Re: [PATCH v3 10/13] scsi: fnic: Add support for multiqueue (MQ) in fnic_main.c

[John Garry <john.g.garry@oracle.com>]

On 15/11/2023 23:20, Karan Tilak Kumar (kartilak) wrote:
>>> +
>>> +     if (intr_mode == VNIC_DEV_INTR_MODE_MSI || intr_mode == VNIC_DEV_INTR_MODE_INTX) {
>>> +             FNIC_MAIN_DBG(KERN_ERR, fnic->lport->host, fnic->fnic_num,
>>> +                     "intr_mode is not msix\n");
>>                        Are these checks just paranoia? I mean that it is strange to have
>>                        fnic_mq_map_queues_cpus() called but not be required to do anything.
>>
> Unified Computing Servers Management (UCSM) is a GUI tool to configure Cisco Servers.
> There are interrupt options that can be modified to INTX or MSI or MSI-x.
> All these options are still supported.
> 
> However, we do not support multiqueue (MQ) on MSI or INTX.

By this I assume it means nr_hw_queues = 1 for MSI or INTX

> These checks are present to only prevent an MQ "misconfiguration".

If you check blk_mq_update_queue_map(), for set->ops->map_queues unset 
we call blk_mq_map_queues() - I am just wondering what does the 
equivalent to blk_mq_map_queues() for you in these other modes.

I am concerned that it is not proper that we have a set->ops->map_queues 
method, but it does nothing in some scenarios.

Thanks,
John