linux/include/xen/interface/vcpu.h
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   1/******************************************************************************
   2 * vcpu.h
   3 *
   4 * VCPU initialisation, query, and hotplug.
   5 *
   6 * Permission is hereby granted, free of charge, to any person obtaining a copy
   7 * of this software and associated documentation files (the "Software"), to
   8 * deal in the Software without restriction, including without limitation the
   9 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
  10 * sell copies of the Software, and to permit persons to whom the Software is
  11 * furnished to do so, subject to the following conditions:
  12 *
  13 * The above copyright notice and this permission notice shall be included in
  14 * all copies or substantial portions of the Software.
  15 *
  16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  19 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  21 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  22 * DEALINGS IN THE SOFTWARE.
  23 *
  24 * Copyright (c) 2005, Keir Fraser <keir@xensource.com>
  25 */
  26
  27#ifndef __XEN_PUBLIC_VCPU_H__
  28#define __XEN_PUBLIC_VCPU_H__
  29
  30/*
  31 * Prototype for this hypercall is:
  32 *      int vcpu_op(int cmd, int vcpuid, void *extra_args)
  33 * @cmd            == VCPUOP_??? (VCPU operation).
  34 * @vcpuid         == VCPU to operate on.
  35 * @extra_args == Operation-specific extra arguments (NULL if none).
  36 */
  37
  38/*
  39 * Initialise a VCPU. Each VCPU can be initialised only once. A
  40 * newly-initialised VCPU will not run until it is brought up by VCPUOP_up.
  41 *
  42 * @extra_arg == pointer to vcpu_guest_context structure containing initial
  43 *                               state for the VCPU.
  44 */
  45#define VCPUOP_initialise                        0
  46
  47/*
  48 * Bring up a VCPU. This makes the VCPU runnable. This operation will fail
  49 * if the VCPU has not been initialised (VCPUOP_initialise).
  50 */
  51#define VCPUOP_up                                        1
  52
  53/*
  54 * Bring down a VCPU (i.e., make it non-runnable).
  55 * There are a few caveats that callers should observe:
  56 *      1. This operation may return, and VCPU_is_up may return false, before the
  57 *         VCPU stops running (i.e., the command is asynchronous). It is a good
  58 *         idea to ensure that the VCPU has entered a non-critical loop before
  59 *         bringing it down. Alternatively, this operation is guaranteed
  60 *         synchronous if invoked by the VCPU itself.
  61 *      2. After a VCPU is initialised, there is currently no way to drop all its
  62 *         references to domain memory. Even a VCPU that is down still holds
  63 *         memory references via its pagetable base pointer and GDT. It is good
  64 *         practise to move a VCPU onto an 'idle' or default page table, LDT and
  65 *         GDT before bringing it down.
  66 */
  67#define VCPUOP_down                                      2
  68
  69/* Returns 1 if the given VCPU is up. */
  70#define VCPUOP_is_up                             3
  71
  72/*
  73 * Return information about the state and running time of a VCPU.
  74 * @extra_arg == pointer to vcpu_runstate_info structure.
  75 */
  76#define VCPUOP_get_runstate_info         4
  77struct vcpu_runstate_info {
  78                /* VCPU's current state (RUNSTATE_*). */
  79                int              state;
  80                /* When was current state entered (system time, ns)? */
  81                uint64_t state_entry_time;
  82                /*
  83                 * Time spent in each RUNSTATE_* (ns). The sum of these times is
  84                 * guaranteed not to drift from system time.
  85                 */
  86                uint64_t time[4];
  87};
  88DEFINE_GUEST_HANDLE_STRUCT(vcpu_runstate_info);
  89
  90/* VCPU is currently running on a physical CPU. */
  91#define RUNSTATE_running  0
  92
  93/* VCPU is runnable, but not currently scheduled on any physical CPU. */
  94#define RUNSTATE_runnable 1
  95
  96/* VCPU is blocked (a.k.a. idle). It is therefore not runnable. */
  97#define RUNSTATE_blocked  2
  98
  99/*
 100 * VCPU is not runnable, but it is not blocked.
 101 * This is a 'catch all' state for things like hotplug and pauses by the
 102 * system administrator (or for critical sections in the hypervisor).
 103 * RUNSTATE_blocked dominates this state (it is the preferred state).
 104 */
 105#define RUNSTATE_offline  3
 106
 107/*
 108 * Register a shared memory area from which the guest may obtain its own
 109 * runstate information without needing to execute a hypercall.
 110 * Notes:
 111 *      1. The registered address may be virtual or physical, depending on the
 112 *         platform. The virtual address should be registered on x86 systems.
 113 *      2. Only one shared area may be registered per VCPU. The shared area is
 114 *         updated by the hypervisor each time the VCPU is scheduled. Thus
 115 *         runstate.state will always be RUNSTATE_running and
 116 *         runstate.state_entry_time will indicate the system time at which the
 117 *         VCPU was last scheduled to run.
 118 * @extra_arg == pointer to vcpu_register_runstate_memory_area structure.
 119 */
 120#define VCPUOP_register_runstate_memory_area 5
 121struct vcpu_register_runstate_memory_area {
 122                union {
 123                                GUEST_HANDLE(vcpu_runstate_info) h;
 124                                struct vcpu_runstate_info *v;
 125                                uint64_t p;
 126                } addr;
 127};
 128
 129/*
 130 * Set or stop a VCPU's periodic timer. Every VCPU has one periodic timer
 131 * which can be set via these commands. Periods smaller than one millisecond
 132 * may not be supported.
 133 */
 134#define VCPUOP_set_periodic_timer        6 /* arg == vcpu_set_periodic_timer_t */
 135#define VCPUOP_stop_periodic_timer       7 /* arg == NULL */
 136struct vcpu_set_periodic_timer {
 137                uint64_t period_ns;
 138};
 139DEFINE_GUEST_HANDLE_STRUCT(vcpu_set_periodic_timer);
 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 */
 147struct vcpu_set_singleshot_timer {
 148                uint64_t timeout_abs_ns;
 149                uint32_t flags;                    /* VCPU_SSHOTTMR_??? */
 150};
 151DEFINE_GUEST_HANDLE_STRUCT(vcpu_set_singleshot_timer);
 152
 153/* Flags to VCPUOP_set_singleshot_timer. */
 154 /* Require the timeout to be in the future (return -ETIME if it's passed). */
 155#define _VCPU_SSHOTTMR_future (0)
 156#define VCPU_SSHOTTMR_future  (1U << _VCPU_SSHOTTMR_future)
 157
 158/*
 159 * Register a memory location in the guest address space for the
 160 * vcpu_info structure.  This allows the guest to place the vcpu_info
 161 * structure in a convenient place, such as in a per-cpu data area.
 162 * The pointer need not be page aligned, but the structure must not
 163 * cross a page boundary.
 164 */
 165#define VCPUOP_register_vcpu_info   10  /* arg == struct vcpu_info */
 166struct vcpu_register_vcpu_info {
 167    uint64_t mfn;    /* mfn of page to place vcpu_info */
 168    uint32_t offset; /* offset within page */
 169    uint32_t rsvd;   /* unused */
 170};
 171DEFINE_GUEST_HANDLE_STRUCT(vcpu_register_vcpu_info);
 172
 173#endif /* __XEN_PUBLIC_VCPU_H__ */
 174