xref: /illumos-gate/usr/src/uts/common/xen/sys/gnttab.h (revision 2d6eb4a5)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #ifndef	_SYS_GNTTAB_H
28 #define	_SYS_GNTTAB_H
29 
30 /*
31  * gnttab.h
32  *
33  * Two sets of functionality:
34  * 1. Granting foreign access to our memory reservation.
35  * 2. Accessing others' memory reservations via grant references.
36  * (i.e., mechanisms for both sender and recipient of grant references)
37  *
38  * Copyright (c) 2004-2005, K A Fraser
39  * Copyright (c) 2005, Christopher Clark
40  *
41  * This program is free software; you can redistribute it and/or
42  * modify it under the terms of the GNU General Public License version 2
43  * as published by the Free Software Foundation; or, when distributed
44  * separately from the Linux kernel or incorporated into other
45  * software packages, subject to the following license:
46  *
47  * Permission is hereby granted, free of charge, to any person obtaining a copy
48  * of this source file (the "Software"), to deal in the Software without
49  * restriction, including without limitation the rights to use, copy, modify,
50  * merge, publish, distribute, sublicense, and/or sell copies of the Software,
51  * and to permit persons to whom the Software is furnished to do so, subject to
52  * the following conditions:
53  *
54  * The above copyright notice and this permission notice shall be included in
55  * all copies or substantial portions of the Software.
56  *
57  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
58  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
59  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
60  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
61  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
62  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
63  * IN THE SOFTWARE.
64  */
65 
66 #include <sys/hypervisor.h>
67 #include <xen/public/grant_table.h>
68 #include <xen/public/features.h>
69 
70 #ifdef __cplusplus
71 extern "C" {
72 #endif
73 
74 struct gnttab_free_callback {
75 	struct gnttab_free_callback *next;
76 	void (*fn)(void *);
77 	void *arg;
78 	uint16_t count;
79 };
80 
81 /*
82  * For i86xpv the "frames" in grant table terminology are really MFNs.
83  */
84 typedef mfn_t gnttab_frame_t;
85 #define	FRAME_TO_MA(f)	((maddr_t)(f) << PAGESHIFT)
86 
87 int gnttab_grant_foreign_access(domid_t, gnttab_frame_t, int readonly);
88 
89 /*
90  * End access through the given grant reference, iff the grant entry is no
91  * longer in use.  Return 1 if the grant entry was freed, 0 if it is still in
92  * use.
93  */
94 int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly);
95 
96 /*
97  * Eventually end access through the given grant reference, and once that
98  * access has been ended, free the given page too.  Access will be ended
99  * immediately iff the grant entry is not in use, otherwise it will happen
100  * some time later.  page may be 0, in which case no freeing will occur.
101  */
102 void gnttab_end_foreign_access(grant_ref_t ref, int readonly,
103 	gnttab_frame_t page);
104 
105 int gnttab_grant_foreign_transfer(domid_t domid, pfn_t pfn);
106 
107 gnttab_frame_t gnttab_end_foreign_transfer_ref(grant_ref_t ref);
108 gnttab_frame_t gnttab_end_foreign_transfer(grant_ref_t ref);
109 
110 int gnttab_query_foreign_access(grant_ref_t ref);
111 
112 /*
113  * operations on reserved batches of grant references
114  */
115 int gnttab_alloc_grant_references(uint16_t count, grant_ref_t *pprivate_head);
116 
117 void gnttab_free_grant_reference(grant_ref_t ref);
118 
119 void gnttab_free_grant_references(grant_ref_t head);
120 
121 int gnttab_empty_grant_references(const grant_ref_t *pprivate_head);
122 
123 int gnttab_claim_grant_reference(grant_ref_t *pprivate_head);
124 
125 void gnttab_release_grant_reference(grant_ref_t *private_head,
126 	grant_ref_t release);
127 
128 void gnttab_request_free_callback(struct gnttab_free_callback *callback,
129 	void (*fn)(void *), void *arg, uint16_t count);
130 
131 void gnttab_cancel_free_callback(struct gnttab_free_callback *callback);
132 
133 void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid,
134 	gnttab_frame_t frame, int readonly);
135 
136 void gnttab_grant_foreign_transfer_ref(grant_ref_t, domid_t domid,
137 	pfn_t pfn);
138 
139 #define	gnttab_map_vaddr(map) ((void *)(map.host_virt_addr))
140 
141 /*
142  * framework
143  */
144 void gnttab_init(void);
145 void gnttab_suspend(void);
146 void gnttab_resume(void);
147 
148 #ifdef	__cplusplus
149 }
150 #endif
151 
152 #endif /* _SYS_GNTTAB_H */
153