xref: /freebsd/usr.sbin/bhyve/pci_virtio_block.c (revision 4c9e27bd0a5f7fda85b0c0bf750575aee300a172)
1 /*-
2  * Copyright (c) 2011 NetApp, Inc.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/linker_set.h>
34 #include <sys/stat.h>
35 #include <sys/uio.h>
36 #include <sys/ioctl.h>
37 #include <sys/disk.h>
38 
39 #include <errno.h>
40 #include <fcntl.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <stdint.h>
44 #include <string.h>
45 #include <strings.h>
46 #include <unistd.h>
47 #include <assert.h>
48 #include <pthread.h>
49 #include <md5.h>
50 
51 #include "bhyverun.h"
52 #include "pci_emul.h"
53 #include "virtio.h"
54 
55 #ifndef min
56 #define	min(a, b)	((a) < (b) ? (a) : (b))
57 #endif
58 
59 #define VTBLK_RINGSZ	64
60 
61 #define VTBLK_MAXSEGS	32
62 
63 #define VTBLK_S_OK	0
64 #define VTBLK_S_IOERR	1
65 #define	VTBLK_S_UNSUPP	2
66 
67 #define	VTBLK_BLK_ID_BYTES	20
68 
69 /* Capability bits */
70 #define	VTBLK_F_SEG_MAX		(1 << 2)	/* Maximum request segments */
71 #define	VTBLK_F_BLK_SIZE       	(1 << 6)	/* cfg block size valid */
72 
73 /*
74  * Host capabilities
75  */
76 #define VTBLK_S_HOSTCAPS      \
77   ( VTBLK_F_SEG_MAX  |						    \
78     VTBLK_F_BLK_SIZE |						    \
79     VIRTIO_RING_F_INDIRECT_DESC )	/* indirect descriptors */
80 
81 /*
82  * Config space "registers"
83  */
84 struct vtblk_config {
85 	uint64_t	vbc_capacity;
86 	uint32_t	vbc_size_max;
87 	uint32_t	vbc_seg_max;
88 	uint16_t	vbc_geom_c;
89 	uint8_t		vbc_geom_h;
90 	uint8_t		vbc_geom_s;
91 	uint32_t	vbc_blk_size;
92 	uint32_t	vbc_sectors_max;
93 } __packed;
94 
95 /*
96  * Fixed-size block header
97  */
98 struct virtio_blk_hdr {
99 #define	VBH_OP_READ		0
100 #define	VBH_OP_WRITE		1
101 #define	VBH_OP_IDENT		8
102 #define	VBH_FLAG_BARRIER	0x80000000	/* OR'ed into vbh_type */
103 	uint32_t       	vbh_type;
104 	uint32_t	vbh_ioprio;
105 	uint64_t	vbh_sector;
106 } __packed;
107 
108 /*
109  * Debug printf
110  */
111 static int pci_vtblk_debug;
112 #define DPRINTF(params) if (pci_vtblk_debug) printf params
113 #define WPRINTF(params) printf params
114 
115 /*
116  * Per-device softc
117  */
118 struct pci_vtblk_softc {
119 	struct virtio_softc vbsc_vs;
120 	struct vqueue_info vbsc_vq;
121 	int		vbsc_fd;
122 	struct vtblk_config vbsc_cfg;
123 	char vbsc_ident[VTBLK_BLK_ID_BYTES];
124 };
125 
126 static void pci_vtblk_reset(void *);
127 static void pci_vtblk_notify(void *, struct vqueue_info *);
128 static int pci_vtblk_cfgread(void *, int, int, uint32_t *);
129 static int pci_vtblk_cfgwrite(void *, int, int, uint32_t);
130 
131 static struct virtio_consts vtblk_vi_consts = {
132 	"vtblk",		/* our name */
133 	1,			/* we support 1 virtqueue */
134 	sizeof(struct vtblk_config), /* config reg size */
135 	pci_vtblk_reset,	/* reset */
136 	pci_vtblk_notify,	/* device-wide qnotify */
137 	pci_vtblk_cfgread,	/* read PCI config */
138 	pci_vtblk_cfgwrite,	/* write PCI config */
139 	VTBLK_S_HOSTCAPS,	/* our capabilities */
140 };
141 
142 static void
143 pci_vtblk_reset(void *vsc)
144 {
145 	struct pci_vtblk_softc *sc = vsc;
146 
147 	DPRINTF(("vtblk: device reset requested !\n"));
148 	vi_reset_dev(&sc->vbsc_vs);
149 }
150 
151 static void
152 pci_vtblk_proc(struct pci_vtblk_softc *sc, struct vqueue_info *vq)
153 {
154 	struct virtio_blk_hdr *vbh;
155 	uint8_t *status;
156 	int i, n;
157 	int err;
158 	int iolen;
159 	int writeop, type;
160 	off_t offset;
161 	struct iovec iov[VTBLK_MAXSEGS + 2];
162 	uint16_t flags[VTBLK_MAXSEGS + 2];
163 
164 	n = vq_getchain(vq, iov, VTBLK_MAXSEGS + 2, flags);
165 
166 	/*
167 	 * The first descriptor will be the read-only fixed header,
168 	 * and the last is for status (hence +2 above and below).
169 	 * The remaining iov's are the actual data I/O vectors.
170 	 *
171 	 * XXX - note - this fails on crash dump, which does a
172 	 * VIRTIO_BLK_T_FLUSH with a zero transfer length
173 	 */
174 	assert(n >= 2 && n <= VTBLK_MAXSEGS + 2);
175 
176 	assert((flags[0] & VRING_DESC_F_WRITE) == 0);
177 	assert(iov[0].iov_len == sizeof(struct virtio_blk_hdr));
178 	vbh = iov[0].iov_base;
179 
180 	status = iov[--n].iov_base;
181 	assert(iov[n].iov_len == 1);
182 	assert(flags[n] & VRING_DESC_F_WRITE);
183 
184 	/*
185 	 * XXX
186 	 * The guest should not be setting the BARRIER flag because
187 	 * we don't advertise the capability.
188 	 */
189 	type = vbh->vbh_type & ~VBH_FLAG_BARRIER;
190 	writeop = (type == VBH_OP_WRITE);
191 
192 	offset = vbh->vbh_sector * DEV_BSIZE;
193 
194 	iolen = 0;
195 	for (i = 1; i < n; i++) {
196 		/*
197 		 * - write op implies read-only descriptor,
198 		 * - read/ident op implies write-only descriptor,
199 		 * therefore test the inverse of the descriptor bit
200 		 * to the op.
201 		 */
202 		assert(((flags[i] & VRING_DESC_F_WRITE) == 0) == writeop);
203 		iolen += iov[i].iov_len;
204 	}
205 
206 	DPRINTF(("virtio-block: %s op, %d bytes, %d segs, offset %ld\n\r",
207 		 writeop ? "write" : "read/ident", iolen, i - 1, offset));
208 
209 	switch (type) {
210 	case VBH_OP_WRITE:
211 		err = pwritev(sc->vbsc_fd, iov + 1, i - 1, offset);
212 		break;
213 	case VBH_OP_READ:
214 		err = preadv(sc->vbsc_fd, iov + 1, i - 1, offset);
215 		break;
216 	case VBH_OP_IDENT:
217 		/* Assume a single buffer */
218 		strlcpy(iov[1].iov_base, sc->vbsc_ident,
219 		    min(iov[1].iov_len, sizeof(sc->vbsc_ident)));
220 		err = 0;
221 		break;
222 	default:
223 		err = -ENOSYS;
224 		break;
225 	}
226 
227 	/* convert errno into a virtio block error return */
228 	if (err < 0) {
229 		if (err == -ENOSYS)
230 			*status = VTBLK_S_UNSUPP;
231 		else
232 			*status = VTBLK_S_IOERR;
233 	} else
234 		*status = VTBLK_S_OK;
235 
236 	/*
237 	 * Return the descriptor back to the host.
238 	 * We wrote 1 byte (our status) to host.
239 	 */
240 	vq_relchain(vq, 1);
241 }
242 
243 static void
244 pci_vtblk_notify(void *vsc, struct vqueue_info *vq)
245 {
246 	struct pci_vtblk_softc *sc = vsc;
247 
248 	vq_startchains(vq);
249 	while (vq_has_descs(vq))
250 		pci_vtblk_proc(sc, vq);
251 	vq_endchains(vq, 1);	/* Generate interrupt if appropriate. */
252 }
253 
254 static int
255 pci_vtblk_init(struct vmctx *ctx, struct pci_devinst *pi, char *opts)
256 {
257 	struct stat sbuf;
258 	MD5_CTX mdctx;
259 	u_char digest[16];
260 	struct pci_vtblk_softc *sc;
261 	off_t size;
262 	int fd;
263 	int sectsz;
264 
265 	if (opts == NULL) {
266 		printf("virtio-block: backing device required\n");
267 		return (1);
268 	}
269 
270 	/*
271 	 * The supplied backing file has to exist
272 	 */
273 	fd = open(opts, O_RDWR);
274 	if (fd < 0) {
275 		perror("Could not open backing file");
276 		return (1);
277 	}
278 
279 	if (fstat(fd, &sbuf) < 0) {
280 		perror("Could not stat backing file");
281 		close(fd);
282 		return (1);
283 	}
284 
285 	/*
286 	 * Deal with raw devices
287 	 */
288 	size = sbuf.st_size;
289 	sectsz = DEV_BSIZE;
290 	if (S_ISCHR(sbuf.st_mode)) {
291 		if (ioctl(fd, DIOCGMEDIASIZE, &size) < 0 ||
292 		    ioctl(fd, DIOCGSECTORSIZE, &sectsz)) {
293 			perror("Could not fetch dev blk/sector size");
294 			close(fd);
295 			return (1);
296 		}
297 		assert(size != 0);
298 		assert(sectsz != 0);
299 	}
300 
301 	sc = malloc(sizeof(struct pci_vtblk_softc));
302 	memset(sc, 0, sizeof(struct pci_vtblk_softc));
303 
304 	/* record fd of storage device/file */
305 	sc->vbsc_fd = fd;
306 
307 	/* init virtio softc and virtqueues */
308 	vi_softc_linkup(&sc->vbsc_vs, &vtblk_vi_consts, sc, pi, &sc->vbsc_vq);
309 	sc->vbsc_vq.vq_qsize = VTBLK_RINGSZ;
310 	/* sc->vbsc_vq.vq_notify = we have no per-queue notify */
311 
312 	/*
313 	 * Create an identifier for the backing file. Use parts of the
314 	 * md5 sum of the filename
315 	 */
316 	MD5Init(&mdctx);
317 	MD5Update(&mdctx, opts, strlen(opts));
318 	MD5Final(digest, &mdctx);
319 	sprintf(sc->vbsc_ident, "BHYVE-%02X%02X-%02X%02X-%02X%02X",
320 	    digest[0], digest[1], digest[2], digest[3], digest[4], digest[5]);
321 
322 	/* setup virtio block config space */
323 	sc->vbsc_cfg.vbc_capacity = size / DEV_BSIZE; /* 512-byte units */
324 	sc->vbsc_cfg.vbc_seg_max = VTBLK_MAXSEGS;
325 	sc->vbsc_cfg.vbc_blk_size = sectsz;
326 	sc->vbsc_cfg.vbc_size_max = 0;	/* not negotiated */
327 	sc->vbsc_cfg.vbc_geom_c = 0;	/* no geometry */
328 	sc->vbsc_cfg.vbc_geom_h = 0;
329 	sc->vbsc_cfg.vbc_geom_s = 0;
330 	sc->vbsc_cfg.vbc_sectors_max = 0;
331 
332 	/*
333 	 * Should we move some of this into virtio.c?  Could
334 	 * have the device, class, and subdev_0 as fields in
335 	 * the virtio constants structure.
336 	 */
337 	pci_set_cfgdata16(pi, PCIR_DEVICE, VIRTIO_DEV_BLOCK);
338 	pci_set_cfgdata16(pi, PCIR_VENDOR, VIRTIO_VENDOR);
339 	pci_set_cfgdata8(pi, PCIR_CLASS, PCIC_STORAGE);
340 	pci_set_cfgdata16(pi, PCIR_SUBDEV_0, VIRTIO_TYPE_BLOCK);
341 
342 	if (vi_intr_init(&sc->vbsc_vs, 1, fbsdrun_virtio_msix()))
343 		return (1);
344 	vi_set_io_bar(&sc->vbsc_vs, 0);
345 	return (0);
346 }
347 
348 static int
349 pci_vtblk_cfgwrite(void *vsc, int offset, int size, uint32_t value)
350 {
351 
352 	DPRINTF(("vtblk: write to readonly reg %d\n\r", offset));
353 	return (1);
354 }
355 
356 static int
357 pci_vtblk_cfgread(void *vsc, int offset, int size, uint32_t *retval)
358 {
359 	struct pci_vtblk_softc *sc = vsc;
360 	void *ptr;
361 
362 	/* our caller has already verified offset and size */
363 	ptr = (uint8_t *)&sc->vbsc_cfg + offset;
364 	memcpy(retval, ptr, size);
365 	return (0);
366 }
367 
368 struct pci_devemu pci_de_vblk = {
369 	.pe_emu =	"virtio-blk",
370 	.pe_init =	pci_vtblk_init,
371 	.pe_barwrite =	vi_pci_write,
372 	.pe_barread =	vi_pci_read
373 };
374 PCI_EMUL_SET(pci_de_vblk);
375