From mboxrd@z Thu Jan 1 00:00:00 1970 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 Sender: fluxion From: Michael Roth Date: Mon, 3 Dec 2012 16:44:36 -0600 Message-Id: <1354574681-28954-7-git-send-email-mdroth@linux.vnet.ibm.com> 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> Subject: [Qemu-devel] [PATCH 39/43] virtio-scsi: Fix subtle (guest) endian bug List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-stable@nongnu.org Cc: aliguori@us.ibm.com, qemu-devel@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); } -- 1.7.9.5