1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2011 NetApp, Inc.
5 * All rights reserved.
6 * Copyright (c) 2019 Joyent, Inc.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * $FreeBSD: stable/11/usr.sbin/bhyve/pci_virtio_block.c 348375 2019-05-29 23:11:07Z jhb $
30 */
31
32#include <sys/cdefs.h>
33__FBSDID("$FreeBSD: stable/11/usr.sbin/bhyve/pci_virtio_block.c 348375 2019-05-29 23:11:07Z jhb $");
34
35#include <sys/param.h>
36#include <sys/linker_set.h>
37#include <sys/stat.h>
38#include <sys/uio.h>
39#include <sys/ioctl.h>
40#include <sys/disk.h>
41
42#include <errno.h>
43#include <fcntl.h>
44#include <stdio.h>
45#include <stdlib.h>
46#include <stdint.h>
47#include <string.h>
48#include <strings.h>
49#include <unistd.h>
50#include <assert.h>
51#include <pthread.h>
52#include <md5.h>
53
54#include "bhyverun.h"
55#include "pci_emul.h"
56#include "virtio.h"
57#include "block_if.h"
58
59#define VTBLK_RINGSZ	128
60
61_Static_assert(VTBLK_RINGSZ <= BLOCKIF_RING_MAX, "Each ring entry must be able to queue a request");
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 + 1
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#define	VTBLK_F_FLUSH		(1 << 9)	/* Cache flush support */
73#define	VTBLK_F_TOPOLOGY	(1 << 10)	/* Optimal I/O alignment */
74
75/*
76 * Host capabilities
77 */
78#define VTBLK_S_HOSTCAPS      \
79  ( VTBLK_F_SEG_MAX  |						    \
80    VTBLK_F_BLK_SIZE |						    \
81    VTBLK_F_FLUSH    |						    \
82    VTBLK_F_TOPOLOGY |						    \
83    VIRTIO_RING_F_INDIRECT_DESC )	/* indirect descriptors */
84
85/*
86 * Config space "registers"
87 */
88struct vtblk_config {
89	uint64_t	vbc_capacity;
90	uint32_t	vbc_size_max;
91	uint32_t	vbc_seg_max;
92	struct {
93		uint16_t cylinders;
94		uint8_t heads;
95		uint8_t sectors;
96	} vbc_geometry;
97	uint32_t	vbc_blk_size;
98	struct {
99		uint8_t physical_block_exp;
100		uint8_t alignment_offset;
101		uint16_t min_io_size;
102		uint32_t opt_io_size;
103	} vbc_topology;
104	uint8_t		vbc_writeback;
105} __packed;
106
107/*
108 * Fixed-size block header
109 */
110struct virtio_blk_hdr {
111#define	VBH_OP_READ		0
112#define	VBH_OP_WRITE		1
113#define	VBH_OP_FLUSH		4
114#define	VBH_OP_FLUSH_OUT	5
115#define	VBH_OP_IDENT		8
116#define	VBH_FLAG_BARRIER	0x80000000	/* OR'ed into vbh_type */
117	uint32_t       	vbh_type;
118	uint32_t	vbh_ioprio;
119	uint64_t	vbh_sector;
120} __packed;
121
122/*
123 * Debug printf
124 */
125static int pci_vtblk_debug;
126#define DPRINTF(params) if (pci_vtblk_debug) printf params
127#define WPRINTF(params) printf params
128
129struct pci_vtblk_ioreq {
130	struct blockif_req		io_req;
131	struct pci_vtblk_softc	       *io_sc;
132	uint8_t			       *io_status;
133	uint16_t			io_idx;
134};
135
136/*
137 * Per-device softc
138 */
139struct pci_vtblk_softc {
140	struct virtio_softc vbsc_vs;
141	pthread_mutex_t vsc_mtx;
142	struct vqueue_info vbsc_vq;
143	struct vtblk_config vbsc_cfg;
144	struct blockif_ctxt *bc;
145	char vbsc_ident[VTBLK_BLK_ID_BYTES];
146	struct pci_vtblk_ioreq vbsc_ios[VTBLK_RINGSZ];
147};
148
149static void pci_vtblk_reset(void *);
150static void pci_vtblk_notify(void *, struct vqueue_info *);
151static int pci_vtblk_cfgread(void *, int, int, uint32_t *);
152static int pci_vtblk_cfgwrite(void *, int, int, uint32_t);
153
154static struct virtio_consts vtblk_vi_consts = {
155	"vtblk",		/* our name */
156	1,			/* we support 1 virtqueue */
157	sizeof(struct vtblk_config), /* config reg size */
158	pci_vtblk_reset,	/* reset */
159	pci_vtblk_notify,	/* device-wide qnotify */
160	pci_vtblk_cfgread,	/* read PCI config */
161	pci_vtblk_cfgwrite,	/* write PCI config */
162	NULL,			/* apply negotiated features */
163	VTBLK_S_HOSTCAPS,	/* our capabilities */
164};
165
166static void
167pci_vtblk_reset(void *vsc)
168{
169	struct pci_vtblk_softc *sc = vsc;
170
171	DPRINTF(("vtblk: device reset requested !\n"));
172	vi_reset_dev(&sc->vbsc_vs);
173}
174
175static void
176pci_vtblk_done(struct blockif_req *br, int err)
177{
178	struct pci_vtblk_ioreq *io = br->br_param;
179	struct pci_vtblk_softc *sc = io->io_sc;
180
181	/* convert errno into a virtio block error return */
182	if (err == EOPNOTSUPP || err == ENOSYS)
183		*io->io_status = VTBLK_S_UNSUPP;
184	else if (err != 0)
185		*io->io_status = VTBLK_S_IOERR;
186	else
187		*io->io_status = VTBLK_S_OK;
188
189	/*
190	 * Return the descriptor back to the host.
191	 * We wrote 1 byte (our status) to host.
192	 */
193	pthread_mutex_lock(&sc->vsc_mtx);
194	vq_relchain(&sc->vbsc_vq, io->io_idx, 1);
195	vq_endchains(&sc->vbsc_vq, 0);
196	pthread_mutex_unlock(&sc->vsc_mtx);
197}
198
199static void
200pci_vtblk_proc(struct pci_vtblk_softc *sc, struct vqueue_info *vq)
201{
202	struct virtio_blk_hdr *vbh;
203	struct pci_vtblk_ioreq *io;
204	int i, n;
205	int err;
206	ssize_t iolen;
207	int writeop, type;
208	struct iovec iov[BLOCKIF_IOV_MAX + 2];
209	uint16_t idx, flags[BLOCKIF_IOV_MAX + 2];
210
211	n = vq_getchain(vq, &idx, iov, BLOCKIF_IOV_MAX + 2, flags);
212
213	/*
214	 * The first descriptor will be the read-only fixed header,
215	 * and the last is for status (hence +2 above and below).
216	 * The remaining iov's are the actual data I/O vectors.
217	 *
218	 * XXX - note - this fails on crash dump, which does a
219	 * VIRTIO_BLK_T_FLUSH with a zero transfer length
220	 */
221	assert(n >= 2 && n <= BLOCKIF_IOV_MAX + 2);
222
223	io = &sc->vbsc_ios[idx];
224	assert((flags[0] & VRING_DESC_F_WRITE) == 0);
225	assert(iov[0].iov_len == sizeof(struct virtio_blk_hdr));
226	vbh = iov[0].iov_base;
227	memcpy(&io->io_req.br_iov, &iov[1], sizeof(struct iovec) * (n - 2));
228	io->io_req.br_iovcnt = n - 2;
229	io->io_req.br_offset = vbh->vbh_sector * DEV_BSIZE;
230	io->io_status = iov[--n].iov_base;
231	assert(iov[n].iov_len == 1);
232	assert(flags[n] & VRING_DESC_F_WRITE);
233
234	/*
235	 * XXX
236	 * The guest should not be setting the BARRIER flag because
237	 * we don't advertise the capability.
238	 */
239	type = vbh->vbh_type & ~VBH_FLAG_BARRIER;
240	writeop = (type == VBH_OP_WRITE);
241
242	iolen = 0;
243	for (i = 1; i < n; i++) {
244		/*
245		 * - write op implies read-only descriptor,
246		 * - read/ident op implies write-only descriptor,
247		 * therefore test the inverse of the descriptor bit
248		 * to the op.
249		 */
250		assert(((flags[i] & VRING_DESC_F_WRITE) == 0) == writeop);
251		iolen += iov[i].iov_len;
252	}
253	io->io_req.br_resid = iolen;
254
255	DPRINTF(("virtio-block: %s op, %zd bytes, %d segs, offset %ld\n\r",
256		 writeop ? "write" : "read/ident", iolen, i - 1,
257		 io->io_req.br_offset));
258
259	switch (type) {
260	case VBH_OP_READ:
261		err = blockif_read(sc->bc, &io->io_req);
262		break;
263	case VBH_OP_WRITE:
264		err = blockif_write(sc->bc, &io->io_req);
265		break;
266	case VBH_OP_FLUSH:
267	case VBH_OP_FLUSH_OUT:
268		err = blockif_flush(sc->bc, &io->io_req);
269		break;
270	case VBH_OP_IDENT:
271		/* Assume a single buffer */
272		/* S/n equal to buffer is not zero-terminated. */
273		memset(iov[1].iov_base, 0, iov[1].iov_len);
274		strncpy(iov[1].iov_base, sc->vbsc_ident,
275		    MIN(iov[1].iov_len, sizeof(sc->vbsc_ident)));
276		pci_vtblk_done(&io->io_req, 0);
277		return;
278	default:
279		pci_vtblk_done(&io->io_req, EOPNOTSUPP);
280		return;
281	}
282	assert(err == 0);
283}
284
285static void
286pci_vtblk_notify(void *vsc, struct vqueue_info *vq)
287{
288	struct pci_vtblk_softc *sc = vsc;
289
290	while (vq_has_descs(vq))
291		pci_vtblk_proc(sc, vq);
292}
293
294static int
295pci_vtblk_init(struct vmctx *ctx, struct pci_devinst *pi, char *opts)
296{
297	char bident[sizeof("XX:X:X")];
298	struct blockif_ctxt *bctxt;
299	MD5_CTX mdctx;
300	u_char digest[16];
301	struct pci_vtblk_softc *sc;
302	off_t size;
303	int i, sectsz, sts, sto;
304
305	if (opts == NULL) {
306		printf("virtio-block: backing device required\n");
307		return (1);
308	}
309
310	/*
311	 * The supplied backing file has to exist
312	 */
313	snprintf(bident, sizeof(bident), "%d:%d", pi->pi_slot, pi->pi_func);
314	bctxt = blockif_open(opts, bident);
315	if (bctxt == NULL) {
316		perror("Could not open backing file");
317		return (1);
318	}
319
320	size = blockif_size(bctxt);
321	sectsz = blockif_sectsz(bctxt);
322	blockif_psectsz(bctxt, &sts, &sto);
323
324	sc = calloc(1, sizeof(struct pci_vtblk_softc));
325	sc->bc = bctxt;
326	for (i = 0; i < VTBLK_RINGSZ; i++) {
327		struct pci_vtblk_ioreq *io = &sc->vbsc_ios[i];
328		io->io_req.br_callback = pci_vtblk_done;
329		io->io_req.br_param = io;
330		io->io_sc = sc;
331		io->io_idx = i;
332	}
333
334	pthread_mutex_init(&sc->vsc_mtx, NULL);
335
336	/* init virtio softc and virtqueues */
337	vi_softc_linkup(&sc->vbsc_vs, &vtblk_vi_consts, sc, pi, &sc->vbsc_vq);
338	sc->vbsc_vs.vs_mtx = &sc->vsc_mtx;
339
340	sc->vbsc_vq.vq_qsize = VTBLK_RINGSZ;
341	/* sc->vbsc_vq.vq_notify = we have no per-queue notify */
342
343	/*
344	 * Create an identifier for the backing file. Use parts of the
345	 * md5 sum of the filename
346	 */
347	MD5Init(&mdctx);
348	MD5Update(&mdctx, opts, strlen(opts));
349	MD5Final(digest, &mdctx);
350	snprintf(sc->vbsc_ident, VTBLK_BLK_ID_BYTES,
351	    "BHYVE-%02X%02X-%02X%02X-%02X%02X",
352	    digest[0], digest[1], digest[2], digest[3], digest[4], digest[5]);
353
354	/* setup virtio block config space */
355	sc->vbsc_cfg.vbc_capacity = size / DEV_BSIZE; /* 512-byte units */
356	sc->vbsc_cfg.vbc_size_max = 0;	/* not negotiated */
357
358	/*
359	 * If Linux is presented with a seg_max greater than the virtio queue
360	 * size, it can stumble into situations where it violates its own
361	 * invariants and panics.  For safety, we keep seg_max clamped, paying
362	 * heed to the two extra descriptors needed for the header and status
363	 * of a request.
364	 */
365	sc->vbsc_cfg.vbc_seg_max = MIN(VTBLK_RINGSZ - 2, BLOCKIF_IOV_MAX);
366	sc->vbsc_cfg.vbc_geometry.cylinders = 0;	/* no geometry */
367	sc->vbsc_cfg.vbc_geometry.heads = 0;
368	sc->vbsc_cfg.vbc_geometry.sectors = 0;
369	sc->vbsc_cfg.vbc_blk_size = sectsz;
370	sc->vbsc_cfg.vbc_topology.physical_block_exp =
371	    (sts > sectsz) ? (ffsll(sts / sectsz) - 1) : 0;
372	sc->vbsc_cfg.vbc_topology.alignment_offset =
373	    (sto != 0) ? ((sts - sto) / sectsz) : 0;
374	sc->vbsc_cfg.vbc_topology.min_io_size = 0;
375	sc->vbsc_cfg.vbc_topology.opt_io_size = 0;
376	sc->vbsc_cfg.vbc_writeback = 0;
377
378	/*
379	 * Should we move some of this into virtio.c?  Could
380	 * have the device, class, and subdev_0 as fields in
381	 * the virtio constants structure.
382	 */
383	pci_set_cfgdata16(pi, PCIR_DEVICE, VIRTIO_DEV_BLOCK);
384	pci_set_cfgdata16(pi, PCIR_VENDOR, VIRTIO_VENDOR);
385	pci_set_cfgdata8(pi, PCIR_CLASS, PCIC_STORAGE);
386	pci_set_cfgdata16(pi, PCIR_SUBDEV_0, VIRTIO_TYPE_BLOCK);
387	pci_set_cfgdata16(pi, PCIR_SUBVEND_0, VIRTIO_VENDOR);
388
389	if (vi_intr_init(&sc->vbsc_vs, 1, fbsdrun_virtio_msix())) {
390		blockif_close(sc->bc);
391		free(sc);
392		return (1);
393	}
394	vi_set_io_bar(&sc->vbsc_vs, 0);
395	return (0);
396}
397
398static int
399pci_vtblk_cfgwrite(void *vsc, int offset, int size, uint32_t value)
400{
401
402	DPRINTF(("vtblk: write to readonly reg %d\n\r", offset));
403	return (1);
404}
405
406static int
407pci_vtblk_cfgread(void *vsc, int offset, int size, uint32_t *retval)
408{
409	struct pci_vtblk_softc *sc = vsc;
410	void *ptr;
411
412	/* our caller has already verified offset and size */
413	ptr = (uint8_t *)&sc->vbsc_cfg + offset;
414	memcpy(retval, ptr, size);
415	return (0);
416}
417
418struct pci_devemu pci_de_vblk = {
419	.pe_emu =	"virtio-blk",
420	.pe_init =	pci_vtblk_init,
421	.pe_barwrite =	vi_pci_write,
422	.pe_barread =	vi_pci_read
423};
424PCI_EMUL_SET(pci_de_vblk);
425