Il 14/03/2013 12:10, Michael S. Tsirkin ha scritto:
> Add field for guest to specify command size for virtio-blk.
>
> Signed-off-by: Michael S. Tsirkin <[email protected]>
> ---
> virtio-spec.lyx | 83
> +++++++++++++++++++++++++++++++++++++++++++++++++++++----
> 1 file changed, 78 insertions(+), 5 deletions(-)
>
> diff --git a/virtio-spec.lyx b/virtio-spec.lyx
> index a8ce3f9..fea97ed 100644
> --- a/virtio-spec.lyx
> +++ b/virtio-spec.lyx
> @@ -5826,6 +5826,16 @@ VIRTIO_BLK_F_TOPOLOGY (10) Device exports information
> on optimal I/O alignment.
> \change_inserted 1531152142 1341302349
> VIRTIO_BLK_F_CONFIG_WCE (11) Device can toggle its cache between writeback
> and writethrough modes.
> +\change_inserted 1986246365 1363257418
> +
> +\end_layout
> +
> +\begin_layout Description
> +
> +\change_inserted 1986246365 1363258629
> +VIRTIO_BLK_F_CMD_SIZE (12) cmd_size field is valid.
SCSI_CMD_SIZE and scsi_cmd_size please.
> +\change_inserted 1531152142 1341302349
> +
> \end_layout
>
> \end_deeper
> @@ -5994,6 +6004,30 @@ struct virtio_blk_config {
> \change_inserted 1531152142 1341301918
>
> u8 writeback;
> +\change_inserted 1986246365 1363257385
> +
> +\end_layout
> +
> +\begin_layout Plain Layout
> +
> +\change_inserted 1986246365 1363258610
> +
> + u8 reserved[3];
> +\end_layout
> +
> +\begin_layout Plain Layout
> +
> +\change_inserted 1986246365 1363259147
> +
> + // buffer length for cmd field in requests.
size of the cmd field in VIRTIO_BLK_T_SCSI_CMD requests.
> + reset value 0.
> +\end_layout
> +
> +\begin_layout Plain Layout
> +
> +\change_inserted 1986246365 1363257810
> +
> + u32 cmd_size;
scsi_cmd_size
> \change_unchanged
>
> \end_layout
> @@ -6085,6 +6119,21 @@ Until version 1.1, QEMU remained in writeback mode
> even after a guest announced
> \end_inset
>
> .
> +\change_inserted 1986246365 1363258989
> +
> +\end_layout
> +
> +\begin_layout Enumerate
> +
> +\change_inserted 1986246365 1363259237
> +If VIRTIO_BLK_F_SCSI_CMD_SIZE is negotiated, Guest should set the desired
> + size for scsi commands to the
If both VIRTIO_BLK_F_SCSI and VIRTIO_BLK_F_SCSI_CMD_SIZE are negotiated,
the driver should write a non-zero value to the scsi_cmd_size field
before sending a VIRTIO_BLK_T_SCSI_CMD request.
> +\emph on
> +cmd_size
> +\emph default
> +field.
> +\change_unchanged
> +
> \end_layout
>
> \begin_layout Section*
> @@ -6369,8 +6418,33 @@ cmd
> \emph default
> field is only present for scsi packet command requests, and indicates the
> command to perform.
> - This field must reside in a single, separate read-only buffer; command
> - length can be derived from the length of this buffer.
> +
> +\change_inserted 1986246365 1363258881
> +If VIRTIO_BLK_F_SCSI_CMD_SIZE feature bit is negotiated, Guest must set
> + the command length by writing it to the cmd_size field in configuration
> + space
If the VIRTIO_BLK_F_SCSI_CMD_SIZE feature bit is negotiated, the driver
should write the length of the cmd field to the scsi_cmd_size field of
the configuration space.
(please make sure bold and emphasis are consistent)
> +\begin_inset Foot
> +status open
> +
> +\begin_layout Plain Layout
> +
> +\change_inserted 1986246365 1363258931
> +Guest should always set cmd_size during initialization.
scsi_cmd_size
> +\change_unchanged
> +
> +\end_layout
> +
> +\end_inset
> +
> +.
> + If VIRTIO_BLK_F_SCSI_CMD_SIZE is not negotiated,
> +\change_deleted 1986246365 1363258703
> +T
> +\change_inserted 1986246365 1363258703
> +t
> +\change_unchanged
> +his field must reside in a single, separate read-only buffer; command length
> + can be derived from the length of this buffer.
the command length...
>
> \end_layout
>
>
Thanks,
Paolo
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