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authorDavid Gibson <david@gibson.dropbear.id.au>2012-11-26 12:33:52 +1100
committerDoug Goldstein <cardoe@cardoe.com>2012-12-13 15:31:59 -0600
commit6b4950c36dea3fafefac88883fc0421913e22b75 (patch)
tree4db432f636dc445a1cfe764038111a64a0150a5f
parentvirtio-scsi: Fix some endian bugs with virtio-scsi (diff)
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virtio-scsi: Fix subtle (guest) endian bug
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 <pbonzini@redhat.com> Cc: Paul 'Rusty' Russell <rusty@rustcorp.com.au> Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> (cherry picked from commit 863d1050c96cff91dd478767c0da9cc288575919) Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com> (cherry picked from commit bf47da47dbcbf2c90119ba0bd45560d5b2f1dd13)
-rw-r--r--hw/virtio-scsi.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/hw/virtio-scsi.c b/hw/virtio-scsi.c
index c6d529036..5fcbdd8b5 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);
}