1 /******************************************************************************
2  * callback.h
3  *
4  * Register guest OS callbacks with Xen.
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to
8  * deal in the Software without restriction, including without limitation the
9  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
10  * sell copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
22  * DEALINGS IN THE SOFTWARE.
23  *
24  * Copyright (c) 2006, Ian Campbell
25  */
26 
27 #ifndef __XEN_PUBLIC_CALLBACK_H__
28 #define __XEN_PUBLIC_CALLBACK_H__
29 
30 #include "xen.h"
31 
32 /*
33  * Prototype for this hypercall is:
34  *   long callback_op(int cmd, void *extra_args)
35  * @cmd        == CALLBACKOP_??? (callback operation).
36  * @extra_args == Operation-specific extra arguments (NULL if none).
37  */
38 
39 /* ia64, x86: Callback for event delivery. */
40 #define CALLBACKTYPE_event                 0
41 
42 /* x86: Failsafe callback when guest state cannot be restored by Xen. */
43 #define CALLBACKTYPE_failsafe              1
44 
45 /* x86/64 hypervisor: Syscall by 64-bit guest app ('64-on-64-on-64'). */
46 #define CALLBACKTYPE_syscall               2
47 
48 /*
49  * x86/32 hypervisor: Only available on x86/32 when supervisor_mode_kernel
50  *     feature is enabled. Do not use this callback type in new code.
51  */
52 #define CALLBACKTYPE_sysenter_deprecated   3
53 
54 /* x86: Callback for NMI delivery. */
55 #define CALLBACKTYPE_nmi                   4
56 
57 /*
58  * x86: sysenter is only available as follows:
59  * - 32-bit hypervisor: with the supervisor_mode_kernel feature enabled
60  * - 64-bit hypervisor: 32-bit guest applications on Intel CPUs
61  *                      ('32-on-32-on-64', '32-on-64-on-64')
62  *                      [nb. also 64-bit guest applications on Intel CPUs
63  *                           ('64-on-64-on-64'), but syscall is preferred]
64  */
65 #define CALLBACKTYPE_sysenter              5
66 
67 /*
68  * x86/64 hypervisor: Syscall by 32-bit guest app on AMD CPUs
69  *                    ('32-on-32-on-64', '32-on-64-on-64')
70  */
71 #define CALLBACKTYPE_syscall32             7
72 
73 /*
74  * Disable event deliver during callback? This flag is ignored for event and
75  * NMI callbacks: event delivery is unconditionally disabled.
76  */
77 #define _CALLBACKF_mask_events             0
78 #define CALLBACKF_mask_events              (1U << _CALLBACKF_mask_events)
79 
80 /*
81  * Register a callback.
82  */
83 #define CALLBACKOP_register                0
84 struct callback_register {
85 	uint16_t type;
86 	uint16_t flags;
87 	xen_callback_t address;
88 };
89 
90 /*
91  * Unregister a callback.
92  *
93  * Not all callbacks can be unregistered. -EINVAL will be returned if
94  * you attempt to unregister such a callback.
95  */
96 #define CALLBACKOP_unregister              1
97 struct callback_unregister {
98     uint16_t type;
99     uint16_t _unused;
100 };
101 
102 #endif /* __XEN_PUBLIC_CALLBACK_H__ */
103