1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2009, Microsoft Corporation.
4 *
5 * Authors:
6 * Haiyang Zhang <haiyangz@microsoft.com>
7 * Hank Janssen <hjanssen@microsoft.com>
8 */
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11 #include <linux/io.h>
12 #include <linux/kernel.h>
13 #include <linux/mm.h>
14 #include <linux/slab.h>
15 #include <linux/vmalloc.h>
16 #include <linux/hyperv.h>
17 #include <linux/random.h>
18 #include <linux/clockchips.h>
19 #include <linux/delay.h>
20 #include <linux/interrupt.h>
21 #include <linux/export.h>
22 #include <clocksource/hyperv_timer.h>
23 #include <asm/mshyperv.h>
24 #include <linux/set_memory.h>
25 #include "hyperv_vmbus.h"
26
27 /* The one and only */
28 struct hv_context hv_context;
29 EXPORT_SYMBOL_FOR_MODULES(hv_context, "mshv_vtl");
30
31 /*
32 * hv_init - Main initialization routine.
33 *
34 * This routine must be called before any other routines in here are called
35 */
hv_init(void)36 int hv_init(void)
37 {
38 hv_context.cpu_context = alloc_percpu(struct hv_per_cpu_context);
39 if (!hv_context.cpu_context)
40 return -ENOMEM;
41 return 0;
42 }
43
44 /*
45 * hv_post_message - Post a message using the hypervisor message IPC.
46 *
47 * This involves a hypercall.
48 */
hv_post_message(union hv_connection_id connection_id,enum hv_message_type message_type,void * payload,size_t payload_size)49 int hv_post_message(union hv_connection_id connection_id,
50 enum hv_message_type message_type,
51 void *payload, size_t payload_size)
52 {
53 struct hv_input_post_message *aligned_msg;
54 unsigned long flags;
55 u64 status;
56
57 if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT)
58 return -EMSGSIZE;
59
60 local_irq_save(flags);
61
62 /*
63 * A TDX VM with the paravisor must use the decrypted post_msg_page: see
64 * the comment in struct hv_per_cpu_context. A SNP VM with the paravisor
65 * can use the encrypted hyperv_pcpu_input_arg because it copies the
66 * input into the GHCB page, which has been decrypted by the paravisor.
67 */
68 if (hv_isolation_type_tdx() && ms_hyperv.paravisor_present)
69 aligned_msg = this_cpu_ptr(hv_context.cpu_context)->post_msg_page;
70 else
71 aligned_msg = *this_cpu_ptr(hyperv_pcpu_input_arg);
72
73 aligned_msg->connectionid = connection_id;
74 aligned_msg->reserved = 0;
75 aligned_msg->message_type = message_type;
76 aligned_msg->payload_size = payload_size;
77 memcpy((void *)aligned_msg->payload, payload, payload_size);
78
79 if (ms_hyperv.paravisor_present && !vmbus_is_confidential()) {
80 /*
81 * If the VMBus isn't confidential, use the CoCo-specific
82 * mechanism to communicate with the hypervisor.
83 */
84 if (hv_isolation_type_tdx())
85 status = hv_tdx_hypercall(HVCALL_POST_MESSAGE,
86 virt_to_phys(aligned_msg), 0);
87 else if (hv_isolation_type_snp())
88 status = hv_ghcb_hypercall(HVCALL_POST_MESSAGE,
89 aligned_msg, NULL,
90 sizeof(*aligned_msg));
91 else
92 status = HV_STATUS_INVALID_PARAMETER;
93 } else {
94 u64 control = HVCALL_POST_MESSAGE;
95
96 control |= hv_nested ? HV_HYPERCALL_NESTED : 0;
97 /*
98 * If there is no paravisor, this will go to the hypervisor.
99 * In the Confidential VMBus case, there is the paravisor
100 * to which this will trap.
101 */
102 status = hv_do_hypercall(control, aligned_msg, NULL);
103 }
104
105 local_irq_restore(flags);
106
107 return hv_result(status);
108 }
109 EXPORT_SYMBOL_FOR_MODULES(hv_post_message, "mshv_vtl");
110
hv_alloc_page(void ** page,bool decrypt,const char * note)111 static int hv_alloc_page(void **page, bool decrypt, const char *note)
112 {
113 int ret = 0;
114
115 /*
116 * After the page changes its encryption status, its contents might
117 * appear scrambled on some hardware. Thus `get_zeroed_page` would
118 * zero the page out in vain, so do that explicitly exactly once.
119 *
120 * By default, the page is allocated encrypted in a CoCo VM.
121 */
122 *page = (void *)__get_free_page(GFP_KERNEL);
123 if (!*page)
124 return -ENOMEM;
125
126 if (decrypt)
127 ret = set_memory_decrypted((unsigned long)*page, 1);
128 if (ret)
129 goto failed;
130
131 memset(*page, 0, PAGE_SIZE);
132 return 0;
133
134 failed:
135 /*
136 * Report the failure but don't put the page back on the free list as
137 * its encryption status is unknown.
138 */
139 pr_err("allocation failed for %s page, error %d, decrypted %d\n",
140 note, ret, decrypt);
141 *page = NULL;
142 return ret;
143 }
144
hv_free_page(void ** page,bool encrypt,const char * note)145 static int hv_free_page(void **page, bool encrypt, const char *note)
146 {
147 int ret = 0;
148
149 if (!*page)
150 return 0;
151
152 if (encrypt)
153 ret = set_memory_encrypted((unsigned long)*page, 1);
154
155 /*
156 * In the case of the failure, the page is leaked. Something is wrong,
157 * prefer to lose the page with the unknown encryption status and stay afloat.
158 */
159 if (ret)
160 pr_err("deallocation failed for %s page, error %d, encrypt %d\n",
161 note, ret, encrypt);
162 else
163 free_page((unsigned long)*page);
164
165 *page = NULL;
166
167 return ret;
168 }
169
hv_synic_alloc(void)170 int hv_synic_alloc(void)
171 {
172 int cpu, ret = -ENOMEM;
173 struct hv_per_cpu_context *hv_cpu;
174 const bool decrypt = !vmbus_is_confidential();
175
176 /*
177 * First, zero all per-cpu memory areas so hv_synic_free() can
178 * detect what memory has been allocated and cleanup properly
179 * after any failures.
180 */
181 for_each_present_cpu(cpu) {
182 hv_cpu = per_cpu_ptr(hv_context.cpu_context, cpu);
183 memset(hv_cpu, 0, sizeof(*hv_cpu));
184 }
185
186 hv_context.hv_numa_map = kcalloc(nr_node_ids, sizeof(struct cpumask),
187 GFP_KERNEL);
188 if (!hv_context.hv_numa_map) {
189 pr_err("Unable to allocate NUMA map\n");
190 goto err;
191 }
192
193 for_each_present_cpu(cpu) {
194 hv_cpu = per_cpu_ptr(hv_context.cpu_context, cpu);
195
196 tasklet_init(&hv_cpu->msg_dpc,
197 vmbus_on_msg_dpc, (unsigned long)hv_cpu);
198
199 if (ms_hyperv.paravisor_present && hv_isolation_type_tdx()) {
200 ret = hv_alloc_page(&hv_cpu->post_msg_page,
201 decrypt, "post msg");
202 if (ret)
203 goto err;
204 }
205
206 /*
207 * If these SynIC pages are not allocated, SIEF and SIM pages
208 * are configured using what the root partition or the paravisor
209 * provides upon reading the SIEFP and SIMP registers.
210 */
211 if (!ms_hyperv.paravisor_present && !hv_root_partition()) {
212 ret = hv_alloc_page(&hv_cpu->hyp_synic_message_page,
213 decrypt, "hypervisor SynIC msg");
214 if (ret)
215 goto err;
216 ret = hv_alloc_page(&hv_cpu->hyp_synic_event_page,
217 decrypt, "hypervisor SynIC event");
218 if (ret)
219 goto err;
220 }
221
222 if (vmbus_is_confidential()) {
223 ret = hv_alloc_page(&hv_cpu->para_synic_message_page,
224 false, "paravisor SynIC msg");
225 if (ret)
226 goto err;
227 ret = hv_alloc_page(&hv_cpu->para_synic_event_page,
228 false, "paravisor SynIC event");
229 if (ret)
230 goto err;
231 }
232 }
233
234 return 0;
235
236 err:
237 /*
238 * Any memory allocations that succeeded will be freed when
239 * the caller cleans up by calling hv_synic_free()
240 */
241 return ret;
242 }
243
hv_synic_free(void)244 void hv_synic_free(void)
245 {
246 int cpu;
247 const bool encrypt = !vmbus_is_confidential();
248
249 for_each_present_cpu(cpu) {
250 struct hv_per_cpu_context *hv_cpu =
251 per_cpu_ptr(hv_context.cpu_context, cpu);
252
253 if (ms_hyperv.paravisor_present && hv_isolation_type_tdx())
254 hv_free_page(&hv_cpu->post_msg_page,
255 encrypt, "post msg");
256 if (!ms_hyperv.paravisor_present && !hv_root_partition()) {
257 hv_free_page(&hv_cpu->hyp_synic_event_page,
258 encrypt, "hypervisor SynIC event");
259 hv_free_page(&hv_cpu->hyp_synic_message_page,
260 encrypt, "hypervisor SynIC msg");
261 }
262 if (vmbus_is_confidential()) {
263 hv_free_page(&hv_cpu->para_synic_event_page,
264 false, "paravisor SynIC event");
265 hv_free_page(&hv_cpu->para_synic_message_page,
266 false, "paravisor SynIC msg");
267 }
268 }
269
270 kfree(hv_context.hv_numa_map);
271 }
272
273 /*
274 * hv_hyp_synic_enable_regs - Initialize the Synthetic Interrupt Controller
275 * with the hypervisor.
276 */
hv_hyp_synic_enable_regs(unsigned int cpu)277 void hv_hyp_synic_enable_regs(unsigned int cpu)
278 {
279 struct hv_per_cpu_context *hv_cpu =
280 per_cpu_ptr(hv_context.cpu_context, cpu);
281 union hv_synic_simp simp;
282 union hv_synic_siefp siefp;
283 union hv_synic_sint shared_sint;
284
285 /* Setup the Synic's message page with the hypervisor. */
286 simp.as_uint64 = hv_get_msr(HV_MSR_SIMP);
287 simp.simp_enabled = 1;
288
289 if (ms_hyperv.paravisor_present || hv_root_partition()) {
290 /* Mask out vTOM bit. ioremap_cache() maps decrypted */
291 u64 base = (simp.base_simp_gpa << HV_HYP_PAGE_SHIFT) &
292 ~ms_hyperv.shared_gpa_boundary;
293 hv_cpu->hyp_synic_message_page =
294 (void *)ioremap_cache(base, HV_HYP_PAGE_SIZE);
295 if (!hv_cpu->hyp_synic_message_page)
296 pr_err("Fail to map synic message page.\n");
297 } else {
298 simp.base_simp_gpa = virt_to_phys(hv_cpu->hyp_synic_message_page)
299 >> HV_HYP_PAGE_SHIFT;
300 }
301
302 hv_set_msr(HV_MSR_SIMP, simp.as_uint64);
303
304 /* Setup the Synic's event page with the hypervisor. */
305 siefp.as_uint64 = hv_get_msr(HV_MSR_SIEFP);
306 siefp.siefp_enabled = 1;
307
308 if (ms_hyperv.paravisor_present || hv_root_partition()) {
309 /* Mask out vTOM bit. ioremap_cache() maps decrypted */
310 u64 base = (siefp.base_siefp_gpa << HV_HYP_PAGE_SHIFT) &
311 ~ms_hyperv.shared_gpa_boundary;
312 hv_cpu->hyp_synic_event_page =
313 (void *)ioremap_cache(base, HV_HYP_PAGE_SIZE);
314 if (!hv_cpu->hyp_synic_event_page)
315 pr_err("Fail to map synic event page.\n");
316 } else {
317 siefp.base_siefp_gpa = virt_to_phys(hv_cpu->hyp_synic_event_page)
318 >> HV_HYP_PAGE_SHIFT;
319 }
320
321 hv_set_msr(HV_MSR_SIEFP, siefp.as_uint64);
322 hv_enable_coco_interrupt(cpu, vmbus_interrupt, true);
323
324 /* Setup the shared SINT. */
325 if (vmbus_irq != -1)
326 enable_percpu_irq(vmbus_irq, 0);
327 shared_sint.as_uint64 = hv_get_msr(HV_MSR_SINT0 + VMBUS_MESSAGE_SINT);
328
329 shared_sint.vector = vmbus_interrupt;
330 shared_sint.masked = false;
331 shared_sint.auto_eoi = hv_recommend_using_aeoi();
332 hv_set_msr(HV_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
333 }
334
hv_hyp_synic_enable_interrupts(void)335 static void hv_hyp_synic_enable_interrupts(void)
336 {
337 union hv_synic_scontrol sctrl;
338
339 /* Enable the global synic bit */
340 sctrl.as_uint64 = hv_get_msr(HV_MSR_SCONTROL);
341 sctrl.enable = 1;
342
343 hv_set_msr(HV_MSR_SCONTROL, sctrl.as_uint64);
344 }
345
hv_para_synic_enable_regs(unsigned int cpu)346 static void hv_para_synic_enable_regs(unsigned int cpu)
347 {
348 union hv_synic_simp simp;
349 union hv_synic_siefp siefp;
350 struct hv_per_cpu_context *hv_cpu
351 = per_cpu_ptr(hv_context.cpu_context, cpu);
352
353 /* Setup the Synic's message page with the paravisor. */
354 simp.as_uint64 = hv_para_get_synic_register(HV_MSR_SIMP);
355 simp.simp_enabled = 1;
356 simp.base_simp_gpa = virt_to_phys(hv_cpu->para_synic_message_page)
357 >> HV_HYP_PAGE_SHIFT;
358 hv_para_set_synic_register(HV_MSR_SIMP, simp.as_uint64);
359
360 /* Setup the Synic's event page with the paravisor. */
361 siefp.as_uint64 = hv_para_get_synic_register(HV_MSR_SIEFP);
362 siefp.siefp_enabled = 1;
363 siefp.base_siefp_gpa = virt_to_phys(hv_cpu->para_synic_event_page)
364 >> HV_HYP_PAGE_SHIFT;
365 hv_para_set_synic_register(HV_MSR_SIEFP, siefp.as_uint64);
366 }
367
hv_para_synic_enable_interrupts(void)368 static void hv_para_synic_enable_interrupts(void)
369 {
370 union hv_synic_scontrol sctrl;
371
372 /* Enable the global synic bit */
373 sctrl.as_uint64 = hv_para_get_synic_register(HV_MSR_SCONTROL);
374 sctrl.enable = 1;
375 hv_para_set_synic_register(HV_MSR_SCONTROL, sctrl.as_uint64);
376 }
377
hv_synic_init(unsigned int cpu)378 int hv_synic_init(unsigned int cpu)
379 {
380 if (vmbus_is_confidential())
381 hv_para_synic_enable_regs(cpu);
382
383 /*
384 * The SINT is set in hv_hyp_synic_enable_regs() by calling
385 * hv_set_msr(). hv_set_msr() in turn has special case code for the
386 * SINT MSRs that write to the hypervisor version of the MSR *and*
387 * the paravisor version of the MSR (but *without* the proxy bit when
388 * VMBus is confidential).
389 *
390 * Then enable interrupts via the paravisor if VMBus is confidential,
391 * and otherwise via the hypervisor.
392 */
393
394 hv_hyp_synic_enable_regs(cpu);
395 if (vmbus_is_confidential())
396 hv_para_synic_enable_interrupts();
397 else
398 hv_hyp_synic_enable_interrupts();
399
400 hv_stimer_legacy_init(cpu, VMBUS_MESSAGE_SINT);
401
402 return 0;
403 }
404
hv_hyp_synic_disable_regs(unsigned int cpu)405 void hv_hyp_synic_disable_regs(unsigned int cpu)
406 {
407 struct hv_per_cpu_context *hv_cpu =
408 per_cpu_ptr(hv_context.cpu_context, cpu);
409 union hv_synic_sint shared_sint;
410 union hv_synic_simp simp;
411 union hv_synic_siefp siefp;
412
413 shared_sint.as_uint64 = hv_get_msr(HV_MSR_SINT0 + VMBUS_MESSAGE_SINT);
414
415 shared_sint.masked = 1;
416
417 /* Need to correctly cleanup in the case of SMP!!! */
418 /* Disable the interrupt */
419 hv_set_msr(HV_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
420 hv_enable_coco_interrupt(cpu, vmbus_interrupt, false);
421
422 simp.as_uint64 = hv_get_msr(HV_MSR_SIMP);
423 /*
424 * In Isolation VM, simp and sief pages are allocated by
425 * paravisor. These pages also will be used by kdump
426 * kernel. So just reset enable bit here and keep page
427 * addresses.
428 */
429 simp.simp_enabled = 0;
430 if (ms_hyperv.paravisor_present || hv_root_partition()) {
431 if (hv_cpu->hyp_synic_message_page) {
432 iounmap(hv_cpu->hyp_synic_message_page);
433 hv_cpu->hyp_synic_message_page = NULL;
434 }
435 } else {
436 simp.base_simp_gpa = 0;
437 }
438
439 hv_set_msr(HV_MSR_SIMP, simp.as_uint64);
440
441 siefp.as_uint64 = hv_get_msr(HV_MSR_SIEFP);
442 siefp.siefp_enabled = 0;
443
444 if (ms_hyperv.paravisor_present || hv_root_partition()) {
445 if (hv_cpu->hyp_synic_event_page) {
446 iounmap(hv_cpu->hyp_synic_event_page);
447 hv_cpu->hyp_synic_event_page = NULL;
448 }
449 } else {
450 siefp.base_siefp_gpa = 0;
451 }
452
453 hv_set_msr(HV_MSR_SIEFP, siefp.as_uint64);
454 }
455
hv_hyp_synic_disable_interrupts(void)456 static void hv_hyp_synic_disable_interrupts(void)
457 {
458 union hv_synic_scontrol sctrl;
459
460 /* Disable the global synic bit */
461 sctrl.as_uint64 = hv_get_msr(HV_MSR_SCONTROL);
462 sctrl.enable = 0;
463 hv_set_msr(HV_MSR_SCONTROL, sctrl.as_uint64);
464 }
465
hv_para_synic_disable_regs(unsigned int cpu)466 static void hv_para_synic_disable_regs(unsigned int cpu)
467 {
468 union hv_synic_simp simp;
469 union hv_synic_siefp siefp;
470
471 /* Disable SynIC's message page in the paravisor. */
472 simp.as_uint64 = hv_para_get_synic_register(HV_MSR_SIMP);
473 simp.simp_enabled = 0;
474 hv_para_set_synic_register(HV_MSR_SIMP, simp.as_uint64);
475
476 /* Disable SynIC's event page in the paravisor. */
477 siefp.as_uint64 = hv_para_get_synic_register(HV_MSR_SIEFP);
478 siefp.siefp_enabled = 0;
479 hv_para_set_synic_register(HV_MSR_SIEFP, siefp.as_uint64);
480 }
481
hv_para_synic_disable_interrupts(void)482 static void hv_para_synic_disable_interrupts(void)
483 {
484 union hv_synic_scontrol sctrl;
485
486 /* Disable the global synic bit */
487 sctrl.as_uint64 = hv_para_get_synic_register(HV_MSR_SCONTROL);
488 sctrl.enable = 0;
489 hv_para_set_synic_register(HV_MSR_SCONTROL, sctrl.as_uint64);
490 }
491
492 #define HV_MAX_TRIES 3
493 /*
494 * Scan the event flags page of 'this' CPU looking for any bit that is set. If we find one
495 * bit set, then wait for a few milliseconds. Repeat these steps for a maximum of 3 times.
496 * Return 'true', if there is still any set bit after this operation; 'false', otherwise.
497 *
498 * If a bit is set, that means there is a pending channel interrupt. The expectation is
499 * that the normal interrupt handling mechanism will find and process the channel interrupt
500 * "very soon", and in the process clear the bit.
501 */
__hv_synic_event_pending(union hv_synic_event_flags * event,int sint)502 static bool __hv_synic_event_pending(union hv_synic_event_flags *event, int sint)
503 {
504 unsigned long *recv_int_page;
505 bool pending;
506 u32 relid;
507 int tries = 0;
508
509 if (!event)
510 return false;
511
512 event += sint;
513 recv_int_page = event->flags; /* assumes VMBus version >= VERSION_WIN8 */
514 retry:
515 pending = false;
516 for_each_set_bit(relid, recv_int_page, HV_EVENT_FLAGS_COUNT) {
517 /* Special case - VMBus channel protocol messages */
518 if (relid == 0)
519 continue;
520 pending = true;
521 break;
522 }
523 if (pending && tries++ < HV_MAX_TRIES) {
524 usleep_range(10000, 20000);
525 goto retry;
526 }
527 return pending;
528 }
529
hv_synic_event_pending(void)530 static bool hv_synic_event_pending(void)
531 {
532 struct hv_per_cpu_context *hv_cpu = this_cpu_ptr(hv_context.cpu_context);
533 union hv_synic_event_flags *hyp_synic_event_page = hv_cpu->hyp_synic_event_page;
534 union hv_synic_event_flags *para_synic_event_page = hv_cpu->para_synic_event_page;
535
536 return
537 __hv_synic_event_pending(hyp_synic_event_page, VMBUS_MESSAGE_SINT) ||
538 __hv_synic_event_pending(para_synic_event_page, VMBUS_MESSAGE_SINT);
539 }
540
hv_pick_new_cpu(struct vmbus_channel * channel)541 static int hv_pick_new_cpu(struct vmbus_channel *channel)
542 {
543 int ret = -EBUSY;
544 int start;
545 int cpu;
546
547 lockdep_assert_cpus_held();
548 lockdep_assert_held(&vmbus_connection.channel_mutex);
549
550 /*
551 * We can't assume that the relevant interrupts will be sent before
552 * the cpu is offlined on older versions of hyperv.
553 */
554 if (vmbus_proto_version < VERSION_WIN10_V5_3)
555 return -EBUSY;
556
557 start = get_random_u32_below(nr_cpu_ids);
558
559 for_each_cpu_wrap(cpu, cpu_online_mask, start) {
560 if (channel->target_cpu == cpu ||
561 channel->target_cpu == VMBUS_CONNECT_CPU)
562 continue;
563
564 ret = vmbus_channel_set_cpu(channel, cpu);
565 if (!ret)
566 break;
567 }
568
569 if (ret)
570 ret = vmbus_channel_set_cpu(channel, VMBUS_CONNECT_CPU);
571
572 return ret;
573 }
574
575 /*
576 * hv_synic_cleanup - Cleanup routine for hv_synic_init().
577 */
hv_synic_cleanup(unsigned int cpu)578 int hv_synic_cleanup(unsigned int cpu)
579 {
580 struct vmbus_channel *channel, *sc;
581 int ret = 0;
582
583 if (vmbus_connection.conn_state != CONNECTED)
584 goto always_cleanup;
585
586 /*
587 * Hyper-V does not provide a way to change the connect CPU once
588 * it is set; we must prevent the connect CPU from going offline
589 * while the VM is running normally. But in the panic or kexec()
590 * path where the vmbus is already disconnected, the CPU must be
591 * allowed to shut down.
592 */
593 if (cpu == VMBUS_CONNECT_CPU)
594 return -EBUSY;
595
596 /*
597 * Search for channels which are bound to the CPU we're about to
598 * cleanup.
599 */
600 mutex_lock(&vmbus_connection.channel_mutex);
601 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
602 if (channel->target_cpu == cpu) {
603 ret = hv_pick_new_cpu(channel);
604 if (ret) {
605 mutex_unlock(&vmbus_connection.channel_mutex);
606 return ret;
607 }
608 }
609 list_for_each_entry(sc, &channel->sc_list, sc_list) {
610 if (sc->target_cpu == cpu) {
611 ret = hv_pick_new_cpu(sc);
612 if (ret) {
613 mutex_unlock(&vmbus_connection.channel_mutex);
614 return ret;
615 }
616 }
617 }
618 }
619 mutex_unlock(&vmbus_connection.channel_mutex);
620
621 /*
622 * Scan the event flags page looking for bits that are set and waiting
623 * with a timeout for vmbus_chan_sched() to process such bits. If bits
624 * are still set after this operation and VMBus is connected, fail the
625 * CPU offlining operation.
626 */
627 if (vmbus_proto_version >= VERSION_WIN10_V4_1 && hv_synic_event_pending())
628 return -EBUSY;
629
630 always_cleanup:
631 hv_stimer_legacy_cleanup(cpu);
632
633 /*
634 * First, disable the event and message pages
635 * used for communicating with the host, and then
636 * disable the host interrupts if VMBus is not
637 * confidential.
638 */
639 hv_hyp_synic_disable_regs(cpu);
640 if (!vmbus_is_confidential())
641 hv_hyp_synic_disable_interrupts();
642
643 /*
644 * Perform the same steps for the Confidential VMBus.
645 * The sequencing provides the guarantee that no data
646 * may be posted for processing before disabling interrupts.
647 */
648 if (vmbus_is_confidential()) {
649 hv_para_synic_disable_regs(cpu);
650 hv_para_synic_disable_interrupts();
651 }
652 if (vmbus_irq != -1)
653 disable_percpu_irq(vmbus_irq);
654
655 return ret;
656 }
657