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
|
// SPDX-License-Identifier: GPL-2.0
/*
* KVM guest debug register tests
*
* Copyright (C) 2020, Red Hat, Inc.
*/
#include <stdio.h>
#include <string.h>
#include "kvm_util.h"
#include "processor.h"
#define VCPU_ID 0
#define DR6_BD (1 << 13)
#define DR7_GD (1 << 13)
/* For testing data access debug BP */
uint32_t guest_value;
extern unsigned char sw_bp, hw_bp, write_data, ss_start, bd_start;
static void guest_code(void)
{
/*
* Software BP tests.
*
* NOTE: sw_bp need to be before the cmd here, because int3 is an
* exception rather than a normal trap for KVM_SET_GUEST_DEBUG (we
* capture it using the vcpu exception bitmap).
*/
asm volatile("sw_bp: int3");
/* Hardware instruction BP test */
asm volatile("hw_bp: nop");
/* Hardware data BP test */
asm volatile("mov $1234,%%rax;\n\t"
"mov %%rax,%0;\n\t write_data:"
: "=m" (guest_value) : : "rax");
/* Single step test, covers 2 basic instructions and 2 emulated */
asm volatile("ss_start: "
"xor %%rax,%%rax\n\t"
"cpuid\n\t"
"movl $0x1a0,%%ecx\n\t"
"rdmsr\n\t"
: : : "rax", "ecx");
/* DR6.BD test */
asm volatile("bd_start: mov %%dr0, %%rax" : : : "rax");
GUEST_DONE();
}
#define CLEAR_DEBUG() memset(&debug, 0, sizeof(debug))
#define APPLY_DEBUG() vcpu_set_guest_debug(vm, VCPU_ID, &debug)
#define CAST_TO_RIP(v) ((unsigned long long)&(v))
#define SET_RIP(v) do { \
vcpu_regs_get(vm, VCPU_ID, ®s); \
regs.rip = (v); \
vcpu_regs_set(vm, VCPU_ID, ®s); \
} while (0)
#define MOVE_RIP(v) SET_RIP(regs.rip + (v));
int main(void)
{
struct kvm_guest_debug debug;
unsigned long long target_dr6, target_rip;
struct kvm_regs regs;
struct kvm_run *run;
struct kvm_vm *vm;
struct ucall uc;
uint64_t cmd;
int i;
/* Instruction lengths starting at ss_start */
int ss_size[4] = {
3, /* xor */
2, /* cpuid */
5, /* mov */
2, /* rdmsr */
};
if (!kvm_check_cap(KVM_CAP_SET_GUEST_DEBUG)) {
print_skip("KVM_CAP_SET_GUEST_DEBUG not supported");
return 0;
}
vm = vm_create_default(VCPU_ID, 0, guest_code);
vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
run = vcpu_state(vm, VCPU_ID);
/* Test software BPs - int3 */
CLEAR_DEBUG();
debug.control = KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP;
APPLY_DEBUG();
vcpu_run(vm, VCPU_ID);
TEST_ASSERT(run->exit_reason == KVM_EXIT_DEBUG &&
run->debug.arch.exception == BP_VECTOR &&
run->debug.arch.pc == CAST_TO_RIP(sw_bp),
"INT3: exit %d exception %d rip 0x%llx (should be 0x%llx)",
run->exit_reason, run->debug.arch.exception,
run->debug.arch.pc, CAST_TO_RIP(sw_bp));
MOVE_RIP(1);
/* Test instruction HW BP over DR[0-3] */
for (i = 0; i < 4; i++) {
CLEAR_DEBUG();
debug.control = KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_HW_BP;
debug.arch.debugreg[i] = CAST_TO_RIP(hw_bp);
debug.arch.debugreg[7] = 0x400 | (1UL << (2*i+1));
APPLY_DEBUG();
vcpu_run(vm, VCPU_ID);
target_dr6 = 0xffff0ff0 | (1UL << i);
TEST_ASSERT(run->exit_reason == KVM_EXIT_DEBUG &&
run->debug.arch.exception == DB_VECTOR &&
run->debug.arch.pc == CAST_TO_RIP(hw_bp) &&
run->debug.arch.dr6 == target_dr6,
"INS_HW_BP (DR%d): exit %d exception %d rip 0x%llx "
"(should be 0x%llx) dr6 0x%llx (should be 0x%llx)",
i, run->exit_reason, run->debug.arch.exception,
run->debug.arch.pc, CAST_TO_RIP(hw_bp),
run->debug.arch.dr6, target_dr6);
}
/* Skip "nop" */
MOVE_RIP(1);
/* Test data access HW BP over DR[0-3] */
for (i = 0; i < 4; i++) {
CLEAR_DEBUG();
debug.control = KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_HW_BP;
debug.arch.debugreg[i] = CAST_TO_RIP(guest_value);
debug.arch.debugreg[7] = 0x00000400 | (1UL << (2*i+1)) |
(0x000d0000UL << (4*i));
APPLY_DEBUG();
vcpu_run(vm, VCPU_ID);
target_dr6 = 0xffff0ff0 | (1UL << i);
TEST_ASSERT(run->exit_reason == KVM_EXIT_DEBUG &&
run->debug.arch.exception == DB_VECTOR &&
run->debug.arch.pc == CAST_TO_RIP(write_data) &&
run->debug.arch.dr6 == target_dr6,
"DATA_HW_BP (DR%d): exit %d exception %d rip 0x%llx "
"(should be 0x%llx) dr6 0x%llx (should be 0x%llx)",
i, run->exit_reason, run->debug.arch.exception,
run->debug.arch.pc, CAST_TO_RIP(write_data),
run->debug.arch.dr6, target_dr6);
/* Rollback the 4-bytes "mov" */
MOVE_RIP(-7);
}
/* Skip the 4-bytes "mov" */
MOVE_RIP(7);
/* Test single step */
target_rip = CAST_TO_RIP(ss_start);
target_dr6 = 0xffff4ff0ULL;
vcpu_regs_get(vm, VCPU_ID, ®s);
for (i = 0; i < (sizeof(ss_size) / sizeof(ss_size[0])); i++) {
target_rip += ss_size[i];
CLEAR_DEBUG();
debug.control = KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_SINGLESTEP;
debug.arch.debugreg[7] = 0x00000400;
APPLY_DEBUG();
vcpu_run(vm, VCPU_ID);
TEST_ASSERT(run->exit_reason == KVM_EXIT_DEBUG &&
run->debug.arch.exception == DB_VECTOR &&
run->debug.arch.pc == target_rip &&
run->debug.arch.dr6 == target_dr6,
"SINGLE_STEP[%d]: exit %d exception %d rip 0x%llx "
"(should be 0x%llx) dr6 0x%llx (should be 0x%llx)",
i, run->exit_reason, run->debug.arch.exception,
run->debug.arch.pc, target_rip, run->debug.arch.dr6,
target_dr6);
}
/* Finally test global disable */
CLEAR_DEBUG();
debug.control = KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_HW_BP;
debug.arch.debugreg[7] = 0x400 | DR7_GD;
APPLY_DEBUG();
vcpu_run(vm, VCPU_ID);
target_dr6 = 0xffff0ff0 | DR6_BD;
TEST_ASSERT(run->exit_reason == KVM_EXIT_DEBUG &&
run->debug.arch.exception == DB_VECTOR &&
run->debug.arch.pc == CAST_TO_RIP(bd_start) &&
run->debug.arch.dr6 == target_dr6,
"DR7.GD: exit %d exception %d rip 0x%llx "
"(should be 0x%llx) dr6 0x%llx (should be 0x%llx)",
run->exit_reason, run->debug.arch.exception,
run->debug.arch.pc, target_rip, run->debug.arch.dr6,
target_dr6);
/* Disable all debug controls, run to the end */
CLEAR_DEBUG();
APPLY_DEBUG();
vcpu_run(vm, VCPU_ID);
TEST_ASSERT(run->exit_reason == KVM_EXIT_IO, "KVM_EXIT_IO");
cmd = get_ucall(vm, VCPU_ID, &uc);
TEST_ASSERT(cmd == UCALL_DONE, "UCALL_DONE");
kvm_vm_free(vm);
return 0;
}
|
