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
kvm_ptp_get_time(struct kvm_vcpu * vcpu,u64 * val)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
kvm_smccc_default_allowed(u32 func_id)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
kvm_smccc_test_fw_bmap(struct kvm_vcpu * vcpu,u32 func_id)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
kvm_smccc_filter_insert_reserved(struct kvm * kvm)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
kvm_smccc_filter_configured(struct kvm * kvm)167 static bool kvm_smccc_filter_configured(struct kvm *kvm)
168 {
169 return !mtree_empty(&kvm->arch.smccc_filter);
170 }
171
kvm_smccc_set_filter(struct kvm * kvm,struct kvm_smccc_filter __user * uaddr)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
kvm_smccc_filter_get_action(struct kvm * kvm,u32 func_id)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
kvm_smccc_get_action(struct kvm_vcpu * vcpu,u32 func_id)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
kvm_prepare_hypercall_exit(struct kvm_vcpu * vcpu,u32 func_id)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
kvm_smccc_call_handler(struct kvm_vcpu * vcpu)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
kvm_arm_init_hypercalls(struct kvm * kvm)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
kvm_arm_teardown_hypercalls(struct kvm * kvm)410 void kvm_arm_teardown_hypercalls(struct kvm *kvm)
411 {
412 mtree_destroy(&kvm->arch.smccc_filter);
413 }
414
kvm_arm_get_fw_num_regs(struct kvm_vcpu * vcpu)415 int kvm_arm_get_fw_num_regs(struct kvm_vcpu *vcpu)
416 {
417 return ARRAY_SIZE(kvm_arm_fw_reg_ids);
418 }
419
kvm_arm_copy_fw_reg_indices(struct kvm_vcpu * vcpu,u64 __user * uindices)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 */
get_kernel_wa_level(struct kvm_vcpu * vcpu,u64 regid)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
kvm_arm_get_fw_reg(struct kvm_vcpu * vcpu,const struct kvm_one_reg * reg)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
kvm_arm_set_fw_reg_bmap(struct kvm_vcpu * vcpu,u64 reg_id,u64 val)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
kvm_arm_set_fw_reg(struct kvm_vcpu * vcpu,const struct kvm_one_reg * reg)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
kvm_vm_smccc_has_attr(struct kvm * kvm,struct kvm_device_attr * attr)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
kvm_vm_smccc_set_attr(struct kvm * kvm,struct kvm_device_attr * attr)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