xref: /openbmc/linux/include/xen/interface/sched.h (revision e15a5365)
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__ */
184