xref: /kvm-unit-tests/arm/selftest.c (revision 2c96b77ec9d3b1fcec7525174e23a6240ee05949)
1 /*
2  * Test the framework itself. These tests confirm that setup works.
3  *
4  * Copyright (C) 2014, Red Hat Inc, Andrew Jones <drjones@redhat.com>
5  *
6  * This work is licensed under the terms of the GNU LGPL, version 2.
7  */
8 #include <libcflat.h>
9 #include <util.h>
10 #include <devicetree.h>
11 #include <vmalloc.h>
12 #include <asm/setup.h>
13 #include <asm/ptrace.h>
14 #include <asm/asm-offsets.h>
15 #include <asm/processor.h>
16 #include <asm/thread_info.h>
17 #include <asm/psci.h>
18 #include <asm/smp.h>
19 #include <asm/mmu.h>
20 #include <asm/barrier.h>
21 
22 static cpumask_t ready, valid;
23 
24 static void __user_psci_system_off(void)
25 {
26 	psci_system_off();
27 	halt();
28 	__builtin_unreachable();
29 }
30 
31 static void check_setup(int argc, char **argv)
32 {
33 	int nr_tests = 0, len, i;
34 	long val;
35 
36 	for (i = 0; i < argc; ++i) {
37 
38 		len = parse_keyval(argv[i], &val);
39 		if (len == -1)
40 			continue;
41 
42 		argv[i][len] = '\0';
43 		report_prefix_push(argv[i]);
44 
45 		if (strcmp(argv[i], "mem") == 0) {
46 
47 			phys_addr_t memsize = PHYS_END - PHYS_OFFSET;
48 			phys_addr_t expected = ((phys_addr_t)val)*1024*1024;
49 
50 			report(memsize == expected,
51 			       "memory size matches expectation");
52 			report_info("found %" PRIu64 " MB", memsize/1024/1024);
53 			++nr_tests;
54 
55 		} else if (strcmp(argv[i], "smp") == 0) {
56 
57 			report(nr_cpus == (int)val,
58 			       "number of CPUs matches expectation");
59 			report_info("found %d CPUs", nr_cpus);
60 			++nr_tests;
61 		}
62 
63 		report_prefix_pop();
64 	}
65 
66 	if (nr_tests < 2)
67 		report_abort("missing input");
68 }
69 
70 unsigned long check_pabt_invalid_paddr;
71 static bool check_pabt_init(void)
72 {
73 	phys_addr_t highest_end = 0;
74 	unsigned long vaddr;
75 	struct mem_region *r;
76 
77 	/*
78 	 * We need a physical address that isn't backed by anything. Without
79 	 * fully parsing the device tree there's no way to be certain of any
80 	 * address, but an unknown address immediately following the highest
81 	 * memory region has a reasonable chance. This is because we can
82 	 * assume that that memory region could have been larger, if the user
83 	 * had configured more RAM, and therefore no MMIO region should be
84 	 * there.
85 	 */
86 	for (r = mem_regions; r->end; ++r) {
87 		if (r->flags & MR_F_IO)
88 			continue;
89 		if (r->end > highest_end)
90 			highest_end = PAGE_ALIGN(r->end);
91 	}
92 
93 	if (mem_region_get_flags(highest_end) != MR_F_UNKNOWN)
94 		return false;
95 
96 	vaddr = (unsigned long)vmap(highest_end, PAGE_SIZE);
97 	mmu_clear_user(current_thread_info()->pgtable, vaddr);
98 	check_pabt_invalid_paddr = vaddr;
99 
100 	return true;
101 }
102 
103 static struct pt_regs expected_regs;
104 static bool und_works;
105 static bool svc_works;
106 static bool pabt_works;
107 #if defined(__arm__)
108 /*
109  * Capture the current register state and execute an instruction
110  * that causes an exception. The test handler will check that its
111  * capture of the current register state matches the capture done
112  * here.
113  */
114 #define test_exception(pre_insns, excptn_insn, post_insns, clobbers...)	\
115 	asm volatile(							\
116 		pre_insns "\n"						\
117 		"mov	r0, %0\n"					\
118 		"stmia	r0, { r0-lr }\n"				\
119 		"mrs	r1, cpsr\n"					\
120 		"str	r1, [r0, #" xstr(S_PSR) "]\n"			\
121 		"mov	r1, #-1\n"					\
122 		"str	r1, [r0, #" xstr(S_OLD_R0) "]\n"		\
123 		"add	r1, pc, #8\n"					\
124 		"str	r1, [r0, #" xstr(S_R1) "]\n"			\
125 		"str	r1, [r0, #" xstr(S_PC) "]\n"			\
126 		excptn_insn "\n"					\
127 		post_insns "\n"						\
128 	:: "r" (&expected_regs) : "r0", "r1", ##clobbers)
129 
130 static bool check_regs(struct pt_regs *regs)
131 {
132 	unsigned i;
133 
134 	/* exception handlers should always run in svc mode */
135 	if (current_mode() != SVC_MODE)
136 		return false;
137 
138 	for (i = 0; i < ARRAY_SIZE(regs->uregs); ++i) {
139 		if (regs->uregs[i] != expected_regs.uregs[i])
140 			return false;
141 	}
142 
143 	return true;
144 }
145 
146 static void und_handler(struct pt_regs *regs)
147 {
148 	und_works = check_regs(regs);
149 }
150 
151 static bool check_und(void)
152 {
153 	install_exception_handler(EXCPTN_UND, und_handler);
154 
155 	/* issue an instruction to a coprocessor we don't have */
156 	test_exception("", "mcr p2, 0, r0, c0, c0", "", "r0");
157 
158 	install_exception_handler(EXCPTN_UND, NULL);
159 
160 	return und_works;
161 }
162 
163 static void svc_handler(struct pt_regs *regs)
164 {
165 	u32 svc = *(u32 *)(regs->ARM_pc - 4) & 0xffffff;
166 
167 	if (processor_mode(regs) == SVC_MODE) {
168 		/*
169 		 * When issuing an svc from supervisor mode lr_svc will
170 		 * get corrupted. So before issuing the svc, callers must
171 		 * always push it on the stack. We pushed it to offset 4.
172 		 */
173 		regs->ARM_lr = *(unsigned long *)(regs->ARM_sp + 4);
174 	}
175 
176 	svc_works = check_regs(regs) && svc == 123;
177 }
178 
179 static bool check_svc(void)
180 {
181 	install_exception_handler(EXCPTN_SVC, svc_handler);
182 
183 	if (current_mode() == SVC_MODE) {
184 		/*
185 		 * An svc from supervisor mode will corrupt lr_svc and
186 		 * spsr_svc. We need to save/restore them separately.
187 		 */
188 		test_exception(
189 			"mrs	r0, spsr\n"
190 			"push	{ r0,lr }\n",
191 			"svc	#123\n",
192 			"pop	{ r0,lr }\n"
193 			"msr	spsr_cxsf, r0\n",
194 			"r0", "lr"
195 		);
196 	} else {
197 		test_exception("", "svc #123", "");
198 	}
199 
200 	install_exception_handler(EXCPTN_SVC, NULL);
201 
202 	return svc_works;
203 }
204 
205 static void pabt_handler(struct pt_regs *regs)
206 {
207 	expected_regs.ARM_lr = expected_regs.ARM_pc;
208 	expected_regs.ARM_pc = expected_regs.ARM_r9;
209 
210 	pabt_works = check_regs(regs);
211 
212 	regs->ARM_pc = regs->ARM_lr;
213 }
214 
215 static bool check_pabt(void)
216 {
217 	install_exception_handler(EXCPTN_PABT, pabt_handler);
218 
219 	test_exception("ldr	r9, =check_pabt_invalid_paddr\n"
220 		       "ldr	r9, [r9]\n",
221 		       "blx	r9\n",
222 		       "", "r9", "lr");
223 
224 	install_exception_handler(EXCPTN_PABT, NULL);
225 
226 	return pabt_works;
227 }
228 
229 static void user_psci_system_off(struct pt_regs *regs)
230 {
231 	__user_psci_system_off();
232 }
233 #elif defined(__aarch64__)
234 
235 /*
236  * Capture the current register state and execute an instruction
237  * that causes an exception. The test handler will check that its
238  * capture of the current register state matches the capture done
239  * here.
240  */
241 #define test_exception(pre_insns, excptn_insn, post_insns, clobbers...)	\
242 	asm volatile(							\
243 		pre_insns "\n"						\
244 		"mov	x1, %0\n"					\
245 		"ldr	x0, [x1, #" xstr(S_PSTATE) "]\n"		\
246 		"mrs	x1, nzcv\n"					\
247 		"orr	w0, w0, w1\n"					\
248 		"mov	x1, %0\n"					\
249 		"str	w0, [x1, #" xstr(S_PSTATE) "]\n"		\
250 		"mov	x0, sp\n"					\
251 		"str	x0, [x1, #" xstr(S_SP) "]\n"			\
252 		"adr	x0, 1f\n"					\
253 		"str	x0, [x1, #" xstr(S_PC) "]\n"			\
254 		"stp	 x2,  x3, [x1,  #16]\n"				\
255 		"stp	 x4,  x5, [x1,  #32]\n"				\
256 		"stp	 x6,  x7, [x1,  #48]\n"				\
257 		"stp	 x8,  x9, [x1,  #64]\n"				\
258 		"stp	x10, x11, [x1,  #80]\n"				\
259 		"stp	x12, x13, [x1,  #96]\n"				\
260 		"stp	x14, x15, [x1, #112]\n"				\
261 		"stp	x16, x17, [x1, #128]\n"				\
262 		"stp	x18, x19, [x1, #144]\n"				\
263 		"stp	x20, x21, [x1, #160]\n"				\
264 		"stp	x22, x23, [x1, #176]\n"				\
265 		"stp	x24, x25, [x1, #192]\n"				\
266 		"stp	x26, x27, [x1, #208]\n"				\
267 		"stp	x28, x29, [x1, #224]\n"				\
268 		"str	x30, [x1, #" xstr(S_LR) "]\n"			\
269 		"stp	 x0,  x1, [x1]\n"				\
270 	"1:"	excptn_insn "\n"					\
271 		post_insns "\n"						\
272 	:: "r" (&expected_regs) : "x0", "x1", ##clobbers)
273 
274 static bool check_regs(struct pt_regs *regs)
275 {
276 	unsigned i;
277 
278 	/* exception handlers should always run in EL1 */
279 	if (current_level() != CurrentEL_EL1)
280 		return false;
281 
282 	for (i = 0; i < ARRAY_SIZE(regs->regs); ++i) {
283 		if (regs->regs[i] != expected_regs.regs[i])
284 			return false;
285 	}
286 
287 	regs->pstate &= 0xf0000000 /* NZCV */ | 0x3c0 /* DAIF */
288 			| PSR_MODE_MASK;
289 
290 	return regs->sp == expected_regs.sp
291 		&& regs->pc == expected_regs.pc
292 		&& regs->pstate == expected_regs.pstate;
293 }
294 
295 static enum vector check_vector_prep(void)
296 {
297 	unsigned long daif;
298 
299 	if (is_user())
300 		return EL0_SYNC_64;
301 
302 	asm volatile("mrs %0, daif" : "=r" (daif) ::);
303 	expected_regs.pstate = daif | PSR_MODE_EL1h;
304 	return EL1H_SYNC;
305 }
306 
307 static void unknown_handler(struct pt_regs *regs, unsigned int esr __unused)
308 {
309 	und_works = check_regs(regs);
310 	regs->pc += 4;
311 }
312 
313 static bool check_und(void)
314 {
315 	enum vector v = check_vector_prep();
316 
317 	install_exception_handler(v, ESR_EL1_EC_UNKNOWN, unknown_handler);
318 
319 	/* try to read an el2 sysreg from el0/1 */
320 	test_exception("", "mrs x0, sctlr_el2", "", "x0");
321 
322 	install_exception_handler(v, ESR_EL1_EC_UNKNOWN, NULL);
323 
324 	return und_works;
325 }
326 
327 static void svc_handler(struct pt_regs *regs, unsigned int esr)
328 {
329 	u16 svc = esr & 0xffff;
330 
331 	expected_regs.pc += 4;
332 	svc_works = check_regs(regs) && svc == 123;
333 }
334 
335 static bool check_svc(void)
336 {
337 	enum vector v = check_vector_prep();
338 
339 	install_exception_handler(v, ESR_EL1_EC_SVC64, svc_handler);
340 
341 	test_exception("", "svc #123", "");
342 
343 	install_exception_handler(v, ESR_EL1_EC_SVC64, NULL);
344 
345 	return svc_works;
346 }
347 
348 static void pabt_handler(struct pt_regs *regs, unsigned int esr)
349 {
350 	bool is_extabt = (esr & ESR_EL1_FSC_MASK) == ESR_EL1_FSC_EXTABT;
351 
352 	expected_regs.regs[30] = expected_regs.pc + 4;
353 	expected_regs.pc = expected_regs.regs[9];
354 
355 	pabt_works = check_regs(regs) && is_extabt;
356 
357 	regs->pc = regs->regs[30];
358 }
359 
360 static bool check_pabt(void)
361 {
362 	enum vector v = check_vector_prep();
363 
364 	install_exception_handler(v, ESR_EL1_EC_IABT_EL1, pabt_handler);
365 
366 	test_exception("adrp	x9, check_pabt_invalid_paddr\n"
367 		       "add	x9, x9, :lo12:check_pabt_invalid_paddr\n"
368 		       "ldr	x9, [x9]\n",
369 		       "blr	x9\n",
370 		       "", "x9", "x30");
371 
372 	install_exception_handler(v, ESR_EL1_EC_IABT_EL1, NULL);
373 
374 	return pabt_works;
375 }
376 
377 static void user_psci_system_off(struct pt_regs *regs, unsigned int esr)
378 {
379 	__user_psci_system_off();
380 }
381 #endif
382 
383 static void check_vectors(void *arg __unused)
384 {
385 	report(check_und(), "und");
386 	report(check_svc(), "svc");
387 	if (is_user()) {
388 #ifdef __arm__
389 		install_exception_handler(EXCPTN_UND, user_psci_system_off);
390 #else
391 		install_exception_handler(EL0_SYNC_64, ESR_EL1_EC_UNKNOWN,
392 					  user_psci_system_off);
393 #endif
394 	} else {
395 		if (!check_pabt_init())
396 			report_skip("Couldn't guess an invalid physical address");
397 		else
398 			report(check_pabt(), "pabt");
399 	}
400 	exit(report_summary());
401 }
402 
403 static void psci_print(void)
404 {
405 	int ver = psci_invoke(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
406 	report_info("PSCI version: %d.%d", PSCI_VERSION_MAJOR(ver),
407 					  PSCI_VERSION_MINOR(ver));
408 	report_info("PSCI method: %s", psci_invoke == psci_invoke_hvc ?
409 				       "hvc" : "smc");
410 }
411 
412 static void cpu_report(void *data __unused)
413 {
414 	uint64_t mpidr = get_mpidr();
415 	int cpu = smp_processor_id();
416 
417 	if (mpidr_to_cpu(mpidr) == cpu)
418 		cpumask_set_cpu(smp_processor_id(), &valid);
419 	smp_wmb();		/* Paired with rmb in main(). */
420 	cpumask_set_cpu(smp_processor_id(), &ready);
421 	report_info("CPU%3d: MPIDR=%010" PRIx64, cpu, mpidr);
422 }
423 
424 int main(int argc, char **argv)
425 {
426 	report_prefix_push("selftest");
427 
428 	if (argc < 2)
429 		report_abort("no test specified");
430 
431 	report_prefix_push(argv[1]);
432 
433 	if (strcmp(argv[1], "setup") == 0) {
434 
435 		check_setup(argc-2, &argv[2]);
436 
437 	} else if (strcmp(argv[1], "vectors-kernel") == 0) {
438 
439 		check_vectors(NULL);
440 
441 	} else if (strcmp(argv[1], "vectors-user") == 0) {
442 
443 		start_usr(check_vectors, NULL,
444 				(unsigned long)thread_stack_alloc());
445 
446 	} else if (strcmp(argv[1], "smp") == 0) {
447 
448 		psci_print();
449 		on_cpus(cpu_report, NULL);
450 		while (!cpumask_full(&ready))
451 			cpu_relax();
452 		smp_rmb();		/* Paired with wmb in cpu_report(). */
453 		report(cpumask_full(&valid), "MPIDR test on all CPUs");
454 		report_info("%d CPUs reported back", nr_cpus);
455 
456 	} else {
457 		printf("Unknown subtest\n");
458 		abort();
459 	}
460 
461 	return report_summary();
462 }
463