summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/kvm/book3s_rtas.c
blob: cf95cdef73c993f9b7e78aea998f275097ab0a60 (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
/*
 * Copyright 2012 Michael Ellerman, IBM Corporation.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2, as
 * published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/kvm_host.h>
#include <linux/kvm.h>
#include <linux/err.h>

#include <asm/uaccess.h>
#include <asm/kvm_book3s.h>
#include <asm/kvm_ppc.h>
#include <asm/hvcall.h>
#include <asm/rtas.h>

#ifdef CONFIG_KVM_XICS
static void kvm_rtas_set_xive(struct kvm_vcpu *vcpu, struct rtas_args *args)
{
	u32 irq, server, priority;
	int rc;

	if (args->nargs != 3 || args->nret != 1) {
		rc = -3;
		goto out;
	}

	irq = args->args[0];
	server = args->args[1];
	priority = args->args[2];

	rc = kvmppc_xics_set_xive(vcpu->kvm, irq, server, priority);
	if (rc)
		rc = -3;
out:
	args->rets[0] = rc;
}

static void kvm_rtas_get_xive(struct kvm_vcpu *vcpu, struct rtas_args *args)
{
	u32 irq, server, priority;
	int rc;

	if (args->nargs != 1 || args->nret != 3) {
		rc = -3;
		goto out;
	}

	irq = args->args[0];

	server = priority = 0;
	rc = kvmppc_xics_get_xive(vcpu->kvm, irq, &server, &priority);
	if (rc) {
		rc = -3;
		goto out;
	}

	args->rets[1] = server;
	args->rets[2] = priority;
out:
	args->rets[0] = rc;
}

static void kvm_rtas_int_off(struct kvm_vcpu *vcpu, struct rtas_args *args)
{
	u32 irq;
	int rc;

	if (args->nargs != 1 || args->nret != 1) {
		rc = -3;
		goto out;
	}

	irq = args->args[0];

	rc = kvmppc_xics_int_off(vcpu->kvm, irq);
	if (rc)
		rc = -3;
out:
	args->rets[0] = rc;
}

static void kvm_rtas_int_on(struct kvm_vcpu *vcpu, struct rtas_args *args)
{
	u32 irq;
	int rc;

	if (args->nargs != 1 || args->nret != 1) {
		rc = -3;
		goto out;
	}

	irq = args->args[0];

	rc = kvmppc_xics_int_on(vcpu->kvm, irq);
	if (rc)
		rc = -3;
out:
	args->rets[0] = rc;
}
#endif /* CONFIG_KVM_XICS */

struct rtas_handler {
	void (*handler)(struct kvm_vcpu *vcpu, struct rtas_args *args);
	char *name;
};

static struct rtas_handler rtas_handlers[] = {
#ifdef CONFIG_KVM_XICS
	{ .name = "ibm,set-xive", .handler = kvm_rtas_set_xive },
	{ .name = "ibm,get-xive", .handler = kvm_rtas_get_xive },
	{ .name = "ibm,int-off",  .handler = kvm_rtas_int_off },
	{ .name = "ibm,int-on",   .handler = kvm_rtas_int_on },
#endif
};

struct rtas_token_definition {
	struct list_head list;
	struct rtas_handler *handler;
	u64 token;
};

static int rtas_name_matches(char *s1, char *s2)
{
	struct kvm_rtas_token_args args;
	return !strncmp(s1, s2, sizeof(args.name));
}

static int rtas_token_undefine(struct kvm *kvm, char *name)
{
	struct rtas_token_definition *d, *tmp;

	lockdep_assert_held(&kvm->lock);

	list_for_each_entry_safe(d, tmp, &kvm->arch.rtas_tokens, list) {
		if (rtas_name_matches(d->handler->name, name)) {
			list_del(&d->list);
			kfree(d);
			return 0;
		}
	}

	/* It's not an error to undefine an undefined token */
	return 0;
}

static int rtas_token_define(struct kvm *kvm, char *name, u64 token)
{
	struct rtas_token_definition *d;
	struct rtas_handler *h = NULL;
	bool found;
	int i;

	lockdep_assert_held(&kvm->lock);

	list_for_each_entry(d, &kvm->arch.rtas_tokens, list) {
		if (d->token == token)
			return -EEXIST;
	}

	found = false;
	for (i = 0; i < ARRAY_SIZE(rtas_handlers); i++) {
		h = &rtas_handlers[i];
		if (rtas_name_matches(h->name, name)) {
			found = true;
			break;
		}
	}

	if (!found)
		return -ENOENT;

	d = kzalloc(sizeof(*d), GFP_KERNEL);
	if (!d)
		return -ENOMEM;

	d->handler = h;
	d->token = token;

	list_add_tail(&d->list, &kvm->arch.rtas_tokens);

	return 0;
}

int kvm_vm_ioctl_rtas_define_token(struct kvm *kvm, void __user *argp)
{
	struct kvm_rtas_token_args args;
	int rc;

	if (copy_from_user(&args, argp, sizeof(args)))
		return -EFAULT;

	mutex_lock(&kvm->lock);

	if (args.token)
		rc = rtas_token_define(kvm, args.name, args.token);
	else
		rc = rtas_token_undefine(kvm, args.name);

	mutex_unlock(&kvm->lock);

	return rc;
}

int kvmppc_rtas_hcall(struct kvm_vcpu *vcpu)
{
	struct rtas_token_definition *d;
	struct rtas_args args;
	rtas_arg_t *orig_rets;
	gpa_t args_phys;
	int rc;

	/* r4 contains the guest physical address of the RTAS args */
	args_phys = kvmppc_get_gpr(vcpu, 4);

	rc = kvm_read_guest(vcpu->kvm, args_phys, &args, sizeof(args));
	if (rc)
		goto fail;

	/*
	 * args->rets is a pointer into args->args. Now that we've
	 * copied args we need to fix it up to point into our copy,
	 * not the guest args. We also need to save the original
	 * value so we can restore it on the way out.
	 */
	orig_rets = args.rets;
	args.rets = &args.args[args.nargs];

	mutex_lock(&vcpu->kvm->lock);

	rc = -ENOENT;
	list_for_each_entry(d, &vcpu->kvm->arch.rtas_tokens, list) {
		if (d->token == args.token) {
			d->handler->handler(vcpu, &args);
			rc = 0;
			break;
		}
	}

	mutex_unlock(&vcpu->kvm->lock);

	if (rc == 0) {
		args.rets = orig_rets;
		rc = kvm_write_guest(vcpu->kvm, args_phys, &args, sizeof(args));
		if (rc)
			goto fail;
	}

	return rc;

fail:
	/*
	 * We only get here if the guest has called RTAS with a bogus
	 * args pointer. That means we can't get to the args, and so we
	 * can't fail the RTAS call. So fail right out to userspace,
	 * which should kill the guest.
	 */
	return rc;
}
EXPORT_SYMBOL_GPL(kvmppc_rtas_hcall);

void kvmppc_rtas_tokens_free(struct kvm *kvm)
{
	struct rtas_token_definition *d, *tmp;

	lockdep_assert_held(&kvm->lock);

	list_for_each_entry_safe(d, tmp, &kvm->arch.rtas_tokens, list) {
		list_del(&d->list);
		kfree(d);
	}
}
OpenPOWER on IntegriCloud