xref: /freebsd/sys/dev/nvmf/host/nvmf_sim.c (revision 7937bfbc0ca53fe7cdd0d54414f9296e273a518e)
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 		struct cam_sim *sim = xpt_path_sim(ccb->ccb_h.path);
44 		struct nvmf_softc *sc = cam_sim_softc(sim);
45 
46 		if (nvmf_fail_disconnect || sc->sim_shutdown)
47 			ccb->ccb_h.status = CAM_DEV_NOT_THERE;
48 		else
49 			ccb->ccb_h.status = CAM_REQUEUE_REQ;
50 		xpt_done(ccb);
51 	} else if (ccb->nvmeio.cpl.status != 0) {
52 		ccb->ccb_h.status = CAM_NVME_STATUS_ERROR;
53 		xpt_done(ccb);
54 	} else if (ccb->ccb_h.spriv_ioerror != 0) {
55 		KASSERT(ccb->ccb_h.spriv_ioerror != EJUSTRETURN,
56 		    ("%s: zero sized transfer without CQE error", __func__));
57 		ccb->ccb_h.status = CAM_REQ_CMP_ERR;
58 		xpt_done(ccb);
59 	} else {
60 		ccb->ccb_h.status = CAM_REQ_CMP;
61 		xpt_done(ccb);
62 	}
63 }
64 
65 static void
66 nvmf_ccb_io_complete(void *arg, size_t xfered, int error)
67 {
68 	union ccb *ccb = arg;
69 
70 	/*
71 	 * TODO: Reporting partial completions requires extending
72 	 * nvmeio to support resid and updating nda to handle partial
73 	 * reads, either by returning partial success (or an error) to
74 	 * the caller, or retrying all or part of the request.
75 	 */
76 	ccb->ccb_h.spriv_ioerror = error;
77 	if (error == 0) {
78 		if (xfered == 0) {
79 #ifdef INVARIANTS
80 			/*
81 			 * If the request fails with an error in the CQE
82 			 * there will be no data transferred but also no
83 			 * I/O error.
84 			 */
85 			ccb->ccb_h.spriv_ioerror = EJUSTRETURN;
86 #endif
87 		} else
88 			KASSERT(xfered == ccb->nvmeio.dxfer_len,
89 			    ("%s: partial CCB completion", __func__));
90 	}
91 
92 	nvmf_ccb_done(ccb);
93 }
94 
95 static void
96 nvmf_ccb_complete(void *arg, const struct nvme_completion *cqe)
97 {
98 	union ccb *ccb = arg;
99 
100 	ccb->nvmeio.cpl = *cqe;
101 	nvmf_ccb_done(ccb);
102 }
103 
104 static void
105 nvmf_sim_io(struct nvmf_softc *sc, union ccb *ccb)
106 {
107 	struct ccb_nvmeio *nvmeio = &ccb->nvmeio;
108 	struct memdesc mem;
109 	struct nvmf_request *req;
110 	struct nvmf_host_qpair *qp;
111 
112 	mtx_lock(&sc->sim_mtx);
113 	if (sc->sim_disconnected) {
114 		mtx_unlock(&sc->sim_mtx);
115 		if (nvmf_fail_disconnect || sc->sim_shutdown)
116 			nvmeio->ccb_h.status = CAM_DEV_NOT_THERE;
117 		else
118 			nvmeio->ccb_h.status = CAM_REQUEUE_REQ;
119 		xpt_done(ccb);
120 		return;
121 	}
122 	if (nvmeio->ccb_h.func_code == XPT_NVME_IO)
123 		qp = nvmf_select_io_queue(sc);
124 	else
125 		qp = sc->admin;
126 	req = nvmf_allocate_request(qp, &nvmeio->cmd, nvmf_ccb_complete,
127 	    ccb, M_NOWAIT);
128 	mtx_unlock(&sc->sim_mtx);
129 	if (req == NULL) {
130 		nvmeio->ccb_h.status = CAM_RESRC_UNAVAIL;
131 		xpt_done(ccb);
132 		return;
133 	}
134 
135 	if (nvmeio->dxfer_len != 0) {
136 		refcount_init(ccb_refs(ccb), 2);
137 		mem = memdesc_ccb(ccb);
138 		nvmf_capsule_append_data(req->nc, &mem, nvmeio->dxfer_len,
139 		    (ccb->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_OUT,
140 		    nvmf_ccb_io_complete, ccb);
141 	} else
142 		refcount_init(ccb_refs(ccb), 1);
143 
144 	/*
145 	 * Clear spriv_ioerror as it can hold an earlier error if this
146 	 * CCB was aborted and has been retried.
147 	 */
148 	ccb->ccb_h.spriv_ioerror = 0;
149 	KASSERT(ccb->ccb_h.status == CAM_REQ_INPROG,
150 	    ("%s: incoming CCB is not in-progress", __func__));
151 	ccb->ccb_h.status |= CAM_SIM_QUEUED;
152 	nvmf_submit_request(req);
153 }
154 
155 static void
156 nvmf_sim_action(struct cam_sim *sim, union ccb *ccb)
157 {
158 	struct nvmf_softc *sc = cam_sim_softc(sim);
159 
160 	CAM_DEBUG(ccb->ccb_h.path, CAM_DEBUG_TRACE,
161 	    ("nvmf_sim_action: func= %#x\n",
162 		ccb->ccb_h.func_code));
163 
164 	switch (ccb->ccb_h.func_code) {
165 	case XPT_PATH_INQ:	/* Path routing inquiry */
166 	{
167 		struct ccb_pathinq *cpi = &ccb->cpi;
168 
169 		cpi->version_num = 1;
170 		cpi->hba_inquiry = 0;
171 		cpi->target_sprt = 0;
172 		cpi->hba_misc =  PIM_UNMAPPED | PIM_NOSCAN;
173 		cpi->hba_eng_cnt = 0;
174 		cpi->max_target = 0;
175 		cpi->max_lun = sc->cdata->nn;
176 		cpi->async_flags = 0;
177 		cpi->hpath_id = 0;
178 		cpi->initiator_id = 0;
179 		strlcpy(cpi->sim_vid, "FreeBSD", SIM_IDLEN);
180 		strlcpy(cpi->hba_vid, "NVMeoF", HBA_IDLEN);
181 		strlcpy(cpi->dev_name, cam_sim_name(sim), DEV_IDLEN);
182 		cpi->unit_number = cam_sim_unit(sim);
183 		cpi->bus_id = 0;
184 
185 		/* XXX: Same as iSCSI. */
186 		cpi->base_transfer_speed = 150000;
187 		cpi->protocol = PROTO_NVME;
188 		cpi->protocol_version = sc->vs;
189 		cpi->transport = XPORT_NVMF;
190 		cpi->transport_version = sc->vs;
191 		cpi->xport_specific.nvmf.nsid =
192 		    xpt_path_lun_id(ccb->ccb_h.path);
193 		cpi->xport_specific.nvmf.trtype = sc->trtype;
194 		strlcpy(cpi->xport_specific.nvmf.dev_name,
195 		    device_get_nameunit(sc->dev),
196 		    sizeof(cpi->xport_specific.nvmf.dev_name));
197 		cpi->maxio = sc->max_xfer_size;
198 		cpi->hba_vendor = 0;
199 		cpi->hba_device = 0;
200 		cpi->hba_subvendor = 0;
201 		cpi->hba_subdevice = 0;
202 		cpi->ccb_h.status = CAM_REQ_CMP;
203 		break;
204 	}
205 	case XPT_GET_TRAN_SETTINGS:	/* Get transport settings */
206 	{
207 		struct ccb_trans_settings *cts = &ccb->cts;
208 		struct ccb_trans_settings_nvme *nvme;
209 		struct ccb_trans_settings_nvmf *nvmf;
210 
211 		cts->protocol = PROTO_NVME;
212 		cts->protocol_version = sc->vs;
213 		cts->transport = XPORT_NVMF;
214 		cts->transport_version = sc->vs;
215 
216 		nvme = &cts->proto_specific.nvme;
217 		nvme->valid = CTS_NVME_VALID_SPEC;
218 		nvme->spec = sc->vs;
219 
220 		nvmf = &cts->xport_specific.nvmf;
221 		nvmf->valid = CTS_NVMF_VALID_TRTYPE;
222 		nvmf->trtype = sc->trtype;
223 		cts->ccb_h.status = CAM_REQ_CMP;
224 		break;
225 	}
226 	case XPT_SET_TRAN_SETTINGS:	/* Set transport settings */
227 		/*
228 		 * No transfer settings can be set, but nvme_xpt sends
229 		 * this anyway.
230 		 */
231 		ccb->ccb_h.status = CAM_REQ_CMP;
232 		break;
233 	case XPT_NVME_IO:		/* Execute the requested I/O */
234 	case XPT_NVME_ADMIN:		/* or Admin operation */
235 		nvmf_sim_io(sc, ccb);
236 		return;
237 	default:
238 		/* XXX */
239 		device_printf(sc->dev, "unhandled sim function %#x\n",
240 		    ccb->ccb_h.func_code);
241 		ccb->ccb_h.status = CAM_REQ_INVALID;
242 		break;
243 	}
244 	xpt_done(ccb);
245 }
246 
247 int
248 nvmf_init_sim(struct nvmf_softc *sc)
249 {
250 	struct cam_devq *devq;
251 	int max_trans;
252 
253 	max_trans = sc->max_pending_io * 3 / 4;
254 	devq = cam_simq_alloc(max_trans);
255 	if (devq == NULL) {
256 		device_printf(sc->dev, "Failed to allocate CAM simq\n");
257 		return (ENOMEM);
258 	}
259 
260 	mtx_init(&sc->sim_mtx, "nvmf sim", NULL, MTX_DEF);
261 	sc->sim = cam_sim_alloc(nvmf_sim_action, NULL, "nvme", sc,
262 	    device_get_unit(sc->dev), NULL, max_trans, max_trans, devq);
263 	if (sc->sim == NULL) {
264 		device_printf(sc->dev, "Failed to allocate CAM sim\n");
265 		cam_simq_free(devq);
266 		mtx_destroy(&sc->sim_mtx);
267 		return (ENXIO);
268 	}
269 	if (xpt_bus_register(sc->sim, sc->dev, 0) != CAM_SUCCESS) {
270 		device_printf(sc->dev, "Failed to create CAM bus\n");
271 		cam_sim_free(sc->sim, TRUE);
272 		mtx_destroy(&sc->sim_mtx);
273 		return (ENXIO);
274 	}
275 	if (xpt_create_path(&sc->path, NULL, cam_sim_path(sc->sim),
276 	    CAM_TARGET_WILDCARD, CAM_LUN_WILDCARD) != CAM_REQ_CMP) {
277 		device_printf(sc->dev, "Failed to create CAM path\n");
278 		xpt_bus_deregister(cam_sim_path(sc->sim));
279 		cam_sim_free(sc->sim, TRUE);
280 		mtx_destroy(&sc->sim_mtx);
281 		return (ENXIO);
282 	}
283 	return (0);
284 }
285 
286 void
287 nvmf_sim_rescan_ns(struct nvmf_softc *sc, uint32_t id)
288 {
289 	union ccb *ccb;
290 
291 	ccb = xpt_alloc_ccb_nowait();
292 	if (ccb == NULL) {
293 		device_printf(sc->dev,
294 		    "unable to alloc CCB for rescan of namespace %u\n", id);
295 		return;
296 	}
297 
298 	/*
299 	 * As with nvme_sim, map NVMe namespace IDs onto CAM unit
300 	 * LUNs.
301 	 */
302 	if (xpt_create_path(&ccb->ccb_h.path, NULL, cam_sim_path(sc->sim), 0,
303 	    id) != CAM_REQ_CMP) {
304 		device_printf(sc->dev,
305 		    "Unable to create path for rescan of namespace %u\n", id);
306 		xpt_free_ccb(ccb);
307 		return;
308 	}
309 	xpt_rescan(ccb);
310 }
311 
312 void
313 nvmf_disconnect_sim(struct nvmf_softc *sc)
314 {
315 	mtx_lock(&sc->sim_mtx);
316 	sc->sim_disconnected = true;
317 	xpt_freeze_simq(sc->sim, 1);
318 	mtx_unlock(&sc->sim_mtx);
319 }
320 
321 void
322 nvmf_reconnect_sim(struct nvmf_softc *sc)
323 {
324 	mtx_lock(&sc->sim_mtx);
325 	sc->sim_disconnected = false;
326 	mtx_unlock(&sc->sim_mtx);
327 	xpt_release_simq(sc->sim, 1);
328 }
329 
330 void
331 nvmf_shutdown_sim(struct nvmf_softc *sc)
332 {
333 	mtx_lock(&sc->sim_mtx);
334 	sc->sim_shutdown = true;
335 	mtx_unlock(&sc->sim_mtx);
336 	xpt_release_simq(sc->sim, 1);
337 }
338 
339 void
340 nvmf_destroy_sim(struct nvmf_softc *sc)
341 {
342 	xpt_async(AC_LOST_DEVICE, sc->path, NULL);
343 	if (sc->sim_disconnected)
344 		xpt_release_simq(sc->sim, 1);
345 	xpt_free_path(sc->path);
346 	xpt_bus_deregister(cam_sim_path(sc->sim));
347 	cam_sim_free(sc->sim, TRUE);
348 	mtx_destroy(&sc->sim_mtx);
349 }
350