On 2/25/21 1:42 PM, Tyrel Datwyler wrote:
> A live partition migration (LPM) results in a CRQ disconnect similar to
> a hard reset. In this LPM case the hypervisor moslty perserves the CRQ
> transport such that it simply needs to be reenabled. However, the
> capabilities may have changed such as fewer channels, or no channels at
> all. Further, its possible that there may be sub-CRQ support, but no
> channel support. The CRQ reenable path currently doesn't take any of
> this into consideration.
>
> For simpilicty release and reinitialize sub-CRQs during reenable, and
> set do_enquiry and using_channels with the appropriate values to trigger
> channel renegotiation.
>
> Signed-off-by: Tyrel Datwyler <tyreld@xxxxxxxxxxxxx>
> ---
> drivers/scsi/ibmvscsi/ibmvfc.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c
> index 1bb08e5f3674..6bbc2697ad5a 100644
> --- a/drivers/scsi/ibmvscsi/ibmvfc.c
> +++ b/drivers/scsi/ibmvscsi/ibmvfc.c
> @@ -903,6 +903,9 @@ static int ibmvfc_reenable_crq_queue(struct ibmvfc_host *vhost)
> {
> int rc = 0;
> struct vio_dev *vdev = to_vio_dev(vhost->dev);
> + unsigned long flags;
> +
> + ibmvfc_release_sub_crqs(vhost);
>
> /* Re-enable the CRQ */
> do {
> @@ -914,6 +917,15 @@ static int ibmvfc_reenable_crq_queue(struct ibmvfc_host *vhost)
> if (rc)
> dev_err(vhost->dev, "Error enabling adapter (rc=%d)\n", rc);
>
> + ibmvfc_init_sub_crqs(vhost);
Realized that if this fails it set the do_enquiry flag to zero which the locked
region below will then flip back to one. Need to move sub-crq init to after
locked region.
-T
> +
> + spin_lock_irqsave(vhost->host->host_lock, flags);
> + spin_lock(vhost->crq.q_lock);
> + vhost->do_enquiry = 1;
> + vhost->using_channels = 0;
> + spin_unlock(vhost->crq.q_lock);
> + spin_unlock_irqrestore(vhost->host->host_lock, flags);
> +
> return rc;
> }
>
>
