From patchwork Mon Dec 3 22:44:36 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Roth X-Patchwork-Id: 203476 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 9B5EC2C00A5 for ; Tue, 4 Dec 2012 09:50:41 +1100 (EST) Received: from localhost ([::1]:53106 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TfeqV-0002OL-LF for incoming@patchwork.ozlabs.org; Mon, 03 Dec 2012 17:50:39 -0500 Received: from eggs.gnu.org ([208.118.235.92]:56431) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Tfeq9-0002EK-Tg for qemu-devel@nongnu.org; Mon, 03 Dec 2012 17:50:18 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Tfeq8-0003v5-JF for qemu-devel@nongnu.org; Mon, 03 Dec 2012 17:50:17 -0500 Received: from mail-ie0-f176.google.com ([209.85.223.176]:54782) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Tfeq4-0003t5-6b; Mon, 03 Dec 2012 17:50:12 -0500 Received: by mail-ie0-f176.google.com with SMTP id 13so5535987iea.35 for ; Mon, 03 Dec 2012 14:50:11 -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=ZRoH2Hh1cf4THpJISJpay1O0zNOXy+9B/vwpASV/HPA=; b=zd0Y0g/vU4YrOZ4z7Li5yToLZjzTfh2bOxkgc2D5QjOMwhAivnz8B4oEV9tutXckbL n/z6X3BmziL/nZTsRRhB5intvqo5wGPoEmlOBnmCwRDzwKs27Gw/mwVGT2fwviM2UQ31 jr45QapOTDaIowDPsho/9zmSMZSQ/YWnpsf3wqTomyv+AVSccrf96UAI42LcA/wAQfhj 6s/qlMUFyMJkb/Bl8T+2p1ukQsrSRmlm+IliQJBDH9AFGBu0LtQSXWACFEh2q0NEeo+h /FUerLreXwoOOEH1YUY2l9ivQatrInFkzX/KKebHLPUwrL4E6FXyySO2DlSfHvJVcSXD VonA== Received: by 10.50.0.140 with SMTP id 12mr618713ige.63.1354575011483; Mon, 03 Dec 2012 14:50:11 -0800 (PST) Received: from localhost ([32.97.110.59]) by mx.google.com with ESMTPS id kp4sm8956856igc.1.2012.12.03.14.50.09 (version=TLSv1/SSLv3 cipher=OTHER); Mon, 03 Dec 2012 14:50:10 -0800 (PST) From: Michael Roth To: qemu-stable@nongnu.org Date: Mon, 3 Dec 2012 16:44:36 -0600 Message-Id: <1354574681-28954-7-git-send-email-mdroth@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1354572547-21271-1-git-send-email-mdroth@linux.vnet.ibm.com> References: <1354572547-21271-1-git-send-email-mdroth@linux.vnet.ibm.com> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [fuzzy] X-Received-From: 209.85.223.176 Cc: aliguori@us.ibm.com, qemu-devel@nongnu.org Subject: [Qemu-devel] [PATCH 39/43] 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 (cherry picked from commit 863d1050c96cff91dd478767c0da9cc288575919) Signed-off-by: Michael Roth --- 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 c6d5290..5fcbdd8 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); }