Re: [PATCH 3/5] ibmvfc: make ibmvfc login to fabric

[Tyrel Datwyler <tyreld@linux.ibm.com>]

On 4/8/26 10:07 AM, Dave Marquardt via B4 Relay wrote:
> From: Dave Marquardt <davemarq@linux.ibm.com>
> 
> Make ibmvfc login to fabric when NPIV login returns SUPPORT_SCSI or
> SUPPORT_NVMEOF capabilities.

Again better commit log message here and developer sign off tag.

> ---
>  drivers/scsi/ibmvscsi/ibmvfc.c | 100 ++++++++++++++++++++++++++++++++++++++---
>  drivers/scsi/ibmvscsi/ibmvfc.h |  20 +++++++++
>  2 files changed, 115 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c
> index 808301fa452d..803fc3caa14d 100644
> --- a/drivers/scsi/ibmvscsi/ibmvfc.c
> +++ b/drivers/scsi/ibmvscsi/ibmvfc.c
> @@ -5205,6 +5205,89 @@ static void ibmvfc_discover_targets(struct ibmvfc_host *vhost)
>  		ibmvfc_link_down(vhost, IBMVFC_LINK_DEAD);
>  }
>  
> +static void ibmvfc_fabric_login_done(struct ibmvfc_event *evt)
> +{
> +	struct ibmvfc_fabric_login *rsp = &evt->xfer_iu->fabric_login;
> +	u32 mad_status = be16_to_cpu(rsp->common.status);
> +	struct ibmvfc_host *vhost = evt->vhost;
> +	int level = IBMVFC_DEFAULT_LOG_LEVEL;
> +
> +	ENTER;
> +
> +	switch (mad_status) {
> +	case IBMVFC_MAD_SUCCESS:
> +		vhost->logged_in = 1;

I'm not sure I see the point of setting logged_in here since we already set it
in npiv_login_done.

> +		vhost->fabric_capabilities = rsp->capabilities;

The way this is currently spec'd out there are no linux relevant capabilities
coming from fabric login. So, I'm not sure there is a reason to save them at
this point.

> +		fc_host_port_id(vhost->host) = be64_to_cpu(rsp->nport_id);
> +		ibmvfc_free_event(evt);
> +		break;
> +
> +	case IBMVFC_MAD_FAILED:
> +		if (ibmvfc_retry_cmd(be16_to_cpu(rsp->status), be16_to_cpu(rsp->error)))
> +			level += ibmvfc_retry_host_init(vhost);
> +		else
> +			ibmvfc_link_down(vhost, IBMVFC_LINK_DEAD);
> +		ibmvfc_log(vhost, level, "Fabric Login failed: %s (%x:%x)\n",
> +			   ibmvfc_get_cmd_error(be16_to_cpu(rsp->status), be16_to_cpu(rsp->error)),
> +						be16_to_cpu(rsp->status), be16_to_cpu(rsp->error));
> +		ibmvfc_free_event(evt);
> +		LEAVE;
> +		return;
> +
> +	case IBMVFC_MAD_CRQ_ERROR:
> +		ibmvfc_retry_host_init(vhost);
> +		fallthrough;
> +
> +	case IBMVFC_MAD_DRIVER_FAILED:
> +		ibmvfc_free_event(evt);
> +		LEAVE;
> +		return;
> +
> +	default:
> +		dev_err(vhost->dev, "Invalid fabric Login response: 0x%x\n", mad_status);
> +		ibmvfc_link_down(vhost, IBMVFC_LINK_DEAD);
> +		ibmvfc_free_event(evt);
> +		LEAVE;
> +		return;
> +	}
> +
> +	ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_QUERY);
> +	wake_up(&vhost->work_wait_q);
> +
> +	LEAVE;
> +}
> +
> +static void ibmvfc_fabric_login(struct ibmvfc_host *vhost)
> +{
> +	struct ibmvfc_fabric_login *mad;
> +	struct ibmvfc_event *evt = ibmvfc_get_reserved_event(&vhost->crq);
> +	int level = IBMVFC_DEFAULT_LOG_LEVEL;
> +
> +	if (!evt) {

I think we need to hard reset here or we are dead in the water if there are no
events.

> +		ibmvfc_log(vhost, level, "Fabric Login failed: no available events\n");
> +		return;
> +	}
> +
> +	ibmvfc_init_event(evt, ibmvfc_fabric_login_done, IBMVFC_MAD_FORMAT);
> +	mad = &evt->iu.fabric_login;
> +	memset(mad, 0, sizeof(*mad));
> +	if (vhost->scsi_scrqs.protocol == IBMVFC_PROTO_SCSI)
> +		mad->common.opcode = cpu_to_be32(IBMVFC_FABRIC_LOGIN);
> +	else if (vhost->scsi_scrqs.protocol == IBMVFC_PROTO_NVME)
> +		mad->common.opcode = cpu_to_be32(IBMVFC_NVMF_FABRIC_LOGIN);

The VIOS won't return NVMF support unless we advertise it. So, I think its best
to omit any NVMF releveant changes that are spec'd as they aren't being applied
in a proper workflow here anyways. If the driver advertised both SCSI and NVMF
support the current code would never do a NVMF fabric login as it would never
fall through here.

> +	else {
> +		ibmvfc_log(vhost, level, "Fabric Login failed: unknown protocol\n");
> +		return;
> +	}
> +	mad->common.version = cpu_to_be32(1);
> +	mad->common.length = cpu_to_be16(sizeof(*mad));
> +
> +	ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_INIT_WAIT);
> +
> +	if (ibmvfc_send_event(evt, vhost, default_timeout))
> +		ibmvfc_link_down(vhost, IBMVFC_LINK_DOWN);
> +}
> +
>  static void ibmvfc_channel_setup_done(struct ibmvfc_event *evt)
>  {
>  	struct ibmvfc_host *vhost = evt->vhost;
> @@ -5251,8 +5334,12 @@ static void ibmvfc_channel_setup_done(struct ibmvfc_event *evt)
>  		return;
>  	}
>  
> -	ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_QUERY);
> -	wake_up(&vhost->work_wait_q);
> +	if (ibmvfc_check_caps(vhost, (IBMVFC_SUPPORT_SCSI | IBMVFC_SUPPORT_NVMEOF))) {
> +		ibmvfc_fabric_login(vhost);

Again drop the NVMEOF code.

> +	} else {
> +		ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_QUERY);
> +		wake_up(&vhost->work_wait_q);
> +	}
>  }
>  
>  static void ibmvfc_channel_setup(struct ibmvfc_host *vhost)
> @@ -5443,9 +5530,12 @@ static void ibmvfc_npiv_login_done(struct ibmvfc_event *evt)
>  	vhost->host->can_queue = be32_to_cpu(rsp->max_cmds) - IBMVFC_NUM_INTERNAL_REQ;
>  	vhost->host->max_sectors = npiv_max_sectors;
>  
> -	if (ibmvfc_check_caps(vhost, IBMVFC_CAN_SUPPORT_CHANNELS) && vhost->do_enquiry) {
> -		ibmvfc_channel_enquiry(vhost);
> -	} else {
> +	if (ibmvfc_check_caps(vhost, IBMVFC_CAN_SUPPORT_CHANNELS)) {
> +		if (vhost->do_enquiry)
> +			ibmvfc_channel_enquiry(vhost);

I'm not sure I understand expanding this code to a second if block as there is
no functional change.

> +	} else if (ibmvfc_check_caps(vhost, (IBMVFC_SUPPORT_SCSI | IBMVFC_SUPPORT_NVMEOF)))

Again drop NVMEOF and NVMF related changes.

> +		ibmvfc_fabric_login(vhost);
> +	else {
>  		vhost->do_enquiry = 0;
>  		ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_QUERY);
>  		wake_up(&vhost->work_wait_q);
> diff --git a/drivers/scsi/ibmvscsi/ibmvfc.h b/drivers/scsi/ibmvscsi/ibmvfc.h
> index cd0917f70c6d..4f680c5d9558 100644
> --- a/drivers/scsi/ibmvscsi/ibmvfc.h
> +++ b/drivers/scsi/ibmvscsi/ibmvfc.h
> @@ -138,6 +138,8 @@ enum ibmvfc_mad_types {
>  	IBMVFC_CHANNEL_ENQUIRY	= 0x1000,
>  	IBMVFC_CHANNEL_SETUP	= 0x2000,
>  	IBMVFC_CONNECTION_INFO	= 0x4000,
> +	IBMVFC_FABRIC_LOGIN	= 0x8000,
> +	IBMVFC_NVMF_FABRIC_LOGIN	= 0x8001,
>  };
>  
>  struct ibmvfc_mad_common {
> @@ -227,6 +229,8 @@ struct ibmvfc_npiv_login_resp {
>  #define IBMVFC_MAD_VERSION_CAP		0x20
>  #define IBMVFC_HANDLE_VF_WWPN		0x40
>  #define IBMVFC_CAN_SUPPORT_CHANNELS	0x80
> +#define IBMVFC_SUPPORT_NVMEOF		0x100
> +#define IBMVFC_SUPPORT_SCSI		0x200
>  #define IBMVFC_SUPPORT_NOOP_CMD		0x1000
>  	__be32 max_cmds;
>  	__be32 scsi_id_sz;
> @@ -590,6 +594,19 @@ struct ibmvfc_connection_info {
>  	__be64 reserved[16];
>  } __packed __aligned(8);
>  
> +struct ibmvfc_fabric_login {
> +	struct ibmvfc_mad_common common;
> +	__be64 flags;
> +#define IBMVFC_STRIP_MERGE	0x1
> +#define IBMVFC_LINK_COMMANDS	0x2
> +	__be64 capabilities;
> +	__be64 nport_id;
> +	__be16 status;
> +	__be16 error;
> +	__be32 pad;
> +	__be64 reserved[16];
> +} __packed __aligned(8);
> +
>  struct ibmvfc_trace_start_entry {
>  	u32 xfer_len;
>  } __packed;
> @@ -709,6 +726,7 @@ union ibmvfc_iu {
>  	struct ibmvfc_channel_enquiry channel_enquiry;
>  	struct ibmvfc_channel_setup_mad channel_setup;
>  	struct ibmvfc_connection_info connection_info;
> +	struct ibmvfc_fabric_login fabric_login;
>  } __packed __aligned(8);
>  
>  enum ibmvfc_target_action {
> @@ -921,6 +939,8 @@ struct ibmvfc_host {
>  	struct work_struct rport_add_work_q;
>  	wait_queue_head_t init_wait_q;
>  	wait_queue_head_t work_wait_q;
> +	__be64 fabric_capabilities;
> +	unsigned int login_cap_index;

Lets drop these as they serve no purpose for Linux. If the spec changes to
introduce capabilites releveant to Linux we can add it then.

-Tyrel

>  };
>  
>  #define DBG_CMD(CMD) do { if (ibmvfc_debug) CMD; } while (0)
>