On 5/22/20 11:51 AM, Sudhakar Panneerselvam wrote:
> vhost-scsi pre-allocates the maximum sg entries per command and if a
> command requires more than VHOST_SCSI_PREALLOC_SGLS entries, then that
> command is failed by it. This patch lets vhost communicate the max sg limit
> when it registers vhost_scsi_ops with TCM. With this change, TCM would
> report the max sg entries through "Block Limits" VPD page which will be
> typically queried by the SCSI initiator during device discovery. By knowing
> this limit, the initiator could ensure the maximum transfer length is less
> than or equal to what is reported by vhost-scsi.
>
> Cc: Michael S. Tsirkin <mst@xxxxxxxxxx>
> Cc: Jason Wang <jasowang@xxxxxxxxxx>
> Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> Cc: Stefan Hajnoczi <stefanha@xxxxxxxxxx>
> Signed-off-by: Sudhakar Panneerselvam <sudhakar.panneerselvam@xxxxxxxxxx>
> ---
> drivers/vhost/scsi.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
> index c39952243fd3..8b104f76f324 100644
> --- a/drivers/vhost/scsi.c
> +++ b/drivers/vhost/scsi.c
> @@ -2280,6 +2280,7 @@ static void vhost_scsi_drop_tport(struct se_wwn *wwn)
> static const struct target_core_fabric_ops vhost_scsi_ops = {
> .module = THIS_MODULE,
> .fabric_name = "vhost",
> + .max_data_sg_nents = VHOST_SCSI_PREALLOC_SGLS,
> .tpg_get_wwn = vhost_scsi_get_fabric_wwn,
> .tpg_get_tag = vhost_scsi_get_tpgt,
> .tpg_check_demo_mode = vhost_scsi_check_true,
>
Looks ok to me.
Reviewed-by: Mike Christie <mchristi@xxxxxxxxxx>
