xref: /openbmc/linux/arch/arm64/kvm/guest.c (revision 96de2506)
1 /*
2  * Copyright (C) 2012,2013 - ARM Ltd
3  * Author: Marc Zyngier <marc.zyngier@arm.com>
4  *
5  * Derived from arch/arm/kvm/guest.c:
6  * Copyright (C) 2012 - Virtual Open Systems and Columbia University
7  * Author: Christoffer Dall <c.dall@virtualopensystems.com>
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
20  */
21 
22 #include <linux/errno.h>
23 #include <linux/err.h>
24 #include <linux/kvm_host.h>
25 #include <linux/module.h>
26 #include <linux/vmalloc.h>
27 #include <linux/fs.h>
28 #include <kvm/arm_psci.h>
29 #include <asm/cputype.h>
30 #include <linux/uaccess.h>
31 #include <asm/kvm.h>
32 #include <asm/kvm_emulate.h>
33 #include <asm/kvm_coproc.h>
34 
35 #include "trace.h"
36 
37 #define VM_STAT(x) { #x, offsetof(struct kvm, stat.x), KVM_STAT_VM }
38 #define VCPU_STAT(x) { #x, offsetof(struct kvm_vcpu, stat.x), KVM_STAT_VCPU }
39 
40 struct kvm_stats_debugfs_item debugfs_entries[] = {
41 	VCPU_STAT(hvc_exit_stat),
42 	VCPU_STAT(wfe_exit_stat),
43 	VCPU_STAT(wfi_exit_stat),
44 	VCPU_STAT(mmio_exit_user),
45 	VCPU_STAT(mmio_exit_kernel),
46 	VCPU_STAT(exits),
47 	{ NULL }
48 };
49 
50 int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
51 {
52 	return 0;
53 }
54 
55 static u64 core_reg_offset_from_id(u64 id)
56 {
57 	return id & ~(KVM_REG_ARCH_MASK | KVM_REG_SIZE_MASK | KVM_REG_ARM_CORE);
58 }
59 
60 static int validate_core_offset(const struct kvm_one_reg *reg)
61 {
62 	u64 off = core_reg_offset_from_id(reg->id);
63 	int size;
64 
65 	switch (off) {
66 	case KVM_REG_ARM_CORE_REG(regs.regs[0]) ...
67 	     KVM_REG_ARM_CORE_REG(regs.regs[30]):
68 	case KVM_REG_ARM_CORE_REG(regs.sp):
69 	case KVM_REG_ARM_CORE_REG(regs.pc):
70 	case KVM_REG_ARM_CORE_REG(regs.pstate):
71 	case KVM_REG_ARM_CORE_REG(sp_el1):
72 	case KVM_REG_ARM_CORE_REG(elr_el1):
73 	case KVM_REG_ARM_CORE_REG(spsr[0]) ...
74 	     KVM_REG_ARM_CORE_REG(spsr[KVM_NR_SPSR - 1]):
75 		size = sizeof(__u64);
76 		break;
77 
78 	case KVM_REG_ARM_CORE_REG(fp_regs.vregs[0]) ...
79 	     KVM_REG_ARM_CORE_REG(fp_regs.vregs[31]):
80 		size = sizeof(__uint128_t);
81 		break;
82 
83 	case KVM_REG_ARM_CORE_REG(fp_regs.fpsr):
84 	case KVM_REG_ARM_CORE_REG(fp_regs.fpcr):
85 		size = sizeof(__u32);
86 		break;
87 
88 	default:
89 		return -EINVAL;
90 	}
91 
92 	if (KVM_REG_SIZE(reg->id) == size &&
93 	    IS_ALIGNED(off, size / sizeof(__u32)))
94 		return 0;
95 
96 	return -EINVAL;
97 }
98 
99 static int get_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
100 {
101 	/*
102 	 * Because the kvm_regs structure is a mix of 32, 64 and
103 	 * 128bit fields, we index it as if it was a 32bit
104 	 * array. Hence below, nr_regs is the number of entries, and
105 	 * off the index in the "array".
106 	 */
107 	__u32 __user *uaddr = (__u32 __user *)(unsigned long)reg->addr;
108 	struct kvm_regs *regs = vcpu_gp_regs(vcpu);
109 	int nr_regs = sizeof(*regs) / sizeof(__u32);
110 	u32 off;
111 
112 	/* Our ID is an index into the kvm_regs struct. */
113 	off = core_reg_offset_from_id(reg->id);
114 	if (off >= nr_regs ||
115 	    (off + (KVM_REG_SIZE(reg->id) / sizeof(__u32))) >= nr_regs)
116 		return -ENOENT;
117 
118 	if (validate_core_offset(reg))
119 		return -EINVAL;
120 
121 	if (copy_to_user(uaddr, ((u32 *)regs) + off, KVM_REG_SIZE(reg->id)))
122 		return -EFAULT;
123 
124 	return 0;
125 }
126 
127 static int set_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
128 {
129 	__u32 __user *uaddr = (__u32 __user *)(unsigned long)reg->addr;
130 	struct kvm_regs *regs = vcpu_gp_regs(vcpu);
131 	int nr_regs = sizeof(*regs) / sizeof(__u32);
132 	__uint128_t tmp;
133 	void *valp = &tmp;
134 	u64 off;
135 	int err = 0;
136 
137 	/* Our ID is an index into the kvm_regs struct. */
138 	off = core_reg_offset_from_id(reg->id);
139 	if (off >= nr_regs ||
140 	    (off + (KVM_REG_SIZE(reg->id) / sizeof(__u32))) >= nr_regs)
141 		return -ENOENT;
142 
143 	if (validate_core_offset(reg))
144 		return -EINVAL;
145 
146 	if (KVM_REG_SIZE(reg->id) > sizeof(tmp))
147 		return -EINVAL;
148 
149 	if (copy_from_user(valp, uaddr, KVM_REG_SIZE(reg->id))) {
150 		err = -EFAULT;
151 		goto out;
152 	}
153 
154 	if (off == KVM_REG_ARM_CORE_REG(regs.pstate)) {
155 		u64 mode = (*(u64 *)valp) & PSR_AA32_MODE_MASK;
156 		switch (mode) {
157 		case PSR_AA32_MODE_USR:
158 			if (!system_supports_32bit_el0())
159 				return -EINVAL;
160 			break;
161 		case PSR_AA32_MODE_FIQ:
162 		case PSR_AA32_MODE_IRQ:
163 		case PSR_AA32_MODE_SVC:
164 		case PSR_AA32_MODE_ABT:
165 		case PSR_AA32_MODE_UND:
166 			if (!vcpu_el1_is_32bit(vcpu))
167 				return -EINVAL;
168 			break;
169 		case PSR_MODE_EL0t:
170 		case PSR_MODE_EL1t:
171 		case PSR_MODE_EL1h:
172 			if (vcpu_el1_is_32bit(vcpu))
173 				return -EINVAL;
174 			break;
175 		default:
176 			err = -EINVAL;
177 			goto out;
178 		}
179 	}
180 
181 	memcpy((u32 *)regs + off, valp, KVM_REG_SIZE(reg->id));
182 out:
183 	return err;
184 }
185 
186 int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
187 {
188 	return -EINVAL;
189 }
190 
191 int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
192 {
193 	return -EINVAL;
194 }
195 
196 static unsigned long num_core_regs(void)
197 {
198 	return sizeof(struct kvm_regs) / sizeof(__u32);
199 }
200 
201 /**
202  * ARM64 versions of the TIMER registers, always available on arm64
203  */
204 
205 #define NUM_TIMER_REGS 3
206 
207 static bool is_timer_reg(u64 index)
208 {
209 	switch (index) {
210 	case KVM_REG_ARM_TIMER_CTL:
211 	case KVM_REG_ARM_TIMER_CNT:
212 	case KVM_REG_ARM_TIMER_CVAL:
213 		return true;
214 	}
215 	return false;
216 }
217 
218 static int copy_timer_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
219 {
220 	if (put_user(KVM_REG_ARM_TIMER_CTL, uindices))
221 		return -EFAULT;
222 	uindices++;
223 	if (put_user(KVM_REG_ARM_TIMER_CNT, uindices))
224 		return -EFAULT;
225 	uindices++;
226 	if (put_user(KVM_REG_ARM_TIMER_CVAL, uindices))
227 		return -EFAULT;
228 
229 	return 0;
230 }
231 
232 static int set_timer_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
233 {
234 	void __user *uaddr = (void __user *)(long)reg->addr;
235 	u64 val;
236 	int ret;
237 
238 	ret = copy_from_user(&val, uaddr, KVM_REG_SIZE(reg->id));
239 	if (ret != 0)
240 		return -EFAULT;
241 
242 	return kvm_arm_timer_set_reg(vcpu, reg->id, val);
243 }
244 
245 static int get_timer_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
246 {
247 	void __user *uaddr = (void __user *)(long)reg->addr;
248 	u64 val;
249 
250 	val = kvm_arm_timer_get_reg(vcpu, reg->id);
251 	return copy_to_user(uaddr, &val, KVM_REG_SIZE(reg->id)) ? -EFAULT : 0;
252 }
253 
254 /**
255  * kvm_arm_num_regs - how many registers do we present via KVM_GET_ONE_REG
256  *
257  * This is for all registers.
258  */
259 unsigned long kvm_arm_num_regs(struct kvm_vcpu *vcpu)
260 {
261 	return num_core_regs() + kvm_arm_num_sys_reg_descs(vcpu)
262 		+ kvm_arm_get_fw_num_regs(vcpu)	+ NUM_TIMER_REGS;
263 }
264 
265 /**
266  * kvm_arm_copy_reg_indices - get indices of all registers.
267  *
268  * We do core registers right here, then we append system regs.
269  */
270 int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
271 {
272 	unsigned int i;
273 	const u64 core_reg = KVM_REG_ARM64 | KVM_REG_SIZE_U64 | KVM_REG_ARM_CORE;
274 	int ret;
275 
276 	for (i = 0; i < sizeof(struct kvm_regs) / sizeof(__u32); i++) {
277 		if (put_user(core_reg | i, uindices))
278 			return -EFAULT;
279 		uindices++;
280 	}
281 
282 	ret = kvm_arm_copy_fw_reg_indices(vcpu, uindices);
283 	if (ret)
284 		return ret;
285 	uindices += kvm_arm_get_fw_num_regs(vcpu);
286 
287 	ret = copy_timer_indices(vcpu, uindices);
288 	if (ret)
289 		return ret;
290 	uindices += NUM_TIMER_REGS;
291 
292 	return kvm_arm_copy_sys_reg_indices(vcpu, uindices);
293 }
294 
295 int kvm_arm_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
296 {
297 	/* We currently use nothing arch-specific in upper 32 bits */
298 	if ((reg->id & ~KVM_REG_SIZE_MASK) >> 32 != KVM_REG_ARM64 >> 32)
299 		return -EINVAL;
300 
301 	/* Register group 16 means we want a core register. */
302 	if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_CORE)
303 		return get_core_reg(vcpu, reg);
304 
305 	if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_FW)
306 		return kvm_arm_get_fw_reg(vcpu, reg);
307 
308 	if (is_timer_reg(reg->id))
309 		return get_timer_reg(vcpu, reg);
310 
311 	return kvm_arm_sys_reg_get_reg(vcpu, reg);
312 }
313 
314 int kvm_arm_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
315 {
316 	/* We currently use nothing arch-specific in upper 32 bits */
317 	if ((reg->id & ~KVM_REG_SIZE_MASK) >> 32 != KVM_REG_ARM64 >> 32)
318 		return -EINVAL;
319 
320 	/* Register group 16 means we set a core register. */
321 	if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_CORE)
322 		return set_core_reg(vcpu, reg);
323 
324 	if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_FW)
325 		return kvm_arm_set_fw_reg(vcpu, reg);
326 
327 	if (is_timer_reg(reg->id))
328 		return set_timer_reg(vcpu, reg);
329 
330 	return kvm_arm_sys_reg_set_reg(vcpu, reg);
331 }
332 
333 int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
334 				  struct kvm_sregs *sregs)
335 {
336 	return -EINVAL;
337 }
338 
339 int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
340 				  struct kvm_sregs *sregs)
341 {
342 	return -EINVAL;
343 }
344 
345 int __kvm_arm_vcpu_get_events(struct kvm_vcpu *vcpu,
346 			      struct kvm_vcpu_events *events)
347 {
348 	events->exception.serror_pending = !!(vcpu->arch.hcr_el2 & HCR_VSE);
349 	events->exception.serror_has_esr = cpus_have_const_cap(ARM64_HAS_RAS_EXTN);
350 
351 	if (events->exception.serror_pending && events->exception.serror_has_esr)
352 		events->exception.serror_esr = vcpu_get_vsesr(vcpu);
353 
354 	return 0;
355 }
356 
357 int __kvm_arm_vcpu_set_events(struct kvm_vcpu *vcpu,
358 			      struct kvm_vcpu_events *events)
359 {
360 	bool serror_pending = events->exception.serror_pending;
361 	bool has_esr = events->exception.serror_has_esr;
362 
363 	if (serror_pending && has_esr) {
364 		if (!cpus_have_const_cap(ARM64_HAS_RAS_EXTN))
365 			return -EINVAL;
366 
367 		if (!((events->exception.serror_esr) & ~ESR_ELx_ISS_MASK))
368 			kvm_set_sei_esr(vcpu, events->exception.serror_esr);
369 		else
370 			return -EINVAL;
371 	} else if (serror_pending) {
372 		kvm_inject_vabt(vcpu);
373 	}
374 
375 	return 0;
376 }
377 
378 int __attribute_const__ kvm_target_cpu(void)
379 {
380 	unsigned long implementor = read_cpuid_implementor();
381 	unsigned long part_number = read_cpuid_part_number();
382 
383 	switch (implementor) {
384 	case ARM_CPU_IMP_ARM:
385 		switch (part_number) {
386 		case ARM_CPU_PART_AEM_V8:
387 			return KVM_ARM_TARGET_AEM_V8;
388 		case ARM_CPU_PART_FOUNDATION:
389 			return KVM_ARM_TARGET_FOUNDATION_V8;
390 		case ARM_CPU_PART_CORTEX_A53:
391 			return KVM_ARM_TARGET_CORTEX_A53;
392 		case ARM_CPU_PART_CORTEX_A57:
393 			return KVM_ARM_TARGET_CORTEX_A57;
394 		};
395 		break;
396 	case ARM_CPU_IMP_APM:
397 		switch (part_number) {
398 		case APM_CPU_PART_POTENZA:
399 			return KVM_ARM_TARGET_XGENE_POTENZA;
400 		};
401 		break;
402 	};
403 
404 	/* Return a default generic target */
405 	return KVM_ARM_TARGET_GENERIC_V8;
406 }
407 
408 int kvm_vcpu_preferred_target(struct kvm_vcpu_init *init)
409 {
410 	int target = kvm_target_cpu();
411 
412 	if (target < 0)
413 		return -ENODEV;
414 
415 	memset(init, 0, sizeof(*init));
416 
417 	/*
418 	 * For now, we don't return any features.
419 	 * In future, we might use features to return target
420 	 * specific features available for the preferred
421 	 * target type.
422 	 */
423 	init->target = (__u32)target;
424 
425 	return 0;
426 }
427 
428 int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
429 {
430 	return -EINVAL;
431 }
432 
433 int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
434 {
435 	return -EINVAL;
436 }
437 
438 int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
439 				  struct kvm_translation *tr)
440 {
441 	return -EINVAL;
442 }
443 
444 #define KVM_GUESTDBG_VALID_MASK (KVM_GUESTDBG_ENABLE |    \
445 			    KVM_GUESTDBG_USE_SW_BP | \
446 			    KVM_GUESTDBG_USE_HW | \
447 			    KVM_GUESTDBG_SINGLESTEP)
448 
449 /**
450  * kvm_arch_vcpu_ioctl_set_guest_debug - set up guest debugging
451  * @kvm:	pointer to the KVM struct
452  * @kvm_guest_debug: the ioctl data buffer
453  *
454  * This sets up and enables the VM for guest debugging. Userspace
455  * passes in a control flag to enable different debug types and
456  * potentially other architecture specific information in the rest of
457  * the structure.
458  */
459 int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
460 					struct kvm_guest_debug *dbg)
461 {
462 	int ret = 0;
463 
464 	trace_kvm_set_guest_debug(vcpu, dbg->control);
465 
466 	if (dbg->control & ~KVM_GUESTDBG_VALID_MASK) {
467 		ret = -EINVAL;
468 		goto out;
469 	}
470 
471 	if (dbg->control & KVM_GUESTDBG_ENABLE) {
472 		vcpu->guest_debug = dbg->control;
473 
474 		/* Hardware assisted Break and Watch points */
475 		if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW) {
476 			vcpu->arch.external_debug_state = dbg->arch;
477 		}
478 
479 	} else {
480 		/* If not enabled clear all flags */
481 		vcpu->guest_debug = 0;
482 	}
483 
484 out:
485 	return ret;
486 }
487 
488 int kvm_arm_vcpu_arch_set_attr(struct kvm_vcpu *vcpu,
489 			       struct kvm_device_attr *attr)
490 {
491 	int ret;
492 
493 	switch (attr->group) {
494 	case KVM_ARM_VCPU_PMU_V3_CTRL:
495 		ret = kvm_arm_pmu_v3_set_attr(vcpu, attr);
496 		break;
497 	case KVM_ARM_VCPU_TIMER_CTRL:
498 		ret = kvm_arm_timer_set_attr(vcpu, attr);
499 		break;
500 	default:
501 		ret = -ENXIO;
502 		break;
503 	}
504 
505 	return ret;
506 }
507 
508 int kvm_arm_vcpu_arch_get_attr(struct kvm_vcpu *vcpu,
509 			       struct kvm_device_attr *attr)
510 {
511 	int ret;
512 
513 	switch (attr->group) {
514 	case KVM_ARM_VCPU_PMU_V3_CTRL:
515 		ret = kvm_arm_pmu_v3_get_attr(vcpu, attr);
516 		break;
517 	case KVM_ARM_VCPU_TIMER_CTRL:
518 		ret = kvm_arm_timer_get_attr(vcpu, attr);
519 		break;
520 	default:
521 		ret = -ENXIO;
522 		break;
523 	}
524 
525 	return ret;
526 }
527 
528 int kvm_arm_vcpu_arch_has_attr(struct kvm_vcpu *vcpu,
529 			       struct kvm_device_attr *attr)
530 {
531 	int ret;
532 
533 	switch (attr->group) {
534 	case KVM_ARM_VCPU_PMU_V3_CTRL:
535 		ret = kvm_arm_pmu_v3_has_attr(vcpu, attr);
536 		break;
537 	case KVM_ARM_VCPU_TIMER_CTRL:
538 		ret = kvm_arm_timer_has_attr(vcpu, attr);
539 		break;
540 	default:
541 		ret = -ENXIO;
542 		break;
543 	}
544 
545 	return ret;
546 }
547