Re: [PATCH-v2 1/6] virtio-scsi.h: Add virtio_scsi_cmd_req_pi + VIRTIO_SCSI_F_T10_PI bits

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, May 22, 2014 at 02:26:17AM +0000, Nicholas A. Bellinger wrote:
> From: Nicholas Bellinger <nab@linux-iscsi.org>
> 
> This patch adds a virtio_scsi_cmd_req_pi header as recommened by
> Paolo that contains do_pi_niov + di_pi_niov elements used for
> signaling when protection information buffers are expected to
> preceed the data buffers.
> 
> Also add new VIRTIO_SCSI_F_T10_PI feature bit to be used to signal
> host support.
> 
> v4 changes:
>    - Use pi_bytesout + pi_bytesin instead of niovs (mst + paolo)
> 
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Cc: Martin K. Petersen <martin.petersen@oracle.com>
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: Hannes Reinecke <hare@suse.de>
> Cc: Sagi Grimberg <sagig@dev.mellanox.co.il>
> Cc: H. Peter Anvin <hpa@zytor.com>
> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
> ---
>  include/linux/virtio_scsi.h |   15 ++++++++++++++-
>  1 file changed, 14 insertions(+), 1 deletion(-)
> 
> diff --git a/include/linux/virtio_scsi.h b/include/linux/virtio_scsi.h
> index 4195b97..7344906 100644
> --- a/include/linux/virtio_scsi.h
> +++ b/include/linux/virtio_scsi.h
> @@ -35,11 +35,23 @@ struct virtio_scsi_cmd_req {
>  	u8 lun[8];		/* Logical Unit Number */
>  	u64 tag;		/* Command identifier */
>  	u8 task_attr;		/* Task attribute */
> -	u8 prio;
> +	u8 prio;		/* SAM command priority field */
>  	u8 crn;
>  	u8 cdb[VIRTIO_SCSI_CDB_SIZE];
>  } __packed;
>  
> +/* SCSI command request, followed by protection information */
> +struct virtio_scsi_cmd_req_pi {
> +	u8 lun[8];		/* Logical Unit Number */
> +	u64 tag;		/* Command identifier */
> +	u8 task_attr;		/* Task attribute */
> +	u8 prio;		/* SAM command priority field */
> +	u8 crn;
> +	u32 pi_bytesout;	/* DataOUT PI Number of bytes */
> +	u32 pi_bytesin;		/* DataIN PI Number of bytes */
> +	u8 cdb[VIRTIO_SCSI_CDB_SIZE];
> +} __packed;
> +
>  /* Response, followed by sense data and data-in */
>  struct virtio_scsi_cmd_resp {
>  	u32 sense_len;		/* Sense data length */
> @@ -97,6 +109,7 @@ struct virtio_scsi_config {
>  #define VIRTIO_SCSI_F_INOUT                    0
>  #define VIRTIO_SCSI_F_HOTPLUG                  1
>  #define VIRTIO_SCSI_F_CHANGE                   2
> +#define VIRTIO_SCSI_F_T10_PI		       3


I'd like to add that it's strange to add a macro and
only use it in patch 5.
I believe this is one of the reasons bug in patch 5 went
unnoticed ...

>  
>  /* Response codes */
>  #define VIRTIO_SCSI_S_OK                       0
> -- 
> 1.7.10.4