xref: /linux/include/xen/interface/vcpu.h (revision 93d90ad708b8da6efc0e487b66111aa9db7f70c7)
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 <keir@xensource.com>
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
77 struct vcpu_runstate_info {
78 		/* VCPU's current state (RUNSTATE_*). */
79 		int		 state;
80 		/* When was current state entered (system time, ns)? */
81 		uint64_t state_entry_time;
82 		/*
83 		 * Time spent in each RUNSTATE_* (ns). The sum of these times is
84 		 * guaranteed not to drift from system time.
85 		 */
86 		uint64_t time[4];
87 };
88 DEFINE_GUEST_HANDLE_STRUCT(vcpu_runstate_info);
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
121 struct vcpu_register_runstate_memory_area {
122 		union {
123 				GUEST_HANDLE(vcpu_runstate_info) h;
124 				struct vcpu_runstate_info *v;
125 				uint64_t p;
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 */
136 struct vcpu_set_periodic_timer {
137 		uint64_t period_ns;
138 };
139 DEFINE_GUEST_HANDLE_STRUCT(vcpu_set_periodic_timer);
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 */
147 struct vcpu_set_singleshot_timer {
148 		uint64_t timeout_abs_ns;
149 		uint32_t flags;			   /* VCPU_SSHOTTMR_??? */
150 };
151 DEFINE_GUEST_HANDLE_STRUCT(vcpu_set_singleshot_timer);
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 */
166 struct vcpu_register_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 };
171 DEFINE_GUEST_HANDLE_STRUCT(vcpu_register_vcpu_info);
172 
173 /* Send an NMI to the specified VCPU. @extra_arg == NULL. */
174 #define VCPUOP_send_nmi             11
175 #endif /* __XEN_PUBLIC_VCPU_H__ */
176