On 23/04/2015 20:10, Christoph Hellwig wrote:
> T10 PI is just another optional feature, LLDDs should work without
> the infrastructure.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
> drivers/scsi/Kconfig | 1 -
> drivers/scsi/virtio_scsi.c | 11 ++++++++++-
> 2 files changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
> index b021bcb..896bea6 100644
> --- a/drivers/scsi/Kconfig
> +++ b/drivers/scsi/Kconfig
> @@ -1743,7 +1743,6 @@ config SCSI_BFA_FC
> config SCSI_VIRTIO
> tristate "virtio-scsi support"
> depends on VIRTIO
> - select BLK_DEV_INTEGRITY
> help
> This is the virtual HBA driver for virtio. If the kernel will
> be used in a virtual machine, say Y or M.
> diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
> index f164f24..0f2bb5b 100644
> --- a/drivers/scsi/virtio_scsi.c
> +++ b/drivers/scsi/virtio_scsi.c
> @@ -501,6 +501,7 @@ static void virtio_scsi_init_hdr(struct virtio_device *vdev,
> cmd->crn = 0;
> }
>
> +#ifdef CONFIG_BLK_DEV_INTEGRITY
> static void virtio_scsi_init_hdr_pi(struct virtio_device *vdev,
> struct virtio_scsi_cmd_req_pi *cmd_pi,
> struct scsi_cmnd *sc)
> @@ -524,6 +525,7 @@ static void virtio_scsi_init_hdr_pi(struct virtio_device *vdev,
> blk_rq_sectors(rq) *
> bi->tuple_size);
> }
> +#endif
>
> static int virtscsi_queuecommand(struct virtio_scsi *vscsi,
> struct virtio_scsi_vq *req_vq,
> @@ -546,11 +548,14 @@ static int virtscsi_queuecommand(struct virtio_scsi *vscsi,
>
> BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE);
>
> +#ifdef CONFIG_BLK_DEV_INTEGRITY
> if (virtio_has_feature(vscsi->vdev, VIRTIO_SCSI_F_T10_PI)) {
> virtio_scsi_init_hdr_pi(vscsi->vdev, &cmd->req.cmd_pi, sc);
> memcpy(cmd->req.cmd_pi.cdb, sc->cmnd, sc->cmd_len);
> req_size = sizeof(cmd->req.cmd_pi);
> - } else {
> + } else
> +#endif
> + {
All good so far.
> virtio_scsi_init_hdr(vscsi->vdev, &cmd->req.cmd, sc);
> memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len);
> req_size = sizeof(cmd->req.cmd);
> @@ -1002,6 +1007,7 @@ static int virtscsi_probe(struct virtio_device *vdev)
> shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE;
> shost->nr_hw_queues = num_queues;
>
> +#ifdef VIRTIO_SCSI_F_T10_PI
This symbol is always defined; it is part of the uapi/ header.
I think you wanted #ifdef CONFIG_BLK_DEV_INTEGRITY here as well.
However, you can remove this #ifdef completely. This is because...
> if (virtio_has_feature(vdev, VIRTIO_SCSI_F_T10_PI)) {
... this condition should always be false unless the feature is
negotiated, and the feature should not be negotiated when
CONFIG_BLK_DEV_INTEGRITY is disabled.
Maybe you can add a "WARN_ON(!IS_ENABLED(CONFIG_BLK_DEV_INTEGRITY))"
depending on your taste.
> host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION |
> SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION |
Also, if you leave the #ifdef, host_prot is now unused if
CONFIG_BLK_DEV_INTEGRITY is disabled. If you prefer to keep the #ifdef
you should also change host_prot to a macro (e.g. VIRTIO_SCSI_HOST_PROT)
to silence the compiler warning.
> @@ -1010,6 +1016,7 @@ static int virtscsi_probe(struct virtio_device *vdev)
> scsi_host_set_prot(shost, host_prot);
> scsi_host_set_guard(shost, SHOST_DIX_GUARD_CRC);
> }
> +#endif
>
> err = scsi_add_host(shost, &vdev->dev);
> if (err)
> @@ -1090,7 +1097,9 @@ static struct virtio_device_id id_table[] = {
> static unsigned int features[] = {
> VIRTIO_SCSI_F_HOTPLUG,
> VIRTIO_SCSI_F_CHANGE,
> +#ifdef VIRTIO_SCSI_F_T10_PI
This one definitely should be #ifdef CONFIG_BLK_DEV_INTEGRITY.
Thanks,
Paolo
> VIRTIO_SCSI_F_T10_PI,
> +#endif
> };
>
> static struct virtio_driver virtio_scsi_driver = {
>
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