Re: [PATCH v8 8/9] scsi: ibmvfc: register and use asynchronous sub CRQ for events

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

On 9/9/26 12:08 PM, Dave Marquardt via B4 Relay wrote:
> From: Dave Marquardt <davemarq@linux.ibm.com>
> 
> Wire the async sub-CRQ into the sub-CRQ lifecycle so it is allocated,
> registered, and freed alongside the SCSI channel queues.
> 
> In ibmvfc_init_sub_crqs(), allocate the async sub-CRQ queue buffer via
> ibmvfc_alloc_queue() before allocating the SCSI channels. Register it
> with the VIOS by calling ibmvfc_register_channel() with index -1 (the
> negative-index sentinel introduced in the previous commit). Either
> failure disables multi-queue and aborts init.
> 
> In ibmvfc_release_sub_crqs(), ibmvfc_reenable_crq_queue(), and
> ibmvfc_reset_crq(), deregister and re-register the async sub-CRQ
> alongside the SCSI channel queues.
> 
> In ibmvfc_channel_setup_done(), capture the async sub-CRQ handle
> returned by the VIOS in the channel setup response and store it in
> vhost->async_sub_crq.vios_cookie.
> 
> In ibmvfc_set_login_info(), advertise IBMVFC_USE_ASYNC_SUBQ,
> IBMVFC_CAN_HANDLE_FPIN, and IBMVFC_YES_SCSI capabilities whenever
> multi-queue channels are enabled. IBMVFC_YES_SCSI was previously only
> set for NVMe-enabled configurations; move it to the common multi-queue
> path so it is always advertised when channels are in use.
> 
> Fix a variable-shadowing bug in ibmvfc_register_channel() where the
> irq_failed cleanup loop reused rc for the H_FREE_SUB_CRQ hcall result,
> clobbering the error code returned to the caller. Introduce hcall_rc
> for the cleanup loop instead.
> 
> Guard the memset() in ibmvfc_deregister_channel() behind a check of
> scrq->msgs.handle to prevent a NULL dereference when the function is
> called on a queue that was never allocated, such as async_sub_crq when
> multi-queue is disabled or initialization failed before
> ibmvfc_alloc_queue() was reached.
> 
> Signed-off-by: Dave Marquardt <davemarq@linux.ibm.com>
> ---
Acked-by: Tyrel Datwyler <tyreld@linux.ibm.com>