From patchwork Wed Nov 28 15:21:50 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 202484 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 01D482C0080 for ; Thu, 29 Nov 2012 02:52:23 +1100 (EST) Received: from localhost ([::1]:38493 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TdjTg-00035q-JW for incoming@patchwork.ozlabs.org; Wed, 28 Nov 2012 10:23:08 -0500 Received: from eggs.gnu.org ([208.118.235.92]:40597) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TdjSz-00015s-8L for qemu-devel@nongnu.org; Wed, 28 Nov 2012 10:22:26 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TdjSx-0000r5-4s for qemu-devel@nongnu.org; Wed, 28 Nov 2012 10:22:25 -0500 Received: from mail-pa0-f45.google.com ([209.85.220.45]:54940) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TdjSw-0000qB-Vl for qemu-devel@nongnu.org; Wed, 28 Nov 2012 10:22:23 -0500 Received: by mail-pa0-f45.google.com with SMTP id bg2so6911923pad.4 for ; Wed, 28 Nov 2012 07:22:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:from:to:cc:subject:date:message-id:x-mailer:in-reply-to :references; bh=moKocOvEQIzwJSTmvouCcf8hmRshm7bGCjDaHlwR3NA=; b=aEy2LIhnUkOiiMH/0cDAVGlq7lIMC8iLAgLAOqelkl/IzfjhWUAHlILzNWMjMy3hU4 WVGiXpqa04TWDCWeGhV4dVhJwu2ZHffw4bDaegqG3IePYso3iXzfH5Lh78nt3oXjYlNw ZRkJHwEWpe39fki0ac4WWZ4PeYodzkmb5THdZTMVCd1TL8ryQCNAdG7fQ1skW3cGek/m RMbIxZ9lubfSbHYXIW47Ctwd2b+B8Krt/YiTgVs90JCjs1RkCWj4oiqIMIl70P81vDno f5fyisoihYb4GcZiHpk0Jl3EupfH4n9M/k+9z6qeyxwtWYs9sodV98INbTAhbG/9+8Jn 6pFA== Received: by 10.68.234.167 with SMTP id uf7mr59093610pbc.20.1354116142675; Wed, 28 Nov 2012 07:22:22 -0800 (PST) Received: from yakj.usersys.redhat.com (93-34-169-1.ip50.fastwebnet.it. [93.34.169.1]) by mx.google.com with ESMTPS id p5sm12448779paz.22.2012.11.28.07.22.19 (version=TLSv1/SSLv3 cipher=OTHER); Wed, 28 Nov 2012 07:22:21 -0800 (PST) From: Paolo Bonzini To: qemu-devel@nongnu.org Date: Wed, 28 Nov 2012 16:21:50 +0100 Message-Id: <1354116110-28651-6-git-send-email-pbonzini@redhat.com> X-Mailer: git-send-email 1.8.0 In-Reply-To: <1354116110-28651-1-git-send-email-pbonzini@redhat.com> References: <1354116110-28651-1-git-send-email-pbonzini@redhat.com> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [fuzzy] X-Received-From: 209.85.220.45 Cc: aliguori@us.ibm.com, Paul 'Rusty' Russell , David Gibson Subject: [Qemu-devel] [PATCH 5/5] virtio-scsi: Fix subtle (guest) endian bug X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: David Gibson The virtio-scsi config space is, by specification, in guest endian (which is ill-defined, but there you go). In virtio_scsi_get_config() we set up all the fields in there, using stl_raw(). Which is a problem for the max_channel and max_target fields, which are 16-bit, not 32-bit. For little-endian targets we get away with it by accident, since the first two bytes will still be correct, and the extra two bytes written (with zeroes) will be overwritten correctly by the next store. But for big-endian guests, this means the max_target field ends up as zero, which means the guest will only recognize a single disk on the virtio-scsi bus. This patch fixes the problem. Cc: Paolo Bonzini Cc: Paul 'Rusty' Russell Signed-off-by: David Gibson Signed-off-by: Paolo Bonzini --- hw/virtio-scsi.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/hw/virtio-scsi.c b/hw/virtio-scsi.c index 924fc69..bfe1860 100644 --- a/hw/virtio-scsi.c +++ b/hw/virtio-scsi.c @@ -534,8 +534,8 @@ static void virtio_scsi_get_config(VirtIODevice *vdev, stl_raw(&scsiconf->event_info_size, sizeof(VirtIOSCSIEvent)); stl_raw(&scsiconf->sense_size, s->sense_size); stl_raw(&scsiconf->cdb_size, s->cdb_size); - stl_raw(&scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL); - stl_raw(&scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET); + stw_raw(&scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL); + stw_raw(&scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET); stl_raw(&scsiconf->max_lun, VIRTIO_SCSI_MAX_LUN); }