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 #define EVTCHNOP_init_control 11 75 #define EVTCHNOP_expand_array 12 76 #define EVTCHNOP_set_priority 13 77 /* ` } */ 78 79 typedef uint32_t evtchn_port_t; 80 DEFINE_XEN_GUEST_HANDLE(evtchn_port_t); 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. <remote_dom> 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 * 105 * In case the peer domain has already tried to set our event channel 106 * pending, before it was bound, EVTCHNOP_bind_interdomain always sets 107 * the local event channel pending. 108 * 109 * The usual pattern of use, in the guest's upcall (or subsequent 110 * handler) is as follows: (Re-enable the event channel for subsequent 111 * signalling and then) check for the existence of whatever condition 112 * is being waited for by other means, and take whatever action is 113 * needed (if any). 114 * 115 * NOTES: 116 * 1. <remote_dom> may be DOMID_SELF, allowing loopback connections. 117 */ 118 struct evtchn_bind_interdomain { 119 /* IN parameters. */ 120 domid_t remote_dom; 121 evtchn_port_t remote_port; 122 /* OUT parameters. */ 123 evtchn_port_t local_port; 124 }; 125 typedef struct evtchn_bind_interdomain evtchn_bind_interdomain_t; 126 127 /* 128 * EVTCHNOP_bind_virq: Bind a local event channel to VIRQ <irq> on specified 129 * vcpu. 130 * NOTES: 131 * 1. Virtual IRQs are classified as per-vcpu or global. See the VIRQ list 132 * in xen.h for the classification of each VIRQ. 133 * 2. Global VIRQs must be allocated on VCPU0 but can subsequently be 134 * re-bound via EVTCHNOP_bind_vcpu. 135 * 3. Per-vcpu VIRQs may be bound to at most one event channel per vcpu. 136 * The allocated event channel is bound to the specified vcpu and the 137 * binding cannot be changed. 138 */ 139 struct evtchn_bind_virq { 140 /* IN parameters. */ 141 uint32_t virq; /* enum virq */ 142 uint32_t vcpu; 143 /* OUT parameters. */ 144 evtchn_port_t port; 145 }; 146 typedef struct evtchn_bind_virq evtchn_bind_virq_t; 147 148 /* 149 * EVTCHNOP_bind_pirq: Bind a local event channel to a real IRQ (PIRQ <irq>). 150 * NOTES: 151 * 1. A physical IRQ may be bound to at most one event channel per domain. 152 * 2. Only a sufficiently-privileged domain may bind to a physical IRQ. 153 */ 154 struct evtchn_bind_pirq { 155 /* IN parameters. */ 156 uint32_t pirq; 157 #define BIND_PIRQ__WILL_SHARE 1 158 uint32_t flags; /* BIND_PIRQ__* */ 159 /* OUT parameters. */ 160 evtchn_port_t port; 161 }; 162 typedef struct evtchn_bind_pirq evtchn_bind_pirq_t; 163 164 /* 165 * EVTCHNOP_bind_ipi: Bind a local event channel to receive events. 166 * NOTES: 167 * 1. The allocated event channel is bound to the specified vcpu. The binding 168 * may not be changed. 169 */ 170 struct evtchn_bind_ipi { 171 uint32_t vcpu; 172 /* OUT parameters. */ 173 evtchn_port_t port; 174 }; 175 typedef struct evtchn_bind_ipi evtchn_bind_ipi_t; 176 177 /* 178 * EVTCHNOP_close: Close a local event channel <port>. If the channel is 179 * interdomain then the remote end is placed in the unbound state 180 * (EVTCHNSTAT_unbound), awaiting a new connection. 181 */ 182 struct evtchn_close { 183 /* IN parameters. */ 184 evtchn_port_t port; 185 }; 186 typedef struct evtchn_close evtchn_close_t; 187 188 /* 189 * EVTCHNOP_send: Send an event to the remote end of the channel whose local 190 * endpoint is <port>. 191 */ 192 struct evtchn_send { 193 /* IN parameters. */ 194 evtchn_port_t port; 195 }; 196 typedef struct evtchn_send evtchn_send_t; 197 198 /* 199 * EVTCHNOP_status: Get the current status of the communication channel which 200 * has an endpoint at <dom, port>. 201 * NOTES: 202 * 1. <dom> may be specified as DOMID_SELF. 203 * 2. Only a sufficiently-privileged domain may obtain the status of an event 204 * channel for which <dom> is not DOMID_SELF. 205 */ 206 struct evtchn_status { 207 /* IN parameters */ 208 domid_t dom; 209 evtchn_port_t port; 210 /* OUT parameters */ 211 #define EVTCHNSTAT_closed 0 /* Channel is not in use. */ 212 #define EVTCHNSTAT_unbound 1 /* Channel is waiting interdom connection.*/ 213 #define EVTCHNSTAT_interdomain 2 /* Channel is connected to remote domain. */ 214 #define EVTCHNSTAT_pirq 3 /* Channel is bound to a phys IRQ line. */ 215 #define EVTCHNSTAT_virq 4 /* Channel is bound to a virtual IRQ line */ 216 #define EVTCHNSTAT_ipi 5 /* Channel is bound to a virtual IPI line */ 217 uint32_t status; 218 uint32_t vcpu; /* VCPU to which this channel is bound. */ 219 union { 220 struct { 221 domid_t dom; 222 } unbound; /* EVTCHNSTAT_unbound */ 223 struct { 224 domid_t dom; 225 evtchn_port_t port; 226 } interdomain; /* EVTCHNSTAT_interdomain */ 227 uint32_t pirq; /* EVTCHNSTAT_pirq */ 228 uint32_t virq; /* EVTCHNSTAT_virq */ 229 } u; 230 }; 231 typedef struct evtchn_status evtchn_status_t; 232 233 /* 234 * EVTCHNOP_bind_vcpu: Specify which vcpu a channel should notify when an 235 * event is pending. 236 * NOTES: 237 * 1. IPI-bound channels always notify the vcpu specified at bind time. 238 * This binding cannot be changed. 239 * 2. Per-VCPU VIRQ channels always notify the vcpu specified at bind time. 240 * This binding cannot be changed. 241 * 3. All other channels notify vcpu0 by default. This default is set when 242 * the channel is allocated (a port that is freed and subsequently reused 243 * has its binding reset to vcpu0). 244 */ 245 struct evtchn_bind_vcpu { 246 /* IN parameters. */ 247 evtchn_port_t port; 248 uint32_t vcpu; 249 }; 250 typedef struct evtchn_bind_vcpu evtchn_bind_vcpu_t; 251 252 /* 253 * EVTCHNOP_unmask: Unmask the specified local event-channel port and deliver 254 * a notification to the appropriate VCPU if an event is pending. 255 */ 256 struct evtchn_unmask { 257 /* IN parameters. */ 258 evtchn_port_t port; 259 }; 260 typedef struct evtchn_unmask evtchn_unmask_t; 261 262 /* 263 * EVTCHNOP_reset: Close all event channels associated with specified domain. 264 * NOTES: 265 * 1. <dom> may be specified as DOMID_SELF. 266 * 2. Only a sufficiently-privileged domain may specify other than DOMID_SELF. 267 * 3. Destroys all control blocks and event array, resets event channel 268 * operations to 2-level ABI if called with <dom> == DOMID_SELF and FIFO 269 * ABI was used. Guests should not bind events during EVTCHNOP_reset call 270 * as these events are likely to be lost. 271 */ 272 struct evtchn_reset { 273 /* IN parameters. */ 274 domid_t dom; 275 }; 276 typedef struct evtchn_reset evtchn_reset_t; 277 278 /* 279 * EVTCHNOP_init_control: initialize the control block for the FIFO ABI. 280 * 281 * Note: any events that are currently pending will not be resent and 282 * will be lost. Guests should call this before binding any event to 283 * avoid losing any events. 284 */ 285 struct evtchn_init_control { 286 /* IN parameters. */ 287 uint64_t control_gfn; 288 uint32_t offset; 289 uint32_t vcpu; 290 /* OUT parameters. */ 291 uint8_t link_bits; 292 uint8_t _pad[7]; 293 }; 294 typedef struct evtchn_init_control evtchn_init_control_t; 295 296 /* 297 * EVTCHNOP_expand_array: add an additional page to the event array. 298 */ 299 struct evtchn_expand_array { 300 /* IN parameters. */ 301 uint64_t array_gfn; 302 }; 303 typedef struct evtchn_expand_array evtchn_expand_array_t; 304 305 /* 306 * EVTCHNOP_set_priority: set the priority for an event channel. 307 */ 308 struct evtchn_set_priority { 309 /* IN parameters. */ 310 uint32_t port; 311 uint32_t priority; 312 }; 313 typedef struct evtchn_set_priority evtchn_set_priority_t; 314 315 /* 316 * ` enum neg_errnoval 317 * ` HYPERVISOR_event_channel_op_compat(struct evtchn_op *op) 318 * ` 319 * Superceded by new event_channel_op() hypercall since 0x00030202. 320 */ 321 struct evtchn_op { 322 uint32_t cmd; /* enum event_channel_op */ 323 union { 324 struct evtchn_alloc_unbound alloc_unbound; 325 struct evtchn_bind_interdomain bind_interdomain; 326 struct evtchn_bind_virq bind_virq; 327 struct evtchn_bind_pirq bind_pirq; 328 struct evtchn_bind_ipi bind_ipi; 329 struct evtchn_close close; 330 struct evtchn_send send; 331 struct evtchn_status status; 332 struct evtchn_bind_vcpu bind_vcpu; 333 struct evtchn_unmask unmask; 334 } u; 335 }; 336 typedef struct evtchn_op evtchn_op_t; 337 DEFINE_XEN_GUEST_HANDLE(evtchn_op_t); 338 339 /* 340 * 2-level ABI 341 */ 342 343 #define EVTCHN_2L_NR_CHANNELS (sizeof(xen_ulong_t) * sizeof(xen_ulong_t) * 64) 344 345 /* 346 * FIFO ABI 347 */ 348 349 /* Events may have priorities from 0 (highest) to 15 (lowest). */ 350 #define EVTCHN_FIFO_PRIORITY_MAX 0 351 #define EVTCHN_FIFO_PRIORITY_DEFAULT 7 352 #define EVTCHN_FIFO_PRIORITY_MIN 15 353 354 #define EVTCHN_FIFO_MAX_QUEUES (EVTCHN_FIFO_PRIORITY_MIN + 1) 355 356 typedef uint32_t event_word_t; 357 358 #define EVTCHN_FIFO_PENDING 31 359 #define EVTCHN_FIFO_MASKED 30 360 #define EVTCHN_FIFO_LINKED 29 361 #define EVTCHN_FIFO_BUSY 28 362 363 #define EVTCHN_FIFO_LINK_BITS 17 364 #define EVTCHN_FIFO_LINK_MASK ((1 << EVTCHN_FIFO_LINK_BITS) - 1) 365 366 #define EVTCHN_FIFO_NR_CHANNELS (1 << EVTCHN_FIFO_LINK_BITS) 367 368 struct evtchn_fifo_control_block { 369 uint32_t ready; 370 uint32_t _rsvd; 371 uint32_t head[EVTCHN_FIFO_MAX_QUEUES]; 372 }; 373 typedef struct evtchn_fifo_control_block evtchn_fifo_control_block_t; 374 375 #endif /* __XEN_PUBLIC_EVENT_CHANNEL_H__ */ 376 377 /* 378 * Local variables: 379 * mode: C 380 * c-file-style: "BSD" 381 * c-basic-offset: 4 382 * tab-width: 4 383 * indent-tabs-mode: nil 384 * End: 385 */ 386