include/xen/interface/sched.h

   1 /******************************************************************************
   2  * sched.h
   3  *
   4  * Scheduler state interactions
   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_SCHED_H__
  28 #define __XEN_PUBLIC_SCHED_H__
  29
  30 #include <xen/interface/event_channel.h>
  31
  32 /*
  33  * Guest Scheduler Operations
  34  *
  35  * The SCHEDOP interface provides mechanisms for a guest to interact
  36  * with the scheduler, including yield, blocking and shutting itself
  37  * down.
  38  */
  39
  40 /*
  41  * The prototype for this hypercall is:
  42  * long HYPERVISOR_sched_op(enum sched_op cmd, void *arg, ...)
  43  *
  44  * @cmd == SCHEDOP_??? (scheduler operation).
  45  * @arg == Operation-specific extra argument(s), as described below.
  46  * ...  == Additional Operation-specific extra arguments, described below.
  47  *
  48  * Versions of Xen prior to 3.0.2 provided only the following legacy version
  49  * of this hypercall, supporting only the commands yield, block and shutdown:
  50  *  long sched_op(int cmd, unsigned long arg)
  51  * @cmd == SCHEDOP_??? (scheduler operation).
  52  * @arg == 0               (SCHEDOP_yield and SCHEDOP_block)
  53  *      == SHUTDOWN_* code (SCHEDOP_shutdown)
  54  *
  55  * This legacy version is available to new guests as:
  56  * long HYPERVISOR_sched_op_compat(enum sched_op cmd, unsigned long arg)
  57  */
  58
  59 /*
  60  * Voluntarily yield the CPU.
  61  * @arg == NULL.
  62  */
  63 #define SCHEDOP_yield       0
  64
  65 /*
  66  * Block execution of this VCPU until an event is received for processing.
  67  * If called with event upcalls masked, this operation will atomically
  68  * reenable event delivery and check for pending events before blocking the
  69  * VCPU. This avoids a "wakeup waiting" race.
  70  * @arg == NULL.
  71  */
  72 #define SCHEDOP_block       1
  73
  74 /*
  75  * Halt execution of this domain (all VCPUs) and notify the system controller.
  76  * @arg == pointer to sched_shutdown structure.
  77  *
  78  * If the sched_shutdown_t reason is SHUTDOWN_suspend then
  79  * x86 PV guests must also set RDX (EDX for 32-bit guests) to the MFN
  80  * of the guest's start info page.  RDX/EDX is the third hypercall
  81  * argument.
  82  *
  83  * In addition, which reason is SHUTDOWN_suspend this hypercall
  84  * returns 1 if suspend was cancelled or the domain was merely
  85  * checkpointed, and 0 if it is resuming in a new domain.
  86  */
  87 #define SCHEDOP_shutdown    2
  88
  89 /*
  90  * Poll a set of event-channel ports. Return when one or more are pending. An
  91  * optional timeout may be specified.
  92  * @arg == pointer to sched_poll structure.
  93  */
  94 #define SCHEDOP_poll        3
  95
  96 /*
  97  * Declare a shutdown for another domain. The main use of this function is
  98  * in interpreting shutdown requests and reasons for fully-virtualized
  99  * domains.  A para-virtualized domain may use SCHEDOP_shutdown directly.
 100  * @arg == pointer to sched_remote_shutdown structure.
 101  */
 102 #define SCHEDOP_remote_shutdown        4
 103
 104 /*
 105  * Latch a shutdown code, so that when the domain later shuts down it
 106  * reports this code to the control tools.
 107  * @arg == sched_shutdown, as for SCHEDOP_shutdown.
 108  */
 109 #define SCHEDOP_shutdown_code 5
 110
 111 /*
 112  * Setup, poke and destroy a domain watchdog timer.
 113  * @arg == pointer to sched_watchdog structure.
 114  * With id == 0, setup a domain watchdog timer to cause domain shutdown
 115  *               after timeout, returns watchdog id.
 116  * With id != 0 and timeout == 0, destroy domain watchdog timer.
 117  * With id != 0 and timeout != 0, poke watchdog timer and set new timeout.
 118  */
 119 #define SCHEDOP_watchdog    6
 120
 121 /*
 122  * Override the current vcpu affinity by pinning it to one physical cpu or
 123  * undo this override restoring the previous affinity.
 124  * @arg == pointer to sched_pin_override structure.
 125  *
 126  * A negative pcpu value will undo a previous pin override and restore the
 127  * previous cpu affinity.
 128  * This call is allowed for the hardware domain only and requires the cpu
 129  * to be part of the domain's cpupool.
 130  */
 131 #define SCHEDOP_pin_override 7
 132
 133 struct sched_shutdown {
 134     unsigned int reason; /* SHUTDOWN_* => shutdown reason */
 135 };
 136 DEFINE_GUEST_HANDLE_STRUCT(sched_shutdown);
 137
 138 struct sched_poll {
 139     GUEST_HANDLE(evtchn_port_t) ports;
 140     unsigned int nr_ports;
 141     uint64_t timeout;
 142 };
 143 DEFINE_GUEST_HANDLE_STRUCT(sched_poll);
 144
 145 struct sched_remote_shutdown {
 146     domid_t domain_id;         /* Remote domain ID */
 147     unsigned int reason;       /* SHUTDOWN_* => shutdown reason */
 148 };
 149 DEFINE_GUEST_HANDLE_STRUCT(sched_remote_shutdown);
 150
 151 struct sched_watchdog {
 152     uint32_t id;                /* watchdog ID */
 153     uint32_t timeout;           /* timeout */
 154 };
 155 DEFINE_GUEST_HANDLE_STRUCT(sched_watchdog);
 156
 157 struct sched_pin_override {
 158     int32_t pcpu;
 159 };
 160 DEFINE_GUEST_HANDLE_STRUCT(sched_pin_override);
 161
 162 /*
 163  * Reason codes for SCHEDOP_shutdown. These may be interpreted by control
 164  * software to determine the appropriate action. For the most part, Xen does
 165  * not care about the shutdown code.
 166  */
 167 #define SHUTDOWN_poweroff   0  /* Domain exited normally. Clean up and kill. */
 168 #define SHUTDOWN_reboot     1  /* Clean up, kill, and then restart.          */
 169 #define SHUTDOWN_suspend    2  /* Clean up, save suspend info, kill.         */
 170 #define SHUTDOWN_crash      3  /* Tell controller we've crashed.             */
 171 #define SHUTDOWN_watchdog   4  /* Restart because watchdog time expired.     */
 172
 173 /*
 174  * Domain asked to perform 'soft reset' for it. The expected behavior is to
 175  * reset internal Xen state for the domain returning it to the point where it
 176  * was created but leaving the domain's memory contents and vCPU contexts
 177  * intact. This will allow the domain to start over and set up all Xen specific
 178  * interfaces again.
 179  */
 180 #define SHUTDOWN_soft_reset 5
 181 #define SHUTDOWN_MAX        5  /* Maximum valid shutdown reason.             */
 182
 183 #endif /* __XEN_PUBLIC_SCHED_H__ */