1 /* SPDX-License-Identifier: MIT */
2 /******************************************************************************
3 * vcpu.h
4 *
5 * VCPU initialisation, query, and hotplug.
6 *
7 * Copyright (c) 2005, Keir Fraser <keir@xensource.com>
8 */
9
10 #ifndef __XEN_PUBLIC_VCPU_H__
11 #define __XEN_PUBLIC_VCPU_H__
12
13 /*
14 * Prototype for this hypercall is:
15 * int vcpu_op(int cmd, int vcpuid, void *extra_args)
16 * @cmd == VCPUOP_??? (VCPU operation).
17 * @vcpuid == VCPU to operate on.
18 * @extra_args == Operation-specific extra arguments (NULL if none).
19 */
20
21 /*
22 * Initialise a VCPU. Each VCPU can be initialised only once. A
23 * newly-initialised VCPU will not run until it is brought up by VCPUOP_up.
24 *
25 * @extra_arg == pointer to vcpu_guest_context structure containing initial
26 * state for the VCPU.
27 */
28 #define VCPUOP_initialise 0
29
30 /*
31 * Bring up a VCPU. This makes the VCPU runnable. This operation will fail
32 * if the VCPU has not been initialised (VCPUOP_initialise).
33 */
34 #define VCPUOP_up 1
35
36 /*
37 * Bring down a VCPU (i.e., make it non-runnable).
38 * There are a few caveats that callers should observe:
39 * 1. This operation may return, and VCPU_is_up may return false, before the
40 * VCPU stops running (i.e., the command is asynchronous). It is a good
41 * idea to ensure that the VCPU has entered a non-critical loop before
42 * bringing it down. Alternatively, this operation is guaranteed
43 * synchronous if invoked by the VCPU itself.
44 * 2. After a VCPU is initialised, there is currently no way to drop all its
45 * references to domain memory. Even a VCPU that is down still holds
46 * memory references via its pagetable base pointer and GDT. It is good
47 * practise to move a VCPU onto an 'idle' or default page table, LDT and
48 * GDT before bringing it down.
49 */
50 #define VCPUOP_down 2
51
52 /* Returns 1 if the given VCPU is up. */
53 #define VCPUOP_is_up 3
54
55 /*
56 * Return information about the state and running time of a VCPU.
57 * @extra_arg == pointer to vcpu_runstate_info structure.
58 */
59 #define VCPUOP_get_runstate_info 4
60 struct vcpu_runstate_info {
61 /* VCPU's current state (RUNSTATE_*). */
62 int state;
63 /* When was current state entered (system time, ns)? */
64 uint64_t state_entry_time;
65 /*
66 * Update indicator set in state_entry_time:
67 * When activated via VMASST_TYPE_runstate_update_flag, set during
68 * updates in guest memory mapped copy of vcpu_runstate_info.
69 */
70 #define XEN_RUNSTATE_UPDATE (1ULL << 63)
71 /*
72 * Time spent in each RUNSTATE_* (ns). The sum of these times is
73 * guaranteed not to drift from system time.
74 */
75 uint64_t time[4];
76 };
77 DEFINE_GUEST_HANDLE_STRUCT(vcpu_runstate_info);
78
79 /* VCPU is currently running on a physical CPU. */
80 #define RUNSTATE_running 0
81
82 /* VCPU is runnable, but not currently scheduled on any physical CPU. */
83 #define RUNSTATE_runnable 1
84
85 /* VCPU is blocked (a.k.a. idle). It is therefore not runnable. */
86 #define RUNSTATE_blocked 2
87
88 /*
89 * VCPU is not runnable, but it is not blocked.
90 * This is a 'catch all' state for things like hotplug and pauses by the
91 * system administrator (or for critical sections in the hypervisor).
92 * RUNSTATE_blocked dominates this state (it is the preferred state).
93 */
94 #define RUNSTATE_offline 3
95
96 /*
97 * Register a shared memory area from which the guest may obtain its own
98 * runstate information without needing to execute a hypercall.
99 * Notes:
100 * 1. The registered address may be virtual or physical, depending on the
101 * platform. The virtual address should be registered on x86 systems.
102 * 2. Only one shared area may be registered per VCPU. The shared area is
103 * updated by the hypervisor each time the VCPU is scheduled. Thus
104 * runstate.state will always be RUNSTATE_running and
105 * runstate.state_entry_time will indicate the system time at which the
106 * VCPU was last scheduled to run.
107 * @extra_arg == pointer to vcpu_register_runstate_memory_area structure.
108 */
109 #define VCPUOP_register_runstate_memory_area 5
110 struct vcpu_register_runstate_memory_area {
111 union {
112 GUEST_HANDLE(vcpu_runstate_info) h;
113 struct vcpu_runstate_info *v;
114 uint64_t p;
115 } addr;
116 };
117
118 /*
119 * Set or stop a VCPU's periodic timer. Every VCPU has one periodic timer
120 * which can be set via these commands. Periods smaller than one millisecond
121 * may not be supported.
122 */
123 #define VCPUOP_set_periodic_timer 6 /* arg == vcpu_set_periodic_timer_t */
124 #define VCPUOP_stop_periodic_timer 7 /* arg == NULL */
125 struct vcpu_set_periodic_timer {
126 uint64_t period_ns;
127 };
128 DEFINE_GUEST_HANDLE_STRUCT(vcpu_set_periodic_timer);
129
130 /*
131 * Set or stop a VCPU's single-shot timer. Every VCPU has one single-shot
132 * timer which can be set via these commands.
133 */
134 #define VCPUOP_set_singleshot_timer 8 /* arg == vcpu_set_singleshot_timer_t */
135 #define VCPUOP_stop_singleshot_timer 9 /* arg == NULL */
136 struct vcpu_set_singleshot_timer {
137 uint64_t timeout_abs_ns;
138 uint32_t flags; /* VCPU_SSHOTTMR_??? */
139 };
140 DEFINE_GUEST_HANDLE_STRUCT(vcpu_set_singleshot_timer);
141
142 /* Flags to VCPUOP_set_singleshot_timer. */
143 /* Require the timeout to be in the future (return -ETIME if it's passed). */
144 #define _VCPU_SSHOTTMR_future (0)
145 #define VCPU_SSHOTTMR_future (1U << _VCPU_SSHOTTMR_future)
146
147 /*
148 * Register a memory location in the guest address space for the
149 * vcpu_info structure. This allows the guest to place the vcpu_info
150 * structure in a convenient place, such as in a per-cpu data area.
151 * The pointer need not be page aligned, but the structure must not
152 * cross a page boundary.
153 */
154 #define VCPUOP_register_vcpu_info 10 /* arg == struct vcpu_info */
155 struct vcpu_register_vcpu_info {
156 uint64_t mfn; /* mfn of page to place vcpu_info */
157 uint32_t offset; /* offset within page */
158 uint32_t rsvd; /* unused */
159 };
160 DEFINE_GUEST_HANDLE_STRUCT(vcpu_register_vcpu_info);
161
162 /* Send an NMI to the specified VCPU. @extra_arg == NULL. */
163 #define VCPUOP_send_nmi 11
164
165 /*
166 * Get the physical ID information for a pinned vcpu's underlying physical
167 * processor. The physical ID informmation is architecture-specific.
168 * On x86: id[31:0]=apic_id, id[63:32]=acpi_id.
169 * This command returns -EINVAL if it is not a valid operation for this VCPU.
170 */
171 #define VCPUOP_get_physid 12 /* arg == vcpu_get_physid_t */
172 struct vcpu_get_physid {
173 uint64_t phys_id;
174 };
175 DEFINE_GUEST_HANDLE_STRUCT(vcpu_get_physid);
176 #define xen_vcpu_physid_to_x86_apicid(physid) ((uint32_t)(physid))
177 #define xen_vcpu_physid_to_x86_acpiid(physid) ((uint32_t)((physid) >> 32))
178
179 /*
180 * Register a memory location to get a secondary copy of the vcpu time
181 * parameters. The master copy still exists as part of the vcpu shared
182 * memory area, and this secondary copy is updated whenever the master copy
183 * is updated (and using the same versioning scheme for synchronisation).
184 *
185 * The intent is that this copy may be mapped (RO) into userspace so
186 * that usermode can compute system time using the time info and the
187 * tsc. Usermode will see an array of vcpu_time_info structures, one
188 * for each vcpu, and choose the right one by an existing mechanism
189 * which allows it to get the current vcpu number (such as via a
190 * segment limit). It can then apply the normal algorithm to compute
191 * system time from the tsc.
192 *
193 * @extra_arg == pointer to vcpu_register_time_info_memory_area structure.
194 */
195 #define VCPUOP_register_vcpu_time_memory_area 13
196 DEFINE_GUEST_HANDLE_STRUCT(vcpu_time_info);
197 struct vcpu_register_time_memory_area {
198 union {
199 GUEST_HANDLE(vcpu_time_info) h;
200 struct pvclock_vcpu_time_info *v;
201 uint64_t p;
202 } addr;
203 };
204 DEFINE_GUEST_HANDLE_STRUCT(vcpu_register_time_memory_area);
205
206 #endif /* __XEN_PUBLIC_VCPU_H__ */
207
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