1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2021, Red Hat, Inc.
4  *
5  * Tests for Hyper-V features enablement
6  */
7 #include <asm/kvm_para.h>
8 #include <linux/kvm_para.h>
9 #include <stdint.h>
10 
11 #include "test_util.h"
12 #include "kvm_util.h"
13 #include "processor.h"
14 #include "hyperv.h"
15 
16 #define VCPU_ID 0
17 #define LINUX_OS_ID ((u64)0x8100 << 48)
18 
19 extern unsigned char rdmsr_start;
20 extern unsigned char rdmsr_end;
21 
22 static u64 do_rdmsr(u32 idx)
23 {
24 	u32 lo, hi;
25 
26 	asm volatile("rdmsr_start: rdmsr;"
27 		     "rdmsr_end:"
28 		     : "=a"(lo), "=c"(hi)
29 		     : "c"(idx));
30 
31 	return (((u64) hi) << 32) | lo;
32 }
33 
34 extern unsigned char wrmsr_start;
35 extern unsigned char wrmsr_end;
36 
37 static void do_wrmsr(u32 idx, u64 val)
38 {
39 	u32 lo, hi;
40 
41 	lo = val;
42 	hi = val >> 32;
43 
44 	asm volatile("wrmsr_start: wrmsr;"
45 		     "wrmsr_end:"
46 		     : : "a"(lo), "c"(idx), "d"(hi));
47 }
48 
49 static int nr_gp;
50 static int nr_ud;
51 
52 static inline u64 hypercall(u64 control, vm_vaddr_t input_address,
53 			    vm_vaddr_t output_address)
54 {
55 	u64 hv_status;
56 
57 	asm volatile("mov %3, %%r8\n"
58 		     "vmcall"
59 		     : "=a" (hv_status),
60 		       "+c" (control), "+d" (input_address)
61 		     :  "r" (output_address)
62 		     : "cc", "memory", "r8", "r9", "r10", "r11");
63 
64 	return hv_status;
65 }
66 
67 static void guest_gp_handler(struct ex_regs *regs)
68 {
69 	unsigned char *rip = (unsigned char *)regs->rip;
70 	bool r, w;
71 
72 	r = rip == &rdmsr_start;
73 	w = rip == &wrmsr_start;
74 	GUEST_ASSERT(r || w);
75 
76 	nr_gp++;
77 
78 	if (r)
79 		regs->rip = (uint64_t)&rdmsr_end;
80 	else
81 		regs->rip = (uint64_t)&wrmsr_end;
82 }
83 
84 static void guest_ud_handler(struct ex_regs *regs)
85 {
86 	nr_ud++;
87 	regs->rip += 3;
88 }
89 
90 struct msr_data {
91 	uint32_t idx;
92 	bool available;
93 	bool write;
94 	u64 write_val;
95 };
96 
97 struct hcall_data {
98 	uint64_t control;
99 	uint64_t expect;
100 	bool ud_expected;
101 };
102 
103 static void guest_msr(struct msr_data *msr)
104 {
105 	int i = 0;
106 
107 	while (msr->idx) {
108 		WRITE_ONCE(nr_gp, 0);
109 		if (!msr->write)
110 			do_rdmsr(msr->idx);
111 		else
112 			do_wrmsr(msr->idx, msr->write_val);
113 
114 		if (msr->available)
115 			GUEST_ASSERT(READ_ONCE(nr_gp) == 0);
116 		else
117 			GUEST_ASSERT(READ_ONCE(nr_gp) == 1);
118 
119 		GUEST_SYNC(i++);
120 	}
121 
122 	GUEST_DONE();
123 }
124 
125 static void guest_hcall(vm_vaddr_t pgs_gpa, struct hcall_data *hcall)
126 {
127 	int i = 0;
128 	u64 res, input, output;
129 
130 	wrmsr(HV_X64_MSR_GUEST_OS_ID, LINUX_OS_ID);
131 	wrmsr(HV_X64_MSR_HYPERCALL, pgs_gpa);
132 
133 	while (hcall->control) {
134 		nr_ud = 0;
135 		if (!(hcall->control & HV_HYPERCALL_FAST_BIT)) {
136 			input = pgs_gpa;
137 			output = pgs_gpa + 4096;
138 		} else {
139 			input = output = 0;
140 		}
141 
142 		res = hypercall(hcall->control, input, output);
143 		if (hcall->ud_expected)
144 			GUEST_ASSERT(nr_ud == 1);
145 		else
146 			GUEST_ASSERT(res == hcall->expect);
147 
148 		GUEST_SYNC(i++);
149 	}
150 
151 	GUEST_DONE();
152 }
153 
154 static void hv_set_cpuid(struct kvm_vm *vm, struct kvm_cpuid2 *cpuid,
155 			 struct kvm_cpuid_entry2 *feat,
156 			 struct kvm_cpuid_entry2 *recomm,
157 			 struct kvm_cpuid_entry2 *dbg)
158 {
159 	TEST_ASSERT(set_cpuid(cpuid, feat),
160 		    "failed to set KVM_CPUID_FEATURES leaf");
161 	TEST_ASSERT(set_cpuid(cpuid, recomm),
162 		    "failed to set HYPERV_CPUID_ENLIGHTMENT_INFO leaf");
163 	TEST_ASSERT(set_cpuid(cpuid, dbg),
164 		    "failed to set HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES leaf");
165 	vcpu_set_cpuid(vm, VCPU_ID, cpuid);
166 }
167 
168 static void guest_test_msrs_access(void)
169 {
170 	struct kvm_run *run;
171 	struct kvm_vm *vm;
172 	struct ucall uc;
173 	int stage = 0, r;
174 	struct kvm_cpuid_entry2 feat = {
175 		.function = HYPERV_CPUID_FEATURES
176 	};
177 	struct kvm_cpuid_entry2 recomm = {
178 		.function = HYPERV_CPUID_ENLIGHTMENT_INFO
179 	};
180 	struct kvm_cpuid_entry2 dbg = {
181 		.function = HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES
182 	};
183 	struct kvm_cpuid2 *best;
184 	vm_vaddr_t msr_gva;
185 	struct kvm_enable_cap cap = {
186 		.cap = KVM_CAP_HYPERV_ENFORCE_CPUID,
187 		.args = {1}
188 	};
189 	struct msr_data *msr;
190 
191 	while (true) {
192 		vm = vm_create_default(VCPU_ID, 0, guest_msr);
193 
194 		msr_gva = vm_vaddr_alloc_page(vm);
195 		memset(addr_gva2hva(vm, msr_gva), 0x0, getpagesize());
196 		msr = addr_gva2hva(vm, msr_gva);
197 
198 		vcpu_args_set(vm, VCPU_ID, 1, msr_gva);
199 		vcpu_enable_cap(vm, VCPU_ID, &cap);
200 
201 		vcpu_set_hv_cpuid(vm, VCPU_ID);
202 
203 		best = kvm_get_supported_hv_cpuid();
204 
205 		vm_init_descriptor_tables(vm);
206 		vcpu_init_descriptor_tables(vm, VCPU_ID);
207 		vm_install_exception_handler(vm, GP_VECTOR, guest_gp_handler);
208 
209 		run = vcpu_state(vm, VCPU_ID);
210 
211 		switch (stage) {
212 		case 0:
213 			/*
214 			 * Only available when Hyper-V identification is set
215 			 */
216 			msr->idx = HV_X64_MSR_GUEST_OS_ID;
217 			msr->write = 0;
218 			msr->available = 0;
219 			break;
220 		case 1:
221 			msr->idx = HV_X64_MSR_HYPERCALL;
222 			msr->write = 0;
223 			msr->available = 0;
224 			break;
225 		case 2:
226 			feat.eax |= HV_MSR_HYPERCALL_AVAILABLE;
227 			/*
228 			 * HV_X64_MSR_GUEST_OS_ID has to be written first to make
229 			 * HV_X64_MSR_HYPERCALL available.
230 			 */
231 			msr->idx = HV_X64_MSR_GUEST_OS_ID;
232 			msr->write = 1;
233 			msr->write_val = LINUX_OS_ID;
234 			msr->available = 1;
235 			break;
236 		case 3:
237 			msr->idx = HV_X64_MSR_GUEST_OS_ID;
238 			msr->write = 0;
239 			msr->available = 1;
240 			break;
241 		case 4:
242 			msr->idx = HV_X64_MSR_HYPERCALL;
243 			msr->write = 0;
244 			msr->available = 1;
245 			break;
246 
247 		case 5:
248 			msr->idx = HV_X64_MSR_VP_RUNTIME;
249 			msr->write = 0;
250 			msr->available = 0;
251 			break;
252 		case 6:
253 			feat.eax |= HV_MSR_VP_RUNTIME_AVAILABLE;
254 			msr->write = 0;
255 			msr->available = 1;
256 			break;
257 		case 7:
258 			/* Read only */
259 			msr->write = 1;
260 			msr->write_val = 1;
261 			msr->available = 0;
262 			break;
263 
264 		case 8:
265 			msr->idx = HV_X64_MSR_TIME_REF_COUNT;
266 			msr->write = 0;
267 			msr->available = 0;
268 			break;
269 		case 9:
270 			feat.eax |= HV_MSR_TIME_REF_COUNT_AVAILABLE;
271 			msr->write = 0;
272 			msr->available = 1;
273 			break;
274 		case 10:
275 			/* Read only */
276 			msr->write = 1;
277 			msr->write_val = 1;
278 			msr->available = 0;
279 			break;
280 
281 		case 11:
282 			msr->idx = HV_X64_MSR_VP_INDEX;
283 			msr->write = 0;
284 			msr->available = 0;
285 			break;
286 		case 12:
287 			feat.eax |= HV_MSR_VP_INDEX_AVAILABLE;
288 			msr->write = 0;
289 			msr->available = 1;
290 			break;
291 		case 13:
292 			/* Read only */
293 			msr->write = 1;
294 			msr->write_val = 1;
295 			msr->available = 0;
296 			break;
297 
298 		case 14:
299 			msr->idx = HV_X64_MSR_RESET;
300 			msr->write = 0;
301 			msr->available = 0;
302 			break;
303 		case 15:
304 			feat.eax |= HV_MSR_RESET_AVAILABLE;
305 			msr->write = 0;
306 			msr->available = 1;
307 			break;
308 		case 16:
309 			msr->write = 1;
310 			msr->write_val = 0;
311 			msr->available = 1;
312 			break;
313 
314 		case 17:
315 			msr->idx = HV_X64_MSR_REFERENCE_TSC;
316 			msr->write = 0;
317 			msr->available = 0;
318 			break;
319 		case 18:
320 			feat.eax |= HV_MSR_REFERENCE_TSC_AVAILABLE;
321 			msr->write = 0;
322 			msr->available = 1;
323 			break;
324 		case 19:
325 			msr->write = 1;
326 			msr->write_val = 0;
327 			msr->available = 1;
328 			break;
329 
330 		case 20:
331 			msr->idx = HV_X64_MSR_EOM;
332 			msr->write = 0;
333 			msr->available = 0;
334 			break;
335 		case 21:
336 			/*
337 			 * Remains unavailable even with KVM_CAP_HYPERV_SYNIC2
338 			 * capability enabled and guest visible CPUID bit unset.
339 			 */
340 			cap.cap = KVM_CAP_HYPERV_SYNIC2;
341 			cap.args[0] = 0;
342 			vcpu_enable_cap(vm, VCPU_ID, &cap);
343 			break;
344 		case 22:
345 			feat.eax |= HV_MSR_SYNIC_AVAILABLE;
346 			msr->write = 0;
347 			msr->available = 1;
348 			break;
349 		case 23:
350 			msr->write = 1;
351 			msr->write_val = 0;
352 			msr->available = 1;
353 			break;
354 
355 		case 24:
356 			msr->idx = HV_X64_MSR_STIMER0_CONFIG;
357 			msr->write = 0;
358 			msr->available = 0;
359 			break;
360 		case 25:
361 			feat.eax |= HV_MSR_SYNTIMER_AVAILABLE;
362 			msr->write = 0;
363 			msr->available = 1;
364 			break;
365 		case 26:
366 			msr->write = 1;
367 			msr->write_val = 0;
368 			msr->available = 1;
369 			break;
370 		case 27:
371 			/* Direct mode test */
372 			msr->write = 1;
373 			msr->write_val = 1 << 12;
374 			msr->available = 0;
375 			break;
376 		case 28:
377 			feat.edx |= HV_STIMER_DIRECT_MODE_AVAILABLE;
378 			msr->available = 1;
379 			break;
380 
381 		case 29:
382 			msr->idx = HV_X64_MSR_EOI;
383 			msr->write = 0;
384 			msr->available = 0;
385 			break;
386 		case 30:
387 			feat.eax |= HV_MSR_APIC_ACCESS_AVAILABLE;
388 			msr->write = 1;
389 			msr->write_val = 1;
390 			msr->available = 1;
391 			break;
392 
393 		case 31:
394 			msr->idx = HV_X64_MSR_TSC_FREQUENCY;
395 			msr->write = 0;
396 			msr->available = 0;
397 			break;
398 		case 32:
399 			feat.eax |= HV_ACCESS_FREQUENCY_MSRS;
400 			msr->write = 0;
401 			msr->available = 1;
402 			break;
403 		case 33:
404 			/* Read only */
405 			msr->write = 1;
406 			msr->write_val = 1;
407 			msr->available = 0;
408 			break;
409 
410 		case 34:
411 			msr->idx = HV_X64_MSR_REENLIGHTENMENT_CONTROL;
412 			msr->write = 0;
413 			msr->available = 0;
414 			break;
415 		case 35:
416 			feat.eax |= HV_ACCESS_REENLIGHTENMENT;
417 			msr->write = 0;
418 			msr->available = 1;
419 			break;
420 		case 36:
421 			msr->write = 1;
422 			msr->write_val = 1;
423 			msr->available = 1;
424 			break;
425 		case 37:
426 			/* Can only write '0' */
427 			msr->idx = HV_X64_MSR_TSC_EMULATION_STATUS;
428 			msr->write = 1;
429 			msr->write_val = 1;
430 			msr->available = 0;
431 			break;
432 
433 		case 38:
434 			msr->idx = HV_X64_MSR_CRASH_P0;
435 			msr->write = 0;
436 			msr->available = 0;
437 			break;
438 		case 39:
439 			feat.edx |= HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE;
440 			msr->write = 0;
441 			msr->available = 1;
442 			break;
443 		case 40:
444 			msr->write = 1;
445 			msr->write_val = 1;
446 			msr->available = 1;
447 			break;
448 
449 		case 41:
450 			msr->idx = HV_X64_MSR_SYNDBG_STATUS;
451 			msr->write = 0;
452 			msr->available = 0;
453 			break;
454 		case 42:
455 			feat.edx |= HV_FEATURE_DEBUG_MSRS_AVAILABLE;
456 			dbg.eax |= HV_X64_SYNDBG_CAP_ALLOW_KERNEL_DEBUGGING;
457 			msr->write = 0;
458 			msr->available = 1;
459 			break;
460 		case 43:
461 			msr->write = 1;
462 			msr->write_val = 0;
463 			msr->available = 1;
464 			break;
465 
466 		case 44:
467 			/* END */
468 			msr->idx = 0;
469 			break;
470 		}
471 
472 		hv_set_cpuid(vm, best, &feat, &recomm, &dbg);
473 
474 		if (msr->idx)
475 			pr_debug("Stage %d: testing msr: 0x%x for %s\n", stage,
476 				 msr->idx, msr->write ? "write" : "read");
477 		else
478 			pr_debug("Stage %d: finish\n", stage);
479 
480 		r = _vcpu_run(vm, VCPU_ID);
481 		TEST_ASSERT(!r, "vcpu_run failed: %d\n", r);
482 		TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
483 			    "unexpected exit reason: %u (%s)",
484 			    run->exit_reason, exit_reason_str(run->exit_reason));
485 
486 		switch (get_ucall(vm, VCPU_ID, &uc)) {
487 		case UCALL_SYNC:
488 			TEST_ASSERT(uc.args[1] == 0,
489 				    "Unexpected stage: %ld (0 expected)\n",
490 				    uc.args[1]);
491 			break;
492 		case UCALL_ABORT:
493 			TEST_FAIL("%s at %s:%ld", (const char *)uc.args[0],
494 				  __FILE__, uc.args[1]);
495 			return;
496 		case UCALL_DONE:
497 			return;
498 		}
499 
500 		stage++;
501 		kvm_vm_free(vm);
502 	}
503 }
504 
505 static void guest_test_hcalls_access(void)
506 {
507 	struct kvm_run *run;
508 	struct kvm_vm *vm;
509 	struct ucall uc;
510 	int stage = 0, r;
511 	struct kvm_cpuid_entry2 feat = {
512 		.function = HYPERV_CPUID_FEATURES,
513 		.eax = HV_MSR_HYPERCALL_AVAILABLE
514 	};
515 	struct kvm_cpuid_entry2 recomm = {
516 		.function = HYPERV_CPUID_ENLIGHTMENT_INFO
517 	};
518 	struct kvm_cpuid_entry2 dbg = {
519 		.function = HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES
520 	};
521 	struct kvm_enable_cap cap = {
522 		.cap = KVM_CAP_HYPERV_ENFORCE_CPUID,
523 		.args = {1}
524 	};
525 	vm_vaddr_t hcall_page, hcall_params;
526 	struct hcall_data *hcall;
527 	struct kvm_cpuid2 *best;
528 
529 	while (true) {
530 		vm = vm_create_default(VCPU_ID, 0, guest_hcall);
531 
532 		vm_init_descriptor_tables(vm);
533 		vcpu_init_descriptor_tables(vm, VCPU_ID);
534 		vm_install_exception_handler(vm, UD_VECTOR, guest_ud_handler);
535 
536 		/* Hypercall input/output */
537 		hcall_page = vm_vaddr_alloc_pages(vm, 2);
538 		hcall = addr_gva2hva(vm, hcall_page);
539 		memset(addr_gva2hva(vm, hcall_page), 0x0, 2 * getpagesize());
540 
541 		hcall_params = vm_vaddr_alloc_page(vm);
542 		memset(addr_gva2hva(vm, hcall_params), 0x0, getpagesize());
543 
544 		vcpu_args_set(vm, VCPU_ID, 2, addr_gva2gpa(vm, hcall_page), hcall_params);
545 		vcpu_enable_cap(vm, VCPU_ID, &cap);
546 
547 		vcpu_set_hv_cpuid(vm, VCPU_ID);
548 
549 		best = kvm_get_supported_hv_cpuid();
550 
551 		run = vcpu_state(vm, VCPU_ID);
552 
553 		switch (stage) {
554 		case 0:
555 			hcall->control = 0xdeadbeef;
556 			hcall->expect = HV_STATUS_INVALID_HYPERCALL_CODE;
557 			break;
558 
559 		case 1:
560 			hcall->control = HVCALL_POST_MESSAGE;
561 			hcall->expect = HV_STATUS_ACCESS_DENIED;
562 			break;
563 		case 2:
564 			feat.ebx |= HV_POST_MESSAGES;
565 			hcall->expect = HV_STATUS_INVALID_HYPERCALL_INPUT;
566 			break;
567 
568 		case 3:
569 			hcall->control = HVCALL_SIGNAL_EVENT;
570 			hcall->expect = HV_STATUS_ACCESS_DENIED;
571 			break;
572 		case 4:
573 			feat.ebx |= HV_SIGNAL_EVENTS;
574 			hcall->expect = HV_STATUS_INVALID_HYPERCALL_INPUT;
575 			break;
576 
577 		case 5:
578 			hcall->control = HVCALL_RESET_DEBUG_SESSION;
579 			hcall->expect = HV_STATUS_INVALID_HYPERCALL_CODE;
580 			break;
581 		case 6:
582 			dbg.eax |= HV_X64_SYNDBG_CAP_ALLOW_KERNEL_DEBUGGING;
583 			hcall->expect = HV_STATUS_ACCESS_DENIED;
584 			break;
585 		case 7:
586 			feat.ebx |= HV_DEBUGGING;
587 			hcall->expect = HV_STATUS_OPERATION_DENIED;
588 			break;
589 
590 		case 8:
591 			hcall->control = HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE;
592 			hcall->expect = HV_STATUS_ACCESS_DENIED;
593 			break;
594 		case 9:
595 			recomm.eax |= HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED;
596 			hcall->expect = HV_STATUS_SUCCESS;
597 			break;
598 		case 10:
599 			hcall->control = HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX;
600 			hcall->expect = HV_STATUS_ACCESS_DENIED;
601 			break;
602 		case 11:
603 			recomm.eax |= HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED;
604 			hcall->expect = HV_STATUS_SUCCESS;
605 			break;
606 
607 		case 12:
608 			hcall->control = HVCALL_SEND_IPI;
609 			hcall->expect = HV_STATUS_ACCESS_DENIED;
610 			break;
611 		case 13:
612 			recomm.eax |= HV_X64_CLUSTER_IPI_RECOMMENDED;
613 			hcall->expect = HV_STATUS_INVALID_HYPERCALL_INPUT;
614 			break;
615 		case 14:
616 			/* Nothing in 'sparse banks' -> success */
617 			hcall->control = HVCALL_SEND_IPI_EX;
618 			hcall->expect = HV_STATUS_SUCCESS;
619 			break;
620 
621 		case 15:
622 			hcall->control = HVCALL_NOTIFY_LONG_SPIN_WAIT;
623 			hcall->expect = HV_STATUS_ACCESS_DENIED;
624 			break;
625 		case 16:
626 			recomm.ebx = 0xfff;
627 			hcall->expect = HV_STATUS_SUCCESS;
628 			break;
629 		case 17:
630 			/* XMM fast hypercall */
631 			hcall->control = HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE | HV_HYPERCALL_FAST_BIT;
632 			hcall->ud_expected = true;
633 			break;
634 		case 18:
635 			feat.edx |= HV_X64_HYPERCALL_XMM_INPUT_AVAILABLE;
636 			hcall->ud_expected = false;
637 			hcall->expect = HV_STATUS_SUCCESS;
638 			break;
639 
640 		case 19:
641 			/* END */
642 			hcall->control = 0;
643 			break;
644 		}
645 
646 		hv_set_cpuid(vm, best, &feat, &recomm, &dbg);
647 
648 		if (hcall->control)
649 			pr_debug("Stage %d: testing hcall: 0x%lx\n", stage,
650 				 hcall->control);
651 		else
652 			pr_debug("Stage %d: finish\n", stage);
653 
654 		r = _vcpu_run(vm, VCPU_ID);
655 		TEST_ASSERT(!r, "vcpu_run failed: %d\n", r);
656 		TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
657 			    "unexpected exit reason: %u (%s)",
658 			    run->exit_reason, exit_reason_str(run->exit_reason));
659 
660 		switch (get_ucall(vm, VCPU_ID, &uc)) {
661 		case UCALL_SYNC:
662 			TEST_ASSERT(uc.args[1] == 0,
663 				    "Unexpected stage: %ld (0 expected)\n",
664 				    uc.args[1]);
665 			break;
666 		case UCALL_ABORT:
667 			TEST_FAIL("%s at %s:%ld", (const char *)uc.args[0],
668 				  __FILE__, uc.args[1]);
669 			return;
670 		case UCALL_DONE:
671 			return;
672 		}
673 
674 		stage++;
675 		kvm_vm_free(vm);
676 	}
677 }
678 
679 int main(void)
680 {
681 	pr_info("Testing access to Hyper-V specific MSRs\n");
682 	guest_test_msrs_access();
683 
684 	pr_info("Testing access to Hyper-V hypercalls\n");
685 	guest_test_hcalls_access();
686 }
687