xref: /freebsd/usr.sbin/bhyve/pci_virtio_9p.c (revision 73577bf01de5c4677dc54d97f93310286c254780)
1 /*-
2  * Copyright (c) 2015 iXsystems Inc.
3  * Copyright (c) 2017-2018 Jakub Klama <jceel@FreeBSD.org>
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer
11  *    in this position and unchanged.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 /*
30  * VirtIO filesystem passthrough using 9p protocol.
31  */
32 
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 #include <sys/param.h>
37 #include <sys/linker_set.h>
38 #include <sys/uio.h>
39 #include <sys/capsicum.h>
40 
41 #include <errno.h>
42 #include <fcntl.h>
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <string.h>
46 #include <unistd.h>
47 #include <assert.h>
48 #include <pthread.h>
49 
50 #include <lib9p.h>
51 #include <backend/fs.h>
52 
53 #include "bhyverun.h"
54 #include "pci_emul.h"
55 #include "virtio.h"
56 
57 #define	VT9P_MAX_IOV	128
58 #define VT9P_RINGSZ	256
59 #define	VT9P_MAXTAGSZ	256
60 #define	VT9P_CONFIGSPACESZ	(VT9P_MAXTAGSZ + sizeof(uint16_t))
61 
62 static int pci_vt9p_debug;
63 #define DPRINTF(params) if (pci_vt9p_debug) printf params
64 #define WPRINTF(params) printf params
65 
66 /*
67  * Per-device softc
68  */
69 struct pci_vt9p_softc {
70 	struct virtio_softc      vsc_vs;
71 	struct vqueue_info       vsc_vq;
72 	pthread_mutex_t          vsc_mtx;
73 	uint64_t                 vsc_cfg;
74 	uint64_t                 vsc_features;
75 	char *                   vsc_rootpath;
76 	struct pci_vt9p_config * vsc_config;
77 	struct l9p_backend *     vsc_fs_backend;
78 	struct l9p_server *      vsc_server;
79         struct l9p_connection *  vsc_conn;
80 };
81 
82 struct pci_vt9p_request {
83 	struct pci_vt9p_softc *	vsr_sc;
84 	struct iovec *		vsr_iov;
85 	size_t			vsr_niov;
86 	size_t			vsr_respidx;
87 	size_t			vsr_iolen;
88 	uint16_t		vsr_idx;
89 };
90 
91 struct pci_vt9p_config {
92 	uint16_t tag_len;
93 	char tag[0];
94 } __attribute__((packed));
95 
96 static int pci_vt9p_send(struct l9p_request *, const struct iovec *,
97     const size_t, const size_t, void *);
98 static void pci_vt9p_drop(struct l9p_request *, const struct iovec *, size_t,
99     void *);
100 static void pci_vt9p_reset(void *);
101 static void pci_vt9p_notify(void *, struct vqueue_info *);
102 static int pci_vt9p_cfgread(void *, int, int, uint32_t *);
103 static void pci_vt9p_neg_features(void *, uint64_t);
104 
105 static struct virtio_consts vt9p_vi_consts = {
106 	"vt9p",			/* our name */
107 	1,			/* we support 1 virtqueue */
108 	VT9P_CONFIGSPACESZ,	/* config reg size */
109 	pci_vt9p_reset,		/* reset */
110 	pci_vt9p_notify,	/* device-wide qnotify */
111 	pci_vt9p_cfgread,	/* read virtio config */
112 	NULL,			/* write virtio config */
113 	pci_vt9p_neg_features,	/* apply negotiated features */
114 	(1 << 0),		/* our capabilities */
115 };
116 
117 
118 static void
119 pci_vt9p_reset(void *vsc)
120 {
121 	struct pci_vt9p_softc *sc;
122 
123 	sc = vsc;
124 
125 	DPRINTF(("vt9p: device reset requested !\n"));
126 	vi_reset_dev(&sc->vsc_vs);
127 }
128 
129 static void
130 pci_vt9p_neg_features(void *vsc, uint64_t negotiated_features)
131 {
132 	struct pci_vt9p_softc *sc = vsc;
133 
134 	sc->vsc_features = negotiated_features;
135 }
136 
137 static int
138 pci_vt9p_cfgread(void *vsc, int offset, int size, uint32_t *retval)
139 {
140 	struct pci_vt9p_softc *sc = vsc;
141 	void *ptr;
142 
143 	ptr = (uint8_t *)sc->vsc_config + offset;
144 	memcpy(retval, ptr, size);
145 	return (0);
146 }
147 
148 static int
149 pci_vt9p_get_buffer(struct l9p_request *req, struct iovec *iov, size_t *niov,
150     void *arg)
151 {
152 	struct pci_vt9p_request *preq = req->lr_aux;
153 	size_t n = preq->vsr_niov - preq->vsr_respidx;
154 
155 	memcpy(iov, preq->vsr_iov + preq->vsr_respidx,
156 	    n * sizeof(struct iovec));
157 	*niov = n;
158 	return (0);
159 }
160 
161 static int
162 pci_vt9p_send(struct l9p_request *req, const struct iovec *iov,
163     const size_t niov, const size_t iolen, void *arg)
164 {
165 	struct pci_vt9p_request *preq = req->lr_aux;
166 	struct pci_vt9p_softc *sc = preq->vsr_sc;
167 
168 	preq->vsr_iolen = iolen;
169 
170 	pthread_mutex_lock(&sc->vsc_mtx);
171 	vq_relchain(&sc->vsc_vq, preq->vsr_idx, preq->vsr_iolen);
172 	vq_endchains(&sc->vsc_vq, 1);
173 	pthread_mutex_unlock(&sc->vsc_mtx);
174 	free(preq);
175 	return (0);
176 }
177 
178 static void
179 pci_vt9p_drop(struct l9p_request *req, const struct iovec *iov, size_t niov,
180     void *arg)
181 {
182 	struct pci_vt9p_request *preq = req->lr_aux;
183 	struct pci_vt9p_softc *sc = preq->vsr_sc;
184 
185 	pthread_mutex_lock(&sc->vsc_mtx);
186 	vq_relchain(&sc->vsc_vq, preq->vsr_idx, 0);
187 	vq_endchains(&sc->vsc_vq, 1);
188 	pthread_mutex_unlock(&sc->vsc_mtx);
189 	free(preq);
190 }
191 
192 static void
193 pci_vt9p_notify(void *vsc, struct vqueue_info *vq)
194 {
195 	struct iovec iov[VT9P_MAX_IOV];
196 	struct pci_vt9p_softc *sc;
197 	struct pci_vt9p_request *preq;
198 	uint16_t idx, n, i;
199 	uint16_t flags[VT9P_MAX_IOV];
200 
201 	sc = vsc;
202 
203 	while (vq_has_descs(vq)) {
204 		n = vq_getchain(vq, &idx, iov, VT9P_MAX_IOV, flags);
205 		preq = calloc(1, sizeof(struct pci_vt9p_request));
206 		preq->vsr_sc = sc;
207 		preq->vsr_idx = idx;
208 		preq->vsr_iov = iov;
209 		preq->vsr_niov = n;
210 		preq->vsr_respidx = 0;
211 
212 		/* Count readable descriptors */
213 		for (i = 0; i < n; i++) {
214 			if (flags[i] & VRING_DESC_F_WRITE)
215 				break;
216 
217 			preq->vsr_respidx++;
218 		}
219 
220 		for (int i = 0; i < n; i++) {
221 			DPRINTF(("vt9p: vt9p_notify(): desc%d base=%p, "
222 			    "len=%zu, flags=0x%04x\r\n", i, iov[i].iov_base,
223 			    iov[i].iov_len, flags[i]));
224 		}
225 
226 		l9p_connection_recv(sc->vsc_conn, iov, preq->vsr_respidx, preq);
227 	}
228 }
229 
230 
231 static int
232 pci_vt9p_init(struct vmctx *ctx, struct pci_devinst *pi, char *opts)
233 {
234 	struct pci_vt9p_softc *sc;
235 	char *opt;
236 	char *sharename = NULL;
237 	char *rootpath = NULL;
238 	int rootfd;
239 	bool ro = false;
240 	cap_rights_t rootcap;
241 
242 	if (opts == NULL) {
243 		printf("virtio-9p: share name and path required\n");
244 		return (1);
245 	}
246 
247 	while ((opt = strsep(&opts, ",")) != NULL) {
248 		if (strchr(opt, '=') != NULL) {
249 			if (sharename != NULL) {
250 				printf("virtio-9p: more than one share name given\n");
251 				return (1);
252 			}
253 
254 			sharename = strsep(&opt, "=");
255 			rootpath = opt;
256 			continue;
257 		}
258 
259 		if (strcmp(opt, "ro") == 0) {
260 			DPRINTF(("read-only mount requested\r\n"));
261 			ro = true;
262 			continue;
263 		}
264 
265 		printf("virtio-9p: invalid option '%s'\n", opt);
266 		return (1);
267 	}
268 
269 	if (strlen(sharename) > VT9P_MAXTAGSZ) {
270 		printf("virtio-9p: share name too long\n");
271 		return (1);
272 	}
273 
274 	rootfd = open(rootpath, O_DIRECTORY);
275 	if (rootfd < 0)
276 		return (-1);
277 
278 	sc = calloc(1, sizeof(struct pci_vt9p_softc));
279 	sc->vsc_config = calloc(1, sizeof(struct pci_vt9p_config) +
280 	    VT9P_MAXTAGSZ);
281 
282 	pthread_mutex_init(&sc->vsc_mtx, NULL);
283 
284 	cap_rights_init(&rootcap,
285 	    CAP_LOOKUP, CAP_ACL_CHECK, CAP_ACL_DELETE, CAP_ACL_GET,
286 	    CAP_ACL_SET, CAP_READ, CAP_WRITE, CAP_SEEK, CAP_FSTAT,
287 	    CAP_CREATE, CAP_FCHMODAT, CAP_FCHOWNAT, CAP_FTRUNCATE,
288 	    CAP_LINKAT_SOURCE, CAP_LINKAT_TARGET, CAP_MKDIRAT, CAP_MKNODAT,
289 	    CAP_PREAD, CAP_PWRITE, CAP_RENAMEAT_SOURCE, CAP_RENAMEAT_TARGET,
290 	    CAP_SEEK, CAP_SYMLINKAT, CAP_UNLINKAT, CAP_EXTATTR_DELETE,
291 	    CAP_EXTATTR_GET, CAP_EXTATTR_LIST, CAP_EXTATTR_SET,
292 	    CAP_FUTIMES, CAP_FSTATFS, CAP_FSYNC, CAP_FPATHCONF);
293 
294 	if (cap_rights_limit(rootfd, &rootcap) != 0)
295 		return (1);
296 
297 	sc->vsc_config->tag_len = (uint16_t)strlen(sharename);
298 	memcpy(sc->vsc_config->tag, sharename, sc->vsc_config->tag_len);
299 
300 	if (l9p_backend_fs_init(&sc->vsc_fs_backend, rootfd, ro) != 0) {
301 		errno = ENXIO;
302 		return (1);
303 	}
304 
305 	if (l9p_server_init(&sc->vsc_server, sc->vsc_fs_backend) != 0) {
306 		errno = ENXIO;
307 		return (1);
308 	}
309 
310 	if (l9p_connection_init(sc->vsc_server, &sc->vsc_conn) != 0) {
311 		errno = EIO;
312 		return (1);
313 	}
314 
315 	sc->vsc_conn->lc_msize = L9P_MAX_IOV * PAGE_SIZE;
316 	sc->vsc_conn->lc_lt.lt_get_response_buffer = pci_vt9p_get_buffer;
317 	sc->vsc_conn->lc_lt.lt_send_response = pci_vt9p_send;
318 	sc->vsc_conn->lc_lt.lt_drop_response = pci_vt9p_drop;
319 
320 	vi_softc_linkup(&sc->vsc_vs, &vt9p_vi_consts, sc, pi, &sc->vsc_vq);
321 	sc->vsc_vs.vs_mtx = &sc->vsc_mtx;
322 	sc->vsc_vq.vq_qsize = VT9P_RINGSZ;
323 
324 	/* initialize config space */
325 	pci_set_cfgdata16(pi, PCIR_DEVICE, VIRTIO_DEV_9P);
326 	pci_set_cfgdata16(pi, PCIR_VENDOR, VIRTIO_VENDOR);
327 	pci_set_cfgdata8(pi, PCIR_CLASS, PCIC_STORAGE);
328 	pci_set_cfgdata16(pi, PCIR_SUBDEV_0, VIRTIO_TYPE_9P);
329 	pci_set_cfgdata16(pi, PCIR_SUBVEND_0, VIRTIO_VENDOR);
330 
331 	if (vi_intr_init(&sc->vsc_vs, 1, fbsdrun_virtio_msix()))
332 		return (1);
333 	vi_set_io_bar(&sc->vsc_vs, 0);
334 
335 	return (0);
336 }
337 
338 struct pci_devemu pci_de_v9p = {
339 	.pe_emu =	"virtio-9p",
340 	.pe_init =	pci_vt9p_init,
341 	.pe_barwrite =	vi_pci_write,
342 	.pe_barread =	vi_pci_read
343 };
344 PCI_EMUL_SET(pci_de_v9p);
345