xref: /linux/drivers/nvme/host/fabrics.h (revision d53b8e36925256097a08d7cb749198d85cbf9b2b)
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  */
29 struct 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  */
39 enum {
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 };
70 
71 /**
72  * struct nvmf_ctrl_options - Used to hold the options specified
73  *			      with the parsing opts enum.
74  * @mask:	Used by the fabrics library to parse through sysfs options
75  *		on adding a NVMe controller.
76  * @max_reconnects: maximum number of allowed reconnect attempts before removing
77  *		the controller, (-1) means reconnect forever, zero means remove
78  *		immediately;
79  * @transport:	Holds the fabric transport "technology name" (for a lack of
80  *		better description) that will be used by an NVMe controller
81  *		being added.
82  * @subsysnqn:	Hold the fully qualified NQN subystem name (format defined
83  *		in the NVMe specification, "NVMe Qualified Names").
84  * @traddr:	The transport-specific TRADDR field for a port on the
85  *              subsystem which is adding a controller.
86  * @trsvcid:	The transport-specific TRSVCID field for a port on the
87  *              subsystem which is adding a controller.
88  * @host_traddr: A transport-specific field identifying the NVME host port
89  *     to use for the connection to the controller.
90  * @host_iface: A transport-specific field identifying the NVME host
91  *     interface to use for the connection to the controller.
92  * @queue_size: Number of IO queue elements.
93  * @nr_io_queues: Number of controller IO queues that will be established.
94  * @reconnect_delay: Time between two consecutive reconnect attempts.
95  * @discovery_nqn: indicates if the subsysnqn is the well-known discovery NQN.
96  * @kato:	Keep-alive timeout.
97  * @host:	Virtual NVMe host, contains the NQN and Host ID.
98  * @dhchap_secret: DH-HMAC-CHAP secret
99  * @dhchap_ctrl_secret: DH-HMAC-CHAP controller secret for bi-directional
100  *              authentication
101  * @keyring:    Keyring to use for key lookups
102  * @tls_key:    TLS key for encrypted connections (TCP)
103  * @tls:        Start TLS encrypted connections (TCP)
104  * @disable_sqflow: disable controller sq flow control
105  * @hdr_digest: generate/verify header digest (TCP)
106  * @data_digest: generate/verify data digest (TCP)
107  * @nr_write_queues: number of queues for write I/O
108  * @nr_poll_queues: number of queues for polling I/O
109  * @tos: type of service
110  * @fast_io_fail_tmo: Fast I/O fail timeout in seconds
111  */
112 struct nvmf_ctrl_options {
113 	unsigned		mask;
114 	int			max_reconnects;
115 	char			*transport;
116 	char			*subsysnqn;
117 	char			*traddr;
118 	char			*trsvcid;
119 	char			*host_traddr;
120 	char			*host_iface;
121 	size_t			queue_size;
122 	unsigned int		nr_io_queues;
123 	unsigned int		reconnect_delay;
124 	bool			discovery_nqn;
125 	bool			duplicate_connect;
126 	unsigned int		kato;
127 	struct nvmf_host	*host;
128 	char			*dhchap_secret;
129 	char			*dhchap_ctrl_secret;
130 	struct key		*keyring;
131 	struct key		*tls_key;
132 	bool			tls;
133 	bool			disable_sqflow;
134 	bool			hdr_digest;
135 	bool			data_digest;
136 	unsigned int		nr_write_queues;
137 	unsigned int		nr_poll_queues;
138 	int			tos;
139 	int			fast_io_fail_tmo;
140 };
141 
142 /*
143  * struct nvmf_transport_ops - used to register a specific
144  *			       fabric implementation of NVMe fabrics.
145  * @entry:		Used by the fabrics library to add the new
146  *			registration entry to its linked-list internal tree.
147  * @module:             Transport module reference
148  * @name:		Name of the NVMe fabric driver implementation.
149  * @required_opts:	sysfs command-line options that must be specified
150  *			when adding a new NVMe controller.
151  * @allowed_opts:	sysfs command-line options that can be specified
152  *			when adding a new NVMe controller.
153  * @create_ctrl():	function pointer that points to a non-NVMe
154  *			implementation-specific fabric technology
155  *			that would go into starting up that fabric
156  *			for the purpose of conneciton to an NVMe controller
157  *			using that fabric technology.
158  *
159  * Notes:
160  *	1. At minimum, 'required_opts' and 'allowed_opts' should
161  *	   be set to the same enum parsing options defined earlier.
162  *	2. create_ctrl() must be defined (even if it does nothing)
163  *	3. struct nvmf_transport_ops must be statically allocated in the
164  *	   modules .bss section so that a pure module_get on @module
165  *	   prevents the memory from beeing freed.
166  */
167 struct nvmf_transport_ops {
168 	struct list_head	entry;
169 	struct module		*module;
170 	const char		*name;
171 	int			required_opts;
172 	int			allowed_opts;
173 	struct nvme_ctrl	*(*create_ctrl)(struct device *dev,
174 					struct nvmf_ctrl_options *opts);
175 };
176 
177 static inline bool
178 nvmf_ctlr_matches_baseopts(struct nvme_ctrl *ctrl,
179 			struct nvmf_ctrl_options *opts)
180 {
181 	enum nvme_ctrl_state state = nvme_ctrl_state(ctrl);
182 
183 	if (state == NVME_CTRL_DELETING ||
184 	    state == NVME_CTRL_DELETING_NOIO ||
185 	    state == NVME_CTRL_DEAD ||
186 	    strcmp(opts->subsysnqn, ctrl->opts->subsysnqn) ||
187 	    strcmp(opts->host->nqn, ctrl->opts->host->nqn) ||
188 	    !uuid_equal(&opts->host->id, &ctrl->opts->host->id))
189 		return false;
190 
191 	return true;
192 }
193 
194 static inline char *nvmf_ctrl_subsysnqn(struct nvme_ctrl *ctrl)
195 {
196 	if (!ctrl->subsys ||
197 	    !strcmp(ctrl->opts->subsysnqn, NVME_DISC_SUBSYS_NAME))
198 		return ctrl->opts->subsysnqn;
199 	return ctrl->subsys->subnqn;
200 }
201 
202 static inline void nvmf_complete_timed_out_request(struct request *rq)
203 {
204 	if (blk_mq_request_started(rq) && !blk_mq_request_completed(rq)) {
205 		nvme_req(rq)->status = NVME_SC_HOST_ABORTED_CMD;
206 		blk_mq_complete_request(rq);
207 	}
208 }
209 
210 static inline unsigned int nvmf_nr_io_queues(struct nvmf_ctrl_options *opts)
211 {
212 	return min(opts->nr_io_queues, num_online_cpus()) +
213 		min(opts->nr_write_queues, num_online_cpus()) +
214 		min(opts->nr_poll_queues, num_online_cpus());
215 }
216 
217 int nvmf_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val);
218 int nvmf_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val);
219 int nvmf_reg_write32(struct nvme_ctrl *ctrl, u32 off, u32 val);
220 int nvmf_subsystem_reset(struct nvme_ctrl *ctrl);
221 int nvmf_connect_admin_queue(struct nvme_ctrl *ctrl);
222 int nvmf_connect_io_queue(struct nvme_ctrl *ctrl, u16 qid);
223 int nvmf_register_transport(struct nvmf_transport_ops *ops);
224 void nvmf_unregister_transport(struct nvmf_transport_ops *ops);
225 void nvmf_free_options(struct nvmf_ctrl_options *opts);
226 int nvmf_get_address(struct nvme_ctrl *ctrl, char *buf, int size);
227 bool nvmf_should_reconnect(struct nvme_ctrl *ctrl, int status);
228 bool nvmf_ip_options_match(struct nvme_ctrl *ctrl,
229 		struct nvmf_ctrl_options *opts);
230 void nvmf_set_io_queues(struct nvmf_ctrl_options *opts, u32 nr_io_queues,
231 			u32 io_queues[HCTX_MAX_TYPES]);
232 void nvmf_map_queues(struct blk_mq_tag_set *set, struct nvme_ctrl *ctrl,
233 		     u32 io_queues[HCTX_MAX_TYPES]);
234 
235 #endif /* _NVME_FABRICS_H */
236