xref: /freebsd/sys/dev/nvmf/host/nvmf_sim.c (revision aa1a8ff2d6dbc51ef058f46f3db5a8bb77967145)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2023-2024 Chelsio Communications, Inc.
5  * Written by: John Baldwin <jhb@FreeBSD.org>
6  */
7 
8 #include <sys/types.h>
9 #include <sys/malloc.h>
10 #include <sys/memdesc.h>
11 #include <sys/refcount.h>
12 
13 #include <cam/cam.h>
14 #include <cam/cam_ccb.h>
15 #include <cam/cam_sim.h>
16 #include <cam/cam_xpt_sim.h>
17 #include <cam/cam_debug.h>
18 
19 #include <dev/nvmf/host/nvmf_var.h>
20 
21 /*
22  * The I/O completion may trigger after the received CQE if the I/O
23  * used a zero-copy mbuf that isn't harvested until after the NIC
24  * driver processes TX completions.  Use spriv_field0 to as a refcount.
25  *
26  * Store any I/O error returned in spriv_field1.
27  */
28 static __inline u_int *
29 ccb_refs(union ccb *ccb)
30 {
31 	return ((u_int *)&ccb->ccb_h.spriv_field0);
32 }
33 
34 #define	spriv_ioerror	spriv_field1
35 
36 static void
37 nvmf_ccb_done(union ccb *ccb)
38 {
39 	if (!refcount_release(ccb_refs(ccb)))
40 		return;
41 
42 	if (nvmf_cqe_aborted(&ccb->nvmeio.cpl)) {
43 		ccb->ccb_h.status = CAM_REQUEUE_REQ;
44 		xpt_done(ccb);
45 	} else if (ccb->nvmeio.cpl.status != 0) {
46 		ccb->ccb_h.status = CAM_NVME_STATUS_ERROR;
47 		xpt_done(ccb);
48 	} else if (ccb->ccb_h.spriv_ioerror != 0) {
49 		KASSERT(ccb->ccb_h.spriv_ioerror != EJUSTRETURN,
50 		    ("%s: zero sized transfer without CQE error", __func__));
51 		ccb->ccb_h.status = CAM_REQ_CMP_ERR;
52 		xpt_done(ccb);
53 	} else {
54 		ccb->ccb_h.status = CAM_REQ_CMP;
55 		xpt_done_direct(ccb);
56 	}
57 }
58 
59 static void
60 nvmf_ccb_io_complete(void *arg, size_t xfered, int error)
61 {
62 	union ccb *ccb = arg;
63 
64 	/*
65 	 * TODO: Reporting partial completions requires extending
66 	 * nvmeio to support resid and updating nda to handle partial
67 	 * reads, either by returning partial success (or an error) to
68 	 * the caller, or retrying all or part of the request.
69 	 */
70 	ccb->ccb_h.spriv_ioerror = error;
71 	if (error == 0) {
72 		if (xfered == 0) {
73 #ifdef INVARIANTS
74 			/*
75 			 * If the request fails with an error in the CQE
76 			 * there will be no data transferred but also no
77 			 * I/O error.
78 			 */
79 			ccb->ccb_h.spriv_ioerror = EJUSTRETURN;
80 #endif
81 		} else
82 			KASSERT(xfered == ccb->nvmeio.dxfer_len,
83 			    ("%s: partial CCB completion", __func__));
84 	}
85 
86 	nvmf_ccb_done(ccb);
87 }
88 
89 static void
90 nvmf_ccb_complete(void *arg, const struct nvme_completion *cqe)
91 {
92 	union ccb *ccb = arg;
93 
94 	ccb->nvmeio.cpl = *cqe;
95 	nvmf_ccb_done(ccb);
96 }
97 
98 static void
99 nvmf_sim_io(struct nvmf_softc *sc, union ccb *ccb)
100 {
101 	struct ccb_nvmeio *nvmeio = &ccb->nvmeio;
102 	struct memdesc mem;
103 	struct nvmf_request *req;
104 	struct nvmf_host_qpair *qp;
105 
106 	mtx_lock(&sc->sim_mtx);
107 	if (sc->sim_disconnected) {
108 		mtx_unlock(&sc->sim_mtx);
109 		nvmeio->ccb_h.status = CAM_REQUEUE_REQ;
110 		xpt_done(ccb);
111 		return;
112 	}
113 	if (nvmeio->ccb_h.func_code == XPT_NVME_IO)
114 		qp = nvmf_select_io_queue(sc);
115 	else
116 		qp = sc->admin;
117 	req = nvmf_allocate_request(qp, &nvmeio->cmd, nvmf_ccb_complete,
118 	    ccb, M_NOWAIT);
119 	if (req == NULL) {
120 		mtx_unlock(&sc->sim_mtx);
121 		nvmeio->ccb_h.status = CAM_RESRC_UNAVAIL;
122 		xpt_done(ccb);
123 		return;
124 	}
125 
126 	if (nvmeio->dxfer_len != 0) {
127 		refcount_init(ccb_refs(ccb), 2);
128 		mem = memdesc_ccb(ccb);
129 		nvmf_capsule_append_data(req->nc, &mem, nvmeio->dxfer_len,
130 		    (ccb->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_OUT,
131 		    nvmf_ccb_io_complete, ccb);
132 	} else
133 		refcount_init(ccb_refs(ccb), 1);
134 
135 	/*
136 	 * Clear spriv_ioerror as it can hold an earlier error if this
137 	 * CCB was aborted and has been retried.
138 	 */
139 	ccb->ccb_h.spriv_ioerror = 0;
140 	KASSERT(ccb->ccb_h.status == CAM_REQ_INPROG,
141 	    ("%s: incoming CCB is not in-progress", __func__));
142 	ccb->ccb_h.status |= CAM_SIM_QUEUED;
143 	nvmf_submit_request(req);
144 	mtx_unlock(&sc->sim_mtx);
145 }
146 
147 static void
148 nvmf_sim_action(struct cam_sim *sim, union ccb *ccb)
149 {
150 	struct nvmf_softc *sc = cam_sim_softc(sim);
151 
152 	CAM_DEBUG(ccb->ccb_h.path, CAM_DEBUG_TRACE,
153 	    ("nvmf_sim_action: func= %#x\n",
154 		ccb->ccb_h.func_code));
155 
156 	switch (ccb->ccb_h.func_code) {
157 	case XPT_PATH_INQ:	/* Path routing inquiry */
158 	{
159 		struct ccb_pathinq *cpi = &ccb->cpi;
160 
161 		cpi->version_num = 1;
162 		cpi->hba_inquiry = 0;
163 		cpi->target_sprt = 0;
164 		cpi->hba_misc =  PIM_UNMAPPED | PIM_NOSCAN;
165 		cpi->hba_eng_cnt = 0;
166 		cpi->max_target = 0;
167 		cpi->max_lun = sc->cdata->nn;
168 		cpi->async_flags = 0;
169 		cpi->hpath_id = 0;
170 		cpi->initiator_id = 0;
171 		strlcpy(cpi->sim_vid, "FreeBSD", SIM_IDLEN);
172 		strlcpy(cpi->hba_vid, "NVMeoF", HBA_IDLEN);
173 		strlcpy(cpi->dev_name, cam_sim_name(sim), DEV_IDLEN);
174 		cpi->unit_number = cam_sim_unit(sim);
175 		cpi->bus_id = 0;
176 
177 		/* XXX: Same as iSCSI. */
178 		cpi->base_transfer_speed = 150000;
179 		cpi->protocol = PROTO_NVME;
180 		cpi->protocol_version = sc->vs;
181 		cpi->transport = XPORT_NVMF;
182 		cpi->transport_version = sc->vs;
183 		cpi->xport_specific.nvmf.nsid =
184 		    xpt_path_lun_id(ccb->ccb_h.path);
185 		cpi->xport_specific.nvmf.trtype = sc->trtype;
186 		strncpy(cpi->xport_specific.nvmf.dev_name,
187 		    device_get_nameunit(sc->dev),
188 		    sizeof(cpi->xport_specific.nvmf.dev_name));
189 		cpi->maxio = sc->max_xfer_size;
190 		cpi->hba_vendor = 0;
191 		cpi->hba_device = 0;
192 		cpi->hba_subvendor = 0;
193 		cpi->hba_subdevice = 0;
194 		cpi->ccb_h.status = CAM_REQ_CMP;
195 		break;
196 	}
197 	case XPT_GET_TRAN_SETTINGS:	/* Get transport settings */
198 	{
199 		struct ccb_trans_settings *cts = &ccb->cts;
200 		struct ccb_trans_settings_nvme *nvme;
201 		struct ccb_trans_settings_nvmf *nvmf;
202 
203 		cts->protocol = PROTO_NVME;
204 		cts->protocol_version = sc->vs;
205 		cts->transport = XPORT_NVMF;
206 		cts->transport_version = sc->vs;
207 
208 		nvme = &cts->proto_specific.nvme;
209 		nvme->valid = CTS_NVME_VALID_SPEC;
210 		nvme->spec = sc->vs;
211 
212 		nvmf = &cts->xport_specific.nvmf;
213 		nvmf->valid = CTS_NVMF_VALID_TRTYPE;
214 		nvmf->trtype = sc->trtype;
215 		cts->ccb_h.status = CAM_REQ_CMP;
216 		break;
217 	}
218 	case XPT_SET_TRAN_SETTINGS:	/* Set transport settings */
219 		/*
220 		 * No transfer settings can be set, but nvme_xpt sends
221 		 * this anyway.
222 		 */
223 		ccb->ccb_h.status = CAM_REQ_CMP;
224 		break;
225 	case XPT_NVME_IO:		/* Execute the requested I/O */
226 	case XPT_NVME_ADMIN:		/* or Admin operation */
227 		nvmf_sim_io(sc, ccb);
228 		return;
229 	default:
230 		/* XXX */
231 		device_printf(sc->dev, "unhandled sim function %#x\n",
232 		    ccb->ccb_h.func_code);
233 		ccb->ccb_h.status = CAM_REQ_INVALID;
234 		break;
235 	}
236 	xpt_done(ccb);
237 }
238 
239 int
240 nvmf_init_sim(struct nvmf_softc *sc)
241 {
242 	struct cam_devq *devq;
243 	int max_trans;
244 
245 	max_trans = sc->max_pending_io * 3 / 4;
246 	devq = cam_simq_alloc(max_trans);
247 	if (devq == NULL) {
248 		device_printf(sc->dev, "Failed to allocate CAM simq\n");
249 		return (ENOMEM);
250 	}
251 
252 	mtx_init(&sc->sim_mtx, "nvmf sim", NULL, MTX_DEF);
253 	sc->sim = cam_sim_alloc(nvmf_sim_action, NULL, "nvme", sc,
254 	    device_get_unit(sc->dev), NULL, max_trans, max_trans, devq);
255 	if (sc->sim == NULL) {
256 		device_printf(sc->dev, "Failed to allocate CAM sim\n");
257 		cam_simq_free(devq);
258 		mtx_destroy(&sc->sim_mtx);
259 		return (ENXIO);
260 	}
261 	if (xpt_bus_register(sc->sim, sc->dev, 0) != CAM_SUCCESS) {
262 		device_printf(sc->dev, "Failed to create CAM bus\n");
263 		cam_sim_free(sc->sim, TRUE);
264 		mtx_destroy(&sc->sim_mtx);
265 		return (ENXIO);
266 	}
267 	if (xpt_create_path(&sc->path, NULL, cam_sim_path(sc->sim),
268 	    CAM_TARGET_WILDCARD, CAM_LUN_WILDCARD) != CAM_REQ_CMP) {
269 		device_printf(sc->dev, "Failed to create CAM path\n");
270 		xpt_bus_deregister(cam_sim_path(sc->sim));
271 		cam_sim_free(sc->sim, TRUE);
272 		mtx_destroy(&sc->sim_mtx);
273 		return (ENXIO);
274 	}
275 	return (0);
276 }
277 
278 void
279 nvmf_sim_rescan_ns(struct nvmf_softc *sc, uint32_t id)
280 {
281 	union ccb *ccb;
282 
283 	ccb = xpt_alloc_ccb_nowait();
284 	if (ccb == NULL) {
285 		device_printf(sc->dev,
286 		    "unable to alloc CCB for rescan of namespace %u\n", id);
287 		return;
288 	}
289 
290 	/*
291 	 * As with nvme_sim, map NVMe namespace IDs onto CAM unit
292 	 * LUNs.
293 	 */
294 	if (xpt_create_path(&ccb->ccb_h.path, NULL, cam_sim_path(sc->sim), 0,
295 	    id) != CAM_REQ_CMP) {
296 		device_printf(sc->dev,
297 		    "Unable to create path for rescan of namespace %u\n", id);
298 		xpt_free_ccb(ccb);
299 		return;
300 	}
301 	xpt_rescan(ccb);
302 }
303 
304 void
305 nvmf_disconnect_sim(struct nvmf_softc *sc)
306 {
307 	mtx_lock(&sc->sim_mtx);
308 	sc->sim_disconnected = true;
309 	xpt_freeze_simq(sc->sim, 1);
310 	mtx_unlock(&sc->sim_mtx);
311 }
312 
313 void
314 nvmf_reconnect_sim(struct nvmf_softc *sc)
315 {
316 	mtx_lock(&sc->sim_mtx);
317 	sc->sim_disconnected = false;
318 	mtx_unlock(&sc->sim_mtx);
319 	xpt_release_simq(sc->sim, 1);
320 }
321 
322 void
323 nvmf_destroy_sim(struct nvmf_softc *sc)
324 {
325 	xpt_async(AC_LOST_DEVICE, sc->path, NULL);
326 	if (sc->sim_disconnected)
327 		xpt_release_simq(sc->sim, 1);
328 	xpt_free_path(sc->path);
329 	xpt_bus_deregister(cam_sim_path(sc->sim));
330 	cam_sim_free(sc->sim, TRUE);
331 	mtx_destroy(&sc->sim_mtx);
332 }
333