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

From: Dave Marquardt <[email-masked]>
Date: Thu, 07 May 2026 17:34:04 -0500

Tyrel Datwyler <[email-masked]> writes:

> On 4/8/26 10:07 AM, Dave Marquardt via B4 Relay wrote:
>> From: Dave Marquardt <[email-masked]>
>> 
>> 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.

Agreed.

>> +		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.

Okay.

>> +		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.

I will add a hard reset here.

>> +		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.

Okay, I'll removed the NVMF changes.

>> +	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.

Okay.

>> +	} 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.

Agreed.

>> +	} else if (ibmvfc_check_caps(vhost, (IBMVFC_SUPPORT_SCSI | IBMVFC_SUPPORT_NVMEOF)))
>
> Again drop NVMEOF and NVMF related changes.

Yes.

>> +		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.

Okay. You discussed fabric_capabilities. I think login_cap_index isn't
useful until patch 4 or 5, so I'll drop it from patch 4.

-Dave