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 = kzalloc_objs(struct cpumask, nr_node_ids);
187 if (!hv_context.hv_numa_map) {
188 pr_err("Unable to allocate NUMA map\n");
189 goto err;
190 }
191
192 for_each_present_cpu(cpu) {
193 hv_cpu = per_cpu_ptr(hv_context.cpu_context, cpu);
194
195 tasklet_init(&hv_cpu->msg_dpc,
196 vmbus_on_msg_dpc, (unsigned long)hv_cpu);
197
198 if (ms_hyperv.paravisor_present && hv_isolation_type_tdx()) {
199 ret = hv_alloc_page(&hv_cpu->post_msg_page,
200 decrypt, "post msg");
201 if (ret)
202 goto err;
203 }
204
205 /*
206 * If these SynIC pages are not allocated, SIEF and SIM pages
207 * are configured using what the root partition or the paravisor
208 * provides upon reading the SIEFP and SIMP registers.
209 */
210 if (!ms_hyperv.paravisor_present && !hv_root_partition()) {
211 ret = hv_alloc_page(&hv_cpu->hyp_synic_message_page,
212 decrypt, "hypervisor SynIC msg");
213 if (ret)
214 goto err;
215 ret = hv_alloc_page(&hv_cpu->hyp_synic_event_page,
216 decrypt, "hypervisor SynIC event");
217 if (ret)
218 goto err;
219 }
220
221 if (vmbus_is_confidential()) {
222 ret = hv_alloc_page(&hv_cpu->para_synic_message_page,
223 false, "paravisor SynIC msg");
224 if (ret)
225 goto err;
226 ret = hv_alloc_page(&hv_cpu->para_synic_event_page,
227 false, "paravisor SynIC event");
228 if (ret)
229 goto err;
230 }
231 }
232
233 return 0;
234
235 err:
236 /*
237 * Any memory allocations that succeeded will be freed when
238 * the caller cleans up by calling hv_synic_free()
239 */
240 return ret;
241 }
242
hv_synic_free(void)243 void hv_synic_free(void)
244 {
245 int cpu;
246 const bool encrypt = !vmbus_is_confidential();
247
248 for_each_present_cpu(cpu) {
249 struct hv_per_cpu_context *hv_cpu =
250 per_cpu_ptr(hv_context.cpu_context, cpu);
251
252 if (ms_hyperv.paravisor_present && hv_isolation_type_tdx())
253 hv_free_page(&hv_cpu->post_msg_page,
254 encrypt, "post msg");
255 if (!ms_hyperv.paravisor_present && !hv_root_partition()) {
256 hv_free_page(&hv_cpu->hyp_synic_event_page,
257 encrypt, "hypervisor SynIC event");
258 hv_free_page(&hv_cpu->hyp_synic_message_page,
259 encrypt, "hypervisor SynIC msg");
260 }
261 if (vmbus_is_confidential()) {
262 hv_free_page(&hv_cpu->para_synic_event_page,
263 false, "paravisor SynIC event");
264 hv_free_page(&hv_cpu->para_synic_message_page,
265 false, "paravisor SynIC msg");
266 }
267 }
268
269 kfree(hv_context.hv_numa_map);
270 }
271
272 /*
273 * hv_hyp_synic_enable_regs - Initialize the Synthetic Interrupt Controller
274 * with the hypervisor.
275 */
hv_hyp_synic_enable_regs(unsigned int cpu)276 void hv_hyp_synic_enable_regs(unsigned int cpu)
277 {
278 struct hv_per_cpu_context *hv_cpu =
279 per_cpu_ptr(hv_context.cpu_context, cpu);
280 union hv_synic_simp simp;
281 union hv_synic_siefp siefp;
282 union hv_synic_sint shared_sint;
283
284 /* Setup the Synic's message page with the hypervisor. */
285 simp.as_uint64 = hv_get_msr(HV_MSR_SIMP);
286 simp.simp_enabled = 1;
287
288 if (ms_hyperv.paravisor_present || hv_root_partition()) {
289 /* Mask out vTOM bit and map as decrypted */
290 u64 base = (simp.base_simp_gpa << HV_HYP_PAGE_SHIFT) &
291 ~ms_hyperv.shared_gpa_boundary;
292 hv_cpu->hyp_synic_message_page =
293 memremap(base, HV_HYP_PAGE_SIZE, MEMREMAP_WB | MEMREMAP_DEC);
294 if (!hv_cpu->hyp_synic_message_page)
295 pr_err("Fail to map synic message page.\n");
296 } else {
297 simp.base_simp_gpa = virt_to_phys(hv_cpu->hyp_synic_message_page)
298 >> HV_HYP_PAGE_SHIFT;
299 }
300
301 hv_set_msr(HV_MSR_SIMP, simp.as_uint64);
302
303 /* Setup the Synic's event page with the hypervisor. */
304 siefp.as_uint64 = hv_get_msr(HV_MSR_SIEFP);
305 siefp.siefp_enabled = 1;
306
307 if (ms_hyperv.paravisor_present || hv_root_partition()) {
308 /* Mask out vTOM bit and map as decrypted */
309 u64 base = (siefp.base_siefp_gpa << HV_HYP_PAGE_SHIFT) &
310 ~ms_hyperv.shared_gpa_boundary;
311 hv_cpu->hyp_synic_event_page =
312 memremap(base, HV_HYP_PAGE_SIZE, MEMREMAP_WB | MEMREMAP_DEC);
313 if (!hv_cpu->hyp_synic_event_page)
314 pr_err("Fail to map synic event page.\n");
315 } else {
316 siefp.base_siefp_gpa = virt_to_phys(hv_cpu->hyp_synic_event_page)
317 >> HV_HYP_PAGE_SHIFT;
318 }
319
320 hv_set_msr(HV_MSR_SIEFP, siefp.as_uint64);
321 hv_enable_coco_interrupt(cpu, vmbus_interrupt, true);
322
323 /* Setup the shared SINT. */
324 if (vmbus_irq != -1)
325 enable_percpu_irq(vmbus_irq, 0);
326 shared_sint.as_uint64 = hv_get_msr(HV_MSR_SINT0 + VMBUS_MESSAGE_SINT);
327
328 shared_sint.vector = vmbus_interrupt;
329 shared_sint.masked = false;
330 shared_sint.auto_eoi = hv_recommend_using_aeoi();
331 hv_set_msr(HV_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
332 }
333
hv_hyp_synic_enable_interrupts(void)334 static void hv_hyp_synic_enable_interrupts(void)
335 {
336 union hv_synic_scontrol sctrl;
337
338 /* Enable the global synic bit */
339 sctrl.as_uint64 = hv_get_msr(HV_MSR_SCONTROL);
340 sctrl.enable = 1;
341
342 hv_set_msr(HV_MSR_SCONTROL, sctrl.as_uint64);
343 }
344
hv_para_synic_enable_regs(unsigned int cpu)345 static void hv_para_synic_enable_regs(unsigned int cpu)
346 {
347 union hv_synic_simp simp;
348 union hv_synic_siefp siefp;
349 struct hv_per_cpu_context *hv_cpu
350 = per_cpu_ptr(hv_context.cpu_context, cpu);
351
352 /* Setup the Synic's message page with the paravisor. */
353 simp.as_uint64 = hv_para_get_synic_register(HV_MSR_SIMP);
354 simp.simp_enabled = 1;
355 simp.base_simp_gpa = virt_to_phys(hv_cpu->para_synic_message_page)
356 >> HV_HYP_PAGE_SHIFT;
357 hv_para_set_synic_register(HV_MSR_SIMP, simp.as_uint64);
358
359 /* Setup the Synic's event page with the paravisor. */
360 siefp.as_uint64 = hv_para_get_synic_register(HV_MSR_SIEFP);
361 siefp.siefp_enabled = 1;
362 siefp.base_siefp_gpa = virt_to_phys(hv_cpu->para_synic_event_page)
363 >> HV_HYP_PAGE_SHIFT;
364 hv_para_set_synic_register(HV_MSR_SIEFP, siefp.as_uint64);
365 }
366
hv_para_synic_enable_interrupts(void)367 static void hv_para_synic_enable_interrupts(void)
368 {
369 union hv_synic_scontrol sctrl;
370
371 /* Enable the global synic bit */
372 sctrl.as_uint64 = hv_para_get_synic_register(HV_MSR_SCONTROL);
373 sctrl.enable = 1;
374 hv_para_set_synic_register(HV_MSR_SCONTROL, sctrl.as_uint64);
375 }
376
hv_synic_init(unsigned int cpu)377 int hv_synic_init(unsigned int cpu)
378 {
379 if (vmbus_is_confidential())
380 hv_para_synic_enable_regs(cpu);
381
382 /*
383 * The SINT is set in hv_hyp_synic_enable_regs() by calling
384 * hv_set_msr(). hv_set_msr() in turn has special case code for the
385 * SINT MSRs that write to the hypervisor version of the MSR *and*
386 * the paravisor version of the MSR (but *without* the proxy bit when
387 * VMBus is confidential).
388 *
389 * Then enable interrupts via the paravisor if VMBus is confidential,
390 * and otherwise via the hypervisor.
391 */
392
393 hv_hyp_synic_enable_regs(cpu);
394 if (vmbus_is_confidential())
395 hv_para_synic_enable_interrupts();
396 else
397 hv_hyp_synic_enable_interrupts();
398
399 hv_stimer_legacy_init(cpu, VMBUS_MESSAGE_SINT);
400
401 return 0;
402 }
403
hv_hyp_synic_disable_regs(unsigned int cpu)404 void hv_hyp_synic_disable_regs(unsigned int cpu)
405 {
406 struct hv_per_cpu_context *hv_cpu =
407 per_cpu_ptr(hv_context.cpu_context, cpu);
408 union hv_synic_sint shared_sint;
409 union hv_synic_simp simp;
410 union hv_synic_siefp siefp;
411
412 shared_sint.as_uint64 = hv_get_msr(HV_MSR_SINT0 + VMBUS_MESSAGE_SINT);
413
414 shared_sint.masked = 1;
415
416 /* Need to correctly cleanup in the case of SMP!!! */
417 /* Disable the interrupt */
418 hv_set_msr(HV_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
419 hv_enable_coco_interrupt(cpu, vmbus_interrupt, false);
420
421 simp.as_uint64 = hv_get_msr(HV_MSR_SIMP);
422 /*
423 * In Isolation VM, simp and sief pages are allocated by
424 * paravisor. These pages also will be used by kdump
425 * kernel. So just reset enable bit here and keep page
426 * addresses.
427 */
428 simp.simp_enabled = 0;
429 if (ms_hyperv.paravisor_present || hv_root_partition()) {
430 if (hv_cpu->hyp_synic_message_page) {
431 memunmap(hv_cpu->hyp_synic_message_page);
432 hv_cpu->hyp_synic_message_page = NULL;
433 }
434 } else {
435 simp.base_simp_gpa = 0;
436 }
437
438 hv_set_msr(HV_MSR_SIMP, simp.as_uint64);
439
440 siefp.as_uint64 = hv_get_msr(HV_MSR_SIEFP);
441 siefp.siefp_enabled = 0;
442
443 if (ms_hyperv.paravisor_present || hv_root_partition()) {
444 if (hv_cpu->hyp_synic_event_page) {
445 memunmap(hv_cpu->hyp_synic_event_page);
446 hv_cpu->hyp_synic_event_page = NULL;
447 }
448 } else {
449 siefp.base_siefp_gpa = 0;
450 }
451
452 hv_set_msr(HV_MSR_SIEFP, siefp.as_uint64);
453 }
454
hv_hyp_synic_disable_interrupts(void)455 static void hv_hyp_synic_disable_interrupts(void)
456 {
457 union hv_synic_scontrol sctrl;
458
459 /* Disable the global synic bit */
460 sctrl.as_uint64 = hv_get_msr(HV_MSR_SCONTROL);
461 sctrl.enable = 0;
462 hv_set_msr(HV_MSR_SCONTROL, sctrl.as_uint64);
463 }
464
hv_para_synic_disable_regs(unsigned int cpu)465 static void hv_para_synic_disable_regs(unsigned int cpu)
466 {
467 union hv_synic_simp simp;
468 union hv_synic_siefp siefp;
469
470 /* Disable SynIC's message page in the paravisor. */
471 simp.as_uint64 = hv_para_get_synic_register(HV_MSR_SIMP);
472 simp.simp_enabled = 0;
473 hv_para_set_synic_register(HV_MSR_SIMP, simp.as_uint64);
474
475 /* Disable SynIC's event page in the paravisor. */
476 siefp.as_uint64 = hv_para_get_synic_register(HV_MSR_SIEFP);
477 siefp.siefp_enabled = 0;
478 hv_para_set_synic_register(HV_MSR_SIEFP, siefp.as_uint64);
479 }
480
hv_para_synic_disable_interrupts(void)481 static void hv_para_synic_disable_interrupts(void)
482 {
483 union hv_synic_scontrol sctrl;
484
485 /* Disable the global synic bit */
486 sctrl.as_uint64 = hv_para_get_synic_register(HV_MSR_SCONTROL);
487 sctrl.enable = 0;
488 hv_para_set_synic_register(HV_MSR_SCONTROL, sctrl.as_uint64);
489 }
490
491 #define HV_MAX_TRIES 3
492 /*
493 * Scan the event flags page of 'this' CPU looking for any bit that is set. If we find one
494 * bit set, then wait for a few milliseconds. Repeat these steps for a maximum of 3 times.
495 * Return 'true', if there is still any set bit after this operation; 'false', otherwise.
496 *
497 * If a bit is set, that means there is a pending channel interrupt. The expectation is
498 * that the normal interrupt handling mechanism will find and process the channel interrupt
499 * "very soon", and in the process clear the bit.
500 */
__hv_synic_event_pending(union hv_synic_event_flags * event,int sint)501 static bool __hv_synic_event_pending(union hv_synic_event_flags *event, int sint)
502 {
503 unsigned long *recv_int_page;
504 bool pending;
505 u32 relid;
506 int tries = 0;
507
508 if (!event)
509 return false;
510
511 event += sint;
512 recv_int_page = event->flags; /* assumes VMBus version >= VERSION_WIN8 */
513 retry:
514 pending = false;
515 for_each_set_bit(relid, recv_int_page, HV_EVENT_FLAGS_COUNT) {
516 /* Special case - VMBus channel protocol messages */
517 if (relid == 0)
518 continue;
519 pending = true;
520 break;
521 }
522 if (pending && tries++ < HV_MAX_TRIES) {
523 usleep_range(10000, 20000);
524 goto retry;
525 }
526 return pending;
527 }
528
hv_synic_event_pending(void)529 static bool hv_synic_event_pending(void)
530 {
531 struct hv_per_cpu_context *hv_cpu = this_cpu_ptr(hv_context.cpu_context);
532 union hv_synic_event_flags *hyp_synic_event_page = hv_cpu->hyp_synic_event_page;
533 union hv_synic_event_flags *para_synic_event_page = hv_cpu->para_synic_event_page;
534
535 return
536 __hv_synic_event_pending(hyp_synic_event_page, VMBUS_MESSAGE_SINT) ||
537 __hv_synic_event_pending(para_synic_event_page, VMBUS_MESSAGE_SINT);
538 }
539
hv_pick_new_cpu(struct vmbus_channel * channel)540 static int hv_pick_new_cpu(struct vmbus_channel *channel)
541 {
542 int ret = -EBUSY;
543 int start;
544 int cpu;
545
546 lockdep_assert_cpus_held();
547 lockdep_assert_held(&vmbus_connection.channel_mutex);
548
549 /*
550 * We can't assume that the relevant interrupts will be sent before
551 * the cpu is offlined on older versions of hyperv.
552 */
553 if (vmbus_proto_version < VERSION_WIN10_V5_3)
554 return -EBUSY;
555
556 start = get_random_u32_below(nr_cpu_ids);
557
558 for_each_cpu_wrap(cpu, cpu_online_mask, start) {
559 if (channel->target_cpu == cpu ||
560 channel->target_cpu == VMBUS_CONNECT_CPU)
561 continue;
562
563 ret = vmbus_channel_set_cpu(channel, cpu);
564 if (!ret)
565 break;
566 }
567
568 if (ret)
569 ret = vmbus_channel_set_cpu(channel, VMBUS_CONNECT_CPU);
570
571 return ret;
572 }
573
574 /*
575 * hv_synic_cleanup - Cleanup routine for hv_synic_init().
576 */
hv_synic_cleanup(unsigned int cpu)577 int hv_synic_cleanup(unsigned int cpu)
578 {
579 struct vmbus_channel *channel, *sc;
580 int ret = 0;
581
582 if (vmbus_connection.conn_state != CONNECTED)
583 goto always_cleanup;
584
585 /*
586 * Hyper-V does not provide a way to change the connect CPU once
587 * it is set; we must prevent the connect CPU from going offline
588 * while the VM is running normally. But in the panic or kexec()
589 * path where the vmbus is already disconnected, the CPU must be
590 * allowed to shut down.
591 */
592 if (cpu == VMBUS_CONNECT_CPU)
593 return -EBUSY;
594
595 /*
596 * Search for channels which are bound to the CPU we're about to
597 * cleanup.
598 */
599 mutex_lock(&vmbus_connection.channel_mutex);
600 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
601 if (channel->target_cpu == cpu) {
602 ret = hv_pick_new_cpu(channel);
603 if (ret) {
604 mutex_unlock(&vmbus_connection.channel_mutex);
605 return ret;
606 }
607 }
608 list_for_each_entry(sc, &channel->sc_list, sc_list) {
609 if (sc->target_cpu == cpu) {
610 ret = hv_pick_new_cpu(sc);
611 if (ret) {
612 mutex_unlock(&vmbus_connection.channel_mutex);
613 return ret;
614 }
615 }
616 }
617 }
618 mutex_unlock(&vmbus_connection.channel_mutex);
619
620 /*
621 * Scan the event flags page looking for bits that are set and waiting
622 * with a timeout for vmbus_chan_sched() to process such bits. If bits
623 * are still set after this operation and VMBus is connected, fail the
624 * CPU offlining operation.
625 */
626 if (vmbus_proto_version >= VERSION_WIN10_V4_1 && hv_synic_event_pending())
627 return -EBUSY;
628
629 always_cleanup:
630 hv_stimer_legacy_cleanup(cpu);
631
632 /*
633 * First, disable the event and message pages
634 * used for communicating with the host, and then
635 * disable the host interrupts if VMBus is not
636 * confidential.
637 */
638 hv_hyp_synic_disable_regs(cpu);
639 if (!vmbus_is_confidential())
640 hv_hyp_synic_disable_interrupts();
641
642 /*
643 * Perform the same steps for the Confidential VMBus.
644 * The sequencing provides the guarantee that no data
645 * may be posted for processing before disabling interrupts.
646 */
647 if (vmbus_is_confidential()) {
648 hv_para_synic_disable_regs(cpu);
649 hv_para_synic_disable_interrupts();
650 }
651 if (vmbus_irq != -1)
652 disable_percpu_irq(vmbus_irq);
653
654 return ret;
655 }
656