xref: /freebsd/usr.sbin/bhyve/block_if.h (revision c66ec88fed842fbaad62c30d510644ceb7bd2d71)
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/uio.h>
42 #include <sys/unistd.h>
43 
44 struct vm_snapshot_meta;
45 
46 
47 /*
48  * BLOCKIF_IOV_MAX is the maximum number of scatter/gather entries in
49  * a single request.  BLOCKIF_RING_MAX is the maxmimum number of
50  * pending requests that can be queued.
51  */
52 #define	BLOCKIF_IOV_MAX		128	/* not practical to be IOV_MAX */
53 #define	BLOCKIF_RING_MAX	128
54 
55 struct blockif_req {
56 	int		br_iovcnt;
57 	off_t		br_offset;
58 	ssize_t		br_resid;
59 	void		(*br_callback)(struct blockif_req *req, int err);
60 	void		*br_param;
61 	struct iovec	br_iov[BLOCKIF_IOV_MAX];
62 };
63 
64 struct blockif_ctxt;
65 struct blockif_ctxt *blockif_open(const char *optstr, const char *ident);
66 off_t	blockif_size(struct blockif_ctxt *bc);
67 void	blockif_chs(struct blockif_ctxt *bc, uint16_t *c, uint8_t *h,
68     uint8_t *s);
69 int	blockif_sectsz(struct blockif_ctxt *bc);
70 void	blockif_psectsz(struct blockif_ctxt *bc, int *size, int *off);
71 int	blockif_queuesz(struct blockif_ctxt *bc);
72 int	blockif_is_ro(struct blockif_ctxt *bc);
73 int	blockif_candelete(struct blockif_ctxt *bc);
74 int	blockif_read(struct blockif_ctxt *bc, struct blockif_req *breq);
75 int	blockif_write(struct blockif_ctxt *bc, struct blockif_req *breq);
76 int	blockif_flush(struct blockif_ctxt *bc, struct blockif_req *breq);
77 int	blockif_delete(struct blockif_ctxt *bc, struct blockif_req *breq);
78 int	blockif_cancel(struct blockif_ctxt *bc, struct blockif_req *breq);
79 int	blockif_close(struct blockif_ctxt *bc);
80 #ifdef BHYVE_SNAPSHOT
81 void	blockif_pause(struct blockif_ctxt *bc);
82 void	blockif_resume(struct blockif_ctxt *bc);
83 int	blockif_snapshot_req(struct blockif_req *br,
84     struct vm_snapshot_meta *meta);
85 int	blockif_snapshot(struct blockif_ctxt *bc,
86     struct vm_snapshot_meta *meta);
87 #endif
88 
89 #endif /* _BLOCK_IF_H_ */
90