[PATCH v6 15/16] lpfc: vmid: Introducing vmid in io path.

Muneendra muneendra.kumar at broadcom.com
Mon Dec 21 19:11:57 EST 2020


From: Gaurav Srivastava <gaurav.srivastava at broadcom.com>

The patch introduces the vmid in the io path. It checks if the vmid is
enabled and if io belongs to a vm or not and acts accordingly. Other
supporing APIs are also included in the patch.

Signed-off-by: Gaurav Srivastava  <gaurav.srivastava at broadcom.com>
Signed-off-by: James Smart <jsmart2021 at gmail.com>

---
v6:
No change

v5:
No change

v4:
No change

v3:
Replaced blkcg_get_app_identifier with blkcg_get_fc_appid

v2:
Ported the patch on top of 5.10/scsi-queue
Added a fix for issuing QFPA command which was not included in the
last submit
---
 drivers/scsi/lpfc/lpfc_scsi.c | 165 ++++++++++++++++++++++++++++++++++
 1 file changed, 165 insertions(+)

diff --git a/drivers/scsi/lpfc/lpfc_scsi.c b/drivers/scsi/lpfc/lpfc_scsi.c
index 53baee21e0f9..21f151492a18 100644
--- a/drivers/scsi/lpfc/lpfc_scsi.c
+++ b/drivers/scsi/lpfc/lpfc_scsi.c
@@ -5279,6 +5279,151 @@ 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 cmmd 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 = 1, i;
+	u8 pending = 0;
+
+	/* 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 FAILURE;
+	}
+
+	/* 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_hastable(vport, hash, uuid);
+	read_unlock(&vport->vmid_lock);
+
+	/* if found, check if its already registered  */
+	if (vmp  && vmp->flag & LPFC_VMID_REGISTERED) {
+		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 IO */
+		rc = 1;
+	} else {
+		/* else, start the process to obtain one as per the */
+		/* switch connected */
+		write_lock(&vport->vmid_lock);
+		vmp = lpfc_get_vmid_from_hastable(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 FAILURE;
+		}
+
+		/* 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) {
+					vmp = vport->vmid + i;
+					break;
+				}
+			}
+		} else {
+			write_unlock(&vport->vmid_lock);
+			return FAILURE;
+		}
+
+		if (vmp && (vmp->flag == LPFC_VMID_SLOT_FREE)) {
+			vmp->vmid_len = len;
+
+			/* Add the vmid and register  */
+			memcpy(vmp->host_vmid, uuid, vmp->vmid_len);
+			vmp->io_rd_cnt = 0;
+			vmp->io_wr_cnt = 0;
+			vmp->flag = LPFC_VMID_SLOT_USED;
+			lpfc_put_vmid_in_hashtable(vport, hash, vmp);
+
+			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));
+
+			/* registration pending */
+			pending = 1;
+			rc = 1;
+		}
+		write_unlock(&vport->vmid_lock);
+
+		/* complete transaction with switch */
+		if (pending) {
+			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);
+			}
+		}
+
+		/* 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 if not 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.
@@ -5304,6 +5449,7 @@ 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();
@@ -5431,6 +5577,25 @@ 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 IO 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);
-- 
2.26.2


-- 
This electronic communication and the information and any files transmitted 
with it, or attached to it, are confidential and are intended solely for 
the use of the individual or entity to whom it is addressed and may contain 
information that is confidential, legally privileged, protected by privacy 
laws, or otherwise restricted from disclosure to anyone else. If you are 
not the intended recipient or the person responsible for delivering the 
e-mail to the intended recipient, you are hereby notified that any use, 
copying, distributing, dissemination, forwarding, printing, or copying of 
this e-mail is strictly prohibited. If you received this e-mail in error, 
please return the e-mail to the sender, delete it from your computer, and 
destroy any printed copy of it.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/pkcs7-signature
Size: 4177 bytes
Desc: S/MIME Cryptographic Signature
URL: <http://lists.infradead.org/pipermail/linux-nvme/attachments/20201222/2a53b307/attachment.p7s>


More information about the Linux-nvme mailing list