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
|
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2023 Ventana Micro Systems Inc.
*/
#include <linux/kconfig.h>
#include <linux/kernel.h>
#include <linux/kvm_host.h>
#include <linux/mm.h>
#include <linux/sizes.h>
#include <asm/bug.h>
#include <asm/current.h>
#include <asm/kvm_vcpu_sbi.h>
#include <asm/page.h>
#include <asm/sbi.h>
#include <asm/uaccess.h>
static void kvm_riscv_vcpu_sbi_sta_reset(struct kvm_vcpu *vcpu)
{
vcpu->arch.sta.shmem = INVALID_GPA;
vcpu->arch.sta.last_steal = 0;
}
void kvm_riscv_vcpu_record_steal_time(struct kvm_vcpu *vcpu)
{
gpa_t shmem = vcpu->arch.sta.shmem;
u64 last_steal = vcpu->arch.sta.last_steal;
__le32 __user *sequence_ptr;
__le64 __user *steal_ptr;
__le32 sequence_le;
__le64 steal_le;
u32 sequence;
u64 steal;
unsigned long hva;
gfn_t gfn;
if (shmem == INVALID_GPA)
return;
/*
* shmem is 64-byte aligned (see the enforcement in
* kvm_sbi_sta_steal_time_set_shmem()) and the size of sbi_sta_struct
* is 64 bytes, so we know all its offsets are in the same page.
*/
gfn = shmem >> PAGE_SHIFT;
hva = kvm_vcpu_gfn_to_hva(vcpu, gfn);
if (WARN_ON(kvm_is_error_hva(hva))) {
vcpu->arch.sta.shmem = INVALID_GPA;
return;
}
sequence_ptr = (__le32 __user *)(hva + offset_in_page(shmem) +
offsetof(struct sbi_sta_struct, sequence));
steal_ptr = (__le64 __user *)(hva + offset_in_page(shmem) +
offsetof(struct sbi_sta_struct, steal));
if (WARN_ON(get_user(sequence_le, sequence_ptr)))
return;
sequence = le32_to_cpu(sequence_le);
sequence += 1;
if (WARN_ON(put_user(cpu_to_le32(sequence), sequence_ptr)))
return;
if (!WARN_ON(get_user(steal_le, steal_ptr))) {
steal = le64_to_cpu(steal_le);
vcpu->arch.sta.last_steal = READ_ONCE(current->sched_info.run_delay);
steal += vcpu->arch.sta.last_steal - last_steal;
WARN_ON(put_user(cpu_to_le64(steal), steal_ptr));
}
sequence += 1;
WARN_ON(put_user(cpu_to_le32(sequence), sequence_ptr));
kvm_vcpu_mark_page_dirty(vcpu, gfn);
}
static int kvm_sbi_sta_steal_time_set_shmem(struct kvm_vcpu *vcpu)
{
struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
unsigned long shmem_phys_lo = cp->a0;
unsigned long shmem_phys_hi = cp->a1;
u32 flags = cp->a2;
struct sbi_sta_struct zero_sta = {0};
gpa_t shmem;
int ret;
if (flags != 0)
return SBI_ERR_INVALID_PARAM;
if (shmem_phys_lo == SBI_SHMEM_DISABLE &&
shmem_phys_hi == SBI_SHMEM_DISABLE) {
vcpu->arch.sta.shmem = INVALID_GPA;
return 0;
}
if (shmem_phys_lo & (SZ_64 - 1))
return SBI_ERR_INVALID_PARAM;
shmem = shmem_phys_lo;
if (shmem_phys_hi != 0) {
if (IS_ENABLED(CONFIG_32BIT))
shmem |= ((gpa_t)shmem_phys_hi << 32);
else
return SBI_ERR_INVALID_ADDRESS;
}
/* No need to check writable slot explicitly as kvm_vcpu_write_guest does it internally */
ret = kvm_vcpu_write_guest(vcpu, shmem, &zero_sta, sizeof(zero_sta));
if (ret)
return SBI_ERR_INVALID_ADDRESS;
vcpu->arch.sta.shmem = shmem;
vcpu->arch.sta.last_steal = current->sched_info.run_delay;
return 0;
}
static int kvm_sbi_ext_sta_handler(struct kvm_vcpu *vcpu, struct kvm_run *run,
struct kvm_vcpu_sbi_return *retdata)
{
struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
unsigned long funcid = cp->a6;
int ret;
switch (funcid) {
case SBI_EXT_STA_STEAL_TIME_SET_SHMEM:
ret = kvm_sbi_sta_steal_time_set_shmem(vcpu);
break;
default:
ret = SBI_ERR_NOT_SUPPORTED;
break;
}
retdata->err_val = ret;
return 0;
}
static unsigned long kvm_sbi_ext_sta_probe(struct kvm_vcpu *vcpu)
{
return !!sched_info_on();
}
static unsigned long kvm_sbi_ext_sta_get_state_reg_count(struct kvm_vcpu *vcpu)
{
return sizeof(struct kvm_riscv_sbi_sta) / sizeof(unsigned long);
}
static int kvm_sbi_ext_sta_get_reg(struct kvm_vcpu *vcpu, unsigned long reg_num,
unsigned long reg_size, void *reg_val)
{
unsigned long *value;
if (reg_size != sizeof(unsigned long))
return -EINVAL;
value = reg_val;
switch (reg_num) {
case KVM_REG_RISCV_SBI_STA_REG(shmem_lo):
*value = (unsigned long)vcpu->arch.sta.shmem;
break;
case KVM_REG_RISCV_SBI_STA_REG(shmem_hi):
if (IS_ENABLED(CONFIG_32BIT))
*value = upper_32_bits(vcpu->arch.sta.shmem);
else
*value = 0;
break;
default:
return -ENOENT;
}
return 0;
}
static int kvm_sbi_ext_sta_set_reg(struct kvm_vcpu *vcpu, unsigned long reg_num,
unsigned long reg_size, const void *reg_val)
{
unsigned long value;
if (reg_size != sizeof(unsigned long))
return -EINVAL;
value = *(const unsigned long *)reg_val;
switch (reg_num) {
case KVM_REG_RISCV_SBI_STA_REG(shmem_lo):
if (IS_ENABLED(CONFIG_32BIT)) {
gpa_t hi = upper_32_bits(vcpu->arch.sta.shmem);
vcpu->arch.sta.shmem = value;
vcpu->arch.sta.shmem |= hi << 32;
} else {
vcpu->arch.sta.shmem = value;
}
break;
case KVM_REG_RISCV_SBI_STA_REG(shmem_hi):
if (IS_ENABLED(CONFIG_32BIT)) {
gpa_t lo = lower_32_bits(vcpu->arch.sta.shmem);
vcpu->arch.sta.shmem = ((gpa_t)value << 32);
vcpu->arch.sta.shmem |= lo;
} else if (value != 0) {
return -EINVAL;
}
break;
default:
return -ENOENT;
}
return 0;
}
const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_sta = {
.extid_start = SBI_EXT_STA,
.extid_end = SBI_EXT_STA,
.handler = kvm_sbi_ext_sta_handler,
.probe = kvm_sbi_ext_sta_probe,
.reset = kvm_riscv_vcpu_sbi_sta_reset,
.state_reg_subtype = KVM_REG_RISCV_SBI_STA,
.get_state_reg_count = kvm_sbi_ext_sta_get_state_reg_count,
.get_state_reg = kvm_sbi_ext_sta_get_reg,
.set_state_reg = kvm_sbi_ext_sta_set_reg,
};
|
