From patchwork Thu Mar 22 07:38:22 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fam Zheng X-Patchwork-Id: 889240 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=2001:4830:134:3::11; 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 [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 406JTR5QYkz9s1P for ; Thu, 22 Mar 2018 18:39:22 +1100 (AEDT) Received: from localhost ([::1]:59228 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eyuof-0003Tn-FO for incoming@patchwork.ozlabs.org; Thu, 22 Mar 2018 03:39:17 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33956) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eyuoH-0003Te-6p for qemu-devel@nongnu.org; Thu, 22 Mar 2018 03:38:54 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eyuoC-0003m9-7l for qemu-devel@nongnu.org; Thu, 22 Mar 2018 03:38:53 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:58232 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eyuoC-0003lt-3c for qemu-devel@nongnu.org; Thu, 22 Mar 2018 03:38:48 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 7F675406805B for ; Thu, 22 Mar 2018 07:38:37 +0000 (UTC) Received: from lemon.usersys.redhat.com (ovpn-12-36.pek2.redhat.com [10.72.12.36]) by smtp.corp.redhat.com (Postfix) with ESMTP id 021DE10EE963; Thu, 22 Mar 2018 07:38:28 +0000 (UTC) From: Fam Zheng To: qemu-devel@nongnu.org Date: Thu, 22 Mar 2018 15:38:22 +0800 Message-Id: <20180322073822.25795-1-famz@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.5]); Thu, 22 Mar 2018 07:38:37 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.5]); Thu, 22 Mar 2018 07:38:37 +0000 (UTC) for IP:'10.11.54.3' DOMAIN:'int-mx03.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'famz@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PATCH] scsi-disk: Don't enlarge min_io_size to max_io_size 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: Paolo Bonzini , Fam Zheng Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Some backends report big max_io_sectors. Making min_io_size the same value in this case will make it impossible for guest to align memory, therefore the disk may not be usable at all. Change the default behavior (when min_io_size and opt_io_size are not specified in the command line), do not assume max_io_sectors is a good value for opt_io_size and min_io_size, use 512 instead. Reported-by: David Gibson Signed-off-by: Fam Zheng --- hw/scsi/scsi-disk.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c index 5b7a48f5a5..76e3c9eaa4 100644 --- a/hw/scsi/scsi-disk.c +++ b/hw/scsi/scsi-disk.c @@ -714,10 +714,8 @@ static int scsi_disk_emulate_inquiry(SCSIRequest *req, uint8_t *outbuf) /* min_io_size and opt_io_size can't be greater than * max_io_sectors */ - min_io_size = - MIN_NON_ZERO(min_io_size, max_io_sectors); - opt_io_size = - MIN_NON_ZERO(opt_io_size, max_io_sectors); + min_io_size = MIN(min_io_size ? : 512, max_io_sectors); + opt_io_size = MIN(opt_io_size ? : 512, max_io_sectors); } /* required VPD size with unmap support */ buflen = 0x40;