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 74 typedef uint32_t evtchn_port_t; 75 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 struct evtchn_alloc_unbound { 86 /* IN parameters */ 87 domid_t dom, remote_dom; 88 /* OUT parameters */ 89 evtchn_port_t port; 90 }; 91 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 struct evtchn_bind_interdomain { 114 /* IN parameters. */ 115 domid_t remote_dom; 116 evtchn_port_t remote_port; 117 /* OUT parameters. */ 118 evtchn_port_t local_port; 119 }; 120 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 struct evtchn_close { 128 /* IN parameters. */ 129 evtchn_port_t port; 130 }; 131 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 struct evtchn_send { 138 /* IN parameters. */ 139 evtchn_port_t port; 140 }; 141 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 struct evtchn_status { 152 /* IN parameters */ 153 domid_t dom; 154 evtchn_port_t port; 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 */ 162 uint32_t status; 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; 170 evtchn_port_t port; 171 } interdomain; /* EVTCHNSTAT_interdomain */ 172 uint32_t pirq; /* EVTCHNSTAT_pirq */ 173 uint32_t virq; /* EVTCHNSTAT_virq */ 174 } u; 175 }; 176 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 struct evtchn_unmask { 183 /* IN parameters. */ 184 evtchn_port_t port; 185 }; 186 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 struct evtchn_reset { 199 /* IN parameters. */ 200 domid_t dom; 201 }; 202 typedef struct evtchn_reset evtchn_reset_t; 203 204 /* 205 * EVTCHNOP_set_priority: set the priority for an event channel. 206 */ 207 struct evtchn_set_priority { 208 /* IN parameters. */ 209 evtchn_port_t port; 210 uint32_t priority; 211 }; 212 typedef struct evtchn_set_priority evtchn_set_priority_t; 213 214 #define EVTCHN_2L_NR_CHANNELS (sizeof(xen_ulong_t) * sizeof(xen_ulong_t) * 64) 215 216 #endif /* __XEN_PUBLIC_EVENT_CHANNEL_H__ */ 217
