1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (C) 2019 Arm Ltd.
3 
4 #include <linux/arm-smccc.h>
5 #include <linux/kvm_host.h>
6 
7 #include <asm/kvm_emulate.h>
8 
9 #include <kvm/arm_hypercalls.h>
10 #include <kvm/arm_psci.h>
11 
12 #define KVM_ARM_SMCCC_STD_FEATURES				\
13 	GENMASK(KVM_REG_ARM_STD_BMAP_BIT_COUNT - 1, 0)
14 #define KVM_ARM_SMCCC_STD_HYP_FEATURES				\
15 	GENMASK(KVM_REG_ARM_STD_HYP_BMAP_BIT_COUNT - 1, 0)
16 #define KVM_ARM_SMCCC_VENDOR_HYP_FEATURES			\
17 	GENMASK(KVM_REG_ARM_VENDOR_HYP_BMAP_BIT_COUNT - 1, 0)
18 #define KVM_ARM_SMCCC_VENDOR_HYP_FEATURES_2			\
19 	GENMASK(KVM_REG_ARM_VENDOR_HYP_BMAP_2_BIT_COUNT - 1, 0)
20 
21 static void kvm_ptp_get_time(struct kvm_vcpu *vcpu, u64 *val)
22 {
23 	struct system_time_snapshot systime_snapshot;
24 	u64 cycles = ~0UL;
25 	u32 feature;
26 
27 	/*
28 	 * system time and counter value must captured at the same
29 	 * time to keep consistency and precision.
30 	 */
31 	ktime_get_snapshot(&systime_snapshot);
32 
33 	/*
34 	 * This is only valid if the current clocksource is the
35 	 * architected counter, as this is the only one the guest
36 	 * can see.
37 	 */
38 	if (systime_snapshot.cs_id != CSID_ARM_ARCH_COUNTER)
39 		return;
40 
41 	/*
42 	 * The guest selects one of the two reference counters
43 	 * (virtual or physical) with the first argument of the SMCCC
44 	 * call. In case the identifier is not supported, error out.
45 	 */
46 	feature = smccc_get_arg1(vcpu);
47 	switch (feature) {
48 	case KVM_PTP_VIRT_COUNTER:
49 		cycles = systime_snapshot.cycles - vcpu->kvm->arch.timer_data.voffset;
50 		break;
51 	case KVM_PTP_PHYS_COUNTER:
52 		cycles = systime_snapshot.cycles - vcpu->kvm->arch.timer_data.poffset;
53 		break;
54 	default:
55 		return;
56 	}
57 
58 	/*
59 	 * This relies on the top bit of val[0] never being set for
60 	 * valid values of system time, because that is *really* far
61 	 * in the future (about 292 years from 1970, and at that stage
62 	 * nobody will give a damn about it).
63 	 */
64 	val[0] = upper_32_bits(systime_snapshot.real);
65 	val[1] = lower_32_bits(systime_snapshot.real);
66 	val[2] = upper_32_bits(cycles);
67 	val[3] = lower_32_bits(cycles);
68 }
69 
70 static bool kvm_smccc_default_allowed(u32 func_id)
71 {
72 	switch (func_id) {
73 	/*
74 	 * List of function-ids that are not gated with the bitmapped
75 	 * feature firmware registers, and are to be allowed for
76 	 * servicing the call by default.
77 	 */
78 	case ARM_SMCCC_VERSION_FUNC_ID:
79 	case ARM_SMCCC_ARCH_FEATURES_FUNC_ID:
80 		return true;
81 	default:
82 		/* PSCI 0.2 and up is in the 0:0x1f range */
83 		if (ARM_SMCCC_OWNER_NUM(func_id) == ARM_SMCCC_OWNER_STANDARD &&
84 		    ARM_SMCCC_FUNC_NUM(func_id) <= 0x1f)
85 			return true;
86 
87 		/*
88 		 * KVM's PSCI 0.1 doesn't comply with SMCCC, and has
89 		 * its own function-id base and range
90 		 */
91 		if (func_id >= KVM_PSCI_FN(0) && func_id <= KVM_PSCI_FN(3))
92 			return true;
93 
94 		return false;
95 	}
96 }
97 
98 static bool kvm_smccc_test_fw_bmap(struct kvm_vcpu *vcpu, u32 func_id)
99 {
100 	struct kvm_smccc_features *smccc_feat = &vcpu->kvm->arch.smccc_feat;
101 
102 	switch (func_id) {
103 	case ARM_SMCCC_TRNG_VERSION:
104 	case ARM_SMCCC_TRNG_FEATURES:
105 	case ARM_SMCCC_TRNG_GET_UUID:
106 	case ARM_SMCCC_TRNG_RND32:
107 	case ARM_SMCCC_TRNG_RND64:
108 		return test_bit(KVM_REG_ARM_STD_BIT_TRNG_V1_0,
109 				&smccc_feat->std_bmap);
110 	case ARM_SMCCC_HV_PV_TIME_FEATURES:
111 	case ARM_SMCCC_HV_PV_TIME_ST:
112 		return test_bit(KVM_REG_ARM_STD_HYP_BIT_PV_TIME,
113 				&smccc_feat->std_hyp_bmap);
114 	case ARM_SMCCC_VENDOR_HYP_KVM_FEATURES_FUNC_ID:
115 	case ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID:
116 		return test_bit(KVM_REG_ARM_VENDOR_HYP_BIT_FUNC_FEAT,
117 				&smccc_feat->vendor_hyp_bmap);
118 	case ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID:
119 		return test_bit(KVM_REG_ARM_VENDOR_HYP_BIT_PTP,
120 				&smccc_feat->vendor_hyp_bmap);
121 	default:
122 		return false;
123 	}
124 }
125 
126 #define SMC32_ARCH_RANGE_BEGIN	ARM_SMCCC_VERSION_FUNC_ID
127 #define SMC32_ARCH_RANGE_END	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,		\
128 						   ARM_SMCCC_SMC_32,		\
129 						   0, ARM_SMCCC_FUNC_MASK)
130 
131 #define SMC64_ARCH_RANGE_BEGIN	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,		\
132 						   ARM_SMCCC_SMC_64,		\
133 						   0, 0)
134 #define SMC64_ARCH_RANGE_END	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,		\
135 						   ARM_SMCCC_SMC_64,		\
136 						   0, ARM_SMCCC_FUNC_MASK)
137 
138 static int kvm_smccc_filter_insert_reserved(struct kvm *kvm)
139 {
140 	int r;
141 
142 	/*
143 	 * Prevent userspace from handling any SMCCC calls in the architecture
144 	 * range, avoiding the risk of misrepresenting Spectre mitigation status
145 	 * to the guest.
146 	 */
147 	r = mtree_insert_range(&kvm->arch.smccc_filter,
148 			       SMC32_ARCH_RANGE_BEGIN, SMC32_ARCH_RANGE_END,
149 			       xa_mk_value(KVM_SMCCC_FILTER_HANDLE),
150 			       GFP_KERNEL_ACCOUNT);
151 	if (r)
152 		goto out_destroy;
153 
154 	r = mtree_insert_range(&kvm->arch.smccc_filter,
155 			       SMC64_ARCH_RANGE_BEGIN, SMC64_ARCH_RANGE_END,
156 			       xa_mk_value(KVM_SMCCC_FILTER_HANDLE),
157 			       GFP_KERNEL_ACCOUNT);
158 	if (r)
159 		goto out_destroy;
160 
161 	return 0;
162 out_destroy:
163 	mtree_destroy(&kvm->arch.smccc_filter);
164 	return r;
165 }
166 
167 static bool kvm_smccc_filter_configured(struct kvm *kvm)
168 {
169 	return !mtree_empty(&kvm->arch.smccc_filter);
170 }
171 
172 static int kvm_smccc_set_filter(struct kvm *kvm, struct kvm_smccc_filter __user *uaddr)
173 {
174 	const void *zero_page = page_to_virt(ZERO_PAGE(0));
175 	struct kvm_smccc_filter filter;
176 	u32 start, end;
177 	int r;
178 
179 	if (copy_from_user(&filter, uaddr, sizeof(filter)))
180 		return -EFAULT;
181 
182 	if (memcmp(filter.pad, zero_page, sizeof(filter.pad)))
183 		return -EINVAL;
184 
185 	start = filter.base;
186 	end = start + filter.nr_functions - 1;
187 
188 	if (end < start || filter.action >= NR_SMCCC_FILTER_ACTIONS)
189 		return -EINVAL;
190 
191 	mutex_lock(&kvm->arch.config_lock);
192 
193 	if (kvm_vm_has_ran_once(kvm)) {
194 		r = -EBUSY;
195 		goto out_unlock;
196 	}
197 
198 	if (!kvm_smccc_filter_configured(kvm)) {
199 		r = kvm_smccc_filter_insert_reserved(kvm);
200 		if (WARN_ON_ONCE(r))
201 			goto out_unlock;
202 	}
203 
204 	r = mtree_insert_range(&kvm->arch.smccc_filter, start, end,
205 			       xa_mk_value(filter.action), GFP_KERNEL_ACCOUNT);
206 out_unlock:
207 	mutex_unlock(&kvm->arch.config_lock);
208 	return r;
209 }
210 
211 static u8 kvm_smccc_filter_get_action(struct kvm *kvm, u32 func_id)
212 {
213 	unsigned long idx = func_id;
214 	void *val;
215 
216 	if (!kvm_smccc_filter_configured(kvm))
217 		return KVM_SMCCC_FILTER_HANDLE;
218 
219 	/*
220 	 * But where's the error handling, you say?
221 	 *
222 	 * mt_find() returns NULL if no entry was found, which just so happens
223 	 * to match KVM_SMCCC_FILTER_HANDLE.
224 	 */
225 	val = mt_find(&kvm->arch.smccc_filter, &idx, idx);
226 	return xa_to_value(val);
227 }
228 
229 static u8 kvm_smccc_get_action(struct kvm_vcpu *vcpu, u32 func_id)
230 {
231 	/*
232 	 * Intervening actions in the SMCCC filter take precedence over the
233 	 * pseudo-firmware register bitmaps.
234 	 */
235 	u8 action = kvm_smccc_filter_get_action(vcpu->kvm, func_id);
236 	if (action != KVM_SMCCC_FILTER_HANDLE)
237 		return action;
238 
239 	if (kvm_smccc_test_fw_bmap(vcpu, func_id) ||
240 	    kvm_smccc_default_allowed(func_id))
241 		return KVM_SMCCC_FILTER_HANDLE;
242 
243 	return KVM_SMCCC_FILTER_DENY;
244 }
245 
246 static void kvm_prepare_hypercall_exit(struct kvm_vcpu *vcpu, u32 func_id)
247 {
248 	u8 ec = ESR_ELx_EC(kvm_vcpu_get_esr(vcpu));
249 	struct kvm_run *run = vcpu->run;
250 	u64 flags = 0;
251 
252 	if (ec == ESR_ELx_EC_SMC32 || ec == ESR_ELx_EC_SMC64)
253 		flags |= KVM_HYPERCALL_EXIT_SMC;
254 
255 	if (!kvm_vcpu_trap_il_is32bit(vcpu))
256 		flags |= KVM_HYPERCALL_EXIT_16BIT;
257 
258 	run->exit_reason = KVM_EXIT_HYPERCALL;
259 	run->hypercall = (typeof(run->hypercall)) {
260 		.nr	= func_id,
261 		.flags	= flags,
262 	};
263 }
264 
265 int kvm_smccc_call_handler(struct kvm_vcpu *vcpu)
266 {
267 	struct kvm_smccc_features *smccc_feat = &vcpu->kvm->arch.smccc_feat;
268 	u32 func_id = smccc_get_function(vcpu);
269 	u64 val[4] = {SMCCC_RET_NOT_SUPPORTED};
270 	u32 feature;
271 	u8 action;
272 	gpa_t gpa;
273 	uuid_t uuid;
274 
275 	action = kvm_smccc_get_action(vcpu, func_id);
276 	switch (action) {
277 	case KVM_SMCCC_FILTER_HANDLE:
278 		break;
279 	case KVM_SMCCC_FILTER_DENY:
280 		goto out;
281 	case KVM_SMCCC_FILTER_FWD_TO_USER:
282 		kvm_prepare_hypercall_exit(vcpu, func_id);
283 		return 0;
284 	default:
285 		WARN_RATELIMIT(1, "Unhandled SMCCC filter action: %d\n", action);
286 		goto out;
287 	}
288 
289 	switch (func_id) {
290 	case ARM_SMCCC_VERSION_FUNC_ID:
291 		val[0] = ARM_SMCCC_VERSION_1_1;
292 		break;
293 	case ARM_SMCCC_ARCH_FEATURES_FUNC_ID:
294 		feature = smccc_get_arg1(vcpu);
295 		switch (feature) {
296 		case ARM_SMCCC_ARCH_WORKAROUND_1:
297 			switch (arm64_get_spectre_v2_state()) {
298 			case SPECTRE_VULNERABLE:
299 				break;
300 			case SPECTRE_MITIGATED:
301 				val[0] = SMCCC_RET_SUCCESS;
302 				break;
303 			case SPECTRE_UNAFFECTED:
304 				val[0] = SMCCC_ARCH_WORKAROUND_RET_UNAFFECTED;
305 				break;
306 			}
307 			break;
308 		case ARM_SMCCC_ARCH_WORKAROUND_2:
309 			switch (arm64_get_spectre_v4_state()) {
310 			case SPECTRE_VULNERABLE:
311 				break;
312 			case SPECTRE_MITIGATED:
313 				/*
314 				 * SSBS everywhere: Indicate no firmware
315 				 * support, as the SSBS support will be
316 				 * indicated to the guest and the default is
317 				 * safe.
318 				 *
319 				 * Otherwise, expose a permanent mitigation
320 				 * to the guest, and hide SSBS so that the
321 				 * guest stays protected.
322 				 */
323 				if (kvm_has_feat(vcpu->kvm, ID_AA64PFR1_EL1, SSBS, IMP))
324 					break;
325 				fallthrough;
326 			case SPECTRE_UNAFFECTED:
327 				val[0] = SMCCC_RET_NOT_REQUIRED;
328 				break;
329 			}
330 			break;
331 		case ARM_SMCCC_ARCH_WORKAROUND_3:
332 			switch (arm64_get_spectre_bhb_state()) {
333 			case SPECTRE_VULNERABLE:
334 				break;
335 			case SPECTRE_MITIGATED:
336 				val[0] = SMCCC_RET_SUCCESS;
337 				break;
338 			case SPECTRE_UNAFFECTED:
339 				val[0] = SMCCC_ARCH_WORKAROUND_RET_UNAFFECTED;
340 				break;
341 			}
342 			break;
343 		case ARM_SMCCC_HV_PV_TIME_FEATURES:
344 			if (test_bit(KVM_REG_ARM_STD_HYP_BIT_PV_TIME,
345 				     &smccc_feat->std_hyp_bmap))
346 				val[0] = SMCCC_RET_SUCCESS;
347 			break;
348 		}
349 		break;
350 	case ARM_SMCCC_HV_PV_TIME_FEATURES:
351 		val[0] = kvm_hypercall_pv_features(vcpu);
352 		break;
353 	case ARM_SMCCC_HV_PV_TIME_ST:
354 		gpa = kvm_init_stolen_time(vcpu);
355 		if (gpa != INVALID_GPA)
356 			val[0] = gpa;
357 		break;
358 	case ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID:
359 		uuid = ARM_SMCCC_VENDOR_HYP_UID_KVM;
360 		val[0] = smccc_uuid_to_reg(&uuid, 0);
361 		val[1] = smccc_uuid_to_reg(&uuid, 1);
362 		val[2] = smccc_uuid_to_reg(&uuid, 2);
363 		val[3] = smccc_uuid_to_reg(&uuid, 3);
364 		break;
365 	case ARM_SMCCC_VENDOR_HYP_KVM_FEATURES_FUNC_ID:
366 		val[0] = smccc_feat->vendor_hyp_bmap;
367 		/* Function numbers 2-63 are reserved for pKVM for now */
368 		val[2] = smccc_feat->vendor_hyp_bmap_2;
369 		break;
370 	case ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID:
371 		kvm_ptp_get_time(vcpu, val);
372 		break;
373 	case ARM_SMCCC_TRNG_VERSION:
374 	case ARM_SMCCC_TRNG_FEATURES:
375 	case ARM_SMCCC_TRNG_GET_UUID:
376 	case ARM_SMCCC_TRNG_RND32:
377 	case ARM_SMCCC_TRNG_RND64:
378 		return kvm_trng_call(vcpu);
379 	default:
380 		return kvm_psci_call(vcpu);
381 	}
382 
383 out:
384 	smccc_set_retval(vcpu, val[0], val[1], val[2], val[3]);
385 	return 1;
386 }
387 
388 static const u64 kvm_arm_fw_reg_ids[] = {
389 	KVM_REG_ARM_PSCI_VERSION,
390 	KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1,
391 	KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2,
392 	KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3,
393 	KVM_REG_ARM_STD_BMAP,
394 	KVM_REG_ARM_STD_HYP_BMAP,
395 	KVM_REG_ARM_VENDOR_HYP_BMAP,
396 	KVM_REG_ARM_VENDOR_HYP_BMAP_2,
397 };
398 
399 void kvm_arm_init_hypercalls(struct kvm *kvm)
400 {
401 	struct kvm_smccc_features *smccc_feat = &kvm->arch.smccc_feat;
402 
403 	smccc_feat->std_bmap = KVM_ARM_SMCCC_STD_FEATURES;
404 	smccc_feat->std_hyp_bmap = KVM_ARM_SMCCC_STD_HYP_FEATURES;
405 	smccc_feat->vendor_hyp_bmap = KVM_ARM_SMCCC_VENDOR_HYP_FEATURES;
406 
407 	mt_init(&kvm->arch.smccc_filter);
408 }
409 
410 void kvm_arm_teardown_hypercalls(struct kvm *kvm)
411 {
412 	mtree_destroy(&kvm->arch.smccc_filter);
413 }
414 
415 int kvm_arm_get_fw_num_regs(struct kvm_vcpu *vcpu)
416 {
417 	return ARRAY_SIZE(kvm_arm_fw_reg_ids);
418 }
419 
420 int kvm_arm_copy_fw_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
421 {
422 	int i;
423 
424 	for (i = 0; i < ARRAY_SIZE(kvm_arm_fw_reg_ids); i++) {
425 		if (put_user(kvm_arm_fw_reg_ids[i], uindices++))
426 			return -EFAULT;
427 	}
428 
429 	return 0;
430 }
431 
432 #define KVM_REG_FEATURE_LEVEL_MASK	GENMASK(3, 0)
433 
434 /*
435  * Convert the workaround level into an easy-to-compare number, where higher
436  * values mean better protection.
437  */
438 static int get_kernel_wa_level(struct kvm_vcpu *vcpu, u64 regid)
439 {
440 	switch (regid) {
441 	case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1:
442 		switch (arm64_get_spectre_v2_state()) {
443 		case SPECTRE_VULNERABLE:
444 			return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_NOT_AVAIL;
445 		case SPECTRE_MITIGATED:
446 			return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_AVAIL;
447 		case SPECTRE_UNAFFECTED:
448 			return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_NOT_REQUIRED;
449 		}
450 		return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_NOT_AVAIL;
451 	case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2:
452 		switch (arm64_get_spectre_v4_state()) {
453 		case SPECTRE_MITIGATED:
454 			/*
455 			 * As for the hypercall discovery, we pretend we
456 			 * don't have any FW mitigation if SSBS is there at
457 			 * all times.
458 			 */
459 			if (kvm_has_feat(vcpu->kvm, ID_AA64PFR1_EL1, SSBS, IMP))
460 				return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_AVAIL;
461 			fallthrough;
462 		case SPECTRE_UNAFFECTED:
463 			return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_REQUIRED;
464 		case SPECTRE_VULNERABLE:
465 			return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_AVAIL;
466 		}
467 		break;
468 	case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3:
469 		switch (arm64_get_spectre_bhb_state()) {
470 		case SPECTRE_VULNERABLE:
471 			return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_NOT_AVAIL;
472 		case SPECTRE_MITIGATED:
473 			return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_AVAIL;
474 		case SPECTRE_UNAFFECTED:
475 			return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_NOT_REQUIRED;
476 		}
477 		return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_NOT_AVAIL;
478 	}
479 
480 	return -EINVAL;
481 }
482 
483 int kvm_arm_get_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
484 {
485 	struct kvm_smccc_features *smccc_feat = &vcpu->kvm->arch.smccc_feat;
486 	void __user *uaddr = (void __user *)(long)reg->addr;
487 	u64 val;
488 
489 	switch (reg->id) {
490 	case KVM_REG_ARM_PSCI_VERSION:
491 		val = kvm_psci_version(vcpu);
492 		break;
493 	case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1:
494 	case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2:
495 	case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3:
496 		val = get_kernel_wa_level(vcpu, reg->id) & KVM_REG_FEATURE_LEVEL_MASK;
497 		break;
498 	case KVM_REG_ARM_STD_BMAP:
499 		val = READ_ONCE(smccc_feat->std_bmap);
500 		break;
501 	case KVM_REG_ARM_STD_HYP_BMAP:
502 		val = READ_ONCE(smccc_feat->std_hyp_bmap);
503 		break;
504 	case KVM_REG_ARM_VENDOR_HYP_BMAP:
505 		val = READ_ONCE(smccc_feat->vendor_hyp_bmap);
506 		break;
507 	case KVM_REG_ARM_VENDOR_HYP_BMAP_2:
508 		val = READ_ONCE(smccc_feat->vendor_hyp_bmap_2);
509 		break;
510 	default:
511 		return -ENOENT;
512 	}
513 
514 	if (copy_to_user(uaddr, &val, KVM_REG_SIZE(reg->id)))
515 		return -EFAULT;
516 
517 	return 0;
518 }
519 
520 static int kvm_arm_set_fw_reg_bmap(struct kvm_vcpu *vcpu, u64 reg_id, u64 val)
521 {
522 	int ret = 0;
523 	struct kvm *kvm = vcpu->kvm;
524 	struct kvm_smccc_features *smccc_feat = &kvm->arch.smccc_feat;
525 	unsigned long *fw_reg_bmap, fw_reg_features;
526 
527 	switch (reg_id) {
528 	case KVM_REG_ARM_STD_BMAP:
529 		fw_reg_bmap = &smccc_feat->std_bmap;
530 		fw_reg_features = KVM_ARM_SMCCC_STD_FEATURES;
531 		break;
532 	case KVM_REG_ARM_STD_HYP_BMAP:
533 		fw_reg_bmap = &smccc_feat->std_hyp_bmap;
534 		fw_reg_features = KVM_ARM_SMCCC_STD_HYP_FEATURES;
535 		break;
536 	case KVM_REG_ARM_VENDOR_HYP_BMAP:
537 		fw_reg_bmap = &smccc_feat->vendor_hyp_bmap;
538 		fw_reg_features = KVM_ARM_SMCCC_VENDOR_HYP_FEATURES;
539 		break;
540 	case KVM_REG_ARM_VENDOR_HYP_BMAP_2:
541 		fw_reg_bmap = &smccc_feat->vendor_hyp_bmap_2;
542 		fw_reg_features = KVM_ARM_SMCCC_VENDOR_HYP_FEATURES_2;
543 		break;
544 	default:
545 		return -ENOENT;
546 	}
547 
548 	/* Check for unsupported bit */
549 	if (val & ~fw_reg_features)
550 		return -EINVAL;
551 
552 	mutex_lock(&kvm->arch.config_lock);
553 
554 	if (kvm_vm_has_ran_once(kvm) && val != *fw_reg_bmap) {
555 		ret = -EBUSY;
556 		goto out;
557 	}
558 
559 	WRITE_ONCE(*fw_reg_bmap, val);
560 out:
561 	mutex_unlock(&kvm->arch.config_lock);
562 	return ret;
563 }
564 
565 int kvm_arm_set_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
566 {
567 	void __user *uaddr = (void __user *)(long)reg->addr;
568 	u64 val;
569 	int wa_level;
570 
571 	if (KVM_REG_SIZE(reg->id) != sizeof(val))
572 		return -ENOENT;
573 	if (copy_from_user(&val, uaddr, KVM_REG_SIZE(reg->id)))
574 		return -EFAULT;
575 
576 	switch (reg->id) {
577 	case KVM_REG_ARM_PSCI_VERSION:
578 	{
579 		bool wants_02;
580 
581 		wants_02 = vcpu_has_feature(vcpu, KVM_ARM_VCPU_PSCI_0_2);
582 
583 		switch (val) {
584 		case KVM_ARM_PSCI_0_1:
585 			if (wants_02)
586 				return -EINVAL;
587 			vcpu->kvm->arch.psci_version = val;
588 			return 0;
589 		case KVM_ARM_PSCI_0_2:
590 		case KVM_ARM_PSCI_1_0:
591 		case KVM_ARM_PSCI_1_1:
592 		case KVM_ARM_PSCI_1_2:
593 		case KVM_ARM_PSCI_1_3:
594 			if (!wants_02)
595 				return -EINVAL;
596 			vcpu->kvm->arch.psci_version = val;
597 			return 0;
598 		}
599 		break;
600 	}
601 
602 	case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1:
603 	case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3:
604 		if (val & ~KVM_REG_FEATURE_LEVEL_MASK)
605 			return -EINVAL;
606 
607 		if (get_kernel_wa_level(vcpu, reg->id) < val)
608 			return -EINVAL;
609 
610 		return 0;
611 
612 	case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2:
613 		if (val & ~(KVM_REG_FEATURE_LEVEL_MASK |
614 			    KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_ENABLED))
615 			return -EINVAL;
616 
617 		/* The enabled bit must not be set unless the level is AVAIL. */
618 		if ((val & KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_ENABLED) &&
619 		    (val & KVM_REG_FEATURE_LEVEL_MASK) != KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_AVAIL)
620 			return -EINVAL;
621 
622 		/*
623 		 * Map all the possible incoming states to the only two we
624 		 * really want to deal with.
625 		 */
626 		switch (val & KVM_REG_FEATURE_LEVEL_MASK) {
627 		case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_AVAIL:
628 		case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_UNKNOWN:
629 			wa_level = KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_AVAIL;
630 			break;
631 		case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_AVAIL:
632 		case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_REQUIRED:
633 			wa_level = KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_REQUIRED;
634 			break;
635 		default:
636 			return -EINVAL;
637 		}
638 
639 		/*
640 		 * We can deal with NOT_AVAIL on NOT_REQUIRED, but not the
641 		 * other way around.
642 		 */
643 		if (get_kernel_wa_level(vcpu, reg->id) < wa_level)
644 			return -EINVAL;
645 
646 		return 0;
647 	case KVM_REG_ARM_STD_BMAP:
648 	case KVM_REG_ARM_STD_HYP_BMAP:
649 	case KVM_REG_ARM_VENDOR_HYP_BMAP:
650 	case KVM_REG_ARM_VENDOR_HYP_BMAP_2:
651 		return kvm_arm_set_fw_reg_bmap(vcpu, reg->id, val);
652 	default:
653 		return -ENOENT;
654 	}
655 
656 	return -EINVAL;
657 }
658 
659 int kvm_vm_smccc_has_attr(struct kvm *kvm, struct kvm_device_attr *attr)
660 {
661 	switch (attr->attr) {
662 	case KVM_ARM_VM_SMCCC_FILTER:
663 		return 0;
664 	default:
665 		return -ENXIO;
666 	}
667 }
668 
669 int kvm_vm_smccc_set_attr(struct kvm *kvm, struct kvm_device_attr *attr)
670 {
671 	void __user *uaddr = (void __user *)attr->addr;
672 
673 	switch (attr->attr) {
674 	case KVM_ARM_VM_SMCCC_FILTER:
675 		return kvm_smccc_set_filter(kvm, uaddr);
676 	default:
677 		return -ENXIO;
678 	}
679 }
680