xref: /freebsd/sys/contrib/xen/xencomm.h (revision 3a9fd8242b35884921dfc4e886f284a75870a536)
1 /*
2  * Permission is hereby granted, free of charge, to any person obtaining a copy
3  * of this software and associated documentation files (the "Software"), to
4  * deal in the Software without restriction, including without limitation the
5  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
6  * sell copies of the Software, and to permit persons to whom the Software is
7  * furnished to do so, subject to the following conditions:
8  *
9  * The above copyright notice and this permission notice shall be included in
10  * all copies or substantial portions of the Software.
11  *
12  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
13  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
14  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
15  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
16  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
17  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
18  * DEALINGS IN THE SOFTWARE.
19  *
20  * Copyright (C) IBM Corp. 2006
21  */
22 
23 #ifndef _XEN_XENCOMM_H_
24 #define _XEN_XENCOMM_H_
25 
26 /* A xencomm descriptor is a scatter/gather list containing physical
27  * addresses corresponding to a virtually contiguous memory area. The
28  * hypervisor translates these physical addresses to machine addresses to copy
29  * to and from the virtually contiguous area.
30  */
31 
32 #define XENCOMM_MAGIC 0x58434F4D /* 'XCOM' */
33 #define XENCOMM_INVALID (~0UL)
34 
35 struct xencomm_desc {
36     uint32_t magic;
37     uint32_t nr_addrs; /* the number of entries in address[] */
38     uint64_t address[0];
39 };
40 
41 #endif /* _XEN_XENCOMM_H_ */
42