xref: /openbmc/linux/arch/arm64/kvm/guest.c (revision 8730046c)
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 <asm/cputype.h>
29 #include <linux/uaccess.h>
30 #include <asm/kvm.h>
31 #include <asm/kvm_emulate.h>
32 #include <asm/kvm_coproc.h>
33 
34 #include "trace.h"
35 
36 #define VM_STAT(x) { #x, offsetof(struct kvm, stat.x), KVM_STAT_VM }
37 #define VCPU_STAT(x) { #x, offsetof(struct kvm_vcpu, stat.x), KVM_STAT_VCPU }
38 
39 struct kvm_stats_debugfs_item debugfs_entries[] = {
40 	VCPU_STAT(hvc_exit_stat),
41 	VCPU_STAT(wfe_exit_stat),
42 	VCPU_STAT(wfi_exit_stat),
43 	VCPU_STAT(mmio_exit_user),
44 	VCPU_STAT(mmio_exit_kernel),
45 	VCPU_STAT(exits),
46 	{ NULL }
47 };
48 
49 int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
50 {
51 	return 0;
52 }
53 
54 static u64 core_reg_offset_from_id(u64 id)
55 {
56 	return id & ~(KVM_REG_ARCH_MASK | KVM_REG_SIZE_MASK | KVM_REG_ARM_CORE);
57 }
58 
59 static int get_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
60 {
61 	/*
62 	 * Because the kvm_regs structure is a mix of 32, 64 and
63 	 * 128bit fields, we index it as if it was a 32bit
64 	 * array. Hence below, nr_regs is the number of entries, and
65 	 * off the index in the "array".
66 	 */
67 	__u32 __user *uaddr = (__u32 __user *)(unsigned long)reg->addr;
68 	struct kvm_regs *regs = vcpu_gp_regs(vcpu);
69 	int nr_regs = sizeof(*regs) / sizeof(__u32);
70 	u32 off;
71 
72 	/* Our ID is an index into the kvm_regs struct. */
73 	off = core_reg_offset_from_id(reg->id);
74 	if (off >= nr_regs ||
75 	    (off + (KVM_REG_SIZE(reg->id) / sizeof(__u32))) >= nr_regs)
76 		return -ENOENT;
77 
78 	if (copy_to_user(uaddr, ((u32 *)regs) + off, KVM_REG_SIZE(reg->id)))
79 		return -EFAULT;
80 
81 	return 0;
82 }
83 
84 static int set_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
85 {
86 	__u32 __user *uaddr = (__u32 __user *)(unsigned long)reg->addr;
87 	struct kvm_regs *regs = vcpu_gp_regs(vcpu);
88 	int nr_regs = sizeof(*regs) / sizeof(__u32);
89 	__uint128_t tmp;
90 	void *valp = &tmp;
91 	u64 off;
92 	int err = 0;
93 
94 	/* Our ID is an index into the kvm_regs struct. */
95 	off = core_reg_offset_from_id(reg->id);
96 	if (off >= nr_regs ||
97 	    (off + (KVM_REG_SIZE(reg->id) / sizeof(__u32))) >= nr_regs)
98 		return -ENOENT;
99 
100 	if (KVM_REG_SIZE(reg->id) > sizeof(tmp))
101 		return -EINVAL;
102 
103 	if (copy_from_user(valp, uaddr, KVM_REG_SIZE(reg->id))) {
104 		err = -EFAULT;
105 		goto out;
106 	}
107 
108 	if (off == KVM_REG_ARM_CORE_REG(regs.pstate)) {
109 		u32 mode = (*(u32 *)valp) & COMPAT_PSR_MODE_MASK;
110 		switch (mode) {
111 		case COMPAT_PSR_MODE_USR:
112 		case COMPAT_PSR_MODE_FIQ:
113 		case COMPAT_PSR_MODE_IRQ:
114 		case COMPAT_PSR_MODE_SVC:
115 		case COMPAT_PSR_MODE_ABT:
116 		case COMPAT_PSR_MODE_UND:
117 		case PSR_MODE_EL0t:
118 		case PSR_MODE_EL1t:
119 		case PSR_MODE_EL1h:
120 			break;
121 		default:
122 			err = -EINVAL;
123 			goto out;
124 		}
125 	}
126 
127 	memcpy((u32 *)regs + off, valp, KVM_REG_SIZE(reg->id));
128 out:
129 	return err;
130 }
131 
132 int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
133 {
134 	return -EINVAL;
135 }
136 
137 int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
138 {
139 	return -EINVAL;
140 }
141 
142 static unsigned long num_core_regs(void)
143 {
144 	return sizeof(struct kvm_regs) / sizeof(__u32);
145 }
146 
147 /**
148  * ARM64 versions of the TIMER registers, always available on arm64
149  */
150 
151 #define NUM_TIMER_REGS 3
152 
153 static bool is_timer_reg(u64 index)
154 {
155 	switch (index) {
156 	case KVM_REG_ARM_TIMER_CTL:
157 	case KVM_REG_ARM_TIMER_CNT:
158 	case KVM_REG_ARM_TIMER_CVAL:
159 		return true;
160 	}
161 	return false;
162 }
163 
164 static int copy_timer_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
165 {
166 	if (put_user(KVM_REG_ARM_TIMER_CTL, uindices))
167 		return -EFAULT;
168 	uindices++;
169 	if (put_user(KVM_REG_ARM_TIMER_CNT, uindices))
170 		return -EFAULT;
171 	uindices++;
172 	if (put_user(KVM_REG_ARM_TIMER_CVAL, uindices))
173 		return -EFAULT;
174 
175 	return 0;
176 }
177 
178 static int set_timer_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
179 {
180 	void __user *uaddr = (void __user *)(long)reg->addr;
181 	u64 val;
182 	int ret;
183 
184 	ret = copy_from_user(&val, uaddr, KVM_REG_SIZE(reg->id));
185 	if (ret != 0)
186 		return -EFAULT;
187 
188 	return kvm_arm_timer_set_reg(vcpu, reg->id, val);
189 }
190 
191 static int get_timer_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
192 {
193 	void __user *uaddr = (void __user *)(long)reg->addr;
194 	u64 val;
195 
196 	val = kvm_arm_timer_get_reg(vcpu, reg->id);
197 	return copy_to_user(uaddr, &val, KVM_REG_SIZE(reg->id)) ? -EFAULT : 0;
198 }
199 
200 /**
201  * kvm_arm_num_regs - how many registers do we present via KVM_GET_ONE_REG
202  *
203  * This is for all registers.
204  */
205 unsigned long kvm_arm_num_regs(struct kvm_vcpu *vcpu)
206 {
207 	return num_core_regs() + kvm_arm_num_sys_reg_descs(vcpu)
208                 + NUM_TIMER_REGS;
209 }
210 
211 /**
212  * kvm_arm_copy_reg_indices - get indices of all registers.
213  *
214  * We do core registers right here, then we append system regs.
215  */
216 int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
217 {
218 	unsigned int i;
219 	const u64 core_reg = KVM_REG_ARM64 | KVM_REG_SIZE_U64 | KVM_REG_ARM_CORE;
220 	int ret;
221 
222 	for (i = 0; i < sizeof(struct kvm_regs) / sizeof(__u32); i++) {
223 		if (put_user(core_reg | i, uindices))
224 			return -EFAULT;
225 		uindices++;
226 	}
227 
228 	ret = copy_timer_indices(vcpu, uindices);
229 	if (ret)
230 		return ret;
231 	uindices += NUM_TIMER_REGS;
232 
233 	return kvm_arm_copy_sys_reg_indices(vcpu, uindices);
234 }
235 
236 int kvm_arm_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
237 {
238 	/* We currently use nothing arch-specific in upper 32 bits */
239 	if ((reg->id & ~KVM_REG_SIZE_MASK) >> 32 != KVM_REG_ARM64 >> 32)
240 		return -EINVAL;
241 
242 	/* Register group 16 means we want a core register. */
243 	if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_CORE)
244 		return get_core_reg(vcpu, reg);
245 
246 	if (is_timer_reg(reg->id))
247 		return get_timer_reg(vcpu, reg);
248 
249 	return kvm_arm_sys_reg_get_reg(vcpu, reg);
250 }
251 
252 int kvm_arm_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
253 {
254 	/* We currently use nothing arch-specific in upper 32 bits */
255 	if ((reg->id & ~KVM_REG_SIZE_MASK) >> 32 != KVM_REG_ARM64 >> 32)
256 		return -EINVAL;
257 
258 	/* Register group 16 means we set a core register. */
259 	if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_CORE)
260 		return set_core_reg(vcpu, reg);
261 
262 	if (is_timer_reg(reg->id))
263 		return set_timer_reg(vcpu, reg);
264 
265 	return kvm_arm_sys_reg_set_reg(vcpu, reg);
266 }
267 
268 int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
269 				  struct kvm_sregs *sregs)
270 {
271 	return -EINVAL;
272 }
273 
274 int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
275 				  struct kvm_sregs *sregs)
276 {
277 	return -EINVAL;
278 }
279 
280 int __attribute_const__ kvm_target_cpu(void)
281 {
282 	unsigned long implementor = read_cpuid_implementor();
283 	unsigned long part_number = read_cpuid_part_number();
284 
285 	switch (implementor) {
286 	case ARM_CPU_IMP_ARM:
287 		switch (part_number) {
288 		case ARM_CPU_PART_AEM_V8:
289 			return KVM_ARM_TARGET_AEM_V8;
290 		case ARM_CPU_PART_FOUNDATION:
291 			return KVM_ARM_TARGET_FOUNDATION_V8;
292 		case ARM_CPU_PART_CORTEX_A53:
293 			return KVM_ARM_TARGET_CORTEX_A53;
294 		case ARM_CPU_PART_CORTEX_A57:
295 			return KVM_ARM_TARGET_CORTEX_A57;
296 		};
297 		break;
298 	case ARM_CPU_IMP_APM:
299 		switch (part_number) {
300 		case APM_CPU_PART_POTENZA:
301 			return KVM_ARM_TARGET_XGENE_POTENZA;
302 		};
303 		break;
304 	};
305 
306 	/* Return a default generic target */
307 	return KVM_ARM_TARGET_GENERIC_V8;
308 }
309 
310 int kvm_vcpu_preferred_target(struct kvm_vcpu_init *init)
311 {
312 	int target = kvm_target_cpu();
313 
314 	if (target < 0)
315 		return -ENODEV;
316 
317 	memset(init, 0, sizeof(*init));
318 
319 	/*
320 	 * For now, we don't return any features.
321 	 * In future, we might use features to return target
322 	 * specific features available for the preferred
323 	 * target type.
324 	 */
325 	init->target = (__u32)target;
326 
327 	return 0;
328 }
329 
330 int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
331 {
332 	return -EINVAL;
333 }
334 
335 int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
336 {
337 	return -EINVAL;
338 }
339 
340 int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
341 				  struct kvm_translation *tr)
342 {
343 	return -EINVAL;
344 }
345 
346 #define KVM_GUESTDBG_VALID_MASK (KVM_GUESTDBG_ENABLE |    \
347 			    KVM_GUESTDBG_USE_SW_BP | \
348 			    KVM_GUESTDBG_USE_HW | \
349 			    KVM_GUESTDBG_SINGLESTEP)
350 
351 /**
352  * kvm_arch_vcpu_ioctl_set_guest_debug - set up guest debugging
353  * @kvm:	pointer to the KVM struct
354  * @kvm_guest_debug: the ioctl data buffer
355  *
356  * This sets up and enables the VM for guest debugging. Userspace
357  * passes in a control flag to enable different debug types and
358  * potentially other architecture specific information in the rest of
359  * the structure.
360  */
361 int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
362 					struct kvm_guest_debug *dbg)
363 {
364 	trace_kvm_set_guest_debug(vcpu, dbg->control);
365 
366 	if (dbg->control & ~KVM_GUESTDBG_VALID_MASK)
367 		return -EINVAL;
368 
369 	if (dbg->control & KVM_GUESTDBG_ENABLE) {
370 		vcpu->guest_debug = dbg->control;
371 
372 		/* Hardware assisted Break and Watch points */
373 		if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW) {
374 			vcpu->arch.external_debug_state = dbg->arch;
375 		}
376 
377 	} else {
378 		/* If not enabled clear all flags */
379 		vcpu->guest_debug = 0;
380 	}
381 	return 0;
382 }
383 
384 int kvm_arm_vcpu_arch_set_attr(struct kvm_vcpu *vcpu,
385 			       struct kvm_device_attr *attr)
386 {
387 	int ret;
388 
389 	switch (attr->group) {
390 	case KVM_ARM_VCPU_PMU_V3_CTRL:
391 		ret = kvm_arm_pmu_v3_set_attr(vcpu, attr);
392 		break;
393 	default:
394 		ret = -ENXIO;
395 		break;
396 	}
397 
398 	return ret;
399 }
400 
401 int kvm_arm_vcpu_arch_get_attr(struct kvm_vcpu *vcpu,
402 			       struct kvm_device_attr *attr)
403 {
404 	int ret;
405 
406 	switch (attr->group) {
407 	case KVM_ARM_VCPU_PMU_V3_CTRL:
408 		ret = kvm_arm_pmu_v3_get_attr(vcpu, attr);
409 		break;
410 	default:
411 		ret = -ENXIO;
412 		break;
413 	}
414 
415 	return ret;
416 }
417 
418 int kvm_arm_vcpu_arch_has_attr(struct kvm_vcpu *vcpu,
419 			       struct kvm_device_attr *attr)
420 {
421 	int ret;
422 
423 	switch (attr->group) {
424 	case KVM_ARM_VCPU_PMU_V3_CTRL:
425 		ret = kvm_arm_pmu_v3_has_attr(vcpu, attr);
426 		break;
427 	default:
428 		ret = -ENXIO;
429 		break;
430 	}
431 
432 	return ret;
433 }
434