fabrics.h

  1/* SPDX-License-Identifier: GPL-2.0 */
  2/*
  3 * NVMe over Fabrics common host code.
  4 * Copyright (c) 2015-2016 HGST, a Western Digital Company.
  5 */
  6#ifndef _NVME_FABRICS_H
  7#define _NVME_FABRICS_H 1
  8
  9#include <linux/in.h>
 10#include <linux/inet.h>
 11
 12#define NVMF_MIN_QUEUE_SIZE	16
 13#define NVMF_MAX_QUEUE_SIZE	1024
 14#define NVMF_DEF_QUEUE_SIZE	128
 15#define NVMF_DEF_RECONNECT_DELAY	10
 16/* default to 600 seconds of reconnect attempts before giving up */
 17#define NVMF_DEF_CTRL_LOSS_TMO		600
 18/* default is -1: the fail fast mechanism is disabled  */
 19#define NVMF_DEF_FAIL_FAST_TMO		-1
 20
 21/*
 22 * Define a host as seen by the target.  We allocate one at boot, but also
 23 * allow the override it when creating controllers.  This is both to provide
 24 * persistence of the Host NQN over multiple boots, and to allow using
 25 * multiple ones, for example in a container scenario.  Because we must not
 26 * use different Host NQNs with the same Host ID we generate a Host ID and
 27 * use this structure to keep track of the relation between the two.
 28 */
 29struct nvmf_host {
 30	struct kref		ref;
 31	struct list_head	list;
 32	char			nqn[NVMF_NQN_SIZE];
 33	uuid_t			id;
 34};
 35
 36/**
 37 * enum nvmf_parsing_opts - used to define the sysfs parsing options used.
 38 */
 39enum {
 40	NVMF_OPT_ERR		= 0,
 41	NVMF_OPT_TRANSPORT	= 1 << 0,
 42	NVMF_OPT_NQN		= 1 << 1,
 43	NVMF_OPT_TRADDR		= 1 << 2,
 44	NVMF_OPT_TRSVCID	= 1 << 3,
 45	NVMF_OPT_QUEUE_SIZE	= 1 << 4,
 46	NVMF_OPT_NR_IO_QUEUES	= 1 << 5,
 47	NVMF_OPT_TL_RETRY_COUNT	= 1 << 6,
 48	NVMF_OPT_KATO		= 1 << 7,
 49	NVMF_OPT_HOSTNQN	= 1 << 8,
 50	NVMF_OPT_RECONNECT_DELAY = 1 << 9,
 51	NVMF_OPT_HOST_TRADDR	= 1 << 10,
 52	NVMF_OPT_CTRL_LOSS_TMO	= 1 << 11,
 53	NVMF_OPT_HOST_ID	= 1 << 12,
 54	NVMF_OPT_DUP_CONNECT	= 1 << 13,
 55	NVMF_OPT_DISABLE_SQFLOW = 1 << 14,
 56	NVMF_OPT_HDR_DIGEST	= 1 << 15,
 57	NVMF_OPT_DATA_DIGEST	= 1 << 16,
 58	NVMF_OPT_NR_WRITE_QUEUES = 1 << 17,
 59	NVMF_OPT_NR_POLL_QUEUES = 1 << 18,
 60	NVMF_OPT_TOS		= 1 << 19,
 61	NVMF_OPT_FAIL_FAST_TMO	= 1 << 20,
 62	NVMF_OPT_HOST_IFACE	= 1 << 21,
 63	NVMF_OPT_DISCOVERY	= 1 << 22,
 64	NVMF_OPT_DHCHAP_SECRET	= 1 << 23,
 65	NVMF_OPT_DHCHAP_CTRL_SECRET = 1 << 24,
 66	NVMF_OPT_TLS		= 1 << 25,
 67	NVMF_OPT_KEYRING	= 1 << 26,
 68	NVMF_OPT_TLS_KEY	= 1 << 27,
 69	NVMF_OPT_CONCAT		= 1 << 28,
 70};
 71
 72/**
 73 * struct nvmf_ctrl_options - Used to hold the options specified
 74 *			      with the parsing opts enum.
 75 * @mask:	Used by the fabrics library to parse through sysfs options
 76 *		on adding a NVMe controller.
 77 * @max_reconnects: maximum number of allowed reconnect attempts before removing
 78 *		the controller, (-1) means reconnect forever, zero means remove
 79 *		immediately;
 80 * @transport:	Holds the fabric transport "technology name" (for a lack of
 81 *		better description) that will be used by an NVMe controller
 82 *		being added.
 83 * @subsysnqn:	Hold the fully qualified NQN subsystem name (format defined
 84 *		in the NVMe specification, "NVMe Qualified Names").
 85 * @traddr:	The transport-specific TRADDR field for a port on the
 86 *              subsystem which is adding a controller.
 87 * @trsvcid:	The transport-specific TRSVCID field for a port on the
 88 *              subsystem which is adding a controller.
 89 * @host_traddr: A transport-specific field identifying the NVME host port
 90 *     to use for the connection to the controller.
 91 * @host_iface: A transport-specific field identifying the NVME host
 92 *     interface to use for the connection to the controller.
 93 * @queue_size: Number of IO queue elements.
 94 * @nr_io_queues: Number of controller IO queues that will be established.
 95 * @reconnect_delay: Time between two consecutive reconnect attempts.
 96 * @discovery_nqn: indicates if the subsysnqn is the well-known discovery NQN.
 97 * @kato:	Keep-alive timeout.
 98 * @host:	Virtual NVMe host, contains the NQN and Host ID.
 99 * @dhchap_secret: DH-HMAC-CHAP secret
100 * @dhchap_ctrl_secret: DH-HMAC-CHAP controller secret for bi-directional
101 *              authentication
102 * @keyring:    Keyring to use for key lookups
103 * @tls_key:    TLS key for encrypted connections (TCP)
104 * @tls:        Start TLS encrypted connections (TCP)
105 * @concat:     Enabled Secure channel concatenation (TCP)
106 * @disable_sqflow: disable controller sq flow control
107 * @hdr_digest: generate/verify header digest (TCP)
108 * @data_digest: generate/verify data digest (TCP)
109 * @nr_write_queues: number of queues for write I/O
110 * @nr_poll_queues: number of queues for polling I/O
111 * @tos: type of service
112 * @fast_io_fail_tmo: Fast I/O fail timeout in seconds
113 */
114struct nvmf_ctrl_options {
115	unsigned		mask;
116	int			max_reconnects;
117	char			*transport;
118	char			*subsysnqn;
119	char			*traddr;
120	char			*trsvcid;
121	char			*host_traddr;
122	char			*host_iface;
123	size_t			queue_size;
124	unsigned int		nr_io_queues;
125	unsigned int		reconnect_delay;
126	bool			discovery_nqn;
127	bool			duplicate_connect;
128	unsigned int		kato;
129	struct nvmf_host	*host;
130	char			*dhchap_secret;
131	char			*dhchap_ctrl_secret;
132	struct key		*keyring;
133	struct key		*tls_key;
134	bool			tls;
135	bool			concat;
136	bool			disable_sqflow;
137	bool			hdr_digest;
138	bool			data_digest;
139	unsigned int		nr_write_queues;
140	unsigned int		nr_poll_queues;
141	int			tos;
142	int			fast_io_fail_tmo;
143};
144
145/*
146 * struct nvmf_transport_ops - used to register a specific
147 *			       fabric implementation of NVMe fabrics.
148 * @entry:		Used by the fabrics library to add the new
149 *			registration entry to its linked-list internal tree.
150 * @module:             Transport module reference
151 * @name:		Name of the NVMe fabric driver implementation.
152 * @required_opts:	sysfs command-line options that must be specified
153 *			when adding a new NVMe controller.
154 * @allowed_opts:	sysfs command-line options that can be specified
155 *			when adding a new NVMe controller.
156 * @create_ctrl():	function pointer that points to a non-NVMe
157 *			implementation-specific fabric technology
158 *			that would go into starting up that fabric
159 *			for the purpose of connection to an NVMe controller
160 *			using that fabric technology.
161 *
162 * Notes:
163 *	1. At minimum, 'required_opts' and 'allowed_opts' should
164 *	   be set to the same enum parsing options defined earlier.
165 *	2. create_ctrl() must be defined (even if it does nothing)
166 *	3. struct nvmf_transport_ops must be statically allocated in the
167 *	   modules .bss section so that a pure module_get on @module
168 *	   prevents the memory from being freed.
169 */
170struct nvmf_transport_ops {
171	struct list_head	entry;
172	struct module		*module;
173	const char		*name;
174	int			required_opts;
175	int			allowed_opts;
176	struct nvme_ctrl	*(*create_ctrl)(struct device *dev,
177					struct nvmf_ctrl_options *opts);
178};
179
180static inline bool
181nvmf_ctlr_matches_baseopts(struct nvme_ctrl *ctrl,
182			struct nvmf_ctrl_options *opts)
183{
184	enum nvme_ctrl_state state = nvme_ctrl_state(ctrl);
185
186	if (state == NVME_CTRL_DELETING ||
187	    state == NVME_CTRL_DELETING_NOIO ||
188	    state == NVME_CTRL_DEAD ||
189	    strcmp(opts->subsysnqn, ctrl->opts->subsysnqn) ||
190	    strcmp(opts->host->nqn, ctrl->opts->host->nqn) ||
191	    !uuid_equal(&opts->host->id, &ctrl->opts->host->id))
192		return false;
193
194	return true;
195}
196
197static inline char *nvmf_ctrl_subsysnqn(struct nvme_ctrl *ctrl)
198{
199	if (!ctrl->subsys ||
200	    !strcmp(ctrl->opts->subsysnqn, NVME_DISC_SUBSYS_NAME))
201		return ctrl->opts->subsysnqn;
202	return ctrl->subsys->subnqn;
203}
204
205static inline void nvmf_complete_timed_out_request(struct request *rq)
206{
207	if (blk_mq_request_started(rq) && !blk_mq_request_completed(rq)) {
208		nvme_req(rq)->status = NVME_SC_HOST_ABORTED_CMD;
209		blk_mq_complete_request(rq);
210	}
211}
212
213static inline unsigned int nvmf_nr_io_queues(struct nvmf_ctrl_options *opts)
214{
215	return min(opts->nr_io_queues, num_online_cpus()) +
216		min(opts->nr_write_queues, num_online_cpus()) +
217		min(opts->nr_poll_queues, num_online_cpus());
218}
219
220static inline unsigned long nvmf_get_virt_boundary(struct nvme_ctrl *ctrl,
221						   bool is_admin)
222{
223	return 0;
224}
225
226int nvmf_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val);
227int nvmf_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val);
228int nvmf_reg_write32(struct nvme_ctrl *ctrl, u32 off, u32 val);
229int nvmf_subsystem_reset(struct nvme_ctrl *ctrl);
230int nvmf_connect_admin_queue(struct nvme_ctrl *ctrl);
231int nvmf_connect_io_queue(struct nvme_ctrl *ctrl, u16 qid);
232int nvmf_register_transport(struct nvmf_transport_ops *ops);
233void nvmf_unregister_transport(struct nvmf_transport_ops *ops);
234void nvmf_free_options(struct nvmf_ctrl_options *opts);
235int nvmf_get_address(struct nvme_ctrl *ctrl, char *buf, int size);
236bool nvmf_should_reconnect(struct nvme_ctrl *ctrl, int status);
237bool nvmf_ip_options_match(struct nvme_ctrl *ctrl,
238		struct nvmf_ctrl_options *opts);
239void nvmf_set_io_queues(struct nvmf_ctrl_options *opts, u32 nr_io_queues,
240			u32 io_queues[HCTX_MAX_TYPES]);
241void nvmf_map_queues(struct blk_mq_tag_set *set, struct nvme_ctrl *ctrl,
242		     u32 io_queues[HCTX_MAX_TYPES]);
243
244#endif /* _NVME_FABRICS_H */