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[Qemu-devel] [PATCH 5/5] virtio-scsi: Fix subtle (guest) endian bug
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PATCH 5/5] virtio-scsi: Fix subtle (guest) endian bug |
Date: |
Wed, 28 Nov 2012 16:21:50 +0100 |
From: David Gibson <address@hidden>
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 <address@hidden>
Cc: Paul 'Rusty' Russell <address@hidden>
Signed-off-by: David Gibson <address@hidden>
Signed-off-by: Paolo Bonzini <address@hidden>
---
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);
}
--
1.8.0
- [Qemu-devel] [PULL 1.3 0/5] SCSI updates for 1.3-rc2, Paolo Bonzini, 2012/11/28
- [Qemu-devel] [PATCH 1/5] iscsi: fix segfault in url parsing, Paolo Bonzini, 2012/11/28
- [Qemu-devel] [PATCH 2/5] iscsi: fix deadlock during login, Paolo Bonzini, 2012/11/28
- [Qemu-devel] [PATCH 5/5] virtio-scsi: Fix subtle (guest) endian bug,
Paolo Bonzini <=
- [Qemu-devel] [PATCH 3/5] iscsi: do not assume device is zero initialized, Paolo Bonzini, 2012/11/28
- [Qemu-devel] [PATCH 4/5] virtio-scsi: Fix some endian bugs with virtio-scsi, Paolo Bonzini, 2012/11/28
- Re: [Qemu-devel] [PULL 1.3 0/5] SCSI updates for 1.3-rc2, Anthony Liguori, 2012/11/28