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 *
276 * Note: When MSHV is present, mshv_synic_cpu_init() intializes further
277 * registers later.
278 */
hv_hyp_synic_enable_regs(unsigned int cpu)279 void hv_hyp_synic_enable_regs(unsigned int cpu)
280 {
281 struct hv_per_cpu_context *hv_cpu =
282 per_cpu_ptr(hv_context.cpu_context, cpu);
283 union hv_synic_simp simp;
284 union hv_synic_siefp siefp;
285 union hv_synic_sint shared_sint;
286
287 /* Setup the Synic's message page with the hypervisor. */
288 simp.as_uint64 = hv_get_msr(HV_MSR_SIMP);
289 simp.simp_enabled = 1;
290
291 if (ms_hyperv.paravisor_present || hv_root_partition()) {
292 /* Mask out vTOM bit and map as decrypted */
293 u64 base = (simp.base_simp_gpa << HV_HYP_PAGE_SHIFT) &
294 ~ms_hyperv.shared_gpa_boundary;
295 hv_cpu->hyp_synic_message_page =
296 memremap(base, HV_HYP_PAGE_SIZE, MEMREMAP_WB | MEMREMAP_DEC);
297 if (!hv_cpu->hyp_synic_message_page)
298 pr_err("Fail to map synic message page.\n");
299 } else {
300 simp.base_simp_gpa = virt_to_phys(hv_cpu->hyp_synic_message_page)
301 >> HV_HYP_PAGE_SHIFT;
302 }
303
304 hv_set_msr(HV_MSR_SIMP, simp.as_uint64);
305
306 /* Setup the Synic's event page with the hypervisor. */
307 siefp.as_uint64 = hv_get_msr(HV_MSR_SIEFP);
308 siefp.siefp_enabled = 1;
309
310 if (ms_hyperv.paravisor_present || hv_root_partition()) {
311 /* Mask out vTOM bit and map as decrypted */
312 u64 base = (siefp.base_siefp_gpa << HV_HYP_PAGE_SHIFT) &
313 ~ms_hyperv.shared_gpa_boundary;
314 hv_cpu->hyp_synic_event_page =
315 memremap(base, HV_HYP_PAGE_SIZE, MEMREMAP_WB | MEMREMAP_DEC);
316 if (!hv_cpu->hyp_synic_event_page)
317 pr_err("Fail to map synic event page.\n");
318 } else {
319 siefp.base_siefp_gpa = virt_to_phys(hv_cpu->hyp_synic_event_page)
320 >> HV_HYP_PAGE_SHIFT;
321 }
322
323 hv_set_msr(HV_MSR_SIEFP, siefp.as_uint64);
324 hv_enable_coco_interrupt(cpu, vmbus_interrupt, true);
325
326 /* Setup the shared SINT. */
327 if (vmbus_irq != -1)
328 enable_percpu_irq(vmbus_irq, 0);
329 shared_sint.as_uint64 = hv_get_msr(HV_MSR_SINT0 + VMBUS_MESSAGE_SINT);
330
331 shared_sint.vector = vmbus_interrupt;
332 shared_sint.masked = false;
333 shared_sint.auto_eoi = hv_recommend_using_aeoi();
334 hv_set_msr(HV_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
335 }
336
hv_hyp_synic_enable_interrupts(void)337 static void hv_hyp_synic_enable_interrupts(void)
338 {
339 union hv_synic_scontrol sctrl;
340
341 /* Enable the global synic bit */
342 sctrl.as_uint64 = hv_get_msr(HV_MSR_SCONTROL);
343 sctrl.enable = 1;
344
345 hv_set_msr(HV_MSR_SCONTROL, sctrl.as_uint64);
346 }
347
hv_para_synic_enable_regs(unsigned int cpu)348 static void hv_para_synic_enable_regs(unsigned int cpu)
349 {
350 union hv_synic_simp simp;
351 union hv_synic_siefp siefp;
352 struct hv_per_cpu_context *hv_cpu
353 = per_cpu_ptr(hv_context.cpu_context, cpu);
354
355 /* Setup the Synic's message page with the paravisor. */
356 simp.as_uint64 = hv_para_get_synic_register(HV_MSR_SIMP);
357 simp.simp_enabled = 1;
358 simp.base_simp_gpa = virt_to_phys(hv_cpu->para_synic_message_page)
359 >> HV_HYP_PAGE_SHIFT;
360 hv_para_set_synic_register(HV_MSR_SIMP, simp.as_uint64);
361
362 /* Setup the Synic's event page with the paravisor. */
363 siefp.as_uint64 = hv_para_get_synic_register(HV_MSR_SIEFP);
364 siefp.siefp_enabled = 1;
365 siefp.base_siefp_gpa = virt_to_phys(hv_cpu->para_synic_event_page)
366 >> HV_HYP_PAGE_SHIFT;
367 hv_para_set_synic_register(HV_MSR_SIEFP, siefp.as_uint64);
368 }
369
hv_para_synic_enable_interrupts(void)370 static void hv_para_synic_enable_interrupts(void)
371 {
372 union hv_synic_scontrol sctrl;
373
374 /* Enable the global synic bit */
375 sctrl.as_uint64 = hv_para_get_synic_register(HV_MSR_SCONTROL);
376 sctrl.enable = 1;
377 hv_para_set_synic_register(HV_MSR_SCONTROL, sctrl.as_uint64);
378 }
379
hv_synic_init(unsigned int cpu)380 int hv_synic_init(unsigned int cpu)
381 {
382 if (vmbus_is_confidential())
383 hv_para_synic_enable_regs(cpu);
384
385 /*
386 * The SINT is set in hv_hyp_synic_enable_regs() by calling
387 * hv_set_msr(). hv_set_msr() in turn has special case code for the
388 * SINT MSRs that write to the hypervisor version of the MSR *and*
389 * the paravisor version of the MSR (but *without* the proxy bit when
390 * VMBus is confidential).
391 *
392 * Then enable interrupts via the paravisor if VMBus is confidential,
393 * and otherwise via the hypervisor.
394 */
395
396 hv_hyp_synic_enable_regs(cpu);
397 if (vmbus_is_confidential())
398 hv_para_synic_enable_interrupts();
399 else
400 hv_hyp_synic_enable_interrupts();
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 memunmap(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 memunmap(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 /*
632 * First, disable the event and message pages
633 * used for communicating with the host, and then
634 * disable the host interrupts if VMBus is not
635 * confidential.
636 */
637 hv_hyp_synic_disable_regs(cpu);
638 if (!vmbus_is_confidential())
639 hv_hyp_synic_disable_interrupts();
640
641 /*
642 * Perform the same steps for the Confidential VMBus.
643 * The sequencing provides the guarantee that no data
644 * may be posted for processing before disabling interrupts.
645 */
646 if (vmbus_is_confidential()) {
647 hv_para_synic_disable_regs(cpu);
648 hv_para_synic_disable_interrupts();
649 }
650 if (vmbus_irq != -1)
651 disable_percpu_irq(vmbus_irq);
652
653 return ret;
654 }
655