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
|
/*
* Check decoding of KVM_* commands of ioctl syscall using /dev/kvm API.
* Based on kvmtest.c from https://lwn.net/Articles/658512/
*
* kvmtest.c author: Josh Triplett <josh@joshtriplett.org>
* Copyright (c) 2015 Intel Corporation
* Copyright (c) 2017-2018 The strace developers.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#include "tests.h"
#if defined HAVE_LINUX_KVM_H \
&& defined HAVE_STRUCT_KVM_REGS \
&& defined HAVE_STRUCT_KVM_SREGS \
&& defined HAVE_STRUCT_KVM_USERSPACE_MEMORY_REGION \
&&(defined __x86_64__ || defined __i386__)
# include <fcntl.h>
# include <stdint.h>
# include <stdio.h>
# include <stdlib.h>
# include <string.h>
# include <sys/ioctl.h>
# include <sys/mman.h>
# include <linux/kvm.h>
static int
kvm_ioctl(int fd, unsigned long cmd, const char *cmd_str, void *arg)
{
int rc = ioctl(fd, cmd, arg);
if (rc < 0)
perror_msg_and_skip("%s", cmd_str);
return rc;
}
#define KVM_IOCTL(fd_, cmd_, arg_) \
kvm_ioctl((fd_), (cmd_), #cmd_, (arg_))
static const char dev[] = "/dev/kvm";
static const char vm_dev[] = "anon_inode:kvm-vm";
static const char vcpu_dev[] = "anon_inode:kvm-vcpu";
static size_t page_size;
extern const char code[];
extern const unsigned short code_size;
__asm__(
".type code, @object \n"
"code: \n"
" mov $0xd80003f8, %edx \n"
" mov $'\n', %al \n"
" out %al, (%dx) \n"
" hlt \n"
".size code, . - code \n"
".type code_size, @object \n"
"code_size: \n"
" .short . - code \n"
".size code_size, . - code_size \n"
);
static void
run_kvm(const int vcpu_fd, struct kvm_run *const run, const size_t mmap_size,
void *const mem)
{
/* Initialize CS to point at 0, via a read-modify-write of sregs. */
struct kvm_sregs sregs;
KVM_IOCTL(vcpu_fd, KVM_GET_SREGS, &sregs);
printf("ioctl(%d<%s>, KVM_GET_SREGS, {cs={base=%#jx, limit=%u, selector=%u"
", type=%u, present=%u, dpl=%u, db=%u, s=%u, l=%u, g=%u, avl=%u}"
", ...}) = 0\n", vcpu_fd, vcpu_dev, (uintmax_t) sregs.cs.base,
sregs.cs.limit, sregs.cs.selector, sregs.cs.type,
sregs.cs.present, sregs.cs.dpl, sregs.cs.db, sregs.cs.s,
sregs.cs.l, sregs.cs.g, sregs.cs.avl);
sregs.cs.base = 0;
sregs.cs.selector = 0;
KVM_IOCTL(vcpu_fd, KVM_SET_SREGS, &sregs);
printf("ioctl(%d<%s>, KVM_SET_SREGS, {cs={base=%#jx, limit=%u"
", selector=%u, type=%u, present=%u, dpl=%u, db=%u, s=%u"
", l=%u, g=%u, avl=%u}, ...}) = 0\n",
vcpu_fd, vcpu_dev, (uintmax_t) sregs.cs.base,
sregs.cs.limit, sregs.cs.selector, sregs.cs.type,
sregs.cs.present, sregs.cs.dpl, sregs.cs.db, sregs.cs.s,
sregs.cs.l, sregs.cs.g, sregs.cs.avl);
/*
* Initialize registers: instruction pointer for our code, addends,
* and initial flags required by x86 architecture.
*/
struct kvm_regs regs = {
.rip = page_size,
.rax = 2,
.rbx = 2,
.rflags = 0x2,
};
KVM_IOCTL(vcpu_fd, KVM_SET_REGS, ®s);
printf("ioctl(%d<%s>, KVM_SET_REGS, {rax=%#jx, ..."
", rsp=%#jx, rbp=%#jx, ..., rip=%#jx, rflags=%#jx}) = 0\n",
vcpu_fd, vcpu_dev, (uintmax_t) regs.rax,
(uintmax_t) regs.rsp, (uintmax_t) regs.rbp,
(uintmax_t) regs.rip, (uintmax_t) regs.rflags);
/* Copy the code */
memcpy(mem, code, code_size);
const char *p = "\n";
/* Repeatedly run code and handle VM exits. */
for (;;) {
KVM_IOCTL(vcpu_fd, KVM_RUN, NULL);
printf("ioctl(%d<%s>, KVM_RUN, 0) = 0\n", vcpu_fd, vcpu_dev);
switch (run->exit_reason) {
case KVM_EXIT_HLT:
if (p)
error_msg_and_fail("premature KVM_EXIT_HLT");
return;
case KVM_EXIT_IO:
if (run->io.direction == KVM_EXIT_IO_OUT
&& run->io.size == 1
&& run->io.port == 0x03f8
&& run->io.count == 1
&& run->io.data_offset < mmap_size
&& p && *p == ((char *) run)[run->io.data_offset])
p = NULL;
else
error_msg_and_fail("unhandled KVM_EXIT_IO");
break;
case KVM_EXIT_MMIO:
error_msg_and_fail("Got an unexpected MMIO exit:"
" phys_addr %#llx,"
" data %02x %02x %02x %02x"
" %02x %02x %02x %02x,"
" len %u, is_write %hhu",
(unsigned long long) run->mmio.phys_addr,
run->mmio.data[0], run->mmio.data[1],
run->mmio.data[2], run->mmio.data[3],
run->mmio.data[4], run->mmio.data[5],
run->mmio.data[6], run->mmio.data[7],
run->mmio.len, run->mmio.is_write);
default:
error_msg_and_fail("exit_reason = %#x",
run->exit_reason);
}
}
}
int
main(void)
{
skip_if_unavailable("/proc/self/fd/");
int kvm = open(dev, O_RDWR);
if (kvm < 0)
perror_msg_and_skip("open: %s", dev);
/* Make sure we have the stable version of the API */
int ret = KVM_IOCTL(kvm, KVM_GET_API_VERSION, 0);
if (ret != KVM_API_VERSION)
error_msg_and_skip("KVM_GET_API_VERSION returned %d"
", KVM_API_VERSION is %d",
kvm, KVM_API_VERSION);
printf("ioctl(%d<%s>, KVM_GET_API_VERSION, 0) = %d\n",
kvm, dev, ret);
int vm_fd = KVM_IOCTL(kvm, KVM_CREATE_VM, 0);
printf("ioctl(%d<%s>, KVM_CREATE_VM, 0) = %d<%s>\n",
kvm, dev, vm_fd, vm_dev);
/* Allocate one aligned page of guest memory to hold the code. */
page_size = get_page_size();
void *const mem = mmap(NULL, page_size, PROT_READ | PROT_WRITE,
MAP_SHARED | MAP_ANONYMOUS, -1, 0);
if (mem == MAP_FAILED)
perror_msg_and_fail("mmap page");
/* Map it to the second page frame (to avoid the real-mode IDT at 0). */
struct kvm_userspace_memory_region region = {
.slot = 0,
.guest_phys_addr = page_size,
.memory_size = page_size,
.userspace_addr = (uintptr_t) mem,
};
KVM_IOCTL(vm_fd, KVM_SET_USER_MEMORY_REGION, ®ion);
printf("ioctl(%d<%s>, KVM_SET_USER_MEMORY_REGION"
", {slot=0, flags=0, guest_phys_addr=%#lx, memory_size=%lu"
", userspace_addr=%p}) = 0\n", vm_fd, vm_dev,
(unsigned long) page_size, (unsigned long) page_size, mem);
int vcpu_fd = KVM_IOCTL(vm_fd, KVM_CREATE_VCPU, NULL);
printf("ioctl(%d<%s>, KVM_CREATE_VCPU, 0) = %d<%s>\n",
vm_fd, vm_dev, vcpu_fd, vcpu_dev);
/* Map the shared kvm_run structure and following data. */
ret = KVM_IOCTL(kvm, KVM_GET_VCPU_MMAP_SIZE, NULL);
struct kvm_run *run;
if (ret < (int) sizeof(*run))
error_msg_and_fail("KVM_GET_VCPU_MMAP_SIZE returned %d < %d",
ret, (int) sizeof(*run));
printf("ioctl(%d<%s>, KVM_GET_VCPU_MMAP_SIZE, 0) = %d\n",
kvm, dev, ret);
const size_t mmap_size = (ret + page_size - 1) & -page_size;
run = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE,
MAP_SHARED, vcpu_fd, 0);
if (run == MAP_FAILED)
perror_msg_and_fail("mmap vcpu");
run_kvm(vcpu_fd, run, mmap_size, mem);
puts("+++ exited with 0 +++");
return 0;
}
#else /* !HAVE_LINUX_KVM_H */
SKIP_MAIN_UNDEFINED("HAVE_LINUX_KVM_H && HAVE_STRUCT_KVM_REGS && "
"HAVE_STRUCT_KVM_SREGS && "
"HAVE_STRUCT_KVM_USERSPACE_MEMORY_REGION && "
"(__x86_64__ || __i386__)")
#endif
|
