Commit 33c79741 authored by Gaurav Srivastava's avatar Gaurav Srivastava Committed by Martin K. Petersen
Browse files

scsi: lpfc: vmid: Introduce VMID in I/O path 

Introduce the VMID in the I/O path. Check if the VMID is enabled and if
the I/O belongs to a VM or not.

Link: https://lore.kernel.org/r/20210608043556.274139-14-muneendra.kumar@broadcom.com


Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
Signed-off-by: default avatarGaurav Srivastava <gaurav.srivastava@broadcom.com>
Signed-off-by: default avatarJames Smart <jsmart2021@gmail.com>
Signed-off-by: default avatarMuneendra Kumar <muneendra.kumar@broadcom.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 0c4792c6

drivers/scsi/lpfc/lpfc_scsi.c

+174 −0
Original line number Diff line number Diff line
@@ -5278,6 +5278,160 @@ static void lpfc_vmid_assign_cs_ctl(struct lpfc_vport *vport, 
	}

}



/*

 * lpfc_vmid_get_appid - get the VMID associated with the UUID

 * @vport: The virtual port for which this call is being executed.

 * @uuid: UUID associated with the VE

 * @cmd: address of scsi_cmd descriptor

 * @tag: VMID tag

 * Returns status of the function

 */

static int lpfc_vmid_get_appid(struct lpfc_vport *vport, char *uuid, struct

			       scsi_cmnd * cmd, union lpfc_vmid_io_tag *tag)

{

	struct lpfc_vmid *vmp = NULL;

	int hash, len, rc, i;



	/* check if QFPA is complete */

	if (lpfc_vmid_is_type_priority_tag(vport) && !(vport->vmid_flag &

	      LPFC_VMID_QFPA_CMPL)) {

		vport->work_port_events |= WORKER_CHECK_VMID_ISSUE_QFPA;

		return -EAGAIN;

	}



	/* search if the UUID has already been mapped to the VMID */

	len = strlen(uuid);

	hash = lpfc_vmid_hash_fn(uuid, len);



	/* search for the VMID in the table */

	read_lock(&vport->vmid_lock);

	vmp = lpfc_get_vmid_from_hashtable(vport, hash, uuid);



	/* if found, check if its already registered  */

	if (vmp  && vmp->flag & LPFC_VMID_REGISTERED) {

		read_unlock(&vport->vmid_lock);

		lpfc_vmid_update_entry(vport, cmd, vmp, tag);

		rc = 0;

	} else if (vmp && (vmp->flag & LPFC_VMID_REQ_REGISTER ||

			   vmp->flag & LPFC_VMID_DE_REGISTER)) {

		/* else if register or dereg request has already been sent */

		/* Hence VMID tag will not be added for this I/O */

		read_unlock(&vport->vmid_lock);

		rc = -EBUSY;

	} else {

		/* The VMID was not found in the hashtable. At this point, */

		/* drop the read lock first before proceeding further */

		read_unlock(&vport->vmid_lock);

		/* start the process to obtain one as per the */

		/* type of the VMID indicated */

		write_lock(&vport->vmid_lock);

		vmp = lpfc_get_vmid_from_hashtable(vport, hash, uuid);



		/* while the read lock was released, in case the entry was */

		/* added by other context or is in process of being added */

		if (vmp && vmp->flag & LPFC_VMID_REGISTERED) {

			lpfc_vmid_update_entry(vport, cmd, vmp, tag);

			write_unlock(&vport->vmid_lock);

			return 0;

		} else if (vmp && vmp->flag & LPFC_VMID_REQ_REGISTER) {

			write_unlock(&vport->vmid_lock);

			return -EBUSY;

		}



		/* else search and allocate a free slot in the hash table */

		if (vport->cur_vmid_cnt < vport->max_vmid) {

			for (i = 0; i < vport->max_vmid; i++) {

				vmp = vport->vmid + i;

				if (vmp->flag == LPFC_VMID_SLOT_FREE)

					break;

			}

			if (i == vport->max_vmid)

				vmp = NULL;

		} else {

			vmp = NULL;

		}



		if (!vmp) {

			write_unlock(&vport->vmid_lock);

			return -ENOMEM;

		}



		/* Add the vmid and register */

		lpfc_put_vmid_in_hashtable(vport, hash, vmp);

		vmp->vmid_len = len;

		memcpy(vmp->host_vmid, uuid, vmp->vmid_len);

		vmp->io_rd_cnt = 0;

		vmp->io_wr_cnt = 0;

		vmp->flag = LPFC_VMID_SLOT_USED;



		vmp->delete_inactive =

			vport->vmid_inactivity_timeout ? 1 : 0;



		/* if type priority tag, get next available VMID */

		if (lpfc_vmid_is_type_priority_tag(vport))

			lpfc_vmid_assign_cs_ctl(vport, vmp);



		/* allocate the per cpu variable for holding */

		/* the last access time stamp only if VMID is enabled */

		if (!vmp->last_io_time)

			vmp->last_io_time = __alloc_percpu(sizeof(u64),

							   __alignof__(struct

							   lpfc_vmid));

		if (!vmp->last_io_time) {

			hash_del(&vmp->hnode);

			vmp->flag = LPFC_VMID_SLOT_FREE;

			write_unlock(&vport->vmid_lock);

			return -EIO;

		}



		write_unlock(&vport->vmid_lock);



		/* complete transaction with switch */

		if (lpfc_vmid_is_type_priority_tag(vport))

			rc = lpfc_vmid_uvem(vport, vmp, true);

		else

			rc = lpfc_vmid_cmd(vport, SLI_CTAS_RAPP_IDENT, vmp);

		if (!rc) {

			write_lock(&vport->vmid_lock);

			vport->cur_vmid_cnt++;

			vmp->flag |= LPFC_VMID_REQ_REGISTER;

			write_unlock(&vport->vmid_lock);

		} else {

			write_lock(&vport->vmid_lock);

			hash_del(&vmp->hnode);

			vmp->flag = LPFC_VMID_SLOT_FREE;

			free_percpu(vmp->last_io_time);

			write_unlock(&vport->vmid_lock);

			return -EIO;

		}



		/* finally, enable the idle timer once */

		if (!(vport->phba->pport->vmid_flag & LPFC_VMID_TIMER_ENBLD)) {

			mod_timer(&vport->phba->inactive_vmid_poll,

				  jiffies +

				  msecs_to_jiffies(1000 * LPFC_VMID_TIMER));

			vport->phba->pport->vmid_flag |= LPFC_VMID_TIMER_ENBLD;

		}

	}

	return rc;

}



/*

 * lpfc_is_command_vm_io - get the UUID from blk cgroup

 * @cmd: Pointer to scsi_cmnd data structure

 * Returns UUID if present, otherwise NULL

 */

static char *lpfc_is_command_vm_io(struct scsi_cmnd *cmd)

{

	char *uuid = NULL;



	if (cmd->request) {

		if (cmd->request->bio)

			uuid = blkcg_get_fc_appid(cmd->request->bio);

	}

	return uuid;

}



/**

 * lpfc_queuecommand - scsi_host_template queuecommand entry point

 * @shost: kernel scsi host pointer.
@@ -5303,6 +5457,7 @@ lpfc_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *cmnd) 
	int err, idx;

#ifdef CONFIG_SCSI_LPFC_DEBUG_FS

	uint64_t start = 0L;

	u8 *uuid = NULL;



	if (phba->ktime_on)

		start = ktime_get_ns();
@@ -5430,6 +5585,25 @@ lpfc_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *cmnd) 
	}





	/* check the necessary and sufficient condition to support VMID */

	if (lpfc_is_vmid_enabled(phba) &&

	    (ndlp->vmid_support ||

	     phba->pport->vmid_priority_tagging ==

	     LPFC_VMID_PRIO_TAG_ALL_TARGETS)) {

		/* is the I/O generated by a VM, get the associated virtual */

		/* entity id */

		uuid = lpfc_is_command_vm_io(cmnd);



		if (uuid) {

			err = lpfc_vmid_get_appid(vport, uuid, cmnd,

				(union lpfc_vmid_io_tag *)

					&lpfc_cmd->cur_iocbq.vmid_tag);

			if (!err)

				lpfc_cmd->cur_iocbq.iocb_flag |= LPFC_IO_VMID;

		}

	}



	atomic_inc(&ndlp->cmd_pending);

#ifdef CONFIG_SCSI_LPFC_DEBUG_FS

	if (unlikely(phba->hdwqstat_on & LPFC_CHECK_SCSI_IO))

		this_cpu_inc(phba->sli4_hba.c_stat->xmt_io);