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vcpu.h
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1 /******************************************************************************
2  * vcpu.h
3  *
4  * VCPU initialisation, query, and hotplug.
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) 2005, Keir Fraser <[email protected]>
25  */
26 
27 #ifndef __XEN_PUBLIC_VCPU_H__
28 #define __XEN_PUBLIC_VCPU_H__
29 
30 /*
31  * Prototype for this hypercall is:
32  * int vcpu_op(int cmd, int vcpuid, void *extra_args)
33  * @cmd == VCPUOP_??? (VCPU operation).
34  * @vcpuid == VCPU to operate on.
35  * @extra_args == Operation-specific extra arguments (NULL if none).
36  */
37 
38 /*
39  * Initialise a VCPU. Each VCPU can be initialised only once. A
40  * newly-initialised VCPU will not run until it is brought up by VCPUOP_up.
41  *
42  * @extra_arg == pointer to vcpu_guest_context structure containing initial
43  * state for the VCPU.
44  */
45 #define VCPUOP_initialise 0
46 
47 /*
48  * Bring up a VCPU. This makes the VCPU runnable. This operation will fail
49  * if the VCPU has not been initialised (VCPUOP_initialise).
50  */
51 #define VCPUOP_up 1
52 
53 /*
54  * Bring down a VCPU (i.e., make it non-runnable).
55  * There are a few caveats that callers should observe:
56  * 1. This operation may return, and VCPU_is_up may return false, before the
57  * VCPU stops running (i.e., the command is asynchronous). It is a good
58  * idea to ensure that the VCPU has entered a non-critical loop before
59  * bringing it down. Alternatively, this operation is guaranteed
60  * synchronous if invoked by the VCPU itself.
61  * 2. After a VCPU is initialised, there is currently no way to drop all its
62  * references to domain memory. Even a VCPU that is down still holds
63  * memory references via its pagetable base pointer and GDT. It is good
64  * practise to move a VCPU onto an 'idle' or default page table, LDT and
65  * GDT before bringing it down.
66  */
67 #define VCPUOP_down 2
68 
69 /* Returns 1 if the given VCPU is up. */
70 #define VCPUOP_is_up 3
71 
72 /*
73  * Return information about the state and running time of a VCPU.
74  * @extra_arg == pointer to vcpu_runstate_info structure.
75  */
76 #define VCPUOP_get_runstate_info 4
78  /* VCPU's current state (RUNSTATE_*). */
79  int state;
80  /* When was current state entered (system time, ns)? */
82  /*
83  * Time spent in each RUNSTATE_* (ns). The sum of these times is
84  * guaranteed not to drift from system time.
85  */
87 };
89 
90 /* VCPU is currently running on a physical CPU. */
91 #define RUNSTATE_running 0
92 
93 /* VCPU is runnable, but not currently scheduled on any physical CPU. */
94 #define RUNSTATE_runnable 1
95 
96 /* VCPU is blocked (a.k.a. idle). It is therefore not runnable. */
97 #define RUNSTATE_blocked 2
98 
99 /*
100  * VCPU is not runnable, but it is not blocked.
101  * This is a 'catch all' state for things like hotplug and pauses by the
102  * system administrator (or for critical sections in the hypervisor).
103  * RUNSTATE_blocked dominates this state (it is the preferred state).
104  */
105 #define RUNSTATE_offline 3
106 
107 /*
108  * Register a shared memory area from which the guest may obtain its own
109  * runstate information without needing to execute a hypercall.
110  * Notes:
111  * 1. The registered address may be virtual or physical, depending on the
112  * platform. The virtual address should be registered on x86 systems.
113  * 2. Only one shared area may be registered per VCPU. The shared area is
114  * updated by the hypervisor each time the VCPU is scheduled. Thus
115  * runstate.state will always be RUNSTATE_running and
116  * runstate.state_entry_time will indicate the system time at which the
117  * VCPU was last scheduled to run.
118  * @extra_arg == pointer to vcpu_register_runstate_memory_area structure.
119  */
120 #define VCPUOP_register_runstate_memory_area 5
122  union {
126  } addr;
127 };
128 
129 /*
130  * Set or stop a VCPU's periodic timer. Every VCPU has one periodic timer
131  * which can be set via these commands. Periods smaller than one millisecond
132  * may not be supported.
133  */
134 #define VCPUOP_set_periodic_timer 6 /* arg == vcpu_set_periodic_timer_t */
135 #define VCPUOP_stop_periodic_timer 7 /* arg == NULL */
138 };
140 
141 /*
142  * Set or stop a VCPU's single-shot timer. Every VCPU has one single-shot
143  * timer which can be set via these commands.
144  */
145 #define VCPUOP_set_singleshot_timer 8 /* arg == vcpu_set_singleshot_timer_t */
146 #define VCPUOP_stop_singleshot_timer 9 /* arg == NULL */
149  uint32_t flags; /* VCPU_SSHOTTMR_??? */
150 };
152 
153 /* Flags to VCPUOP_set_singleshot_timer. */
154  /* Require the timeout to be in the future (return -ETIME if it's passed). */
155 #define _VCPU_SSHOTTMR_future (0)
156 #define VCPU_SSHOTTMR_future (1U << _VCPU_SSHOTTMR_future)
157 
158 /*
159  * Register a memory location in the guest address space for the
160  * vcpu_info structure. This allows the guest to place the vcpu_info
161  * structure in a convenient place, such as in a per-cpu data area.
162  * The pointer need not be page aligned, but the structure must not
163  * cross a page boundary.
164  */
165 #define VCPUOP_register_vcpu_info 10 /* arg == struct vcpu_info */
167  uint64_t mfn; /* mfn of page to place vcpu_info */
168  uint32_t offset; /* offset within page */
169  uint32_t rsvd; /* unused */
170 };
172 
173 #endif /* __XEN_PUBLIC_VCPU_H__ */