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 <xen/interface/event_channel.h> 14 15 /* 16 * 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 /* 43 * Voluntarily yield the CPU. 44 * @arg == NULL. 45 */ 46 #define SCHEDOP_yield 0 47 48 /* 49 * Block execution of this VCPU until an event is received for processing. 50 * If called with event upcalls masked, this operation will atomically 51 * reenable event delivery and check for pending events before blocking the 52 * VCPU. This avoids a "wakeup waiting" race. 53 * @arg == NULL. 54 */ 55 #define SCHEDOP_block 1 56 57 /* 58 * Halt execution of this domain (all VCPUs) and notify the system controller. 59 * @arg == pointer to sched_shutdown structure. 60 * 61 * If the sched_shutdown_t reason is SHUTDOWN_suspend then 62 * x86 PV guests must also set RDX (EDX for 32-bit guests) to the MFN 63 * of the guest's start info page. RDX/EDX is the third hypercall 64 * argument. 65 * 66 * In addition, which reason is SHUTDOWN_suspend this hypercall 67 * returns 1 if suspend was cancelled or the domain was merely 68 * checkpointed, and 0 if it is resuming in a new domain. 69 */ 70 #define SCHEDOP_shutdown 2 71 72 /* 73 * Poll a set of event-channel ports. Return when one or more are pending. An 74 * optional timeout may be specified. 75 * @arg == pointer to sched_poll structure. 76 */ 77 #define SCHEDOP_poll 3 78 79 /* 80 * Declare a shutdown for another domain. The main use of this function is 81 * in interpreting shutdown requests and reasons for fully-virtualized 82 * domains. A para-virtualized domain may use SCHEDOP_shutdown directly. 83 * @arg == pointer to sched_remote_shutdown structure. 84 */ 85 #define SCHEDOP_remote_shutdown 4 86 87 /* 88 * Latch a shutdown code, so that when the domain later shuts down it 89 * reports this code to the control tools. 90 * @arg == sched_shutdown, as for SCHEDOP_shutdown. 91 */ 92 #define SCHEDOP_shutdown_code 5 93 94 /* 95 * Setup, poke and destroy a domain watchdog timer. 96 * @arg == pointer to sched_watchdog structure. 97 * With id == 0, setup a domain watchdog timer to cause domain shutdown 98 * after timeout, returns watchdog id. 99 * With id != 0 and timeout == 0, destroy domain watchdog timer. 100 * With id != 0 and timeout != 0, poke watchdog timer and set new timeout. 101 */ 102 #define SCHEDOP_watchdog 6 103 104 /* 105 * Override the current vcpu affinity by pinning it to one physical cpu or 106 * undo this override restoring the previous affinity. 107 * @arg == pointer to sched_pin_override structure. 108 * 109 * A negative pcpu value will undo a previous pin override and restore the 110 * previous cpu affinity. 111 * This call is allowed for the hardware domain only and requires the cpu 112 * to be part of the domain's cpupool. 113 */ 114 #define SCHEDOP_pin_override 7 115 116 struct sched_shutdown { 117 unsigned int reason; /* SHUTDOWN_* => shutdown reason */ 118 }; 119 DEFINE_GUEST_HANDLE_STRUCT(sched_shutdown); 120 121 struct sched_poll { 122 GUEST_HANDLE(evtchn_port_t) ports; 123 unsigned int nr_ports; 124 uint64_t timeout; 125 }; 126 DEFINE_GUEST_HANDLE_STRUCT(sched_poll); 127 128 struct sched_remote_shutdown { 129 domid_t domain_id; /* Remote domain ID */ 130 unsigned int reason; /* SHUTDOWN_* => shutdown reason */ 131 }; 132 DEFINE_GUEST_HANDLE_STRUCT(sched_remote_shutdown); 133 134 struct sched_watchdog { 135 uint32_t id; /* watchdog ID */ 136 uint32_t timeout; /* timeout */ 137 }; 138 DEFINE_GUEST_HANDLE_STRUCT(sched_watchdog); 139 140 struct sched_pin_override { 141 int32_t pcpu; 142 }; 143 DEFINE_GUEST_HANDLE_STRUCT(sched_pin_override); 144 145 /* 146 * Reason codes for SCHEDOP_shutdown. These may be interpreted by control 147 * software to determine the appropriate action. For the most part, Xen does 148 * not care about the shutdown code. 149 */ 150 #define SHUTDOWN_poweroff 0 /* Domain exited normally. Clean up and kill. */ 151 #define SHUTDOWN_reboot 1 /* Clean up, kill, and then restart. */ 152 #define SHUTDOWN_suspend 2 /* Clean up, save suspend info, kill. */ 153 #define SHUTDOWN_crash 3 /* Tell controller we've crashed. */ 154 #define SHUTDOWN_watchdog 4 /* Restart because watchdog time expired. */ 155 156 /* 157 * Domain asked to perform 'soft reset' for it. The expected behavior is to 158 * reset internal Xen state for the domain returning it to the point where it 159 * was created but leaving the domain's memory contents and vCPU contexts 160 * intact. This will allow the domain to start over and set up all Xen specific 161 * interfaces again. 162 */ 163 #define SHUTDOWN_soft_reset 5 164 #define SHUTDOWN_MAX 5 /* Maximum valid shutdown reason. */ 165 166 #endif /* __XEN_PUBLIC_SCHED_H__ */ 167