Re: [PATCH v9 07/13] lpfc: vmid: Implements ELS commands for appid patch

[Benjamin Block <bblock@linux.ibm.com>]

Hey,

On Wed, Apr 07, 2021 at 04:36:31AM +0530, Muneendra wrote:
> From: Gaurav Srivastava <gaurav.srivastava@broadcom.com>
> 
> This patch implements ELS command like QFPA and UVEM for the priority
> tagging appid support. Other supporting functions are also part of this
> patch.
> 
> Signed-off-by: Gaurav Srivastava  <gaurav.srivastava@broadcom.com>
> Signed-off-by: James Smart <jsmart2021@gmail.com>
> 
> ---
> v9:
> Added a lock while accessing a flag
> 
> v8:
> Added log messages modifications, memory allocation API changes,
> return error codes
> 
> v7:
> No change
> 
> v6:
> Added Forward declarations, static functions and
> removed unused variables
> 
> v5:
> Changed Return code to non-numeric/Symbol.
> Addressed the review comments by Hannes
> 
> v4:
> No change
> 
> v3:
> No change
> 
> v2:
> Ported the patch on top of 5.10/scsi-queue
> ---
>  drivers/scsi/lpfc/lpfc_els.c | 366 ++++++++++++++++++++++++++++++++++-
>  1 file changed, 362 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/scsi/lpfc/lpfc_els.c b/drivers/scsi/lpfc/lpfc_els.c
> index a04546eca18f..22a87559f62d 100644
> --- a/drivers/scsi/lpfc/lpfc_els.c
> +++ b/drivers/scsi/lpfc/lpfc_els.c
> @@ -10260,3 +10309,312 @@ lpfc_sli_abts_recover_port(struct lpfc_vport *vport,
>  	lpfc_unreg_rpi(vport, ndlp);
>  }
>  
> +static void lpfc_init_cs_ctl_bitmap(struct lpfc_vport *vport)
> +{
> +	bitmap_zero(vport->vmid_priority_range, LPFC_VMID_MAX_PRIORITY_RANGE);
> +}
> +
> +static void
> +lpfc_vmid_set_cs_ctl_range(struct lpfc_vport *vport, u32 min, u32 max)
> +{
> +	u32 i;
> +
> +	if ((min > max) || (max > LPFC_VMID_MAX_PRIORITY_RANGE))
> +		return;
> +
> +	for (i = min; i <= max; i++)
> +		set_bit(i, vport->vmid_priority_range);
> +}
> +
> +static void lpfc_vmid_put_cs_ctl(struct lpfc_vport *vport, u32 ctcl_vmid)
> +{
> +	set_bit(ctcl_vmid, vport->vmid_priority_range);
> +}
> +
> +u32 lpfc_vmid_get_cs_ctl(struct lpfc_vport *vport)
> +{
> +	u32 i;
> +
> +	i = find_first_bit(vport->vmid_priority_range,
> +			   LPFC_VMID_MAX_PRIORITY_RANGE);
> +
> +	if (i == LPFC_VMID_MAX_PRIORITY_RANGE)
> +		return 0;
> +
> +	clear_bit(i, vport->vmid_priority_range);
> +	return i;
> +}
> +
> +#define MAX_PRIORITY_DESC	255
> +
> +static void
> +lpfc_cmpl_els_qfpa(struct lpfc_hba *phba, struct lpfc_iocbq *cmdiocb,
> +		   struct lpfc_iocbq *rspiocb)
> +{
> +	struct lpfc_vport *vport = cmdiocb->vport;
> +	struct priority_range_desc *desc;
> +	struct lpfc_dmabuf *prsp = NULL;
> +	struct lpfc_vmid_priority_range *vmid_range = NULL;
> +	u32 *data;
> +	struct lpfc_dmabuf *dmabuf = cmdiocb->context2;
> +	IOCB_t *irsp = &rspiocb->iocb;
> +	u8 *pcmd, max_desc;
> +	u32 len, i;
> +	struct lpfc_nodelist *ndlp = (struct lpfc_nodelist *)cmdiocb->context1;
> +
> +	prsp = list_get_first(&dmabuf->list, struct lpfc_dmabuf, list);
> +	if (!prsp)
> +		goto out;
> +
> +	pcmd = prsp->virt;
> +	data = (u32 *)pcmd;
> +	if (data[0] == ELS_CMD_LS_RJT) {
> +		lpfc_printf_vlog(vport, KERN_WARNING, LOG_SLI,
> +				 "3277 QFPA LS_RJT x%x  x%x\n",
> +				 data[0], data[1]);
> +		goto out;
> +	}
> +	if (irsp->ulpStatus) {
> +		lpfc_printf_vlog(vport, KERN_ERR, LOG_SLI,
> +				 "6529 QFPA failed with status x%x  x%x\n",
> +				 irsp->ulpStatus, irsp->un.ulpWord[4]);
> +		goto out;
> +	}
> +
> +	if (!vport->qfpa_res) {
> +		max_desc = FCELSSIZE / sizeof(*vport->qfpa_res);
> +		vport->qfpa_res = kcalloc(max_desc, sizeof(*vport->qfpa_res),
> +					  GFP_KERNEL);
> +		if (!vport->qfpa_res)
> +			goto out;
> +	}
> +
> +	len = *((u32 *)(pcmd + 4));
> +	len = be32_to_cpu(len);
> +	memcpy(vport->qfpa_res, pcmd, len + 8);
> +	len = len / LPFC_PRIORITY_RANGE_DESC_SIZE;
> +
> +	desc = (struct priority_range_desc *)(pcmd + 8);
> +	vmid_range = vport->vmid_priority.vmid_range;
> +	if (!vmid_range) {
> +		vmid_range = kcalloc(MAX_PRIORITY_DESC, sizeof(*vmid_range),
> +				     GFP_KERNEL);
> +		if (!vmid_range) {
> +			kfree(vport->qfpa_res);
> +			goto out;
> +		}
> +		vport->vmid_priority.vmid_range = vmid_range;
> +	}
> +	vport->vmid_priority.num_descriptors = len;
> +
> +	for (i = 0; i < len; i++, vmid_range++, desc++) {
> +		lpfc_printf_vlog(vport, KERN_DEBUG, LOG_ELS,
> +				 "6539 vmid values low=%d, high=%d, qos=%d, "
> +				 "local ve id=%d\n", desc->lo_range,
> +				 desc->hi_range, desc->qos_priority,
> +				 desc->local_ve_id);
> +
> +		vmid_range->low = desc->lo_range << 1;
> +		if (desc->local_ve_id == QFPA_ODD_ONLY)
> +			vmid_range->low++;
> +		if (desc->qos_priority)
> +			vport->vmid_flag |= LPFC_VMID_QOS_ENABLED;
> +		vmid_range->qos = desc->qos_priority;

I'm curios, if the FC-switch signals it supports QoS for a range here, how
exactly interacts this with the VM IDs that you seem to allocate
dynamically during runtime for cgroups that request specific App IDs?
You don't seem to use `LPFC_VMID_QOS_ENABLED` anywhere else in the
series.

Would different cgroups get different QoS classes/guarantees depending
on the selected VM ID (higher VM ID gets better QoS class, or something
like that?)? Would the tagged traffic be handled differently than the
ordinary traffic in the fabric?

I tried to get something from FC-LS (-5) or FC-FS (-6), but they are extremely
sparse somehow. FC-LS-5 just says "QoS priority provided" for the
field.. and FC-FS doesn't say anything regarding QoS if the tagging
extension in CS_CTL is used.

> +
> +		vmid_range->high = desc->hi_range << 1;
> +		if ((desc->local_ve_id == QFPA_ODD_ONLY) ||
> +		    (desc->local_ve_id == QFPA_EVEN_ODD))
> +			vmid_range->high++;
> +	}
> +	lpfc_init_cs_ctl_bitmap(vport);
> +	for (i = 0; i < vport->vmid_priority.num_descriptors; i++) {
> +		lpfc_vmid_set_cs_ctl_range(vport,
> +				vport->vmid_priority.vmid_range[i].low,
> +				vport->vmid_priority.vmid_range[i].high);
> +	}
> +
> +	vport->vmid_flag |= LPFC_VMID_QFPA_CMPL;
> + out:
> +	lpfc_els_free_iocb(phba, cmdiocb);
> +	lpfc_nlp_put(ndlp);
> +}
> +
> +int lpfc_issue_els_qfpa(struct lpfc_vport *vport)
> +{
> +	struct lpfc_hba *phba = vport->phba;
> +	struct lpfc_nodelist *ndlp;
> +	struct lpfc_iocbq *elsiocb;
> +	u8 *pcmd;
> +	int ret;
> +
> +	ndlp = lpfc_findnode_did(phba->pport, Fabric_DID);
> +	if (!ndlp || ndlp->nlp_state != NLP_STE_UNMAPPED_NODE)
> +		return -ENXIO;
> +
> +	elsiocb = lpfc_prep_els_iocb(vport, 1, LPFC_QFPA_SIZE, 2, ndlp,
> +				     ndlp->nlp_DID, ELS_CMD_QFPA);
> +	if (!elsiocb)
> +		return -ENOMEM;
> +
> +	pcmd = (u8 *)(((struct lpfc_dmabuf *)elsiocb->context2)->virt);
> +
> +	*((u32 *)(pcmd)) = ELS_CMD_QFPA;
> +	pcmd += 4;
> +
> +	elsiocb->iocb_cmpl = lpfc_cmpl_els_qfpa;
> +
> +	elsiocb->context1 = lpfc_nlp_get(ndlp);
> +	if (!elsiocb->context1) {
> +		lpfc_els_free_iocb(vport->phba, elsiocb);
> +		return -ENXIO;
> +	}
> +
> +	ret = lpfc_sli_issue_iocb(phba, LPFC_ELS_RING, elsiocb, 2);
> +	if (ret != IOCB_SUCCESS) {
> +		lpfc_els_free_iocb(phba, elsiocb);
> +		lpfc_nlp_put(ndlp);
> +		return -EIO;
> +	}
> +	vport->vmid_flag &= ~LPFC_VMID_QOS_ENABLED;
> +	return 0;
> +}

-- 
Best Regards, Benjamin Block  / Linux on IBM Z Kernel Development / IBM Systems
IBM Deutschland Research & Development GmbH    /    https://www.ibm.com/privacy
Vorsitz. AufsR.: Gregor Pillen         /        Geschäftsführung: Dirk Wittkopp
Sitz der Gesellschaft: Böblingen / Registergericht: AmtsG Stuttgart, HRB 243294

_______________________________________________
Linux-nvme mailing list
Linux-nvme@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-nvme