xref: /freebsd/usr.sbin/bhyve/block_if.h (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2013  Peter Grehan <grehan@freebsd.org>
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 THE AUTHOR ``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  * $FreeBSD$
29  */
30 
31 /*
32  * The block API to be used by bhyve block-device emulations. The routines
33  * are thread safe, with no assumptions about the context of the completion
34  * callback - it may occur in the caller's context, or asynchronously in
35  * another thread.
36  */
37 
38 #ifndef _BLOCK_IF_H_
39 #define _BLOCK_IF_H_
40 
41 #include <sys/nv.h>
42 #include <sys/uio.h>
43 #include <sys/unistd.h>
44 
45 struct vm_snapshot_meta;
46 
47 
48 /*
49  * BLOCKIF_IOV_MAX is the maximum number of scatter/gather entries in
50  * a single request.  BLOCKIF_RING_MAX is the maxmimum number of
51  * pending requests that can be queued.
52  */
53 #define	BLOCKIF_IOV_MAX		128	/* not practical to be IOV_MAX */
54 #define	BLOCKIF_RING_MAX	128
55 
56 struct blockif_req {
57 	int		br_iovcnt;
58 	off_t		br_offset;
59 	ssize_t		br_resid;
60 	void		(*br_callback)(struct blockif_req *req, int err);
61 	void		*br_param;
62 	struct iovec	br_iov[BLOCKIF_IOV_MAX];
63 };
64 
65 struct blockif_ctxt;
66 
67 typedef void blockif_resize_cb(struct blockif_ctxt *, void *, size_t);
68 
69 int	blockif_legacy_config(nvlist_t *nvl, const char *opts);
70 struct blockif_ctxt *blockif_open(nvlist_t *nvl, const char *ident);
71 int	blockif_register_resize_callback(struct blockif_ctxt *bc,
72     blockif_resize_cb *cb, void *cb_arg);
73 off_t	blockif_size(struct blockif_ctxt *bc);
74 void	blockif_chs(struct blockif_ctxt *bc, uint16_t *c, uint8_t *h,
75     uint8_t *s);
76 int	blockif_sectsz(struct blockif_ctxt *bc);
77 void	blockif_psectsz(struct blockif_ctxt *bc, int *size, int *off);
78 int	blockif_queuesz(struct blockif_ctxt *bc);
79 int	blockif_is_ro(struct blockif_ctxt *bc);
80 int	blockif_candelete(struct blockif_ctxt *bc);
81 int	blockif_read(struct blockif_ctxt *bc, struct blockif_req *breq);
82 int	blockif_write(struct blockif_ctxt *bc, struct blockif_req *breq);
83 int	blockif_flush(struct blockif_ctxt *bc, struct blockif_req *breq);
84 int	blockif_delete(struct blockif_ctxt *bc, struct blockif_req *breq);
85 int	blockif_cancel(struct blockif_ctxt *bc, struct blockif_req *breq);
86 int	blockif_close(struct blockif_ctxt *bc);
87 #ifdef BHYVE_SNAPSHOT
88 void	blockif_pause(struct blockif_ctxt *bc);
89 void	blockif_resume(struct blockif_ctxt *bc);
90 #endif
91 
92 #endif /* _BLOCK_IF_H_ */
93