include/xen/interface/vcpu.h

   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
  77 struct 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 };
  88
  89 /* VCPU is currently running on a physical CPU. */
  90 #define RUNSTATE_running  0
  91
  92 /* VCPU is runnable, but not currently scheduled on any physical CPU. */
  93 #define RUNSTATE_runnable 1
  94
  95 /* VCPU is blocked (a.k.a. idle). It is therefore not runnable. */
  96 #define RUNSTATE_blocked  2
  97
  98 /*
  99  * VCPU is not runnable, but it is not blocked.
 100  * This is a 'catch all' state for things like hotplug and pauses by the
 101  * system administrator (or for critical sections in the hypervisor).
 102  * RUNSTATE_blocked dominates this state (it is the preferred state).
 103  */
 104 #define RUNSTATE_offline  3
 105
 106 /*
 107  * Register a shared memory area from which the guest may obtain its own
 108  * runstate information without needing to execute a hypercall.
 109  * Notes:
 110  *      1. The registered address may be virtual or physical, depending on the
 111  *         platform. The virtual address should be registered on x86 systems.
 112  *      2. Only one shared area may be registered per VCPU. The shared area is
 113  *         updated by the hypervisor each time the VCPU is scheduled. Thus
 114  *         runstate.state will always be RUNSTATE_running and
 115  *         runstate.state_entry_time will indicate the system time at which the
 116  *         VCPU was last scheduled to run.
 117  * @extra_arg == pointer to vcpu_register_runstate_memory_area structure.
 118  */
 119 #define VCPUOP_register_runstate_memory_area 5
 120 struct vcpu_register_runstate_memory_area {
 121                 union {
 122                                 struct vcpu_runstate_info *v;
 123                                 uint64_t p;
 124                 } addr;
 125 };
 126
 127 /*
 128  * Set or stop a VCPU's periodic timer. Every VCPU has one periodic timer
 129  * which can be set via these commands. Periods smaller than one millisecond
 130  * may not be supported.
 131  */
 132 #define VCPUOP_set_periodic_timer        6 /* arg == vcpu_set_periodic_timer_t */
 133 #define VCPUOP_stop_periodic_timer       7 /* arg == NULL */
 134 struct vcpu_set_periodic_timer {
 135                 uint64_t period_ns;
 136 };
 137
 138 /*
 139  * Set or stop a VCPU's single-shot timer. Every VCPU has one single-shot
 140  * timer which can be set via these commands.
 141  */
 142 #define VCPUOP_set_singleshot_timer      8 /* arg == vcpu_set_singleshot_timer_t */
 143 #define VCPUOP_stop_singleshot_timer 9 /* arg == NULL */
 144 struct vcpu_set_singleshot_timer {
 145                 uint64_t timeout_abs_ns;
 146                 uint32_t flags;                    /* VCPU_SSHOTTMR_??? */
 147 };
 148
 149 /* Flags to VCPUOP_set_singleshot_timer. */
 150  /* Require the timeout to be in the future (return -ETIME if it's passed). */
 151 #define _VCPU_SSHOTTMR_future (0)
 152 #define VCPU_SSHOTTMR_future  (1U << _VCPU_SSHOTTMR_future)
 153
 154 /*
 155  * Register a memory location in the guest address space for the
 156  * vcpu_info structure.  This allows the guest to place the vcpu_info
 157  * structure in a convenient place, such as in a per-cpu data area.
 158  * The pointer need not be page aligned, but the structure must not
 159  * cross a page boundary.
 160  */
 161 #define VCPUOP_register_vcpu_info   10  /* arg == struct vcpu_info */
 162 struct vcpu_register_vcpu_info {
 163     uint32_t mfn;               /* mfn of page to place vcpu_info */
 164     uint32_t offset;            /* offset within page */
 165 };
 166
 167 #endif /* __XEN_PUBLIC_VCPU_H__ */