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
60struct 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};
77DEFINE_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
110struct 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 */
125struct vcpu_set_periodic_timer {
126		uint64_t period_ns;
127};
128DEFINE_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 */
136struct vcpu_set_singleshot_timer {
137		uint64_t timeout_abs_ns;
138		uint32_t flags;			   /* VCPU_SSHOTTMR_??? */
139};
140DEFINE_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 */
155struct 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};
160DEFINE_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 */
172struct vcpu_get_physid {
173	uint64_t phys_id;
174};
175DEFINE_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
196DEFINE_GUEST_HANDLE_STRUCT(vcpu_time_info);
197struct 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};
204DEFINE_GUEST_HANDLE_STRUCT(vcpu_register_time_memory_area);
205
206#endif /* __XEN_PUBLIC_VCPU_H__ */
207