pci_virtio_block.c revision 330449 
1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2011 NetApp, Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
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 NETAPP, INC ``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 NETAPP, INC 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 * $FreeBSD: stable/11/usr.sbin/bhyve/pci_virtio_block.c 330449 2018-03-05 07:26:05Z eadler $
29 */
30
31#include <sys/cdefs.h>
32__FBSDID("$FreeBSD: stable/11/usr.sbin/bhyve/pci_virtio_block.c 330449 2018-03-05 07:26:05Z eadler $");
33
34#include <sys/param.h>
35#include <sys/linker_set.h>
36#include <sys/stat.h>
37#include <sys/uio.h>
38#include <sys/ioctl.h>
39#include <sys/disk.h>
40
41#include <errno.h>
42#include <fcntl.h>
43#include <stdio.h>
44#include <stdlib.h>
45#include <stdint.h>
46#include <string.h>
47#include <strings.h>
48#include <unistd.h>
49#include <assert.h>
50#include <pthread.h>
51#include <md5.h>
52
53#include "bhyverun.h"
54#include "pci_emul.h"
55#include "virtio.h"
56#include "block_if.h"
57
58#define VTBLK_RINGSZ	64
59
60#define VTBLK_S_OK	0
61#define VTBLK_S_IOERR	1
62#define	VTBLK_S_UNSUPP	2
63
64#define	VTBLK_BLK_ID_BYTES	20
65
66/* Capability bits */
67#define	VTBLK_F_SEG_MAX		(1 << 2)	/* Maximum request segments */
68#define	VTBLK_F_BLK_SIZE	(1 << 6)	/* cfg block size valid */
69#define	VTBLK_F_FLUSH		(1 << 9)	/* Cache flush support */
70#define	VTBLK_F_TOPOLOGY	(1 << 10)	/* Optimal I/O alignment */
71
72/*
73 * Host capabilities
74 */
75#define VTBLK_S_HOSTCAPS      \
76  ( VTBLK_F_SEG_MAX  |						    \
77    VTBLK_F_BLK_SIZE |						    \
78    VTBLK_F_FLUSH    |						    \
79    VTBLK_F_TOPOLOGY |						    \
80    VIRTIO_RING_F_INDIRECT_DESC )	/* indirect descriptors */
81
82/*
83 * Config space "registers"
84 */
85struct vtblk_config {
86	uint64_t	vbc_capacity;
87	uint32_t	vbc_size_max;
88	uint32_t	vbc_seg_max;
89	struct {
90		uint16_t cylinders;
91		uint8_t heads;
92		uint8_t sectors;
93	} vbc_geometry;
94	uint32_t	vbc_blk_size;
95	struct {
96		uint8_t physical_block_exp;
97		uint8_t alignment_offset;
98		uint16_t min_io_size;
99		uint32_t opt_io_size;
100	} vbc_topology;
101	uint8_t		vbc_writeback;
102} __packed;
103
104/*
105 * Fixed-size block header
106 */
107struct virtio_blk_hdr {
108#define	VBH_OP_READ		0
109#define	VBH_OP_WRITE		1
110#define	VBH_OP_FLUSH		4
111#define	VBH_OP_FLUSH_OUT	5
112#define	VBH_OP_IDENT		8
113#define	VBH_FLAG_BARRIER	0x80000000	/* OR'ed into vbh_type */
114	uint32_t       	vbh_type;
115	uint32_t	vbh_ioprio;
116	uint64_t	vbh_sector;
117} __packed;
118
119/*
120 * Debug printf
121 */
122static int pci_vtblk_debug;
123#define DPRINTF(params) if (pci_vtblk_debug) printf params
124#define WPRINTF(params) printf params
125
126struct pci_vtblk_ioreq {
127	struct blockif_req		io_req;
128	struct pci_vtblk_softc	       *io_sc;
129	uint8_t			       *io_status;
130	uint16_t			io_idx;
131};
132
133/*
134 * Per-device softc
135 */
136struct pci_vtblk_softc {
137	struct virtio_softc vbsc_vs;
138	pthread_mutex_t vsc_mtx;
139	struct vqueue_info vbsc_vq;
140	struct vtblk_config vbsc_cfg;
141	struct blockif_ctxt *bc;
142	char vbsc_ident[VTBLK_BLK_ID_BYTES];
143	struct pci_vtblk_ioreq vbsc_ios[VTBLK_RINGSZ];
144};
145
146static void pci_vtblk_reset(void *);
147static void pci_vtblk_notify(void *, struct vqueue_info *);
148static int pci_vtblk_cfgread(void *, int, int, uint32_t *);
149static int pci_vtblk_cfgwrite(void *, int, int, uint32_t);
150
151static struct virtio_consts vtblk_vi_consts = {
152	"vtblk",		/* our name */
153	1,			/* we support 1 virtqueue */
154	sizeof(struct vtblk_config), /* config reg size */
155	pci_vtblk_reset,	/* reset */
156	pci_vtblk_notify,	/* device-wide qnotify */
157	pci_vtblk_cfgread,	/* read PCI config */
158	pci_vtblk_cfgwrite,	/* write PCI config */
159	NULL,			/* apply negotiated features */
160	VTBLK_S_HOSTCAPS,	/* our capabilities */
161};
162
163static void
164pci_vtblk_reset(void *vsc)
165{
166	struct pci_vtblk_softc *sc = vsc;
167
168	DPRINTF(("vtblk: device reset requested !\n"));
169	vi_reset_dev(&sc->vbsc_vs);
170}
171
172static void
173pci_vtblk_done(struct blockif_req *br, int err)
174{
175	struct pci_vtblk_ioreq *io = br->br_param;
176	struct pci_vtblk_softc *sc = io->io_sc;
177
178	/* convert errno into a virtio block error return */
179	if (err == EOPNOTSUPP || err == ENOSYS)
180		*io->io_status = VTBLK_S_UNSUPP;
181	else if (err != 0)
182		*io->io_status = VTBLK_S_IOERR;
183	else
184		*io->io_status = VTBLK_S_OK;
185
186	/*
187	 * Return the descriptor back to the host.
188	 * We wrote 1 byte (our status) to host.
189	 */
190	pthread_mutex_lock(&sc->vsc_mtx);
191	vq_relchain(&sc->vbsc_vq, io->io_idx, 1);
192	vq_endchains(&sc->vbsc_vq, 0);
193	pthread_mutex_unlock(&sc->vsc_mtx);
194}
195
196static void
197pci_vtblk_proc(struct pci_vtblk_softc *sc, struct vqueue_info *vq)
198{
199	struct virtio_blk_hdr *vbh;
200	struct pci_vtblk_ioreq *io;
201	int i, n;
202	int err;
203	ssize_t iolen;
204	int writeop, type;
205	struct iovec iov[BLOCKIF_IOV_MAX + 2];
206	uint16_t idx, flags[BLOCKIF_IOV_MAX + 2];
207
208	n = vq_getchain(vq, &idx, iov, BLOCKIF_IOV_MAX + 2, flags);
209
210	/*
211	 * The first descriptor will be the read-only fixed header,
212	 * and the last is for status (hence +2 above and below).
213	 * The remaining iov's are the actual data I/O vectors.
214	 *
215	 * XXX - note - this fails on crash dump, which does a
216	 * VIRTIO_BLK_T_FLUSH with a zero transfer length
217	 */
218	assert(n >= 2 && n <= BLOCKIF_IOV_MAX + 2);
219
220	io = &sc->vbsc_ios[idx];
221	assert((flags[0] & VRING_DESC_F_WRITE) == 0);
222	assert(iov[0].iov_len == sizeof(struct virtio_blk_hdr));
223	vbh = iov[0].iov_base;
224	memcpy(&io->io_req.br_iov, &iov[1], sizeof(struct iovec) * (n - 2));
225	io->io_req.br_iovcnt = n - 2;
226	io->io_req.br_offset = vbh->vbh_sector * DEV_BSIZE;
227	io->io_status = iov[--n].iov_base;
228	assert(iov[n].iov_len == 1);
229	assert(flags[n] & VRING_DESC_F_WRITE);
230
231	/*
232	 * XXX
233	 * The guest should not be setting the BARRIER flag because
234	 * we don't advertise the capability.
235	 */
236	type = vbh->vbh_type & ~VBH_FLAG_BARRIER;
237	writeop = (type == VBH_OP_WRITE);
238
239	iolen = 0;
240	for (i = 1; i < n; i++) {
241		/*
242		 * - write op implies read-only descriptor,
243		 * - read/ident op implies write-only descriptor,
244		 * therefore test the inverse of the descriptor bit
245		 * to the op.
246		 */
247		assert(((flags[i] & VRING_DESC_F_WRITE) == 0) == writeop);
248		iolen += iov[i].iov_len;
249	}
250	io->io_req.br_resid = iolen;
251
252	DPRINTF(("virtio-block: %s op, %zd bytes, %d segs, offset %ld\n\r",
253		 writeop ? "write" : "read/ident", iolen, i - 1,
254		 io->io_req.br_offset));
255
256	switch (type) {
257	case VBH_OP_READ:
258		err = blockif_read(sc->bc, &io->io_req);
259		break;
260	case VBH_OP_WRITE:
261		err = blockif_write(sc->bc, &io->io_req);
262		break;
263	case VBH_OP_FLUSH:
264	case VBH_OP_FLUSH_OUT:
265		err = blockif_flush(sc->bc, &io->io_req);
266		break;
267	case VBH_OP_IDENT:
268		/* Assume a single buffer */
269		/* S/n equal to buffer is not zero-terminated. */
270		memset(iov[1].iov_base, 0, iov[1].iov_len);
271		strncpy(iov[1].iov_base, sc->vbsc_ident,
272		    MIN(iov[1].iov_len, sizeof(sc->vbsc_ident)));
273		pci_vtblk_done(&io->io_req, 0);
274		return;
275	default:
276		pci_vtblk_done(&io->io_req, EOPNOTSUPP);
277		return;
278	}
279	assert(err == 0);
280}
281
282static void
283pci_vtblk_notify(void *vsc, struct vqueue_info *vq)
284{
285	struct pci_vtblk_softc *sc = vsc;
286
287	while (vq_has_descs(vq))
288		pci_vtblk_proc(sc, vq);
289}
290
291static int
292pci_vtblk_init(struct vmctx *ctx, struct pci_devinst *pi, char *opts)
293{
294	char bident[sizeof("XX:X:X")];
295	struct blockif_ctxt *bctxt;
296	MD5_CTX mdctx;
297	u_char digest[16];
298	struct pci_vtblk_softc *sc;
299	off_t size;
300	int i, sectsz, sts, sto;
301
302	if (opts == NULL) {
303		printf("virtio-block: backing device required\n");
304		return (1);
305	}
306
307	/*
308	 * The supplied backing file has to exist
309	 */
310	snprintf(bident, sizeof(bident), "%d:%d", pi->pi_slot, pi->pi_func);
311	bctxt = blockif_open(opts, bident);
312	if (bctxt == NULL) {
313		perror("Could not open backing file");
314		return (1);
315	}
316
317	size = blockif_size(bctxt);
318	sectsz = blockif_sectsz(bctxt);
319	blockif_psectsz(bctxt, &sts, &sto);
320
321	sc = calloc(1, sizeof(struct pci_vtblk_softc));
322	sc->bc = bctxt;
323	for (i = 0; i < VTBLK_RINGSZ; i++) {
324		struct pci_vtblk_ioreq *io = &sc->vbsc_ios[i];
325		io->io_req.br_callback = pci_vtblk_done;
326		io->io_req.br_param = io;
327		io->io_sc = sc;
328		io->io_idx = i;
329	}
330
331	pthread_mutex_init(&sc->vsc_mtx, NULL);
332
333	/* init virtio softc and virtqueues */
334	vi_softc_linkup(&sc->vbsc_vs, &vtblk_vi_consts, sc, pi, &sc->vbsc_vq);
335	sc->vbsc_vs.vs_mtx = &sc->vsc_mtx;
336
337	sc->vbsc_vq.vq_qsize = VTBLK_RINGSZ;
338	/* sc->vbsc_vq.vq_notify = we have no per-queue notify */
339
340	/*
341	 * Create an identifier for the backing file. Use parts of the
342	 * md5 sum of the filename
343	 */
344	MD5Init(&mdctx);
345	MD5Update(&mdctx, opts, strlen(opts));
346	MD5Final(digest, &mdctx);
347	sprintf(sc->vbsc_ident, "BHYVE-%02X%02X-%02X%02X-%02X%02X",
348	    digest[0], digest[1], digest[2], digest[3], digest[4], digest[5]);
349
350	/* setup virtio block config space */
351	sc->vbsc_cfg.vbc_capacity = size / DEV_BSIZE; /* 512-byte units */
352	sc->vbsc_cfg.vbc_size_max = 0;	/* not negotiated */
353	sc->vbsc_cfg.vbc_seg_max = BLOCKIF_IOV_MAX;
354	sc->vbsc_cfg.vbc_geometry.cylinders = 0;	/* no geometry */
355	sc->vbsc_cfg.vbc_geometry.heads = 0;
356	sc->vbsc_cfg.vbc_geometry.sectors = 0;
357	sc->vbsc_cfg.vbc_blk_size = sectsz;
358	sc->vbsc_cfg.vbc_topology.physical_block_exp =
359	    (sts > sectsz) ? (ffsll(sts / sectsz) - 1) : 0;
360	sc->vbsc_cfg.vbc_topology.alignment_offset =
361	    (sto != 0) ? ((sts - sto) / sectsz) : 0;
362	sc->vbsc_cfg.vbc_topology.min_io_size = 0;
363	sc->vbsc_cfg.vbc_topology.opt_io_size = 0;
364	sc->vbsc_cfg.vbc_writeback = 0;
365
366	/*
367	 * Should we move some of this into virtio.c?  Could
368	 * have the device, class, and subdev_0 as fields in
369	 * the virtio constants structure.
370	 */
371	pci_set_cfgdata16(pi, PCIR_DEVICE, VIRTIO_DEV_BLOCK);
372	pci_set_cfgdata16(pi, PCIR_VENDOR, VIRTIO_VENDOR);
373	pci_set_cfgdata8(pi, PCIR_CLASS, PCIC_STORAGE);
374	pci_set_cfgdata16(pi, PCIR_SUBDEV_0, VIRTIO_TYPE_BLOCK);
375	pci_set_cfgdata16(pi, PCIR_SUBVEND_0, VIRTIO_VENDOR);
376
377	if (vi_intr_init(&sc->vbsc_vs, 1, fbsdrun_virtio_msix())) {
378		blockif_close(sc->bc);
379		free(sc);
380		return (1);
381	}
382	vi_set_io_bar(&sc->vbsc_vs, 0);
383	return (0);
384}
385
386static int
387pci_vtblk_cfgwrite(void *vsc, int offset, int size, uint32_t value)
388{
389
390	DPRINTF(("vtblk: write to readonly reg %d\n\r", offset));
391	return (1);
392}
393
394static int
395pci_vtblk_cfgread(void *vsc, int offset, int size, uint32_t *retval)
396{
397	struct pci_vtblk_softc *sc = vsc;
398	void *ptr;
399
400	/* our caller has already verified offset and size */
401	ptr = (uint8_t *)&sc->vbsc_cfg + offset;
402	memcpy(retval, ptr, size);
403	return (0);
404}
405
406struct pci_devemu pci_de_vblk = {
407	.pe_emu =	"virtio-blk",
408	.pe_init =	pci_vtblk_init,
409	.pe_barwrite =	vi_pci_write,
410	.pe_barread =	vi_pci_read
411};
412PCI_EMUL_SET(pci_de_vblk);
413