nvme/host/fabrics.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 /*
0003  * NVMe over Fabrics common host code.
0004  * Copyright (c) 2015-2016 HGST, a Western Digital Company.
0005  */
0006 #ifndef _NVME_FABRICS_H
0007 #define _NVME_FABRICS_H 1
0008
0009 #include <linux/in.h>
0010 #include <linux/inet.h>
0011
0012 #define NVMF_MIN_QUEUE_SIZE 16
0013 #define NVMF_MAX_QUEUE_SIZE 1024
0014 #define NVMF_DEF_QUEUE_SIZE 128
0015 #define NVMF_DEF_RECONNECT_DELAY    10
0016 /* default to 600 seconds of reconnect attempts before giving up */
0017 #define NVMF_DEF_CTRL_LOSS_TMO      600
0018 /* default is -1: the fail fast mechanism is disabled  */
0019 #define NVMF_DEF_FAIL_FAST_TMO      -1
0020
0021 /*
0022  * Reserved one command for internal usage.  This command is used for sending
0023  * the connect command, as well as for the keep alive command on the admin
0024  * queue once live.
0025  */
0026 #define NVMF_RESERVED_TAGS  1
0027
0028 /*
0029  * Define a host as seen by the target.  We allocate one at boot, but also
0030  * allow the override it when creating controllers.  This is both to provide
0031  * persistence of the Host NQN over multiple boots, and to allow using
0032  * multiple ones, for example in a container scenario.  Because we must not
0033  * use different Host NQNs with the same Host ID we generate a Host ID and
0034  * use this structure to keep track of the relation between the two.
0035  */
0036 struct nvmf_host {
0037     struct kref     ref;
0038     struct list_head    list;
0039     char            nqn[NVMF_NQN_SIZE];
0040     uuid_t          id;
0041 };
0042
0043 /**
0044  * enum nvmf_parsing_opts - used to define the sysfs parsing options used.
0045  */
0046 enum {
0047     NVMF_OPT_ERR        = 0,
0048     NVMF_OPT_TRANSPORT  = 1 << 0,
0049     NVMF_OPT_NQN        = 1 << 1,
0050     NVMF_OPT_TRADDR     = 1 << 2,
0051     NVMF_OPT_TRSVCID    = 1 << 3,
0052     NVMF_OPT_QUEUE_SIZE = 1 << 4,
0053     NVMF_OPT_NR_IO_QUEUES   = 1 << 5,
0054     NVMF_OPT_TL_RETRY_COUNT = 1 << 6,
0055     NVMF_OPT_KATO       = 1 << 7,
0056     NVMF_OPT_HOSTNQN    = 1 << 8,
0057     NVMF_OPT_RECONNECT_DELAY = 1 << 9,
0058     NVMF_OPT_HOST_TRADDR    = 1 << 10,
0059     NVMF_OPT_CTRL_LOSS_TMO  = 1 << 11,
0060     NVMF_OPT_HOST_ID    = 1 << 12,
0061     NVMF_OPT_DUP_CONNECT    = 1 << 13,
0062     NVMF_OPT_DISABLE_SQFLOW = 1 << 14,
0063     NVMF_OPT_HDR_DIGEST = 1 << 15,
0064     NVMF_OPT_DATA_DIGEST    = 1 << 16,
0065     NVMF_OPT_NR_WRITE_QUEUES = 1 << 17,
0066     NVMF_OPT_NR_POLL_QUEUES = 1 << 18,
0067     NVMF_OPT_TOS        = 1 << 19,
0068     NVMF_OPT_FAIL_FAST_TMO  = 1 << 20,
0069     NVMF_OPT_HOST_IFACE = 1 << 21,
0070     NVMF_OPT_DISCOVERY  = 1 << 22,
0071     NVMF_OPT_DHCHAP_SECRET  = 1 << 23,
0072     NVMF_OPT_DHCHAP_CTRL_SECRET = 1 << 24,
0073 };
0074
0075 /**
0076  * struct nvmf_ctrl_options - Used to hold the options specified
0077  *                with the parsing opts enum.
0078  * @mask:   Used by the fabrics library to parse through sysfs options
0079  *      on adding a NVMe controller.
0080  * @transport:  Holds the fabric transport "technology name" (for a lack of
0081  *      better description) that will be used by an NVMe controller
0082  *      being added.
0083  * @subsysnqn:  Hold the fully qualified NQN subystem name (format defined
0084  *      in the NVMe specification, "NVMe Qualified Names").
0085  * @traddr: The transport-specific TRADDR field for a port on the
0086  *              subsystem which is adding a controller.
0087  * @trsvcid:    The transport-specific TRSVCID field for a port on the
0088  *              subsystem which is adding a controller.
0089  * @host_traddr: A transport-specific field identifying the NVME host port
0090  *     to use for the connection to the controller.
0091  * @host_iface: A transport-specific field identifying the NVME host
0092  *     interface to use for the connection to the controller.
0093  * @queue_size: Number of IO queue elements.
0094  * @nr_io_queues: Number of controller IO queues that will be established.
0095  * @reconnect_delay: Time between two consecutive reconnect attempts.
0096  * @discovery_nqn: indicates if the subsysnqn is the well-known discovery NQN.
0097  * @kato:   Keep-alive timeout.
0098  * @host:   Virtual NVMe host, contains the NQN and Host ID.
0099  * @max_reconnects: maximum number of allowed reconnect attempts before removing
0100  *              the controller, (-1) means reconnect forever, zero means remove
0101  *              immediately;
0102  * @dhchap_secret: DH-HMAC-CHAP secret
0103  * @dhchap_ctrl_secret: DH-HMAC-CHAP controller secret for bi-directional
0104  *              authentication
0105  * @disable_sqflow: disable controller sq flow control
0106  * @hdr_digest: generate/verify header digest (TCP)
0107  * @data_digest: generate/verify data digest (TCP)
0108  * @nr_write_queues: number of queues for write I/O
0109  * @nr_poll_queues: number of queues for polling I/O
0110  * @tos: type of service
0111  * @fast_io_fail_tmo: Fast I/O fail timeout in seconds
0112  */
0113 struct nvmf_ctrl_options {
0114     unsigned        mask;
0115     char            *transport;
0116     char            *subsysnqn;
0117     char            *traddr;
0118     char            *trsvcid;
0119     char            *host_traddr;
0120     char            *host_iface;
0121     size_t          queue_size;
0122     unsigned int        nr_io_queues;
0123     unsigned int        reconnect_delay;
0124     bool            discovery_nqn;
0125     bool            duplicate_connect;
0126     unsigned int        kato;
0127     struct nvmf_host    *host;
0128     int         max_reconnects;
0129     char            *dhchap_secret;
0130     char            *dhchap_ctrl_secret;
0131     bool            disable_sqflow;
0132     bool            hdr_digest;
0133     bool            data_digest;
0134     unsigned int        nr_write_queues;
0135     unsigned int        nr_poll_queues;
0136     int         tos;
0137     int         fast_io_fail_tmo;
0138 };
0139
0140 /*
0141  * struct nvmf_transport_ops - used to register a specific
0142  *                 fabric implementation of NVMe fabrics.
0143  * @entry:      Used by the fabrics library to add the new
0144  *          registration entry to its linked-list internal tree.
0145  * @module:             Transport module reference
0146  * @name:       Name of the NVMe fabric driver implementation.
0147  * @required_opts:  sysfs command-line options that must be specified
0148  *          when adding a new NVMe controller.
0149  * @allowed_opts:   sysfs command-line options that can be specified
0150  *          when adding a new NVMe controller.
0151  * @create_ctrl():  function pointer that points to a non-NVMe
0152  *          implementation-specific fabric technology
0153  *          that would go into starting up that fabric
0154  *          for the purpose of conneciton to an NVMe controller
0155  *          using that fabric technology.
0156  *
0157  * Notes:
0158  *  1. At minimum, 'required_opts' and 'allowed_opts' should
0159  *     be set to the same enum parsing options defined earlier.
0160  *  2. create_ctrl() must be defined (even if it does nothing)
0161  *  3. struct nvmf_transport_ops must be statically allocated in the
0162  *     modules .bss section so that a pure module_get on @module
0163  *     prevents the memory from beeing freed.
0164  */
0165 struct nvmf_transport_ops {
0166     struct list_head    entry;
0167     struct module       *module;
0168     const char      *name;
0169     int         required_opts;
0170     int         allowed_opts;
0171     struct nvme_ctrl    *(*create_ctrl)(struct device *dev,
0172                     struct nvmf_ctrl_options *opts);
0173 };
0174
0175 static inline bool
0176 nvmf_ctlr_matches_baseopts(struct nvme_ctrl *ctrl,
0177             struct nvmf_ctrl_options *opts)
0178 {
0179     if (ctrl->state == NVME_CTRL_DELETING ||
0180         ctrl->state == NVME_CTRL_DELETING_NOIO ||
0181         ctrl->state == NVME_CTRL_DEAD ||
0182         strcmp(opts->subsysnqn, ctrl->opts->subsysnqn) ||
0183         strcmp(opts->host->nqn, ctrl->opts->host->nqn) ||
0184         memcmp(&opts->host->id, &ctrl->opts->host->id, sizeof(uuid_t)))
0185         return false;
0186
0187     return true;
0188 }
0189
0190 static inline char *nvmf_ctrl_subsysnqn(struct nvme_ctrl *ctrl)
0191 {
0192     if (!ctrl->subsys)
0193         return ctrl->opts->subsysnqn;
0194     return ctrl->subsys->subnqn;
0195 }
0196
0197 static inline void nvmf_complete_timed_out_request(struct request *rq)
0198 {
0199     if (blk_mq_request_started(rq) && !blk_mq_request_completed(rq)) {
0200         nvme_req(rq)->status = NVME_SC_HOST_ABORTED_CMD;
0201         blk_mq_complete_request(rq);
0202     }
0203 }
0204
0205 int nvmf_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val);
0206 int nvmf_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val);
0207 int nvmf_reg_write32(struct nvme_ctrl *ctrl, u32 off, u32 val);
0208 int nvmf_connect_admin_queue(struct nvme_ctrl *ctrl);
0209 int nvmf_connect_io_queue(struct nvme_ctrl *ctrl, u16 qid);
0210 int nvmf_register_transport(struct nvmf_transport_ops *ops);
0211 void nvmf_unregister_transport(struct nvmf_transport_ops *ops);
0212 void nvmf_free_options(struct nvmf_ctrl_options *opts);
0213 int nvmf_get_address(struct nvme_ctrl *ctrl, char *buf, int size);
0214 bool nvmf_should_reconnect(struct nvme_ctrl *ctrl);
0215 bool nvmf_ip_options_match(struct nvme_ctrl *ctrl,
0216         struct nvmf_ctrl_options *opts);
0217
0218 #endif /* _NVME_FABRICS_H */