include/hw/xen/interface/sched.h

   1 /* SPDX-License-Identifier: MIT */
   2 /******************************************************************************
   3  * sched.h
   4  *
   5  * Scheduler state interactions
   6  *
   7  * Copyright (c) 2005, Keir Fraser <keir@xensource.com>
   8  */
   9
  10 #ifndef __XEN_PUBLIC_SCHED_H__
  11 #define __XEN_PUBLIC_SCHED_H__
  12
  13 #include "event_channel.h"
  14
  15 /*
  16  * `incontents 150 sched Guest Scheduler Operations
  17  *
  18  * The SCHEDOP interface provides mechanisms for a guest to interact
  19  * with the scheduler, including yield, blocking and shutting itself
  20  * down.
  21  */
  22
  23 /*
  24  * The prototype for this hypercall is:
  25  * ` long HYPERVISOR_sched_op(enum sched_op cmd, void *arg, ...)
  26  *
  27  * @cmd == SCHEDOP_??? (scheduler operation).
  28  * @arg == Operation-specific extra argument(s), as described below.
  29  * ...  == Additional Operation-specific extra arguments, described below.
  30  *
  31  * Versions of Xen prior to 3.0.2 provided only the following legacy version
  32  * of this hypercall, supporting only the commands yield, block and shutdown:
  33  *  long sched_op(int cmd, unsigned long arg)
  34  * @cmd == SCHEDOP_??? (scheduler operation).
  35  * @arg == 0               (SCHEDOP_yield and SCHEDOP_block)
  36  *      == SHUTDOWN_* code (SCHEDOP_shutdown)
  37  *
  38  * This legacy version is available to new guests as:
  39  * ` long HYPERVISOR_sched_op_compat(enum sched_op cmd, unsigned long arg)
  40  */
  41
  42 /* ` enum sched_op { // SCHEDOP_* => struct sched_* */
  43 /*
  44  * Voluntarily yield the CPU.
  45  * @arg == NULL.
  46  */
  47 #define SCHEDOP_yield       0
  48
  49 /*
  50  * Block execution of this VCPU until an event is received for processing.
  51  * If called with event upcalls masked, this operation will atomically
  52  * reenable event delivery and check for pending events before blocking the
  53  * VCPU. This avoids a "wakeup waiting" race.
  54  * @arg == NULL.
  55  */
  56 #define SCHEDOP_block       1
  57
  58 /*
  59  * Halt execution of this domain (all VCPUs) and notify the system controller.
  60  * @arg == pointer to sched_shutdown_t structure.
  61  *
  62  * If the sched_shutdown_t reason is SHUTDOWN_suspend then
  63  * x86 PV guests must also set RDX (EDX for 32-bit guests) to the MFN
  64  * of the guest's start info page.  RDX/EDX is the third hypercall
  65  * argument.
  66  *
  67  * In addition, which reason is SHUTDOWN_suspend this hypercall
  68  * returns 1 if suspend was cancelled or the domain was merely
  69  * checkpointed, and 0 if it is resuming in a new domain.
  70  */
  71 #define SCHEDOP_shutdown    2
  72
  73 /*
  74  * Poll a set of event-channel ports. Return when one or more are pending. An
  75  * optional timeout may be specified.
  76  * @arg == pointer to sched_poll_t structure.
  77  */
  78 #define SCHEDOP_poll        3
  79
  80 /*
  81  * Declare a shutdown for another domain. The main use of this function is
  82  * in interpreting shutdown requests and reasons for fully-virtualized
  83  * domains.  A para-virtualized domain may use SCHEDOP_shutdown directly.
  84  * @arg == pointer to sched_remote_shutdown_t structure.
  85  */
  86 #define SCHEDOP_remote_shutdown        4
  87
  88 /*
  89  * Latch a shutdown code, so that when the domain later shuts down it
  90  * reports this code to the control tools.
  91  * @arg == sched_shutdown_t, as for SCHEDOP_shutdown.
  92  */
  93 #define SCHEDOP_shutdown_code 5
  94
  95 /*
  96  * Setup, poke and destroy a domain watchdog timer.
  97  * @arg == pointer to sched_watchdog_t structure.
  98  * With id == 0, setup a domain watchdog timer to cause domain shutdown
  99  *               after timeout, returns watchdog id.
 100  * With id != 0 and timeout == 0, destroy domain watchdog timer.
 101  * With id != 0 and timeout != 0, poke watchdog timer and set new timeout.
 102  */
 103 #define SCHEDOP_watchdog    6
 104
 105 /*
 106  * Override the current vcpu affinity by pinning it to one physical cpu or
 107  * undo this override restoring the previous affinity.
 108  * @arg == pointer to sched_pin_override_t structure.
 109  *
 110  * A negative pcpu value will undo a previous pin override and restore the
 111  * previous cpu affinity.
 112  * This call is allowed for the hardware domain only and requires the cpu
 113  * to be part of the domain's cpupool.
 114  */
 115 #define SCHEDOP_pin_override 7
 116 /* ` } */
 117
 118 struct sched_shutdown {
 119     unsigned int reason; /* SHUTDOWN_* => enum sched_shutdown_reason */
 120 };
 121 typedef struct sched_shutdown sched_shutdown_t;
 122 DEFINE_XEN_GUEST_HANDLE(sched_shutdown_t);
 123
 124 struct sched_poll {
 125     XEN_GUEST_HANDLE(evtchn_port_t) ports;
 126     unsigned int nr_ports;
 127     uint64_t timeout;
 128 };
 129 typedef struct sched_poll sched_poll_t;
 130 DEFINE_XEN_GUEST_HANDLE(sched_poll_t);
 131
 132 struct sched_remote_shutdown {
 133     domid_t domain_id;         /* Remote domain ID */
 134     unsigned int reason;       /* SHUTDOWN_* => enum sched_shutdown_reason */
 135 };
 136 typedef struct sched_remote_shutdown sched_remote_shutdown_t;
 137 DEFINE_XEN_GUEST_HANDLE(sched_remote_shutdown_t);
 138
 139 struct sched_watchdog {
 140     uint32_t id;                /* watchdog ID */
 141     uint32_t timeout;           /* timeout */
 142 };
 143 typedef struct sched_watchdog sched_watchdog_t;
 144 DEFINE_XEN_GUEST_HANDLE(sched_watchdog_t);
 145
 146 struct sched_pin_override {
 147     int32_t pcpu;
 148 };
 149 typedef struct sched_pin_override sched_pin_override_t;
 150 DEFINE_XEN_GUEST_HANDLE(sched_pin_override_t);
 151
 152 /*
 153  * Reason codes for SCHEDOP_shutdown. These may be interpreted by control
 154  * software to determine the appropriate action. For the most part, Xen does
 155  * not care about the shutdown code.
 156  */
 157 /* ` enum sched_shutdown_reason { */
 158 #define SHUTDOWN_poweroff   0  /* Domain exited normally. Clean up and kill. */
 159 #define SHUTDOWN_reboot     1  /* Clean up, kill, and then restart.          */
 160 #define SHUTDOWN_suspend    2  /* Clean up, save suspend info, kill.         */
 161 #define SHUTDOWN_crash      3  /* Tell controller we've crashed.             */
 162 #define SHUTDOWN_watchdog   4  /* Restart because watchdog time expired.     */
 163
 164 /*
 165  * Domain asked to perform 'soft reset' for it. The expected behavior is to
 166  * reset internal Xen state for the domain returning it to the point where it
 167  * was created but leaving the domain's memory contents and vCPU contexts
 168  * intact. This will allow the domain to start over and set up all Xen specific
 169  * interfaces again.
 170  */
 171 #define SHUTDOWN_soft_reset 5
 172 #define SHUTDOWN_MAX        5  /* Maximum valid shutdown reason.             */
 173 /* ` } */
 174
 175 #endif /* __XEN_PUBLIC_SCHED_H__ */
 176
 177 /*
 178  * Local variables:
 179  * mode: C
 180  * c-file-style: "BSD"
 181  * c-basic-offset: 4
 182  * tab-width: 4
 183  * indent-tabs-mode: nil
 184  * End:
 185  */