xref: /qemu/include/hw/xen/interface/vcpu.h (revision 9c636e0f9644d0778c16f460e0645e2352f42a7a)
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