1 /******************************************************************************
4 * Event channels between domains.
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:
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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
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24 * Copyright (c) 2003-2004, K A Fraser.
27 #ifndef __XEN_PUBLIC_EVENT_CHANNEL_H__
28 #define __XEN_PUBLIC_EVENT_CHANNEL_H__
30 #include <xen/interface/xen.h>
33 * `incontents 150 evtchn Event Channels
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.
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).
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.
50 * Event channels are represented by the evtchn_* fields in
51 * struct shared_info and struct vcpu_info.
56 * ` HYPERVISOR_event_channel_op(enum event_channel_op cmd, void *args)
58 * @cmd == EVTCHNOP_* (event-channel operation).
59 * @args == struct evtchn_* Operation-specific extra arguments (NULL if none).
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
76 typedef uint32_t evtchn_port_t;
77 DEFINE_XEN_GUEST_HANDLE(evtchn_port_t);
80 * EVTCHNOP_alloc_unbound: Allocate a port in domain <dom> and mark as
81 * accepting interdomain bindings from domain <remote_dom>. A fresh port
82 * is allocated in <dom> and returned as <port>.
84 * 1. If the caller is unprivileged then <dom> must be DOMID_SELF.
85 * 2. <rdom> may be DOMID_SELF, allowing loopback connections.
87 struct evtchn_alloc_unbound {
89 domid_t dom, remote_dom;
93 typedef struct evtchn_alloc_unbound evtchn_alloc_unbound_t;
96 * EVTCHNOP_bind_interdomain: Construct an interdomain event channel between
97 * the calling domain and <remote_dom>. <remote_dom,remote_port> must identify
98 * a port that is unbound and marked as accepting bindings from the calling
99 * domain. A fresh port is allocated in the calling domain and returned as
102 * 1. <remote_dom> may be DOMID_SELF, allowing loopback connections.
104 struct evtchn_bind_interdomain {
107 evtchn_port_t remote_port;
108 /* OUT parameters. */
109 evtchn_port_t local_port;
111 typedef struct evtchn_bind_interdomain evtchn_bind_interdomain_t;
114 * EVTCHNOP_bind_virq: Bind a local event channel to VIRQ <irq> on specified
117 * 1. Virtual IRQs are classified as per-vcpu or global. See the VIRQ list
118 * in xen.h for the classification of each VIRQ.
119 * 2. Global VIRQs must be allocated on VCPU0 but can subsequently be
120 * re-bound via EVTCHNOP_bind_vcpu.
121 * 3. Per-vcpu VIRQs may be bound to at most one event channel per vcpu.
122 * The allocated event channel is bound to the specified vcpu and the
123 * binding cannot be changed.
125 struct evtchn_bind_virq {
127 uint32_t virq; /* enum virq */
129 /* OUT parameters. */
132 typedef struct evtchn_bind_virq evtchn_bind_virq_t;
135 * EVTCHNOP_bind_pirq: Bind a local event channel to a real IRQ (PIRQ <irq>).
137 * 1. A physical IRQ may be bound to at most one event channel per domain.
138 * 2. Only a sufficiently-privileged domain may bind to a physical IRQ.
140 struct evtchn_bind_pirq {
143 #define BIND_PIRQ__WILL_SHARE 1
144 uint32_t flags; /* BIND_PIRQ__* */
145 /* OUT parameters. */
148 typedef struct evtchn_bind_pirq evtchn_bind_pirq_t;
151 * EVTCHNOP_bind_ipi: Bind a local event channel to receive events.
153 * 1. The allocated event channel is bound to the specified vcpu. The binding
154 * may not be changed.
156 struct evtchn_bind_ipi {
158 /* OUT parameters. */
161 typedef struct evtchn_bind_ipi evtchn_bind_ipi_t;
164 * EVTCHNOP_close: Close a local event channel <port>. If the channel is
165 * interdomain then the remote end is placed in the unbound state
166 * (EVTCHNSTAT_unbound), awaiting a new connection.
168 struct evtchn_close {
172 typedef struct evtchn_close evtchn_close_t;
175 * EVTCHNOP_send: Send an event to the remote end of the channel whose local
176 * endpoint is <port>.
182 typedef struct evtchn_send evtchn_send_t;
185 * EVTCHNOP_status: Get the current status of the communication channel which
186 * has an endpoint at <dom, port>.
188 * 1. <dom> may be specified as DOMID_SELF.
189 * 2. Only a sufficiently-privileged domain may obtain the status of an event
190 * channel for which <dom> is not DOMID_SELF.
192 struct evtchn_status {
197 #define EVTCHNSTAT_closed 0 /* Channel is not in use. */
198 #define EVTCHNSTAT_unbound 1 /* Channel is waiting interdom connection.*/
199 #define EVTCHNSTAT_interdomain 2 /* Channel is connected to remote domain. */
200 #define EVTCHNSTAT_pirq 3 /* Channel is bound to a phys IRQ line. */
201 #define EVTCHNSTAT_virq 4 /* Channel is bound to a virtual IRQ line */
202 #define EVTCHNSTAT_ipi 5 /* Channel is bound to a virtual IPI line */
204 uint32_t vcpu; /* VCPU to which this channel is bound. */
208 } unbound; /* EVTCHNSTAT_unbound */
212 } interdomain; /* EVTCHNSTAT_interdomain */
213 uint32_t pirq; /* EVTCHNSTAT_pirq */
214 uint32_t virq; /* EVTCHNSTAT_virq */
217 typedef struct evtchn_status evtchn_status_t;
220 * EVTCHNOP_bind_vcpu: Specify which vcpu a channel should notify when an
223 * 1. IPI-bound channels always notify the vcpu specified at bind time.
224 * This binding cannot be changed.
225 * 2. Per-VCPU VIRQ channels always notify the vcpu specified at bind time.
226 * This binding cannot be changed.
227 * 3. All other channels notify vcpu0 by default. This default is set when
228 * the channel is allocated (a port that is freed and subsequently reused
229 * has its binding reset to vcpu0).
231 struct evtchn_bind_vcpu {
236 typedef struct evtchn_bind_vcpu evtchn_bind_vcpu_t;
239 * EVTCHNOP_unmask: Unmask the specified local event-channel port and deliver
240 * a notification to the appropriate VCPU if an event is pending.
242 struct evtchn_unmask {
246 typedef struct evtchn_unmask evtchn_unmask_t;
249 * EVTCHNOP_reset: Close all event channels associated with specified domain.
251 * 1. <dom> may be specified as DOMID_SELF.
252 * 2. Only a sufficiently-privileged domain may specify other than DOMID_SELF.
254 struct evtchn_reset {
258 typedef struct evtchn_reset evtchn_reset_t;
261 * ` enum neg_errnoval
262 * ` HYPERVISOR_event_channel_op_compat(struct evtchn_op *op)
264 * Superceded by new event_channel_op() hypercall since 0x00030202.
267 uint32_t cmd; /* enum event_channel_op */
269 struct evtchn_alloc_unbound alloc_unbound;
270 struct evtchn_bind_interdomain bind_interdomain;
271 struct evtchn_bind_virq bind_virq;
272 struct evtchn_bind_pirq bind_pirq;
273 struct evtchn_bind_ipi bind_ipi;
274 struct evtchn_close close;
275 struct evtchn_send send;
276 struct evtchn_status status;
277 struct evtchn_bind_vcpu bind_vcpu;
278 struct evtchn_unmask unmask;
281 DEFINE_GUEST_HANDLE_STRUCT(evtchn_op);
282 typedef struct evtchn_op evtchn_op_t;
283 DEFINE_XEN_GUEST_HANDLE(evtchn_op_t);
285 #endif /* __XEN_PUBLIC_EVENT_CHANNEL_H__ */