xref: /linux/tools/testing/selftests/kvm/aarch64/set_id_regs.c (revision d129377639907fce7e0a27990e590e4661d3ee02)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * set_id_regs - Test for setting ID register from usersapce.
4  *
5  * Copyright (c) 2023 Google LLC.
6  *
7  *
8  * Test that KVM supports setting ID registers from userspace and handles the
9  * feature set correctly.
10  */
11 
12 #include <stdint.h>
13 #include "kvm_util.h"
14 #include "processor.h"
15 #include "test_util.h"
16 #include <linux/bitfield.h>
17 
18 enum ftr_type {
19 	FTR_EXACT,			/* Use a predefined safe value */
20 	FTR_LOWER_SAFE,			/* Smaller value is safe */
21 	FTR_HIGHER_SAFE,		/* Bigger value is safe */
22 	FTR_HIGHER_OR_ZERO_SAFE,	/* Bigger value is safe, but 0 is biggest */
23 	FTR_END,			/* Mark the last ftr bits */
24 };
25 
26 #define FTR_SIGNED	true	/* Value should be treated as signed */
27 #define FTR_UNSIGNED	false	/* Value should be treated as unsigned */
28 
29 struct reg_ftr_bits {
30 	char *name;
31 	bool sign;
32 	enum ftr_type type;
33 	uint8_t shift;
34 	uint64_t mask;
35 	/*
36 	 * For FTR_EXACT, safe_val is used as the exact safe value.
37 	 * For FTR_LOWER_SAFE, safe_val is used as the minimal safe value.
38 	 */
39 	int64_t safe_val;
40 };
41 
42 struct test_feature_reg {
43 	uint32_t reg;
44 	const struct reg_ftr_bits *ftr_bits;
45 };
46 
47 #define __REG_FTR_BITS(NAME, SIGNED, TYPE, SHIFT, MASK, SAFE_VAL)	\
48 	{								\
49 		.name = #NAME,						\
50 		.sign = SIGNED,						\
51 		.type = TYPE,						\
52 		.shift = SHIFT,						\
53 		.mask = MASK,						\
54 		.safe_val = SAFE_VAL,					\
55 	}
56 
57 #define REG_FTR_BITS(type, reg, field, safe_val) \
58 	__REG_FTR_BITS(reg##_##field, FTR_UNSIGNED, type, reg##_##field##_SHIFT, \
59 		       reg##_##field##_MASK, safe_val)
60 
61 #define S_REG_FTR_BITS(type, reg, field, safe_val) \
62 	__REG_FTR_BITS(reg##_##field, FTR_SIGNED, type, reg##_##field##_SHIFT, \
63 		       reg##_##field##_MASK, safe_val)
64 
65 #define REG_FTR_END					\
66 	{						\
67 		.type = FTR_END,			\
68 	}
69 
70 static const struct reg_ftr_bits ftr_id_aa64dfr0_el1[] = {
71 	S_REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64DFR0_EL1, DoubleLock, 0),
72 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64DFR0_EL1, WRPs, 0),
73 	S_REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64DFR0_EL1, PMUVer, 0),
74 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64DFR0_EL1, DebugVer, ID_AA64DFR0_EL1_DebugVer_IMP),
75 	REG_FTR_END,
76 };
77 
78 static const struct reg_ftr_bits ftr_id_dfr0_el1[] = {
79 	S_REG_FTR_BITS(FTR_LOWER_SAFE, ID_DFR0_EL1, PerfMon, ID_DFR0_EL1_PerfMon_PMUv3),
80 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_DFR0_EL1, CopDbg, ID_DFR0_EL1_CopDbg_Armv8),
81 	REG_FTR_END,
82 };
83 
84 static const struct reg_ftr_bits ftr_id_aa64isar0_el1[] = {
85 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR0_EL1, RNDR, 0),
86 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR0_EL1, TLB, 0),
87 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR0_EL1, TS, 0),
88 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR0_EL1, FHM, 0),
89 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR0_EL1, DP, 0),
90 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR0_EL1, SM4, 0),
91 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR0_EL1, SM3, 0),
92 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR0_EL1, SHA3, 0),
93 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR0_EL1, RDM, 0),
94 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR0_EL1, TME, 0),
95 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR0_EL1, ATOMIC, 0),
96 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR0_EL1, CRC32, 0),
97 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR0_EL1, SHA2, 0),
98 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR0_EL1, SHA1, 0),
99 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR0_EL1, AES, 0),
100 	REG_FTR_END,
101 };
102 
103 static const struct reg_ftr_bits ftr_id_aa64isar1_el1[] = {
104 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR1_EL1, LS64, 0),
105 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR1_EL1, XS, 0),
106 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR1_EL1, I8MM, 0),
107 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR1_EL1, DGH, 0),
108 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR1_EL1, BF16, 0),
109 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR1_EL1, SPECRES, 0),
110 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR1_EL1, SB, 0),
111 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR1_EL1, FRINTTS, 0),
112 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR1_EL1, LRCPC, 0),
113 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR1_EL1, FCMA, 0),
114 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR1_EL1, JSCVT, 0),
115 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR1_EL1, DPB, 0),
116 	REG_FTR_END,
117 };
118 
119 static const struct reg_ftr_bits ftr_id_aa64isar2_el1[] = {
120 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR2_EL1, BC, 0),
121 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR2_EL1, RPRES, 0),
122 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR2_EL1, WFxT, 0),
123 	REG_FTR_END,
124 };
125 
126 static const struct reg_ftr_bits ftr_id_aa64pfr0_el1[] = {
127 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR0_EL1, CSV3, 0),
128 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR0_EL1, CSV2, 0),
129 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR0_EL1, DIT, 0),
130 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR0_EL1, SEL2, 0),
131 	REG_FTR_BITS(FTR_EXACT, ID_AA64PFR0_EL1, GIC, 0),
132 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR0_EL1, EL3, 0),
133 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR0_EL1, EL2, 0),
134 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR0_EL1, EL1, 0),
135 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR0_EL1, EL0, 0),
136 	REG_FTR_END,
137 };
138 
139 static const struct reg_ftr_bits ftr_id_aa64pfr1_el1[] = {
140 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR1_EL1, CSV2_frac, 0),
141 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR1_EL1, SSBS, ID_AA64PFR1_EL1_SSBS_NI),
142 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR1_EL1, BT, 0),
143 	REG_FTR_END,
144 };
145 
146 static const struct reg_ftr_bits ftr_id_aa64mmfr0_el1[] = {
147 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR0_EL1, ECV, 0),
148 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR0_EL1, EXS, 0),
149 	S_REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR0_EL1, TGRAN4, 0),
150 	S_REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR0_EL1, TGRAN64, 0),
151 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR0_EL1, TGRAN16, 0),
152 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR0_EL1, BIGENDEL0, 0),
153 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR0_EL1, SNSMEM, 0),
154 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR0_EL1, BIGEND, 0),
155 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR0_EL1, ASIDBITS, 0),
156 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR0_EL1, PARANGE, 0),
157 	REG_FTR_END,
158 };
159 
160 static const struct reg_ftr_bits ftr_id_aa64mmfr1_el1[] = {
161 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR1_EL1, TIDCP1, 0),
162 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR1_EL1, AFP, 0),
163 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR1_EL1, ETS, 0),
164 	REG_FTR_BITS(FTR_HIGHER_SAFE, ID_AA64MMFR1_EL1, SpecSEI, 0),
165 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR1_EL1, PAN, 0),
166 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR1_EL1, LO, 0),
167 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR1_EL1, HPDS, 0),
168 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR1_EL1, HAFDBS, 0),
169 	REG_FTR_END,
170 };
171 
172 static const struct reg_ftr_bits ftr_id_aa64mmfr2_el1[] = {
173 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR2_EL1, E0PD, 0),
174 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR2_EL1, BBM, 0),
175 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR2_EL1, TTL, 0),
176 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR2_EL1, AT, 0),
177 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR2_EL1, ST, 0),
178 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR2_EL1, VARange, 0),
179 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR2_EL1, IESB, 0),
180 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR2_EL1, LSM, 0),
181 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR2_EL1, UAO, 0),
182 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR2_EL1, CnP, 0),
183 	REG_FTR_END,
184 };
185 
186 static const struct reg_ftr_bits ftr_id_aa64zfr0_el1[] = {
187 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ZFR0_EL1, F64MM, 0),
188 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ZFR0_EL1, F32MM, 0),
189 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ZFR0_EL1, I8MM, 0),
190 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ZFR0_EL1, SM4, 0),
191 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ZFR0_EL1, SHA3, 0),
192 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ZFR0_EL1, BF16, 0),
193 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ZFR0_EL1, BitPerm, 0),
194 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ZFR0_EL1, AES, 0),
195 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ZFR0_EL1, SVEver, 0),
196 	REG_FTR_END,
197 };
198 
199 #define TEST_REG(id, table)			\
200 	{					\
201 		.reg = id,			\
202 		.ftr_bits = &((table)[0]),	\
203 	}
204 
205 static struct test_feature_reg test_regs[] = {
206 	TEST_REG(SYS_ID_AA64DFR0_EL1, ftr_id_aa64dfr0_el1),
207 	TEST_REG(SYS_ID_DFR0_EL1, ftr_id_dfr0_el1),
208 	TEST_REG(SYS_ID_AA64ISAR0_EL1, ftr_id_aa64isar0_el1),
209 	TEST_REG(SYS_ID_AA64ISAR1_EL1, ftr_id_aa64isar1_el1),
210 	TEST_REG(SYS_ID_AA64ISAR2_EL1, ftr_id_aa64isar2_el1),
211 	TEST_REG(SYS_ID_AA64PFR0_EL1, ftr_id_aa64pfr0_el1),
212 	TEST_REG(SYS_ID_AA64PFR1_EL1, ftr_id_aa64pfr1_el1),
213 	TEST_REG(SYS_ID_AA64MMFR0_EL1, ftr_id_aa64mmfr0_el1),
214 	TEST_REG(SYS_ID_AA64MMFR1_EL1, ftr_id_aa64mmfr1_el1),
215 	TEST_REG(SYS_ID_AA64MMFR2_EL1, ftr_id_aa64mmfr2_el1),
216 	TEST_REG(SYS_ID_AA64ZFR0_EL1, ftr_id_aa64zfr0_el1),
217 };
218 
219 #define GUEST_REG_SYNC(id) GUEST_SYNC_ARGS(0, id, read_sysreg_s(id), 0, 0);
220 
221 static void guest_code(void)
222 {
223 	GUEST_REG_SYNC(SYS_ID_AA64DFR0_EL1);
224 	GUEST_REG_SYNC(SYS_ID_DFR0_EL1);
225 	GUEST_REG_SYNC(SYS_ID_AA64ISAR0_EL1);
226 	GUEST_REG_SYNC(SYS_ID_AA64ISAR1_EL1);
227 	GUEST_REG_SYNC(SYS_ID_AA64ISAR2_EL1);
228 	GUEST_REG_SYNC(SYS_ID_AA64PFR0_EL1);
229 	GUEST_REG_SYNC(SYS_ID_AA64MMFR0_EL1);
230 	GUEST_REG_SYNC(SYS_ID_AA64MMFR1_EL1);
231 	GUEST_REG_SYNC(SYS_ID_AA64MMFR2_EL1);
232 	GUEST_REG_SYNC(SYS_ID_AA64ZFR0_EL1);
233 	GUEST_REG_SYNC(SYS_CTR_EL0);
234 
235 	GUEST_DONE();
236 }
237 
238 /* Return a safe value to a given ftr_bits an ftr value */
239 uint64_t get_safe_value(const struct reg_ftr_bits *ftr_bits, uint64_t ftr)
240 {
241 	uint64_t ftr_max = GENMASK_ULL(ARM64_FEATURE_FIELD_BITS - 1, 0);
242 
243 	if (ftr_bits->sign == FTR_UNSIGNED) {
244 		switch (ftr_bits->type) {
245 		case FTR_EXACT:
246 			ftr = ftr_bits->safe_val;
247 			break;
248 		case FTR_LOWER_SAFE:
249 			if (ftr > ftr_bits->safe_val)
250 				ftr--;
251 			break;
252 		case FTR_HIGHER_SAFE:
253 			if (ftr < ftr_max)
254 				ftr++;
255 			break;
256 		case FTR_HIGHER_OR_ZERO_SAFE:
257 			if (ftr == ftr_max)
258 				ftr = 0;
259 			else if (ftr != 0)
260 				ftr++;
261 			break;
262 		default:
263 			break;
264 		}
265 	} else if (ftr != ftr_max) {
266 		switch (ftr_bits->type) {
267 		case FTR_EXACT:
268 			ftr = ftr_bits->safe_val;
269 			break;
270 		case FTR_LOWER_SAFE:
271 			if (ftr > ftr_bits->safe_val)
272 				ftr--;
273 			break;
274 		case FTR_HIGHER_SAFE:
275 			if (ftr < ftr_max - 1)
276 				ftr++;
277 			break;
278 		case FTR_HIGHER_OR_ZERO_SAFE:
279 			if (ftr != 0 && ftr != ftr_max - 1)
280 				ftr++;
281 			break;
282 		default:
283 			break;
284 		}
285 	}
286 
287 	return ftr;
288 }
289 
290 /* Return an invalid value to a given ftr_bits an ftr value */
291 uint64_t get_invalid_value(const struct reg_ftr_bits *ftr_bits, uint64_t ftr)
292 {
293 	uint64_t ftr_max = GENMASK_ULL(ARM64_FEATURE_FIELD_BITS - 1, 0);
294 
295 	if (ftr_bits->sign == FTR_UNSIGNED) {
296 		switch (ftr_bits->type) {
297 		case FTR_EXACT:
298 			ftr = max((uint64_t)ftr_bits->safe_val + 1, ftr + 1);
299 			break;
300 		case FTR_LOWER_SAFE:
301 			ftr++;
302 			break;
303 		case FTR_HIGHER_SAFE:
304 			ftr--;
305 			break;
306 		case FTR_HIGHER_OR_ZERO_SAFE:
307 			if (ftr == 0)
308 				ftr = ftr_max;
309 			else
310 				ftr--;
311 			break;
312 		default:
313 			break;
314 		}
315 	} else if (ftr != ftr_max) {
316 		switch (ftr_bits->type) {
317 		case FTR_EXACT:
318 			ftr = max((uint64_t)ftr_bits->safe_val + 1, ftr + 1);
319 			break;
320 		case FTR_LOWER_SAFE:
321 			ftr++;
322 			break;
323 		case FTR_HIGHER_SAFE:
324 			ftr--;
325 			break;
326 		case FTR_HIGHER_OR_ZERO_SAFE:
327 			if (ftr == 0)
328 				ftr = ftr_max - 1;
329 			else
330 				ftr--;
331 			break;
332 		default:
333 			break;
334 		}
335 	} else {
336 		ftr = 0;
337 	}
338 
339 	return ftr;
340 }
341 
342 static uint64_t test_reg_set_success(struct kvm_vcpu *vcpu, uint64_t reg,
343 				     const struct reg_ftr_bits *ftr_bits)
344 {
345 	uint8_t shift = ftr_bits->shift;
346 	uint64_t mask = ftr_bits->mask;
347 	uint64_t val, new_val, ftr;
348 
349 	vcpu_get_reg(vcpu, reg, &val);
350 	ftr = (val & mask) >> shift;
351 
352 	ftr = get_safe_value(ftr_bits, ftr);
353 
354 	ftr <<= shift;
355 	val &= ~mask;
356 	val |= ftr;
357 
358 	vcpu_set_reg(vcpu, reg, val);
359 	vcpu_get_reg(vcpu, reg, &new_val);
360 	TEST_ASSERT_EQ(new_val, val);
361 
362 	return new_val;
363 }
364 
365 static void test_reg_set_fail(struct kvm_vcpu *vcpu, uint64_t reg,
366 			      const struct reg_ftr_bits *ftr_bits)
367 {
368 	uint8_t shift = ftr_bits->shift;
369 	uint64_t mask = ftr_bits->mask;
370 	uint64_t val, old_val, ftr;
371 	int r;
372 
373 	vcpu_get_reg(vcpu, reg, &val);
374 	ftr = (val & mask) >> shift;
375 
376 	ftr = get_invalid_value(ftr_bits, ftr);
377 
378 	old_val = val;
379 	ftr <<= shift;
380 	val &= ~mask;
381 	val |= ftr;
382 
383 	r = __vcpu_set_reg(vcpu, reg, val);
384 	TEST_ASSERT(r < 0 && errno == EINVAL,
385 		    "Unexpected KVM_SET_ONE_REG error: r=%d, errno=%d", r, errno);
386 
387 	vcpu_get_reg(vcpu, reg, &val);
388 	TEST_ASSERT_EQ(val, old_val);
389 }
390 
391 static uint64_t test_reg_vals[KVM_ARM_FEATURE_ID_RANGE_SIZE];
392 
393 #define encoding_to_range_idx(encoding)							\
394 	KVM_ARM_FEATURE_ID_RANGE_IDX(sys_reg_Op0(encoding), sys_reg_Op1(encoding),	\
395 				     sys_reg_CRn(encoding), sys_reg_CRm(encoding),	\
396 				     sys_reg_Op2(encoding))
397 
398 
399 static void test_vm_ftr_id_regs(struct kvm_vcpu *vcpu, bool aarch64_only)
400 {
401 	uint64_t masks[KVM_ARM_FEATURE_ID_RANGE_SIZE];
402 	struct reg_mask_range range = {
403 		.addr = (__u64)masks,
404 	};
405 	int ret;
406 
407 	/* KVM should return error when reserved field is not zero */
408 	range.reserved[0] = 1;
409 	ret = __vm_ioctl(vcpu->vm, KVM_ARM_GET_REG_WRITABLE_MASKS, &range);
410 	TEST_ASSERT(ret, "KVM doesn't check invalid parameters.");
411 
412 	/* Get writable masks for feature ID registers */
413 	memset(range.reserved, 0, sizeof(range.reserved));
414 	vm_ioctl(vcpu->vm, KVM_ARM_GET_REG_WRITABLE_MASKS, &range);
415 
416 	for (int i = 0; i < ARRAY_SIZE(test_regs); i++) {
417 		const struct reg_ftr_bits *ftr_bits = test_regs[i].ftr_bits;
418 		uint32_t reg_id = test_regs[i].reg;
419 		uint64_t reg = KVM_ARM64_SYS_REG(reg_id);
420 		int idx;
421 
422 		/* Get the index to masks array for the idreg */
423 		idx = encoding_to_range_idx(reg_id);
424 
425 		for (int j = 0;  ftr_bits[j].type != FTR_END; j++) {
426 			/* Skip aarch32 reg on aarch64 only system, since they are RAZ/WI. */
427 			if (aarch64_only && sys_reg_CRm(reg_id) < 4) {
428 				ksft_test_result_skip("%s on AARCH64 only system\n",
429 						      ftr_bits[j].name);
430 				continue;
431 			}
432 
433 			/* Make sure the feature field is writable */
434 			TEST_ASSERT_EQ(masks[idx] & ftr_bits[j].mask, ftr_bits[j].mask);
435 
436 			test_reg_set_fail(vcpu, reg, &ftr_bits[j]);
437 
438 			test_reg_vals[idx] = test_reg_set_success(vcpu, reg,
439 								  &ftr_bits[j]);
440 
441 			ksft_test_result_pass("%s\n", ftr_bits[j].name);
442 		}
443 	}
444 }
445 
446 static void test_guest_reg_read(struct kvm_vcpu *vcpu)
447 {
448 	bool done = false;
449 	struct ucall uc;
450 
451 	while (!done) {
452 		vcpu_run(vcpu);
453 
454 		switch (get_ucall(vcpu, &uc)) {
455 		case UCALL_ABORT:
456 			REPORT_GUEST_ASSERT(uc);
457 			break;
458 		case UCALL_SYNC:
459 			/* Make sure the written values are seen by guest */
460 			TEST_ASSERT_EQ(test_reg_vals[encoding_to_range_idx(uc.args[2])],
461 				       uc.args[3]);
462 			break;
463 		case UCALL_DONE:
464 			done = true;
465 			break;
466 		default:
467 			TEST_FAIL("Unexpected ucall: %lu", uc.cmd);
468 		}
469 	}
470 }
471 
472 /* Politely lifted from arch/arm64/include/asm/cache.h */
473 /* Ctypen, bits[3(n - 1) + 2 : 3(n - 1)], for n = 1 to 7 */
474 #define CLIDR_CTYPE_SHIFT(level)	(3 * (level - 1))
475 #define CLIDR_CTYPE_MASK(level)		(7 << CLIDR_CTYPE_SHIFT(level))
476 #define CLIDR_CTYPE(clidr, level)	\
477 	(((clidr) & CLIDR_CTYPE_MASK(level)) >> CLIDR_CTYPE_SHIFT(level))
478 
479 static void test_clidr(struct kvm_vcpu *vcpu)
480 {
481 	uint64_t clidr;
482 	int level;
483 
484 	vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(SYS_CLIDR_EL1), &clidr);
485 
486 	/* find the first empty level in the cache hierarchy */
487 	for (level = 1; level < 7; level++) {
488 		if (!CLIDR_CTYPE(clidr, level))
489 			break;
490 	}
491 
492 	/*
493 	 * If you have a mind-boggling 7 levels of cache, congratulations, you
494 	 * get to fix this.
495 	 */
496 	TEST_ASSERT(level <= 7, "can't find an empty level in cache hierarchy");
497 
498 	/* stick in a unified cache level */
499 	clidr |= BIT(2) << CLIDR_CTYPE_SHIFT(level);
500 
501 	vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_CLIDR_EL1), clidr);
502 	test_reg_vals[encoding_to_range_idx(SYS_CLIDR_EL1)] = clidr;
503 }
504 
505 static void test_ctr(struct kvm_vcpu *vcpu)
506 {
507 	u64 ctr;
508 
509 	vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(SYS_CTR_EL0), &ctr);
510 	ctr &= ~CTR_EL0_DIC_MASK;
511 	if (ctr & CTR_EL0_IminLine_MASK)
512 		ctr--;
513 
514 	vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_CTR_EL0), ctr);
515 	test_reg_vals[encoding_to_range_idx(SYS_CTR_EL0)] = ctr;
516 }
517 
518 static void test_vcpu_ftr_id_regs(struct kvm_vcpu *vcpu)
519 {
520 	u64 val;
521 
522 	test_clidr(vcpu);
523 	test_ctr(vcpu);
524 
525 	vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(SYS_MPIDR_EL1), &val);
526 	val++;
527 	vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_MPIDR_EL1), val);
528 
529 	test_reg_vals[encoding_to_range_idx(SYS_MPIDR_EL1)] = val;
530 	ksft_test_result_pass("%s\n", __func__);
531 }
532 
533 static void test_assert_id_reg_unchanged(struct kvm_vcpu *vcpu, uint32_t encoding)
534 {
535 	size_t idx = encoding_to_range_idx(encoding);
536 	uint64_t observed;
537 
538 	vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(encoding), &observed);
539 	TEST_ASSERT_EQ(test_reg_vals[idx], observed);
540 }
541 
542 static void test_reset_preserves_id_regs(struct kvm_vcpu *vcpu)
543 {
544 	/*
545 	 * Calls KVM_ARM_VCPU_INIT behind the scenes, which will do an
546 	 * architectural reset of the vCPU.
547 	 */
548 	aarch64_vcpu_setup(vcpu, NULL);
549 
550 	for (int i = 0; i < ARRAY_SIZE(test_regs); i++)
551 		test_assert_id_reg_unchanged(vcpu, test_regs[i].reg);
552 
553 	test_assert_id_reg_unchanged(vcpu, SYS_MPIDR_EL1);
554 	test_assert_id_reg_unchanged(vcpu, SYS_CLIDR_EL1);
555 	test_assert_id_reg_unchanged(vcpu, SYS_CTR_EL0);
556 
557 	ksft_test_result_pass("%s\n", __func__);
558 }
559 
560 int main(void)
561 {
562 	struct kvm_vcpu *vcpu;
563 	struct kvm_vm *vm;
564 	bool aarch64_only;
565 	uint64_t val, el0;
566 	int test_cnt;
567 
568 	TEST_REQUIRE(kvm_has_cap(KVM_CAP_ARM_SUPPORTED_REG_MASK_RANGES));
569 
570 	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
571 
572 	/* Check for AARCH64 only system */
573 	vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(SYS_ID_AA64PFR0_EL1), &val);
574 	el0 = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_EL0), val);
575 	aarch64_only = (el0 == ID_AA64PFR0_EL1_ELx_64BIT_ONLY);
576 
577 	ksft_print_header();
578 
579 	test_cnt = ARRAY_SIZE(ftr_id_aa64dfr0_el1) + ARRAY_SIZE(ftr_id_dfr0_el1) +
580 		   ARRAY_SIZE(ftr_id_aa64isar0_el1) + ARRAY_SIZE(ftr_id_aa64isar1_el1) +
581 		   ARRAY_SIZE(ftr_id_aa64isar2_el1) + ARRAY_SIZE(ftr_id_aa64pfr0_el1) +
582 		   ARRAY_SIZE(ftr_id_aa64pfr1_el1) + ARRAY_SIZE(ftr_id_aa64mmfr0_el1) +
583 		   ARRAY_SIZE(ftr_id_aa64mmfr1_el1) + ARRAY_SIZE(ftr_id_aa64mmfr2_el1) +
584 		   ARRAY_SIZE(ftr_id_aa64zfr0_el1) - ARRAY_SIZE(test_regs) + 2;
585 
586 	ksft_set_plan(test_cnt);
587 
588 	test_vm_ftr_id_regs(vcpu, aarch64_only);
589 	test_vcpu_ftr_id_regs(vcpu);
590 
591 	test_guest_reg_read(vcpu);
592 
593 	test_reset_preserves_id_regs(vcpu);
594 
595 	kvm_vm_free(vm);
596 
597 	ksft_finished();
598 }
599