1 /******************************************************************************
2 * event_channel.h
3 *
4 * Event channels between domains.
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) 2003-2004, K A Fraser.
25 */
26
27 #ifndef __XEN_PUBLIC_EVENT_CHANNEL_H__
28 #define __XEN_PUBLIC_EVENT_CHANNEL_H__
29
30 #include "xen.h"
31
32 /*
33 * `incontents 150 evtchn Event Channels
34 *
35 * Event channels are the basic primitive provided by Xen for event
36 * notifications. An event is the Xen equivalent of a hardware
37 * interrupt. They essentially store one bit of information, the event
38 * of interest is signalled by transitioning this bit from 0 to 1.
39 *
40 * Notifications are received by a guest via an upcall from Xen,
41 * indicating when an event arrives (setting the bit). Further
42 * notifications are masked until the bit is cleared again (therefore,
43 * guests must check the value of the bit after re-enabling event
44 * delivery to ensure no missed notifications).
45 *
46 * Event notifications can be masked by setting a flag; this is
47 * equivalent to disabling interrupts and can be used to ensure
48 * atomicity of certain operations in the guest kernel.
49 *
50 * Event channels are represented by the evtchn_* fields in
51 * struct shared_info and struct vcpu_info.
52 */
53
54 /*
55 * ` enum neg_errnoval
56 * ` HYPERVISOR_event_channel_op(enum event_channel_op cmd, void *args)
57 * `
58 * @cmd == EVTCHNOP_* (event-channel operation).
59 * @args == struct evtchn_* Operation-specific extra arguments (NULL if none).
60 */
61
62 /* ` enum event_channel_op { // EVTCHNOP_* => struct evtchn_* */
63 #define EVTCHNOP_bind_interdomain 0
64 #define EVTCHNOP_bind_virq 1
65 #define EVTCHNOP_bind_pirq 2
66 #define EVTCHNOP_close 3
67 #define EVTCHNOP_send 4
68 #define EVTCHNOP_status 5
69 #define EVTCHNOP_alloc_unbound 6
70 #define EVTCHNOP_bind_ipi 7
71 #define EVTCHNOP_bind_vcpu 8
72 #define EVTCHNOP_unmask 9
73 #define EVTCHNOP_reset 10
74 /* ` } */
75
76 #ifndef __XEN_EVTCHN_PORT_DEFINED__
77 typedef uint32_t evtchn_port_t;
78 DEFINE_XEN_GUEST_HANDLE(evtchn_port_t);
79 #define __XEN_EVTCHN_PORT_DEFINED__ 1
80 #endif
81
82 /*
83 * EVTCHNOP_alloc_unbound: Allocate a port in domain <dom> and mark as
84 * accepting interdomain bindings from domain <remote_dom>. A fresh port
85 * is allocated in <dom> and returned as <port>.
86 * NOTES:
87 * 1. If the caller is unprivileged then <dom> must be DOMID_SELF.
88 * 2. <rdom> may be DOMID_SELF, allowing loopback connections.
89 */
90 struct evtchn_alloc_unbound {
91 /* IN parameters */
92 domid_t dom, remote_dom;
93 /* OUT parameters */
94 evtchn_port_t port;
95 };
96 typedef struct evtchn_alloc_unbound evtchn_alloc_unbound_t;
97
98 /*
99 * EVTCHNOP_bind_interdomain: Construct an interdomain event channel between
100 * the calling domain and <remote_dom>. <remote_dom,remote_port> must identify
101 * a port that is unbound and marked as accepting bindings from the calling
102 * domain. A fresh port is allocated in the calling domain and returned as
103 * <local_port>.
104 * NOTES:
105 * 1. <remote_dom> may be DOMID_SELF, allowing loopback connections.
106 */
107 struct evtchn_bind_interdomain {
108 /* IN parameters. */
109 domid_t remote_dom;
110 evtchn_port_t remote_port;
111 /* OUT parameters. */
112 evtchn_port_t local_port;
113 };
114 typedef struct evtchn_bind_interdomain evtchn_bind_interdomain_t;
115
116 /*
117 * EVTCHNOP_bind_virq: Bind a local event channel to VIRQ <irq> on specified
118 * vcpu.
119 * NOTES:
120 * 1. Virtual IRQs are classified as per-vcpu or global. See the VIRQ list
121 * in xen.h for the classification of each VIRQ.
122 * 2. Global VIRQs must be allocated on VCPU0 but can subsequently be
123 * re-bound via EVTCHNOP_bind_vcpu.
124 * 3. Per-vcpu VIRQs may be bound to at most one event channel per vcpu.
125 * The allocated event channel is bound to the specified vcpu and the
126 * binding cannot be changed.
127 */
128 struct evtchn_bind_virq {
129 /* IN parameters. */
130 uint32_t virq; /* enum virq */
131 uint32_t vcpu;
132 /* OUT parameters. */
133 evtchn_port_t port;
134 };
135 typedef struct evtchn_bind_virq evtchn_bind_virq_t;
136
137 /*
138 * EVTCHNOP_bind_pirq: Bind a local event channel to a real IRQ (PIRQ <irq>).
139 * NOTES:
140 * 1. A physical IRQ may be bound to at most one event channel per domain.
141 * 2. Only a sufficiently-privileged domain may bind to a physical IRQ.
142 */
143 struct evtchn_bind_pirq {
144 /* IN parameters. */
145 uint32_t pirq;
146 #define BIND_PIRQ__WILL_SHARE 1
147 uint32_t flags; /* BIND_PIRQ__* */
148 /* OUT parameters. */
149 evtchn_port_t port;
150 };
151 typedef struct evtchn_bind_pirq evtchn_bind_pirq_t;
152
153 /*
154 * EVTCHNOP_bind_ipi: Bind a local event channel to receive events.
155 * NOTES:
156 * 1. The allocated event channel is bound to the specified vcpu. The binding
157 * may not be changed.
158 */
159 struct evtchn_bind_ipi {
160 uint32_t vcpu;
161 /* OUT parameters. */
162 evtchn_port_t port;
163 };
164 typedef struct evtchn_bind_ipi evtchn_bind_ipi_t;
165
166 /*
167 * EVTCHNOP_close: Close a local event channel <port>. If the channel is
168 * interdomain then the remote end is placed in the unbound state
169 * (EVTCHNSTAT_unbound), awaiting a new connection.
170 */
171 struct evtchn_close {
172 /* IN parameters. */
173 evtchn_port_t port;
174 };
175 typedef struct evtchn_close evtchn_close_t;
176
177 /*
178 * EVTCHNOP_send: Send an event to the remote end of the channel whose local
179 * endpoint is <port>.
180 */
181 struct evtchn_send {
182 /* IN parameters. */
183 evtchn_port_t port;
184 };
185 typedef struct evtchn_send evtchn_send_t;
186
187 /*
188 * EVTCHNOP_status: Get the current status of the communication channel which
189 * has an endpoint at <dom, port>.
190 * NOTES:
191 * 1. <dom> may be specified as DOMID_SELF.
192 * 2. Only a sufficiently-privileged domain may obtain the status of an event
193 * channel for which <dom> is not DOMID_SELF.
194 */
195 struct evtchn_status {
196 /* IN parameters */
197 domid_t dom;
198 evtchn_port_t port;
199 /* OUT parameters */
200 #define EVTCHNSTAT_closed 0 /* Channel is not in use. */
201 #define EVTCHNSTAT_unbound 1 /* Channel is waiting interdom connection.*/
202 #define EVTCHNSTAT_interdomain 2 /* Channel is connected to remote domain. */
203 #define EVTCHNSTAT_pirq 3 /* Channel is bound to a phys IRQ line. */
204 #define EVTCHNSTAT_virq 4 /* Channel is bound to a virtual IRQ line */
205 #define EVTCHNSTAT_ipi 5 /* Channel is bound to a virtual IPI line */
206 uint32_t status;
207 uint32_t vcpu; /* VCPU to which this channel is bound. */
208 union {
209 struct {
210 domid_t dom;
211 } unbound; /* EVTCHNSTAT_unbound */
212 struct {
213 domid_t dom;
214 evtchn_port_t port;
215 } interdomain; /* EVTCHNSTAT_interdomain */
216 uint32_t pirq; /* EVTCHNSTAT_pirq */
217 uint32_t virq; /* EVTCHNSTAT_virq */
218 } u;
219 };
220 typedef struct evtchn_status evtchn_status_t;
221
222 /*
223 * EVTCHNOP_bind_vcpu: Specify which vcpu a channel should notify when an
224 * event is pending.
225 * NOTES:
226 * 1. IPI-bound channels always notify the vcpu specified at bind time.
227 * This binding cannot be changed.
228 * 2. Per-VCPU VIRQ channels always notify the vcpu specified at bind time.
229 * This binding cannot be changed.
230 * 3. All other channels notify vcpu0 by default. This default is set when
231 * the channel is allocated (a port that is freed and subsequently reused
232 * has its binding reset to vcpu0).
233 */
234 struct evtchn_bind_vcpu {
235 /* IN parameters. */
236 evtchn_port_t port;
237 uint32_t vcpu;
238 };
239 typedef struct evtchn_bind_vcpu evtchn_bind_vcpu_t;
240
241 /*
242 * EVTCHNOP_unmask: Unmask the specified local event-channel port and deliver
243 * a notification to the appropriate VCPU if an event is pending.
244 */
245 struct evtchn_unmask {
246 /* IN parameters. */
247 evtchn_port_t port;
248 };
249 typedef struct evtchn_unmask evtchn_unmask_t;
250
251 /*
252 * EVTCHNOP_reset: Close all event channels associated with specified domain.
253 * NOTES:
254 * 1. <dom> may be specified as DOMID_SELF.
255 * 2. Only a sufficiently-privileged domain may specify other than DOMID_SELF.
256 */
257 struct evtchn_reset {
258 /* IN parameters. */
259 domid_t dom;
260 };
261 typedef struct evtchn_reset evtchn_reset_t;
262
263 /*
264 * ` enum neg_errnoval
265 * ` HYPERVISOR_event_channel_op_compat(struct evtchn_op *op)
266 * `
267 * Superceded by new event_channel_op() hypercall since 0x00030202.
268 */
269 struct evtchn_op {
270 uint32_t cmd; /* enum event_channel_op */
271 union {
272 struct evtchn_alloc_unbound alloc_unbound;
273 struct evtchn_bind_interdomain bind_interdomain;
274 struct evtchn_bind_virq bind_virq;
275 struct evtchn_bind_pirq bind_pirq;
276 struct evtchn_bind_ipi bind_ipi;
277 struct evtchn_close close;
278 struct evtchn_send send;
279 struct evtchn_status status;
280 struct evtchn_bind_vcpu bind_vcpu;
281 struct evtchn_unmask unmask;
282 } u;
283 };
284 typedef struct evtchn_op evtchn_op_t;
285 DEFINE_XEN_GUEST_HANDLE(evtchn_op_t);
286
287 #endif /* __XEN_PUBLIC_EVENT_CHANNEL_H__ */
288
289 /*
290 * Local variables:
291 * mode: C
292 * c-set-style: "BSD"
293 * c-basic-offset: 4
294 * tab-width: 4
295 * indent-tabs-mode: nil
296 * End:
297 */
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