Re: [PATCH v4 01/21] ibmvfc: add vhost fields and defaults for MQ enablement

[John Garry <john.garry@xxxxxxxxxx>]

On 11/01/2021 23:12, Tyrel Datwyler wrote:
> Introduce several new vhost fields for managing MQ state of the adapter
> as well as initial defaults for MQ enablement.
>
> Signed-off-by: Tyrel Datwyler <tyreld@xxxxxxxxxxxxx>
> ---
>   drivers/scsi/ibmvscsi/ibmvfc.c | 8 ++++++++
>   drivers/scsi/ibmvscsi/ibmvfc.h | 9 +++++++++
>   2 files changed, 17 insertions(+)
>
> diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c
> index ba95438a8912..9200fe49c57e 100644
> --- a/drivers/scsi/ibmvscsi/ibmvfc.c
> +++ b/drivers/scsi/ibmvscsi/ibmvfc.c
> @@ -3302,6 +3302,7 @@ static struct scsi_host_template driver_template = {
>   	.max_sectors = IBMVFC_MAX_SECTORS,
>   	.shost_attrs = ibmvfc_attrs,
>   	.track_queue_depth = 1,
> +	.host_tagset = 1,

Good to see another user :)

I didn't check the whole series very thoroughly, but I guess that you 
only need to set this when shost->nr_hw_queues > 1. Having said that, it 
should be fine when shost->nr_hw_queues = 0 or 1.

Thanks,
John

>   };
>   
>   /**
> @@ -5290,6 +5291,7 @@ static int ibmvfc_probe(struct vio_dev *vdev, const struct vio_device_id *id)
>   	shost->max_sectors = IBMVFC_MAX_SECTORS;
>   	shost->max_cmd_len = IBMVFC_MAX_CDB_LEN;
>   	shost->unique_id = shost->host_no;
> +	shost->nr_hw_queues = IBMVFC_MQ ? IBMVFC_SCSI_HW_QUEUES : 1;
>   
>   	vhost = shost_priv(shost);
>   	INIT_LIST_HEAD(&vhost->targets);
> @@ -5300,6 +5302,12 @@ static int ibmvfc_probe(struct vio_dev *vdev, const struct vio_device_id *id)
>   	vhost->partition_number = -1;
>   	vhost->log_level = log_level;
>   	vhost->task_set = 1;
> +
> +	vhost->mq_enabled = IBMVFC_MQ;
> +	vhost->client_scsi_channels = IBMVFC_SCSI_CHANNELS;
> +	vhost->using_channels = 0;
> +	vhost->do_enquiry = 1;
> +
>   	strcpy(vhost->partition_name, "UNKNOWN");
>   	init_waitqueue_head(&vhost->work_wait_q);
>   	init_waitqueue_head(&vhost->init_wait_q);
> diff --git a/drivers/scsi/ibmvscsi/ibmvfc.h b/drivers/scsi/ibmvscsi/ibmvfc.h
> index 632e977449c5..dd6d89292867 100644
> --- a/drivers/scsi/ibmvscsi/ibmvfc.h
> +++ b/drivers/scsi/ibmvscsi/ibmvfc.h
> @@ -41,6 +41,11 @@
>   #define IBMVFC_DEFAULT_LOG_LEVEL	2
>   #define IBMVFC_MAX_CDB_LEN		16
>   #define IBMVFC_CLS3_ERROR		0
> +#define IBMVFC_MQ			0
> +#define IBMVFC_SCSI_CHANNELS		0
> +#define IBMVFC_SCSI_HW_QUEUES		1
> +#define IBMVFC_MIG_NO_SUB_TO_CRQ	0
> +#define IBMVFC_MIG_NO_N_TO_M		0
>   
>   /*
>    * Ensure we have resources for ERP and initialization:
> @@ -840,6 +845,10 @@ struct ibmvfc_host {
>   	int delay_init;
>   	int scan_complete;
>   	int logged_in;
> +	int mq_enabled;
> +	int using_channels;
> +	int do_enquiry;
> +	int client_scsi_channels;
>   	int aborting_passthru;
>   	int events_to_log;
>   #define IBMVFC_AE_LINKUP	0x0001