Il 23/11/2012 06:08, David Gibson ha scritto:
> The virtio-scsi specification does not specify the correct endianness for
> fields in the request structure. It's therefore best to assume that it is
> "guest native" endian since that's the (stupid and poorly defined) norm in
> virtio.
Indeed.
> However, the qemu device for virtio-scsi has no byteswaps at all, and so
> will break if the guest has different endianness from the host. This patch
> fixes it by adding tswap() calls for the sense_len and resid fields in
> the request structure. In theory status_qualifier needs swaps as well,
> but that field is never actually touched. The tag field is a uint64_t, but
> since its value is completely arbitrary, it might as well be uint8_t[8]
> and so it does not need swapping.
Thanks, I adjusted the patch to use a separate variable for the argument
of tswap32 and pushed to the scsi branch.
Paolo
> Cc: Paolo Bonzini <pbonz...@redhat.com>
> Cc: Paul 'Rusty' Russell <ru...@rustcorp.com.au>
> Signed-off-by: David Gibson <da...@gibson.dropbear.id.au>
> ---
> hw/virtio-scsi.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/hw/virtio-scsi.c b/hw/virtio-scsi.c
> index 7d546f6..9d27d1d 100644
> --- a/hw/virtio-scsi.c
> +++ b/hw/virtio-scsi.c
> @@ -428,11 +428,12 @@ static void virtio_scsi_command_complete(SCSIRequest
> *r, uint32_t status,
> req->resp.cmd->response = VIRTIO_SCSI_S_OK;
> req->resp.cmd->status = status;
> if (req->resp.cmd->status == GOOD) {
> - req->resp.cmd->resid = resid;
> + req->resp.cmd->resid = tswap32(resid);
> } else {
> req->resp.cmd->resid = 0;
> req->resp.cmd->sense_len =
> - scsi_req_get_sense(r, req->resp.cmd->sense,
> VIRTIO_SCSI_SENSE_SIZE);
> + tswap32(scsi_req_get_sense(r, req->resp.cmd->sense,
> + VIRTIO_SCSI_SENSE_SIZE));
> }
> virtio_scsi_complete_req(req);
> }
>
