From nobody Sat Oct 25 21:46:08 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; 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 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 152170439169762.59666172170091; Thu, 22 Mar 2018 00:39:51 -0700 (PDT) Received: from localhost ([::1]:59230 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eyupC-00044P-ET for importer@patchew.org; Thu, 22 Mar 2018 03:39:50 -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+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" 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) =20 /* min_io_size and opt_io_size can't be greater than * max_io_sectors */ - min_io_size =3D - MIN_NON_ZERO(min_io_size, max_io_sectors); - opt_io_size =3D - MIN_NON_ZERO(opt_io_size, max_io_sectors); + min_io_size =3D MIN(min_io_size ? : 512, max_io_sectors); + opt_io_size =3D MIN(opt_io_size ? : 512, max_io_sectors); } /* required VPD size with unmap support */ buflen =3D 0x40; --=20 2.14.3