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

[John Garry]

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 <tyr...@linux.ibm.com>
---
  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