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  *  3. New code wants to prefer VCPUOP_register_runstate_phys_area, and only
114  *     fall back to the operation here for backwards compatibility.
115  * @extra_arg == pointer to vcpu_register_runstate_memory_area structure.
116  */
117 #define VCPUOP_register_runstate_memory_area 5
118 struct vcpu_register_runstate_memory_area {
119     union {
120         XEN_GUEST_HANDLE(vcpu_runstate_info_t) h;
121         struct vcpu_runstate_info *v;
122         uint64_t p;
123     } addr;
124 };
125 typedef struct vcpu_register_runstate_memory_area vcpu_register_runstate_memory_area_t;
126 DEFINE_XEN_GUEST_HANDLE(vcpu_register_runstate_memory_area_t);
127 
128 /*
129  * Set or stop a VCPU's periodic timer. Every VCPU has one periodic timer
130  * which can be set via these commands. Periods smaller than one millisecond
131  * may not be supported.
132  */
133 #define VCPUOP_set_periodic_timer    6 /* arg == vcpu_set_periodic_timer_t */
134 #define VCPUOP_stop_periodic_timer   7 /* arg == NULL */
135 struct vcpu_set_periodic_timer {
136     uint64_t period_ns;
137 };
138 typedef struct vcpu_set_periodic_timer vcpu_set_periodic_timer_t;
139 DEFINE_XEN_GUEST_HANDLE(vcpu_set_periodic_timer_t);
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;   /* Absolute system time value in nanoseconds. */
149     uint32_t flags;            /* VCPU_SSHOTTMR_??? */
150 };
151 typedef struct vcpu_set_singleshot_timer vcpu_set_singleshot_timer_t;
152 DEFINE_XEN_GUEST_HANDLE(vcpu_set_singleshot_timer_t);
153 
154 /* Flags to VCPUOP_set_singleshot_timer. */
155  /*
156   * Request the timeout to be in the future (return -ETIME if it's passed)
157   * but can be ignored by the hypervisor.
158   */
159 #define _VCPU_SSHOTTMR_future (0)
160 #define VCPU_SSHOTTMR_future  (1U << _VCPU_SSHOTTMR_future)
161 
162 /*
163  * Register a memory location in the guest address space for the
164  * vcpu_info structure.  This allows the guest to place the vcpu_info
165  * structure in a convenient place, such as in a per-cpu data area.
166  * The pointer need not be page aligned, but the structure must not
167  * cross a page boundary.
168  *
169  * This may be called only once per vcpu.
170  */
171 #define VCPUOP_register_vcpu_info   10  /* arg == vcpu_register_vcpu_info_t */
172 struct vcpu_register_vcpu_info {
173     uint64_t mfn;    /* mfn of page to place vcpu_info */
174     uint32_t offset; /* offset within page */
175     uint32_t rsvd;   /* unused */
176 };
177 typedef struct vcpu_register_vcpu_info vcpu_register_vcpu_info_t;
178 DEFINE_XEN_GUEST_HANDLE(vcpu_register_vcpu_info_t);
179 
180 /* Send an NMI to the specified VCPU. @extra_arg == NULL. */
181 #define VCPUOP_send_nmi             11
182 
183 /*
184  * Get the physical ID information for a pinned vcpu's underlying physical
185  * processor.  The physical ID informmation is architecture-specific.
186  * On x86: id[31:0]=apic_id, id[63:32]=acpi_id.
187  * This command returns -EINVAL if it is not a valid operation for this VCPU.
188  */
189 #define VCPUOP_get_physid           12 /* arg == vcpu_get_physid_t */
190 struct vcpu_get_physid {
191     uint64_t phys_id;
192 };
193 typedef struct vcpu_get_physid vcpu_get_physid_t;
194 DEFINE_XEN_GUEST_HANDLE(vcpu_get_physid_t);
195 #define xen_vcpu_physid_to_x86_apicid(physid) ((uint32_t)(physid))
196 #define xen_vcpu_physid_to_x86_acpiid(physid) ((uint32_t)((physid) >> 32))
197 
198 /*
199  * Register a memory location to get a secondary copy of the vcpu time
200  * parameters.  The master copy still exists as part of the vcpu shared
201  * memory area, and this secondary copy is updated whenever the master copy
202  * is updated (and using the same versioning scheme for synchronisation).
203  *
204  * The intent is that this copy may be mapped (RO) into userspace so
205  * that usermode can compute system time using the time info and the
206  * tsc.  Usermode will see an array of vcpu_time_info structures, one
207  * for each vcpu, and choose the right one by an existing mechanism
208  * which allows it to get the current vcpu number (such as via a
209  * segment limit).  It can then apply the normal algorithm to compute
210  * system time from the tsc.
211  *
212  * New code wants to prefer VCPUOP_register_vcpu_time_phys_area, and only
213  * fall back to the operation here for backwards compatibility.
214  *
215  * @extra_arg == pointer to vcpu_register_time_info_memory_area structure.
216  */
217 #define VCPUOP_register_vcpu_time_memory_area   13
218 DEFINE_XEN_GUEST_HANDLE(vcpu_time_info_t);
219 struct vcpu_register_time_memory_area {
220     union {
221         XEN_GUEST_HANDLE(vcpu_time_info_t) h;
222         struct vcpu_time_info *v;
223         uint64_t p;
224     } addr;
225 };
226 typedef struct vcpu_register_time_memory_area vcpu_register_time_memory_area_t;
227 DEFINE_XEN_GUEST_HANDLE(vcpu_register_time_memory_area_t);
228 
229 /*
230  * Like the respective VCPUOP_register_*_memory_area, just using the "addr.p"
231  * field of the supplied struct as a guest physical address (i.e. in GFN space).
232  * The respective area may not cross a page boundary.  Pass ~0 to unregister an
233  * area.  Note that as long as an area is registered by physical address, the
234  * linear address based area will not be serviced (updated) by the hypervisor.
235  *
236  * Note that the area registered via VCPUOP_register_runstate_memory_area will
237  * be updated in the same manner as the one registered via virtual address PLUS
238  * VMASST_TYPE_runstate_update_flag engaged by the domain.
239  *
240  * XENFEAT_{runstate,vcpu_time}_phys_area feature bits signal the availability
241  * of these ops.
242  */
243 #define VCPUOP_register_runstate_phys_area      14
244 #define VCPUOP_register_vcpu_time_phys_area     15
245 
246 #endif /* __XEN_PUBLIC_VCPU_H__ */
247 
248 /*
249  * Local variables:
250  * mode: C
251  * c-file-style: "BSD"
252  * c-basic-offset: 4
253  * tab-width: 4
254  * indent-tabs-mode: nil
255  * End:
256  */
257