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1 0 : /* 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 0 : #define EVTCHNOP_bind_interdomain 0
57 0 : #define EVTCHNOP_bind_virq 1
58 0 : #define EVTCHNOP_bind_pirq 2
59 0 : #define EVTCHNOP_close 3
60 0 : #define EVTCHNOP_send 4
61 0 : #define EVTCHNOP_status 5
62 0 : #define EVTCHNOP_alloc_unbound 6
63 0 : #define EVTCHNOP_bind_ipi 7
64 0 : #define EVTCHNOP_bind_vcpu 8
65 0 : #define EVTCHNOP_unmask 9
66 0 : #define EVTCHNOP_reset 10
67 0 : #define EVTCHNOP_init_control 11
68 0 : #define EVTCHNOP_expand_array 12
69 0 : #define EVTCHNOP_set_priority 13
70 : #ifdef __XEN__
71 : #define EVTCHNOP_reset_cont 14
72 : #endif
73 :
74 0 : typedef uint32_t evtchn_port_t;
75 0 : DEFINE_XEN_GUEST_HANDLE(evtchn_port_t);
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 : */
85 0 : struct evtchn_alloc_unbound {
86 : /* IN parameters */
87 0 : domid_t dom, remote_dom;
88 : /* OUT parameters */
89 0 : evtchn_port_t port;
90 : };
91 0 : typedef struct evtchn_alloc_unbound evtchn_alloc_unbound_t;
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 : */
113 0 : struct evtchn_bind_interdomain {
114 : /* IN parameters. */
115 0 : domid_t remote_dom;
116 0 : evtchn_port_t remote_port;
117 : /* OUT parameters. */
118 0 : evtchn_port_t local_port;
119 : };
120 0 : typedef struct evtchn_bind_interdomain evtchn_bind_interdomain_t;
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 : */
127 0 : struct evtchn_close {
128 : /* IN parameters. */
129 0 : evtchn_port_t port;
130 : };
131 0 : typedef struct evtchn_close evtchn_close_t;
132 :
133 : /*
134 : * EVTCHNOP_send: Send an event to the remote end of the channel whose local
135 : * endpoint is <port>.
136 : */
137 0 : struct evtchn_send {
138 : /* IN parameters. */
139 0 : evtchn_port_t port;
140 : };
141 0 : typedef struct evtchn_send evtchn_send_t;
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 : */
151 0 : struct evtchn_status {
152 : /* IN parameters */
153 0 : domid_t dom;
154 0 : evtchn_port_t port;
155 : /* OUT parameters */
156 0 : #define EVTCHNSTAT_closed 0 /* Channel is not in use. */
157 0 : #define EVTCHNSTAT_unbound 1 /* Channel is waiting interdom connection.*/
158 0 : #define EVTCHNSTAT_interdomain 2 /* Channel is connected to remote domain. */
159 0 : #define EVTCHNSTAT_pirq 3 /* Channel is bound to a phys IRQ line. */
160 0 : #define EVTCHNSTAT_virq 4 /* Channel is bound to a virtual IRQ line */
161 0 : #define EVTCHNSTAT_ipi 5 /* Channel is bound to a virtual IPI line */
162 0 : uint32_t status;
163 0 : uint32_t vcpu; /* VCPU to which this channel is bound. */
164 : union {
165 : struct {
166 : domid_t dom;
167 0 : } unbound; /* EVTCHNSTAT_unbound */
168 : struct {
169 : domid_t dom;
170 : evtchn_port_t port;
171 0 : } interdomain; /* EVTCHNSTAT_interdomain */
172 0 : uint32_t pirq; /* EVTCHNSTAT_pirq */
173 0 : uint32_t virq; /* EVTCHNSTAT_virq */
174 0 : } u;
175 : };
176 0 : typedef struct evtchn_status evtchn_status_t;
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 : */
182 0 : struct evtchn_unmask {
183 : /* IN parameters. */
184 0 : evtchn_port_t port;
185 : };
186 0 : typedef struct evtchn_unmask evtchn_unmask_t;
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 : */
198 0 : struct evtchn_reset {
199 : /* IN parameters. */
200 0 : domid_t dom;
201 : };
202 0 : typedef struct evtchn_reset evtchn_reset_t;
203 :
204 : /*
205 : * EVTCHNOP_set_priority: set the priority for an event channel.
206 : */
207 0 : struct evtchn_set_priority {
208 : /* IN parameters. */
209 0 : evtchn_port_t port;
210 0 : uint32_t priority;
211 : };
212 0 : typedef struct evtchn_set_priority evtchn_set_priority_t;
213 :
214 0 : #define EVTCHN_2L_NR_CHANNELS (sizeof(xen_ulong_t) * sizeof(xen_ulong_t) * 64)
215 :
216 : #endif /* __XEN_PUBLIC_EVENT_CHANNEL_H__ */
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