z for ; Thu, 16 May 2019 23:34:08 +1000 (AEST) Received: from localhost ([127.0.0.1]:57822 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hRGWK-0006B1-Ln for incoming@patchwork.ozlabs.org; Thu, 16 May 2019 09:34:04 -0400 Received: from eggs.gnu.org ([209.51.188.92]:43654) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hRGVs-0006Aq-Sj for qemu-devel@nongnu.org; Thu, 16 May 2019 09:33:39 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hRGVp-0006pI-Rg for qemu-devel@nongnu.org; Thu, 16 May 2019 09:33:36 -0400 Received: from mx1.redhat.com ([209.132.183.28]:13066) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hRGVp-0006hv-LB; Thu, 16 May 2019 09:33:33 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 9E307307D84D; Thu, 16 May 2019 13:33:30 +0000 (UTC) Received: from localhost (dhcp-192-222.str.redhat.com [10.33.192.222]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 48BE35D6A9; Thu, 16 May 2019 13:33:30 +0000 (UTC) From: Cornelia Huck To: Halil Pasic , Christian Borntraeger Date: Thu, 16 May 2019 15:33:27 +0200 Message-Id: <20190516133327.11430-1-cohuck@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.48]); Thu, 16 May 2019 13:33:30 +0000 (UTC) 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 v4] 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, Pierre Morel Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" 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. Reviewed-by: Eric Farman Signed-off-by: Cornelia Huck --- Will queue this unless someone complains. v3 -> v4: use MEMTX_OK [Eric] v2 -> v3: fixed checks even more [Pierre] v1 -> v2: fixed checks for command type [Eric] --- 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..ad310b9f94bc 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 == CDS_OP_A) { goto incr; } - ret = address_space_rw(&address_space_memory, cds->cda, - MEMTXATTRS_UNSPECIFIED, buff, len, op); + if (!cds->do_skip) { + ret = address_space_rw(&address_space_memory, cds->cda, + MEMTXATTRS_UNSPECIFIED, buff, len, op); + } else { + ret = MEMTX_OK; + } if (ret != MEMTX_OK) { cds->flags |= 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 = MIN(len, cont_left); if (op != CDS_OP_A) { - ret = address_space_rw(&address_space_memory, cds->cda, - MEMTXATTRS_UNSPECIFIED, buff, iter_len, op); + if (!cds->do_skip) { + ret = address_space_rw(&address_space_memory, cds->cda, + MEMTXATTRS_UNSPECIFIED, buff, iter_len, + op); + } else { + ret = MEMTX_OK; + } if (ret != MEMTX_OK) { /* assume inaccessible address */ ret = -EINVAL; /* channel program check */ @@ -968,6 +977,11 @@ void ccw_dstream_init(CcwDataStream *cds, CCW1 const *ccw, ORB const *orb) cds->count = ccw->count; cds->cda_orig = ccw->cda; + /* skip is only effective for read, read backwards, or sense commands */ + cds->do_skip = (ccw->flags & CCW_FLAG_SKIP) && + ((ccw->cmd_code & 0x0f) == CCW_CMD_BASIC_SENSE || + (ccw->cmd_code & 0x03) == 0x02 /* read */ || + (ccw->cmd_code & 0x0f) == 0x0c /* read backwards */); ccw_dstream_rewind(cds); if (!(cds->flags & CDS_F_IDA)) { cds->op_handler = 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; /*