xref: /openbmc/linux/include/xen/interface/vcpu.h (revision 2cf1c348)
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