xref: /qemu/include/hw/xen/interface/vcpu.h (revision 73b49878)
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 #include "xen.h"
14 
15 /*
16  * Prototype for this hypercall is:
17  *  long vcpu_op(int cmd, unsigned int vcpuid, void *extra_args)
18  * @cmd        == VCPUOP_??? (VCPU operation).
19  * @vcpuid     == VCPU to operate on.
20  * @extra_args == Operation-specific extra arguments (NULL if none).
21  */
22 
23 /*
24  * Initialise a VCPU. Each VCPU can be initialised only once. A
25  * newly-initialised VCPU will not run until it is brought up by VCPUOP_up.
26  *
27  * @extra_arg == For PV or ARM guests this is a pointer to a vcpu_guest_context
28  *               structure containing the initial state for the VCPU. For x86
29  *               HVM based guests this is a pointer to a vcpu_hvm_context
30  *               structure.
31  */
32 #define VCPUOP_initialise            0
33 
34 /*
35  * Bring up a VCPU. This makes the VCPU runnable. This operation will fail
36  * if the VCPU has not been initialised (VCPUOP_initialise).
37  */
38 #define VCPUOP_up                    1
39 
40 /*
41  * Bring down a VCPU (i.e., make it non-runnable).
42  * There are a few caveats that callers should observe:
43  *  1. This operation may return, and VCPU_is_up may return false, before the
44  *     VCPU stops running (i.e., the command is asynchronous). It is a good
45  *     idea to ensure that the VCPU has entered a non-critical loop before
46  *     bringing it down. Alternatively, this operation is guaranteed
47  *     synchronous if invoked by the VCPU itself.
48  *  2. After a VCPU is initialised, there is currently no way to drop all its
49  *     references to domain memory. Even a VCPU that is down still holds
50  *     memory references via its pagetable base pointer and GDT. It is good
51  *     practise to move a VCPU onto an 'idle' or default page table, LDT and
52  *     GDT before bringing it down.
53  */
54 #define VCPUOP_down                  2
55 
56 /* Returns 1 if the given VCPU is up. */
57 #define VCPUOP_is_up                 3
58 
59 /*
60  * Return information about the state and running time of a VCPU.
61  * @extra_arg == pointer to vcpu_runstate_info structure.
62  */
63 #define VCPUOP_get_runstate_info     4
64 struct vcpu_runstate_info {
65     /* VCPU's current state (RUNSTATE_*). */
66     int      state;
67     /* When was current state entered (system time, ns)? */
68     uint64_t state_entry_time;
69     /*
70      * Update indicator set in state_entry_time:
71      * When activated via VMASST_TYPE_runstate_update_flag, set during
72      * updates in guest memory mapped copy of vcpu_runstate_info.
73      */
74 #define XEN_RUNSTATE_UPDATE          (xen_mk_ullong(1) << 63)
75     /*
76      * Time spent in each RUNSTATE_* (ns). The sum of these times is
77      * guaranteed not to drift from system time.
78      */
79     uint64_t time[4];
80 };
81 typedef struct vcpu_runstate_info vcpu_runstate_info_t;
82 DEFINE_XEN_GUEST_HANDLE(vcpu_runstate_info_t);
83 
84 /* VCPU is currently running on a physical CPU. */
85 #define RUNSTATE_running  0
86 
87 /* VCPU is runnable, but not currently scheduled on any physical CPU. */
88 #define RUNSTATE_runnable 1
89 
90 /* VCPU is blocked (a.k.a. idle). It is therefore not runnable. */
91 #define RUNSTATE_blocked  2
92 
93 /*
94  * VCPU is not runnable, but it is not blocked.
95  * This is a 'catch all' state for things like hotplug and pauses by the
96  * system administrator (or for critical sections in the hypervisor).
97  * RUNSTATE_blocked dominates this state (it is the preferred state).
98  */
99 #define RUNSTATE_offline  3
100 
101 /*
102  * Register a shared memory area from which the guest may obtain its own
103  * runstate information without needing to execute a hypercall.
104  * Notes:
105  *  1. The registered address may be virtual or physical or guest handle,
106  *     depending on the platform. Virtual address or guest handle should be
107  *     registered on x86 systems.
108  *  2. Only one shared area may be registered per VCPU. The shared area is
109  *     updated by the hypervisor each time the VCPU is scheduled. Thus
110  *     runstate.state will always be RUNSTATE_running and
111  *     runstate.state_entry_time will indicate the system time at which the
112  *     VCPU was last scheduled to run.
113  * @extra_arg == pointer to vcpu_register_runstate_memory_area structure.
114  */
115 #define VCPUOP_register_runstate_memory_area 5
116 struct vcpu_register_runstate_memory_area {
117     union {
118         XEN_GUEST_HANDLE(vcpu_runstate_info_t) h;
119         struct vcpu_runstate_info *v;
120         uint64_t p;
121     } addr;
122 };
123 typedef struct vcpu_register_runstate_memory_area vcpu_register_runstate_memory_area_t;
124 DEFINE_XEN_GUEST_HANDLE(vcpu_register_runstate_memory_area_t);
125 
126 /*
127  * Set or stop a VCPU's periodic timer. Every VCPU has one periodic timer
128  * which can be set via these commands. Periods smaller than one millisecond
129  * may not be supported.
130  */
131 #define VCPUOP_set_periodic_timer    6 /* arg == vcpu_set_periodic_timer_t */
132 #define VCPUOP_stop_periodic_timer   7 /* arg == NULL */
133 struct vcpu_set_periodic_timer {
134     uint64_t period_ns;
135 };
136 typedef struct vcpu_set_periodic_timer vcpu_set_periodic_timer_t;
137 DEFINE_XEN_GUEST_HANDLE(vcpu_set_periodic_timer_t);
138 
139 /*
140  * Set or stop a VCPU's single-shot timer. Every VCPU has one single-shot
141  * timer which can be set via these commands.
142  */
143 #define VCPUOP_set_singleshot_timer  8 /* arg == vcpu_set_singleshot_timer_t */
144 #define VCPUOP_stop_singleshot_timer 9 /* arg == NULL */
145 struct vcpu_set_singleshot_timer {
146     uint64_t timeout_abs_ns;   /* Absolute system time value in nanoseconds. */
147     uint32_t flags;            /* VCPU_SSHOTTMR_??? */
148 };
149 typedef struct vcpu_set_singleshot_timer vcpu_set_singleshot_timer_t;
150 DEFINE_XEN_GUEST_HANDLE(vcpu_set_singleshot_timer_t);
151 
152 /* Flags to VCPUOP_set_singleshot_timer. */
153  /* Require the timeout to be in the future (return -ETIME if it's passed). */
154 #define _VCPU_SSHOTTMR_future (0)
155 #define VCPU_SSHOTTMR_future  (1U << _VCPU_SSHOTTMR_future)
156 
157 /*
158  * Register a memory location in the guest address space for the
159  * vcpu_info structure.  This allows the guest to place the vcpu_info
160  * structure in a convenient place, such as in a per-cpu data area.
161  * The pointer need not be page aligned, but the structure must not
162  * cross a page boundary.
163  *
164  * This may be called only once per vcpu.
165  */
166 #define VCPUOP_register_vcpu_info   10  /* arg == vcpu_register_vcpu_info_t */
167 struct vcpu_register_vcpu_info {
168     uint64_t mfn;    /* mfn of page to place vcpu_info */
169     uint32_t offset; /* offset within page */
170     uint32_t rsvd;   /* unused */
171 };
172 typedef struct vcpu_register_vcpu_info vcpu_register_vcpu_info_t;
173 DEFINE_XEN_GUEST_HANDLE(vcpu_register_vcpu_info_t);
174 
175 /* Send an NMI to the specified VCPU. @extra_arg == NULL. */
176 #define VCPUOP_send_nmi             11
177 
178 /*
179  * Get the physical ID information for a pinned vcpu's underlying physical
180  * processor.  The physical ID informmation is architecture-specific.
181  * On x86: id[31:0]=apic_id, id[63:32]=acpi_id.
182  * This command returns -EINVAL if it is not a valid operation for this VCPU.
183  */
184 #define VCPUOP_get_physid           12 /* arg == vcpu_get_physid_t */
185 struct vcpu_get_physid {
186     uint64_t phys_id;
187 };
188 typedef struct vcpu_get_physid vcpu_get_physid_t;
189 DEFINE_XEN_GUEST_HANDLE(vcpu_get_physid_t);
190 #define xen_vcpu_physid_to_x86_apicid(physid) ((uint32_t)(physid))
191 #define xen_vcpu_physid_to_x86_acpiid(physid) ((uint32_t)((physid) >> 32))
192 
193 /*
194  * Register a memory location to get a secondary copy of the vcpu time
195  * parameters.  The master copy still exists as part of the vcpu shared
196  * memory area, and this secondary copy is updated whenever the master copy
197  * is updated (and using the same versioning scheme for synchronisation).
198  *
199  * The intent is that this copy may be mapped (RO) into userspace so
200  * that usermode can compute system time using the time info and the
201  * tsc.  Usermode will see an array of vcpu_time_info structures, one
202  * for each vcpu, and choose the right one by an existing mechanism
203  * which allows it to get the current vcpu number (such as via a
204  * segment limit).  It can then apply the normal algorithm to compute
205  * system time from the tsc.
206  *
207  * @extra_arg == pointer to vcpu_register_time_info_memory_area structure.
208  */
209 #define VCPUOP_register_vcpu_time_memory_area   13
210 DEFINE_XEN_GUEST_HANDLE(vcpu_time_info_t);
211 struct vcpu_register_time_memory_area {
212     union {
213         XEN_GUEST_HANDLE(vcpu_time_info_t) h;
214         struct vcpu_time_info *v;
215         uint64_t p;
216     } addr;
217 };
218 typedef struct vcpu_register_time_memory_area vcpu_register_time_memory_area_t;
219 DEFINE_XEN_GUEST_HANDLE(vcpu_register_time_memory_area_t);
220 
221 #endif /* __XEN_PUBLIC_VCPU_H__ */
222 
223 /*
224  * Local variables:
225  * mode: C
226  * c-file-style: "BSD"
227  * c-basic-offset: 4
228  * tab-width: 4
229  * indent-tabs-mode: nil
230  * End:
231  */
232