Zephyr API Documentation  3.6.99
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event_channel.h
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1/* SPDX-License-Identifier: MIT */
2
3/******************************************************************************
4 * event_channel.h
5 *
6 * Event channels between domains.
7 *
8 * Permission is hereby granted, free of charge, to any person obtaining a copy
9 * of this software and associated documentation files (the "Software"), to
10 * deal in the Software without restriction, including without limitation the
11 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
12 * sell copies of the Software, and to permit persons to whom the Software is
13 * furnished to do so, subject to the following conditions:
14 *
15 * The above copyright notice and this permission notice shall be included in
16 * all copies or substantial portions of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
21 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
23 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
24 * DEALINGS IN THE SOFTWARE.
25 *
26 * Copyright (c) 2003-2004, K A Fraser.
27 */
28
29#ifndef __XEN_PUBLIC_EVENT_CHANNEL_H__
30#define __XEN_PUBLIC_EVENT_CHANNEL_H__
31
32#include "xen.h"
33
34/*
35 * `incontents 150 evtchn Event Channels
36 *
37 * Event channels are the basic primitive provided by Xen for event
38 * notifications. An event is the Xen equivalent of a hardware
39 * interrupt. They essentially store one bit of information, the event
40 * of interest is signalled by transitioning this bit from 0 to 1.
41 *
42 * Notifications are received by a guest via an upcall from Xen,
43 * indicating when an event arrives (setting the bit). Further
44 * notifications are masked until the bit is cleared again (therefore,
45 * guests must check the value of the bit after re-enabling event
46 * delivery to ensure no missed notifications).
47 *
48 * Event notifications can be masked by setting a flag; this is
49 * equivalent to disabling interrupts and can be used to ensure
50 * atomicity of certain operations in the guest kernel.
51 *
52 * Event channels are represented by the evtchn_* fields in
53 * struct shared_info and struct vcpu_info.
54 */
55
56#define EVTCHNOP_bind_interdomain 0
57#define EVTCHNOP_bind_virq 1
58#define EVTCHNOP_bind_pirq 2
59#define EVTCHNOP_close 3
60#define EVTCHNOP_send 4
61#define EVTCHNOP_status 5
62#define EVTCHNOP_alloc_unbound 6
63#define EVTCHNOP_bind_ipi 7
64#define EVTCHNOP_bind_vcpu 8
65#define EVTCHNOP_unmask 9
66#define EVTCHNOP_reset 10
67#define EVTCHNOP_init_control 11
68#define EVTCHNOP_expand_array 12
69#define EVTCHNOP_set_priority 13
70#ifdef __XEN__
71#define EVTCHNOP_reset_cont 14
72#endif
73
76
77/*
78 * EVTCHNOP_alloc_unbound: Allocate a port in domain <dom> and mark as
79 * accepting interdomain bindings from domain <remote_dom>. A fresh port
80 * is allocated in <dom> and returned as <port>.
81 * NOTES:
82 * 1. If the caller is unprivileged then <dom> must be DOMID_SELF.
83 * 2. <remote_dom> may be DOMID_SELF, allowing loopback connections.
84 */
86 /* IN parameters */
88 /* OUT parameters */
90};
92
93/*
94 * EVTCHNOP_bind_interdomain: Construct an interdomain event channel between
95 * the calling domain and <remote_dom>. <remote_dom,remote_port> must identify
96 * a port that is unbound and marked as accepting bindings from the calling
97 * domain. A fresh port is allocated in the calling domain and returned as
98 * <local_port>.
99 *
100 * In case the peer domain has already tried to set our event channel
101 * pending, before it was bound, EVTCHNOP_bind_interdomain always sets
102 * the local event channel pending.
103 *
104 * The usual pattern of use, in the guest's upcall (or subsequent
105 * handler) is as follows: (Re-enable the event channel for subsequent
106 * signalling and then) check for the existence of whatever condition
107 * is being waited for by other means, and take whatever action is
108 * needed (if any).
109 *
110 * NOTES:
111 * 1. <remote_dom> may be DOMID_SELF, allowing loopback connections.
112 */
114 /* IN parameters. */
117 /* OUT parameters. */
119};
121
122/*
123 * EVTCHNOP_close: Close a local event channel <port>. If the channel is
124 * interdomain then the remote end is placed in the unbound state
125 * (EVTCHNSTAT_unbound), awaiting a new connection.
126 */
128 /* IN parameters. */
130};
132
133/*
134 * EVTCHNOP_send: Send an event to the remote end of the channel whose local
135 * endpoint is <port>.
136 */
138 /* IN parameters. */
140};
142
143/*
144 * EVTCHNOP_status: Get the current status of the communication channel which
145 * has an endpoint at <dom, port>.
146 * NOTES:
147 * 1. <dom> may be specified as DOMID_SELF.
148 * 2. Only a sufficiently-privileged domain may obtain the status of an event
149 * channel for which <dom> is not DOMID_SELF.
150 */
152 /* IN parameters */
155 /* OUT parameters */
156#define EVTCHNSTAT_closed 0 /* Channel is not in use. */
157#define EVTCHNSTAT_unbound 1 /* Channel is waiting interdom connection.*/
158#define EVTCHNSTAT_interdomain 2 /* Channel is connected to remote domain. */
159#define EVTCHNSTAT_pirq 3 /* Channel is bound to a phys IRQ line. */
160#define EVTCHNSTAT_virq 4 /* Channel is bound to a virtual IRQ line */
161#define EVTCHNSTAT_ipi 5 /* Channel is bound to a virtual IPI line */
163 uint32_t vcpu; /* VCPU to which this channel is bound. */
164 union {
165 struct {
166 domid_t dom;
167 } unbound; /* EVTCHNSTAT_unbound */
168 struct {
169 domid_t dom;
171 } interdomain; /* EVTCHNSTAT_interdomain */
172 uint32_t pirq; /* EVTCHNSTAT_pirq */
173 uint32_t virq; /* EVTCHNSTAT_virq */
174 } u;
175};
177
178/*
179 * EVTCHNOP_unmask: Unmask the specified local event-channel port and deliver
180 * a notification to the appropriate VCPU if an event is pending.
181 */
183 /* IN parameters. */
185};
187
188/*
189 * EVTCHNOP_reset: Close all event channels associated with specified domain.
190 * NOTES:
191 * 1. <dom> may be specified as DOMID_SELF.
192 * 2. Only a sufficiently-privileged domain may specify other than DOMID_SELF.
193 * 3. Destroys all control blocks and event array, resets event channel
194 * operations to 2-level ABI if called with <dom> == DOMID_SELF and FIFO
195 * ABI was used. Guests should not bind events during EVTCHNOP_reset call
196 * as these events are likely to be lost.
197 */
199 /* IN parameters. */
201};
203
204/*
205 * EVTCHNOP_set_priority: set the priority for an event channel.
206 */
208 /* IN parameters. */
211};
213
214#define EVTCHN_2L_NR_CHANNELS (sizeof(xen_ulong_t) * sizeof(xen_ulong_t) * 64)
215
216#endif /* __XEN_PUBLIC_EVENT_CHANNEL_H__ */
#define DEFINE_XEN_GUEST_HANDLE(name)
Definition: arch-arm.h:192
uint32_t evtchn_port_t
Definition: event_channel.h:74
__UINT32_TYPE__ uint32_t
Definition: stdint.h:90
Definition: event_channel.h:85
domid_t remote_dom
Definition: event_channel.h:87
domid_t dom
Definition: event_channel.h:87
evtchn_port_t port
Definition: event_channel.h:89
Definition: event_channel.h:113
evtchn_port_t remote_port
Definition: event_channel.h:116
domid_t remote_dom
Definition: event_channel.h:115
evtchn_port_t local_port
Definition: event_channel.h:118
Definition: event_channel.h:127
evtchn_port_t port
Definition: event_channel.h:129
Definition: event_channel.h:198
domid_t dom
Definition: event_channel.h:200
Definition: event_channel.h:137
evtchn_port_t port
Definition: event_channel.h:139
Definition: event_channel.h:207
uint32_t priority
Definition: event_channel.h:210
evtchn_port_t port
Definition: event_channel.h:209
Definition: event_channel.h:151
struct evtchn_status::@417::@419 interdomain
uint32_t status
Definition: event_channel.h:162
evtchn_port_t port
Definition: event_channel.h:154
union evtchn_status::@417 u
uint32_t vcpu
Definition: event_channel.h:163
domid_t dom
Definition: event_channel.h:153
uint32_t pirq
Definition: event_channel.h:172
uint32_t virq
Definition: event_channel.h:173
struct evtchn_status::@417::@418 unbound
Definition: event_channel.h:182
evtchn_port_t port
Definition: event_channel.h:184
uint16_t domid_t
Definition: xen.h:217