summaryrefslogtreecommitdiff
path: root/arch/riscv/kvm/vcpu_sbi.c
blob: 9cd97091c7233089ff71207c6da8280f2bcba0c6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2019 Western Digital Corporation or its affiliates.
 *
 * Authors:
 *     Atish Patra <atish.patra@wdc.com>
 */

#include <linux/errno.h>
#include <linux/err.h>
#include <linux/kvm_host.h>
#include <asm/sbi.h>
#include <asm/kvm_vcpu_sbi.h>

#ifndef CONFIG_RISCV_SBI_V01
static const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_v01 = {
	.extid_start = -1UL,
	.extid_end = -1UL,
	.handler = NULL,
};
#endif

#ifndef CONFIG_RISCV_PMU_SBI
static const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_pmu = {
	.extid_start = -1UL,
	.extid_end = -1UL,
	.handler = NULL,
};
#endif

struct kvm_riscv_sbi_extension_entry {
	enum KVM_RISCV_SBI_EXT_ID ext_idx;
	const struct kvm_vcpu_sbi_extension *ext_ptr;
};

static const struct kvm_riscv_sbi_extension_entry sbi_ext[] = {
	{
		.ext_idx = KVM_RISCV_SBI_EXT_V01,
		.ext_ptr = &vcpu_sbi_ext_v01,
	},
	{
		.ext_idx = KVM_RISCV_SBI_EXT_MAX, /* Can't be disabled */
		.ext_ptr = &vcpu_sbi_ext_base,
	},
	{
		.ext_idx = KVM_RISCV_SBI_EXT_TIME,
		.ext_ptr = &vcpu_sbi_ext_time,
	},
	{
		.ext_idx = KVM_RISCV_SBI_EXT_IPI,
		.ext_ptr = &vcpu_sbi_ext_ipi,
	},
	{
		.ext_idx = KVM_RISCV_SBI_EXT_RFENCE,
		.ext_ptr = &vcpu_sbi_ext_rfence,
	},
	{
		.ext_idx = KVM_RISCV_SBI_EXT_SRST,
		.ext_ptr = &vcpu_sbi_ext_srst,
	},
	{
		.ext_idx = KVM_RISCV_SBI_EXT_HSM,
		.ext_ptr = &vcpu_sbi_ext_hsm,
	},
	{
		.ext_idx = KVM_RISCV_SBI_EXT_PMU,
		.ext_ptr = &vcpu_sbi_ext_pmu,
	},
	{
		.ext_idx = KVM_RISCV_SBI_EXT_EXPERIMENTAL,
		.ext_ptr = &vcpu_sbi_ext_experimental,
	},
	{
		.ext_idx = KVM_RISCV_SBI_EXT_VENDOR,
		.ext_ptr = &vcpu_sbi_ext_vendor,
	},
};

void kvm_riscv_vcpu_sbi_forward(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
	struct kvm_cpu_context *cp = &vcpu->arch.guest_context;

	vcpu->arch.sbi_context.return_handled = 0;
	vcpu->stat.ecall_exit_stat++;
	run->exit_reason = KVM_EXIT_RISCV_SBI;
	run->riscv_sbi.extension_id = cp->a7;
	run->riscv_sbi.function_id = cp->a6;
	run->riscv_sbi.args[0] = cp->a0;
	run->riscv_sbi.args[1] = cp->a1;
	run->riscv_sbi.args[2] = cp->a2;
	run->riscv_sbi.args[3] = cp->a3;
	run->riscv_sbi.args[4] = cp->a4;
	run->riscv_sbi.args[5] = cp->a5;
	run->riscv_sbi.ret[0] = cp->a0;
	run->riscv_sbi.ret[1] = cp->a1;
}

void kvm_riscv_vcpu_sbi_system_reset(struct kvm_vcpu *vcpu,
				     struct kvm_run *run,
				     u32 type, u64 reason)
{
	unsigned long i;
	struct kvm_vcpu *tmp;

	kvm_for_each_vcpu(i, tmp, vcpu->kvm)
		tmp->arch.power_off = true;
	kvm_make_all_cpus_request(vcpu->kvm, KVM_REQ_SLEEP);

	memset(&run->system_event, 0, sizeof(run->system_event));
	run->system_event.type = type;
	run->system_event.ndata = 1;
	run->system_event.data[0] = reason;
	run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
}

int kvm_riscv_vcpu_sbi_return(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
	struct kvm_cpu_context *cp = &vcpu->arch.guest_context;

	/* Handle SBI return only once */
	if (vcpu->arch.sbi_context.return_handled)
		return 0;
	vcpu->arch.sbi_context.return_handled = 1;

	/* Update return values */
	cp->a0 = run->riscv_sbi.ret[0];
	cp->a1 = run->riscv_sbi.ret[1];

	/* Move to next instruction */
	vcpu->arch.guest_context.sepc += 4;

	return 0;
}

static int riscv_vcpu_set_sbi_ext_single(struct kvm_vcpu *vcpu,
					 unsigned long reg_num,
					 unsigned long reg_val)
{
	unsigned long i;
	const struct kvm_riscv_sbi_extension_entry *sext = NULL;
	struct kvm_vcpu_sbi_context *scontext = &vcpu->arch.sbi_context;

	if (reg_num >= KVM_RISCV_SBI_EXT_MAX)
		return -ENOENT;

	if (reg_val != 1 && reg_val != 0)
		return -EINVAL;

	for (i = 0; i < ARRAY_SIZE(sbi_ext); i++) {
		if (sbi_ext[i].ext_idx == reg_num) {
			sext = &sbi_ext[i];
			break;
		}
	}
	if (!sext)
		return -ENOENT;

	/*
	 * We can't set the extension status to available here, since it may
	 * have a probe() function which needs to confirm availability first,
	 * but it may be too early to call that here. We can set the status to
	 * unavailable, though.
	 */
	if (!reg_val)
		scontext->ext_status[sext->ext_idx] =
			KVM_RISCV_SBI_EXT_UNAVAILABLE;

	return 0;
}

static int riscv_vcpu_get_sbi_ext_single(struct kvm_vcpu *vcpu,
					 unsigned long reg_num,
					 unsigned long *reg_val)
{
	unsigned long i;
	const struct kvm_riscv_sbi_extension_entry *sext = NULL;
	struct kvm_vcpu_sbi_context *scontext = &vcpu->arch.sbi_context;

	if (reg_num >= KVM_RISCV_SBI_EXT_MAX)
		return -ENOENT;

	for (i = 0; i < ARRAY_SIZE(sbi_ext); i++) {
		if (sbi_ext[i].ext_idx == reg_num) {
			sext = &sbi_ext[i];
			break;
		}
	}
	if (!sext)
		return -ENOENT;

	/*
	 * If the extension status is still uninitialized, then we should probe
	 * to determine if it's available, but it may be too early to do that
	 * here. The best we can do is report that the extension has not been
	 * disabled, i.e. we return 1 when the extension is available and also
	 * when it only may be available.
	 */
	*reg_val = scontext->ext_status[sext->ext_idx] !=
				KVM_RISCV_SBI_EXT_UNAVAILABLE;

	return 0;
}

static int riscv_vcpu_set_sbi_ext_multi(struct kvm_vcpu *vcpu,
					unsigned long reg_num,
					unsigned long reg_val, bool enable)
{
	unsigned long i, ext_id;

	if (reg_num > KVM_REG_RISCV_SBI_MULTI_REG_LAST)
		return -ENOENT;

	for_each_set_bit(i, &reg_val, BITS_PER_LONG) {
		ext_id = i + reg_num * BITS_PER_LONG;
		if (ext_id >= KVM_RISCV_SBI_EXT_MAX)
			break;

		riscv_vcpu_set_sbi_ext_single(vcpu, ext_id, enable);
	}

	return 0;
}

static int riscv_vcpu_get_sbi_ext_multi(struct kvm_vcpu *vcpu,
					unsigned long reg_num,
					unsigned long *reg_val)
{
	unsigned long i, ext_id, ext_val;

	if (reg_num > KVM_REG_RISCV_SBI_MULTI_REG_LAST)
		return -ENOENT;

	for (i = 0; i < BITS_PER_LONG; i++) {
		ext_id = i + reg_num * BITS_PER_LONG;
		if (ext_id >= KVM_RISCV_SBI_EXT_MAX)
			break;

		ext_val = 0;
		riscv_vcpu_get_sbi_ext_single(vcpu, ext_id, &ext_val);
		if (ext_val)
			*reg_val |= KVM_REG_RISCV_SBI_MULTI_MASK(ext_id);
	}

	return 0;
}

int kvm_riscv_vcpu_set_reg_sbi_ext(struct kvm_vcpu *vcpu,
				   const struct kvm_one_reg *reg)
{
	unsigned long __user *uaddr =
			(unsigned long __user *)(unsigned long)reg->addr;
	unsigned long reg_num = reg->id & ~(KVM_REG_ARCH_MASK |
					    KVM_REG_SIZE_MASK |
					    KVM_REG_RISCV_SBI_EXT);
	unsigned long reg_val, reg_subtype;

	if (KVM_REG_SIZE(reg->id) != sizeof(unsigned long))
		return -EINVAL;

	if (vcpu->arch.ran_atleast_once)
		return -EBUSY;

	reg_subtype = reg_num & KVM_REG_RISCV_SUBTYPE_MASK;
	reg_num &= ~KVM_REG_RISCV_SUBTYPE_MASK;

	if (copy_from_user(&reg_val, uaddr, KVM_REG_SIZE(reg->id)))
		return -EFAULT;

	switch (reg_subtype) {
	case KVM_REG_RISCV_SBI_SINGLE:
		return riscv_vcpu_set_sbi_ext_single(vcpu, reg_num, reg_val);
	case KVM_REG_RISCV_SBI_MULTI_EN:
		return riscv_vcpu_set_sbi_ext_multi(vcpu, reg_num, reg_val, true);
	case KVM_REG_RISCV_SBI_MULTI_DIS:
		return riscv_vcpu_set_sbi_ext_multi(vcpu, reg_num, reg_val, false);
	default:
		return -ENOENT;
	}

	return 0;
}

int kvm_riscv_vcpu_get_reg_sbi_ext(struct kvm_vcpu *vcpu,
				   const struct kvm_one_reg *reg)
{
	int rc;
	unsigned long __user *uaddr =
			(unsigned long __user *)(unsigned long)reg->addr;
	unsigned long reg_num = reg->id & ~(KVM_REG_ARCH_MASK |
					    KVM_REG_SIZE_MASK |
					    KVM_REG_RISCV_SBI_EXT);
	unsigned long reg_val, reg_subtype;

	if (KVM_REG_SIZE(reg->id) != sizeof(unsigned long))
		return -EINVAL;

	reg_subtype = reg_num & KVM_REG_RISCV_SUBTYPE_MASK;
	reg_num &= ~KVM_REG_RISCV_SUBTYPE_MASK;

	reg_val = 0;
	switch (reg_subtype) {
	case KVM_REG_RISCV_SBI_SINGLE:
		rc = riscv_vcpu_get_sbi_ext_single(vcpu, reg_num, &reg_val);
		break;
	case KVM_REG_RISCV_SBI_MULTI_EN:
	case KVM_REG_RISCV_SBI_MULTI_DIS:
		rc = riscv_vcpu_get_sbi_ext_multi(vcpu, reg_num, &reg_val);
		if (!rc && reg_subtype == KVM_REG_RISCV_SBI_MULTI_DIS)
			reg_val = ~reg_val;
		break;
	default:
		rc = -ENOENT;
	}
	if (rc)
		return rc;

	if (copy_to_user(uaddr, &reg_val, KVM_REG_SIZE(reg->id)))
		return -EFAULT;

	return 0;
}

const struct kvm_vcpu_sbi_extension *kvm_vcpu_sbi_find_ext(
				struct kvm_vcpu *vcpu, unsigned long extid)
{
	struct kvm_vcpu_sbi_context *scontext = &vcpu->arch.sbi_context;
	const struct kvm_riscv_sbi_extension_entry *entry;
	const struct kvm_vcpu_sbi_extension *ext;
	int i;

	for (i = 0; i < ARRAY_SIZE(sbi_ext); i++) {
		entry = &sbi_ext[i];
		ext = entry->ext_ptr;

		if (ext->extid_start <= extid && ext->extid_end >= extid) {
			if (entry->ext_idx >= KVM_RISCV_SBI_EXT_MAX ||
			    scontext->ext_status[entry->ext_idx] ==
						KVM_RISCV_SBI_EXT_AVAILABLE)
				return ext;
			if (scontext->ext_status[entry->ext_idx] ==
						KVM_RISCV_SBI_EXT_UNAVAILABLE)
				return NULL;
			if (ext->probe && !ext->probe(vcpu)) {
				scontext->ext_status[entry->ext_idx] =
					KVM_RISCV_SBI_EXT_UNAVAILABLE;
				return NULL;
			}

			scontext->ext_status[entry->ext_idx] =
				KVM_RISCV_SBI_EXT_AVAILABLE;
			return ext;
		}
	}

	return NULL;
}

int kvm_riscv_vcpu_sbi_ecall(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
	int ret = 1;
	bool next_sepc = true;
	struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
	const struct kvm_vcpu_sbi_extension *sbi_ext;
	struct kvm_cpu_trap utrap = {0};
	struct kvm_vcpu_sbi_return sbi_ret = {
		.out_val = 0,
		.err_val = 0,
		.utrap = &utrap,
	};
	bool ext_is_v01 = false;

	sbi_ext = kvm_vcpu_sbi_find_ext(vcpu, cp->a7);
	if (sbi_ext && sbi_ext->handler) {
#ifdef CONFIG_RISCV_SBI_V01
		if (cp->a7 >= SBI_EXT_0_1_SET_TIMER &&
		    cp->a7 <= SBI_EXT_0_1_SHUTDOWN)
			ext_is_v01 = true;
#endif
		ret = sbi_ext->handler(vcpu, run, &sbi_ret);
	} else {
		/* Return error for unsupported SBI calls */
		cp->a0 = SBI_ERR_NOT_SUPPORTED;
		goto ecall_done;
	}

	/*
	 * When the SBI extension returns a Linux error code, it exits the ioctl
	 * loop and forwards the error to userspace.
	 */
	if (ret < 0) {
		next_sepc = false;
		goto ecall_done;
	}

	/* Handle special error cases i.e trap, exit or userspace forward */
	if (sbi_ret.utrap->scause) {
		/* No need to increment sepc or exit ioctl loop */
		ret = 1;
		sbi_ret.utrap->sepc = cp->sepc;
		kvm_riscv_vcpu_trap_redirect(vcpu, sbi_ret.utrap);
		next_sepc = false;
		goto ecall_done;
	}

	/* Exit ioctl loop or Propagate the error code the guest */
	if (sbi_ret.uexit) {
		next_sepc = false;
		ret = 0;
	} else {
		cp->a0 = sbi_ret.err_val;
		ret = 1;
	}
ecall_done:
	if (next_sepc)
		cp->sepc += 4;
	/* a1 should only be updated when we continue the ioctl loop */
	if (!ext_is_v01 && ret == 1)
		cp->a1 = sbi_ret.out_val;

	return ret;
}