Merge remote-tracking branch 'remotes/dgilbert-gitlab/tags/pull-migration-20210726a...
[qemu/armbru.git] / hw / hyperv / hyperv.c
blobcb1074f234c896a0544009ad2eb41202339fe467
1 /*
2 * Hyper-V guest/hypervisor interaction
4 * Copyright (c) 2015-2018 Virtuozzo International GmbH.
6 * This work is licensed under the terms of the GNU GPL, version 2 or later.
7 * See the COPYING file in the top-level directory.
8 */
10 #include "qemu/osdep.h"
11 #include "qemu/main-loop.h"
12 #include "qemu/module.h"
13 #include "qapi/error.h"
14 #include "exec/address-spaces.h"
15 #include "sysemu/kvm.h"
16 #include "qemu/bitops.h"
17 #include "qemu/error-report.h"
18 #include "qemu/lockable.h"
19 #include "qemu/queue.h"
20 #include "qemu/rcu.h"
21 #include "qemu/rcu_queue.h"
22 #include "hw/hyperv/hyperv.h"
23 #include "qom/object.h"
25 struct SynICState {
26 DeviceState parent_obj;
28 CPUState *cs;
30 bool enabled;
31 hwaddr msg_page_addr;
32 hwaddr event_page_addr;
33 MemoryRegion msg_page_mr;
34 MemoryRegion event_page_mr;
35 struct hyperv_message_page *msg_page;
36 struct hyperv_event_flags_page *event_page;
39 #define TYPE_SYNIC "hyperv-synic"
40 OBJECT_DECLARE_SIMPLE_TYPE(SynICState, SYNIC)
42 static bool synic_enabled;
44 bool hyperv_is_synic_enabled(void)
46 return synic_enabled;
49 static SynICState *get_synic(CPUState *cs)
51 return SYNIC(object_resolve_path_component(OBJECT(cs), "synic"));
54 static void synic_update(SynICState *synic, bool enable,
55 hwaddr msg_page_addr, hwaddr event_page_addr)
58 synic->enabled = enable;
59 if (synic->msg_page_addr != msg_page_addr) {
60 if (synic->msg_page_addr) {
61 memory_region_del_subregion(get_system_memory(),
62 &synic->msg_page_mr);
64 if (msg_page_addr) {
65 memory_region_add_subregion(get_system_memory(), msg_page_addr,
66 &synic->msg_page_mr);
68 synic->msg_page_addr = msg_page_addr;
70 if (synic->event_page_addr != event_page_addr) {
71 if (synic->event_page_addr) {
72 memory_region_del_subregion(get_system_memory(),
73 &synic->event_page_mr);
75 if (event_page_addr) {
76 memory_region_add_subregion(get_system_memory(), event_page_addr,
77 &synic->event_page_mr);
79 synic->event_page_addr = event_page_addr;
83 void hyperv_synic_update(CPUState *cs, bool enable,
84 hwaddr msg_page_addr, hwaddr event_page_addr)
86 SynICState *synic = get_synic(cs);
88 if (!synic) {
89 return;
92 synic_update(synic, enable, msg_page_addr, event_page_addr);
95 static void synic_realize(DeviceState *dev, Error **errp)
97 Object *obj = OBJECT(dev);
98 SynICState *synic = SYNIC(dev);
99 char *msgp_name, *eventp_name;
100 uint32_t vp_index;
102 /* memory region names have to be globally unique */
103 vp_index = hyperv_vp_index(synic->cs);
104 msgp_name = g_strdup_printf("synic-%u-msg-page", vp_index);
105 eventp_name = g_strdup_printf("synic-%u-event-page", vp_index);
107 memory_region_init_ram(&synic->msg_page_mr, obj, msgp_name,
108 sizeof(*synic->msg_page), &error_abort);
109 memory_region_init_ram(&synic->event_page_mr, obj, eventp_name,
110 sizeof(*synic->event_page), &error_abort);
111 synic->msg_page = memory_region_get_ram_ptr(&synic->msg_page_mr);
112 synic->event_page = memory_region_get_ram_ptr(&synic->event_page_mr);
114 g_free(msgp_name);
115 g_free(eventp_name);
117 static void synic_reset(DeviceState *dev)
119 SynICState *synic = SYNIC(dev);
120 memset(synic->msg_page, 0, sizeof(*synic->msg_page));
121 memset(synic->event_page, 0, sizeof(*synic->event_page));
122 synic_update(synic, false, 0, 0);
125 static void synic_class_init(ObjectClass *klass, void *data)
127 DeviceClass *dc = DEVICE_CLASS(klass);
129 dc->realize = synic_realize;
130 dc->reset = synic_reset;
131 dc->user_creatable = false;
134 void hyperv_synic_add(CPUState *cs)
136 Object *obj;
137 SynICState *synic;
139 obj = object_new(TYPE_SYNIC);
140 synic = SYNIC(obj);
141 synic->cs = cs;
142 object_property_add_child(OBJECT(cs), "synic", obj);
143 object_unref(obj);
144 qdev_realize(DEVICE(obj), NULL, &error_abort);
145 synic_enabled = true;
148 void hyperv_synic_reset(CPUState *cs)
150 SynICState *synic = get_synic(cs);
152 if (synic) {
153 device_legacy_reset(DEVICE(synic));
157 static const TypeInfo synic_type_info = {
158 .name = TYPE_SYNIC,
159 .parent = TYPE_DEVICE,
160 .instance_size = sizeof(SynICState),
161 .class_init = synic_class_init,
164 static void synic_register_types(void)
166 type_register_static(&synic_type_info);
169 type_init(synic_register_types)
172 * KVM has its own message producers (SynIC timers). To guarantee
173 * serialization with both KVM vcpu and the guest cpu, the messages are first
174 * staged in an intermediate area and then posted to the SynIC message page in
175 * the vcpu thread.
177 typedef struct HvSintStagedMessage {
178 /* message content staged by hyperv_post_msg */
179 struct hyperv_message msg;
180 /* callback + data (r/o) to complete the processing in a BH */
181 HvSintMsgCb cb;
182 void *cb_data;
183 /* message posting status filled by cpu_post_msg */
184 int status;
185 /* passing the buck: */
186 enum {
187 /* initial state */
188 HV_STAGED_MSG_FREE,
190 * hyperv_post_msg (e.g. in main loop) grabs the staged area (FREE ->
191 * BUSY), copies msg, and schedules cpu_post_msg on the assigned cpu
193 HV_STAGED_MSG_BUSY,
195 * cpu_post_msg (vcpu thread) tries to copy staged msg to msg slot,
196 * notify the guest, records the status, marks the posting done (BUSY
197 * -> POSTED), and schedules sint_msg_bh BH
199 HV_STAGED_MSG_POSTED,
201 * sint_msg_bh (BH) verifies that the posting is done, runs the
202 * callback, and starts over (POSTED -> FREE)
204 } state;
205 } HvSintStagedMessage;
207 struct HvSintRoute {
208 uint32_t sint;
209 SynICState *synic;
210 int gsi;
211 EventNotifier sint_set_notifier;
212 EventNotifier sint_ack_notifier;
214 HvSintStagedMessage *staged_msg;
216 unsigned refcount;
219 static CPUState *hyperv_find_vcpu(uint32_t vp_index)
221 CPUState *cs = qemu_get_cpu(vp_index);
222 assert(hyperv_vp_index(cs) == vp_index);
223 return cs;
227 * BH to complete the processing of a staged message.
229 static void sint_msg_bh(void *opaque)
231 HvSintRoute *sint_route = opaque;
232 HvSintStagedMessage *staged_msg = sint_route->staged_msg;
234 if (qatomic_read(&staged_msg->state) != HV_STAGED_MSG_POSTED) {
235 /* status nor ready yet (spurious ack from guest?), ignore */
236 return;
239 staged_msg->cb(staged_msg->cb_data, staged_msg->status);
240 staged_msg->status = 0;
242 /* staged message processing finished, ready to start over */
243 qatomic_set(&staged_msg->state, HV_STAGED_MSG_FREE);
244 /* drop the reference taken in hyperv_post_msg */
245 hyperv_sint_route_unref(sint_route);
249 * Worker to transfer the message from the staging area into the SynIC message
250 * page in vcpu context.
252 static void cpu_post_msg(CPUState *cs, run_on_cpu_data data)
254 HvSintRoute *sint_route = data.host_ptr;
255 HvSintStagedMessage *staged_msg = sint_route->staged_msg;
256 SynICState *synic = sint_route->synic;
257 struct hyperv_message *dst_msg;
258 bool wait_for_sint_ack = false;
260 assert(staged_msg->state == HV_STAGED_MSG_BUSY);
262 if (!synic->enabled || !synic->msg_page_addr) {
263 staged_msg->status = -ENXIO;
264 goto posted;
267 dst_msg = &synic->msg_page->slot[sint_route->sint];
269 if (dst_msg->header.message_type != HV_MESSAGE_NONE) {
270 dst_msg->header.message_flags |= HV_MESSAGE_FLAG_PENDING;
271 staged_msg->status = -EAGAIN;
272 wait_for_sint_ack = true;
273 } else {
274 memcpy(dst_msg, &staged_msg->msg, sizeof(*dst_msg));
275 staged_msg->status = hyperv_sint_route_set_sint(sint_route);
278 memory_region_set_dirty(&synic->msg_page_mr, 0, sizeof(*synic->msg_page));
280 posted:
281 qatomic_set(&staged_msg->state, HV_STAGED_MSG_POSTED);
283 * Notify the msg originator of the progress made; if the slot was busy we
284 * set msg_pending flag in it so it will be the guest who will do EOM and
285 * trigger the notification from KVM via sint_ack_notifier
287 if (!wait_for_sint_ack) {
288 aio_bh_schedule_oneshot(qemu_get_aio_context(), sint_msg_bh,
289 sint_route);
294 * Post a Hyper-V message to the staging area, for delivery to guest in the
295 * vcpu thread.
297 int hyperv_post_msg(HvSintRoute *sint_route, struct hyperv_message *src_msg)
299 HvSintStagedMessage *staged_msg = sint_route->staged_msg;
301 assert(staged_msg);
303 /* grab the staging area */
304 if (qatomic_cmpxchg(&staged_msg->state, HV_STAGED_MSG_FREE,
305 HV_STAGED_MSG_BUSY) != HV_STAGED_MSG_FREE) {
306 return -EAGAIN;
309 memcpy(&staged_msg->msg, src_msg, sizeof(*src_msg));
311 /* hold a reference on sint_route until the callback is finished */
312 hyperv_sint_route_ref(sint_route);
314 /* schedule message posting attempt in vcpu thread */
315 async_run_on_cpu(sint_route->synic->cs, cpu_post_msg,
316 RUN_ON_CPU_HOST_PTR(sint_route));
317 return 0;
320 static void sint_ack_handler(EventNotifier *notifier)
322 HvSintRoute *sint_route = container_of(notifier, HvSintRoute,
323 sint_ack_notifier);
324 event_notifier_test_and_clear(notifier);
327 * the guest consumed the previous message so complete the current one with
328 * -EAGAIN and let the msg originator retry
330 aio_bh_schedule_oneshot(qemu_get_aio_context(), sint_msg_bh, sint_route);
334 * Set given event flag for a given sint on a given vcpu, and signal the sint.
336 int hyperv_set_event_flag(HvSintRoute *sint_route, unsigned eventno)
338 int ret;
339 SynICState *synic = sint_route->synic;
340 unsigned long *flags, set_mask;
341 unsigned set_idx;
343 if (eventno > HV_EVENT_FLAGS_COUNT) {
344 return -EINVAL;
346 if (!synic->enabled || !synic->event_page_addr) {
347 return -ENXIO;
350 set_idx = BIT_WORD(eventno);
351 set_mask = BIT_MASK(eventno);
352 flags = synic->event_page->slot[sint_route->sint].flags;
354 if ((qatomic_fetch_or(&flags[set_idx], set_mask) & set_mask) != set_mask) {
355 memory_region_set_dirty(&synic->event_page_mr, 0,
356 sizeof(*synic->event_page));
357 ret = hyperv_sint_route_set_sint(sint_route);
358 } else {
359 ret = 0;
361 return ret;
364 HvSintRoute *hyperv_sint_route_new(uint32_t vp_index, uint32_t sint,
365 HvSintMsgCb cb, void *cb_data)
367 HvSintRoute *sint_route;
368 EventNotifier *ack_notifier;
369 int r, gsi;
370 CPUState *cs;
371 SynICState *synic;
373 cs = hyperv_find_vcpu(vp_index);
374 if (!cs) {
375 return NULL;
378 synic = get_synic(cs);
379 if (!synic) {
380 return NULL;
383 sint_route = g_new0(HvSintRoute, 1);
384 r = event_notifier_init(&sint_route->sint_set_notifier, false);
385 if (r) {
386 goto err;
390 ack_notifier = cb ? &sint_route->sint_ack_notifier : NULL;
391 if (ack_notifier) {
392 sint_route->staged_msg = g_new0(HvSintStagedMessage, 1);
393 sint_route->staged_msg->cb = cb;
394 sint_route->staged_msg->cb_data = cb_data;
396 r = event_notifier_init(ack_notifier, false);
397 if (r) {
398 goto err_sint_set_notifier;
401 event_notifier_set_handler(ack_notifier, sint_ack_handler);
404 gsi = kvm_irqchip_add_hv_sint_route(kvm_state, vp_index, sint);
405 if (gsi < 0) {
406 goto err_gsi;
409 r = kvm_irqchip_add_irqfd_notifier_gsi(kvm_state,
410 &sint_route->sint_set_notifier,
411 ack_notifier, gsi);
412 if (r) {
413 goto err_irqfd;
415 sint_route->gsi = gsi;
416 sint_route->synic = synic;
417 sint_route->sint = sint;
418 sint_route->refcount = 1;
420 return sint_route;
422 err_irqfd:
423 kvm_irqchip_release_virq(kvm_state, gsi);
424 err_gsi:
425 if (ack_notifier) {
426 event_notifier_set_handler(ack_notifier, NULL);
427 event_notifier_cleanup(ack_notifier);
428 g_free(sint_route->staged_msg);
430 err_sint_set_notifier:
431 event_notifier_cleanup(&sint_route->sint_set_notifier);
432 err:
433 g_free(sint_route);
435 return NULL;
438 void hyperv_sint_route_ref(HvSintRoute *sint_route)
440 sint_route->refcount++;
443 void hyperv_sint_route_unref(HvSintRoute *sint_route)
445 if (!sint_route) {
446 return;
449 assert(sint_route->refcount > 0);
451 if (--sint_route->refcount) {
452 return;
455 kvm_irqchip_remove_irqfd_notifier_gsi(kvm_state,
456 &sint_route->sint_set_notifier,
457 sint_route->gsi);
458 kvm_irqchip_release_virq(kvm_state, sint_route->gsi);
459 if (sint_route->staged_msg) {
460 event_notifier_set_handler(&sint_route->sint_ack_notifier, NULL);
461 event_notifier_cleanup(&sint_route->sint_ack_notifier);
462 g_free(sint_route->staged_msg);
464 event_notifier_cleanup(&sint_route->sint_set_notifier);
465 g_free(sint_route);
468 int hyperv_sint_route_set_sint(HvSintRoute *sint_route)
470 return event_notifier_set(&sint_route->sint_set_notifier);
473 typedef struct MsgHandler {
474 struct rcu_head rcu;
475 QLIST_ENTRY(MsgHandler) link;
476 uint32_t conn_id;
477 HvMsgHandler handler;
478 void *data;
479 } MsgHandler;
481 typedef struct EventFlagHandler {
482 struct rcu_head rcu;
483 QLIST_ENTRY(EventFlagHandler) link;
484 uint32_t conn_id;
485 EventNotifier *notifier;
486 } EventFlagHandler;
488 static QLIST_HEAD(, MsgHandler) msg_handlers;
489 static QLIST_HEAD(, EventFlagHandler) event_flag_handlers;
490 static QemuMutex handlers_mutex;
492 static void __attribute__((constructor)) hv_init(void)
494 QLIST_INIT(&msg_handlers);
495 QLIST_INIT(&event_flag_handlers);
496 qemu_mutex_init(&handlers_mutex);
499 int hyperv_set_msg_handler(uint32_t conn_id, HvMsgHandler handler, void *data)
501 int ret;
502 MsgHandler *mh;
504 QEMU_LOCK_GUARD(&handlers_mutex);
505 QLIST_FOREACH(mh, &msg_handlers, link) {
506 if (mh->conn_id == conn_id) {
507 if (handler) {
508 ret = -EEXIST;
509 } else {
510 QLIST_REMOVE_RCU(mh, link);
511 g_free_rcu(mh, rcu);
512 ret = 0;
514 return ret;
518 if (handler) {
519 mh = g_new(MsgHandler, 1);
520 mh->conn_id = conn_id;
521 mh->handler = handler;
522 mh->data = data;
523 QLIST_INSERT_HEAD_RCU(&msg_handlers, mh, link);
524 ret = 0;
525 } else {
526 ret = -ENOENT;
529 return ret;
532 uint16_t hyperv_hcall_post_message(uint64_t param, bool fast)
534 uint16_t ret;
535 hwaddr len;
536 struct hyperv_post_message_input *msg;
537 MsgHandler *mh;
539 if (fast) {
540 return HV_STATUS_INVALID_HYPERCALL_CODE;
542 if (param & (__alignof__(*msg) - 1)) {
543 return HV_STATUS_INVALID_ALIGNMENT;
546 len = sizeof(*msg);
547 msg = cpu_physical_memory_map(param, &len, 0);
548 if (len < sizeof(*msg)) {
549 ret = HV_STATUS_INSUFFICIENT_MEMORY;
550 goto unmap;
552 if (msg->payload_size > sizeof(msg->payload)) {
553 ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
554 goto unmap;
557 ret = HV_STATUS_INVALID_CONNECTION_ID;
558 WITH_RCU_READ_LOCK_GUARD() {
559 QLIST_FOREACH_RCU(mh, &msg_handlers, link) {
560 if (mh->conn_id == (msg->connection_id & HV_CONNECTION_ID_MASK)) {
561 ret = mh->handler(msg, mh->data);
562 break;
567 unmap:
568 cpu_physical_memory_unmap(msg, len, 0, 0);
569 return ret;
572 static int set_event_flag_handler(uint32_t conn_id, EventNotifier *notifier)
574 int ret;
575 EventFlagHandler *handler;
577 QEMU_LOCK_GUARD(&handlers_mutex);
578 QLIST_FOREACH(handler, &event_flag_handlers, link) {
579 if (handler->conn_id == conn_id) {
580 if (notifier) {
581 ret = -EEXIST;
582 } else {
583 QLIST_REMOVE_RCU(handler, link);
584 g_free_rcu(handler, rcu);
585 ret = 0;
587 return ret;
591 if (notifier) {
592 handler = g_new(EventFlagHandler, 1);
593 handler->conn_id = conn_id;
594 handler->notifier = notifier;
595 QLIST_INSERT_HEAD_RCU(&event_flag_handlers, handler, link);
596 ret = 0;
597 } else {
598 ret = -ENOENT;
601 return ret;
604 static bool process_event_flags_userspace;
606 int hyperv_set_event_flag_handler(uint32_t conn_id, EventNotifier *notifier)
608 if (!process_event_flags_userspace &&
609 !kvm_check_extension(kvm_state, KVM_CAP_HYPERV_EVENTFD)) {
610 process_event_flags_userspace = true;
612 warn_report("Hyper-V event signaling is not supported by this kernel; "
613 "using slower userspace hypercall processing");
616 if (!process_event_flags_userspace) {
617 struct kvm_hyperv_eventfd hvevfd = {
618 .conn_id = conn_id,
619 .fd = notifier ? event_notifier_get_fd(notifier) : -1,
620 .flags = notifier ? 0 : KVM_HYPERV_EVENTFD_DEASSIGN,
623 return kvm_vm_ioctl(kvm_state, KVM_HYPERV_EVENTFD, &hvevfd);
625 return set_event_flag_handler(conn_id, notifier);
628 uint16_t hyperv_hcall_signal_event(uint64_t param, bool fast)
630 EventFlagHandler *handler;
632 if (unlikely(!fast)) {
633 hwaddr addr = param;
635 if (addr & (__alignof__(addr) - 1)) {
636 return HV_STATUS_INVALID_ALIGNMENT;
639 param = ldq_phys(&address_space_memory, addr);
643 * Per spec, bits 32-47 contain the extra "flag number". However, we
644 * have no use for it, and in all known usecases it is zero, so just
645 * report lookup failure if it isn't.
647 if (param & 0xffff00000000ULL) {
648 return HV_STATUS_INVALID_PORT_ID;
650 /* remaining bits are reserved-zero */
651 if (param & ~HV_CONNECTION_ID_MASK) {
652 return HV_STATUS_INVALID_HYPERCALL_INPUT;
655 RCU_READ_LOCK_GUARD();
656 QLIST_FOREACH_RCU(handler, &event_flag_handlers, link) {
657 if (handler->conn_id == param) {
658 event_notifier_set(handler->notifier);
659 return 0;
662 return HV_STATUS_INVALID_CONNECTION_ID;