2 This file is part of systemd.
4 Copyright 2011 Lennart Poettering
6 systemd is free software; you can redistribute it and/or modify it
7 under the terms of the GNU Lesser General Public License as published by
8 the Free Software Foundation; either version 2.1 of the License, or
9 (at your option) any later version.
11 systemd is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public License
17 along with systemd; If not, see <http://www.gnu.org/licenses/>.
26 #include "alloc-util.h"
27 #include "dirent-util.h"
31 #include "process-util.h"
32 #include "stat-util.h"
33 #include "string-table.h"
34 #include "string-util.h"
38 static int detect_vm_cpuid(void) {
40 /* CPUID is an x86 specific interface. */
41 #if defined(__i386__) || defined(__x86_64__)
46 } cpuid_vendor_table
[] = {
47 { "XenVMMXenVMM", VIRTUALIZATION_XEN
},
48 { "KVMKVMKVM", VIRTUALIZATION_KVM
},
49 /* http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1009458 */
50 { "VMwareVMware", VIRTUALIZATION_VMWARE
},
51 /* http://msdn.microsoft.com/en-us/library/ff542428.aspx */
52 { "Microsoft Hv", VIRTUALIZATION_MICROSOFT
},
53 /* https://wiki.freebsd.org/bhyve */
54 { "bhyve bhyve ", VIRTUALIZATION_BHYVE
},
60 /* http://lwn.net/Articles/301888/ */
62 #if defined (__i386__)
65 #elif defined (__amd64__)
70 /* First detect whether there is a hypervisor */
72 __asm__
__volatile__ (
73 /* ebx/rbx is being used for PIC! */
74 " push %%"REG_b
" \n\t"
78 : "=a" (eax
), "=c" (ecx
)
82 hypervisor
= !!(ecx
& 0x80000000U
);
91 /* There is a hypervisor, see what it is */
93 __asm__
__volatile__ (
94 /* ebx/rbx is being used for PIC! */
95 " push %%"REG_b
" \n\t"
100 : "=a" (eax
), "=r" (sig
.sig32
[0]), "=c" (sig
.sig32
[1]), "=d" (sig
.sig32
[2])
104 log_debug("Virtualization found, CPUID=%s", sig
.text
);
106 for (j
= 0; j
< ELEMENTSOF(cpuid_vendor_table
); j
++)
107 if (streq(sig
.text
, cpuid_vendor_table
[j
].cpuid
))
108 return cpuid_vendor_table
[j
].id
;
110 return VIRTUALIZATION_VM_OTHER
;
113 log_debug("No virtualization found in CPUID");
115 return VIRTUALIZATION_NONE
;
118 static int detect_vm_device_tree(void) {
119 #if defined(__arm__) || defined(__aarch64__) || defined(__powerpc__) || defined(__powerpc64__)
120 _cleanup_free_
char *hvtype
= NULL
;
123 r
= read_one_line_file("/proc/device-tree/hypervisor/compatible", &hvtype
);
125 _cleanup_closedir_
DIR *dir
= NULL
;
128 dir
= opendir("/proc/device-tree");
130 if (errno
== ENOENT
) {
131 log_debug_errno(errno
, "/proc/device-tree: %m");
132 return VIRTUALIZATION_NONE
;
137 FOREACH_DIRENT(dent
, dir
, return -errno
)
138 if (strstr(dent
->d_name
, "fw-cfg")) {
139 log_debug("Virtualization QEMU: \"fw-cfg\" present in /proc/device-tree/%s", dent
->d_name
);
140 return VIRTUALIZATION_QEMU
;
143 log_debug("No virtualization found in /proc/device-tree/*");
144 return VIRTUALIZATION_NONE
;
148 log_debug("Virtualization %s found in /proc/device-tree/hypervisor/compatible", hvtype
);
149 if (streq(hvtype
, "linux,kvm"))
150 return VIRTUALIZATION_KVM
;
151 else if (strstr(hvtype
, "xen"))
152 return VIRTUALIZATION_XEN
;
154 return VIRTUALIZATION_VM_OTHER
;
156 log_debug("This platform does not support /proc/device-tree");
157 return VIRTUALIZATION_NONE
;
161 static int detect_vm_dmi(void) {
162 #if defined(__i386__) || defined(__x86_64__) || defined(__arm__) || defined(__aarch64__)
164 static const char *const dmi_vendors
[] = {
165 "/sys/class/dmi/id/product_name", /* Test this before sys_vendor to detect KVM over QEMU */
166 "/sys/class/dmi/id/sys_vendor",
167 "/sys/class/dmi/id/board_vendor",
168 "/sys/class/dmi/id/bios_vendor"
171 static const struct {
174 } dmi_vendor_table
[] = {
175 { "KVM", VIRTUALIZATION_KVM
},
176 { "QEMU", VIRTUALIZATION_QEMU
},
177 /* http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1009458 */
178 { "VMware", VIRTUALIZATION_VMWARE
},
179 { "VMW", VIRTUALIZATION_VMWARE
},
180 { "innotek GmbH", VIRTUALIZATION_ORACLE
},
181 { "Xen", VIRTUALIZATION_XEN
},
182 { "Bochs", VIRTUALIZATION_BOCHS
},
183 { "Parallels", VIRTUALIZATION_PARALLELS
},
184 /* https://wiki.freebsd.org/bhyve */
185 { "BHYVE", VIRTUALIZATION_BHYVE
},
190 for (i
= 0; i
< ELEMENTSOF(dmi_vendors
); i
++) {
191 _cleanup_free_
char *s
= NULL
;
194 r
= read_one_line_file(dmi_vendors
[i
], &s
);
204 for (j
= 0; j
< ELEMENTSOF(dmi_vendor_table
); j
++)
205 if (startswith(s
, dmi_vendor_table
[j
].vendor
)) {
206 log_debug("Virtualization %s found in DMI (%s)", s
, dmi_vendors
[i
]);
207 return dmi_vendor_table
[j
].id
;
212 log_debug("No virtualization found in DMI");
214 return VIRTUALIZATION_NONE
;
217 static int detect_vm_xen(void) {
218 /* Check for Dom0 will be executed later in detect_vm_xen_dom0
219 Thats why we dont check the content of /proc/xen/capabilities here. */
220 if (access("/proc/xen/capabilities", F_OK
) < 0) {
221 log_debug("Virtualization XEN not found, /proc/xen/capabilities does not exist");
222 return VIRTUALIZATION_NONE
;
225 log_debug("Virtualization XEN found (/proc/xen/capabilities exists)");
226 return VIRTUALIZATION_XEN
;
230 static bool detect_vm_xen_dom0(void) {
231 _cleanup_free_
char *domcap
= NULL
;
235 r
= read_one_line_file("/proc/xen/capabilities", &domcap
);
237 log_debug("Virtualization XEN not found, /proc/xen/capabilities does not exist");
244 while ((cap
= strsep(&i
, ",")))
245 if (streq(cap
, "control_d"))
248 log_debug("Virtualization XEN DomU found (/proc/xen/capabilites)");
252 log_debug("Virtualization XEN Dom0 ignored (/proc/xen/capabilities)");
256 static int detect_vm_hypervisor(void) {
257 _cleanup_free_
char *hvtype
= NULL
;
260 r
= read_one_line_file("/sys/hypervisor/type", &hvtype
);
262 return VIRTUALIZATION_NONE
;
266 log_debug("Virtualization %s found in /sys/hypervisor/type", hvtype
);
268 if (streq(hvtype
, "xen"))
269 return VIRTUALIZATION_XEN
;
271 return VIRTUALIZATION_VM_OTHER
;
274 static int detect_vm_uml(void) {
275 _cleanup_free_
char *cpuinfo_contents
= NULL
;
278 /* Detect User-Mode Linux by reading /proc/cpuinfo */
279 r
= read_full_file("/proc/cpuinfo", &cpuinfo_contents
, NULL
);
283 if (strstr(cpuinfo_contents
, "\nvendor_id\t: User Mode Linux\n")) {
284 log_debug("UML virtualization found in /proc/cpuinfo");
285 return VIRTUALIZATION_UML
;
288 log_debug("No virtualization found in /proc/cpuinfo.");
289 return VIRTUALIZATION_NONE
;
292 static int detect_vm_zvm(void) {
294 #if defined(__s390__)
295 _cleanup_free_
char *t
= NULL
;
298 r
= get_proc_field("/proc/sysinfo", "VM00 Control Program", WHITESPACE
, &t
);
300 return VIRTUALIZATION_NONE
;
304 log_debug("Virtualization %s found in /proc/sysinfo", t
);
305 if (streq(t
, "z/VM"))
306 return VIRTUALIZATION_ZVM
;
308 return VIRTUALIZATION_KVM
;
310 log_debug("This platform does not support /proc/sysinfo");
311 return VIRTUALIZATION_NONE
;
315 /* Returns a short identifier for the various VM implementations */
316 int detect_vm(void) {
317 static thread_local
int cached_found
= _VIRTUALIZATION_INVALID
;
320 if (cached_found
>= 0)
323 /* We have to use the correct order here:
324 * Some virtualization technologies do use KVM hypervisor but are
325 * expected to be detected as something else. So detect DMI first.
327 * An example is Virtualbox since version 5.0, which uses KVM backend.
328 * Detection via DMI works corretly, the CPU ID would find KVM
333 if (r
!= VIRTUALIZATION_NONE
)
336 r
= detect_vm_cpuid();
339 if (r
!= VIRTUALIZATION_NONE
)
342 /* x86 xen will most likely be detected by cpuid. If not (most likely
343 * because we're not an x86 guest), then we should try the xen capabilities
344 * file next. If that's not found, then we check for the high-level
345 * hypervisor sysfs file:
347 * https://bugs.freedesktop.org/show_bug.cgi?id=77271 */
352 if (r
!= VIRTUALIZATION_NONE
)
355 r
= detect_vm_hypervisor();
358 if (r
!= VIRTUALIZATION_NONE
)
361 r
= detect_vm_device_tree();
364 if (r
!= VIRTUALIZATION_NONE
)
370 if (r
!= VIRTUALIZATION_NONE
)
378 /* x86 xen Dom0 is detected as XEN in hypervisor and maybe others.
379 * In order to detect the Dom0 as not virtualization we need to
381 if (r
== VIRTUALIZATION_XEN
&& detect_vm_xen_dom0())
382 r
= VIRTUALIZATION_NONE
;
385 log_debug("Found VM virtualization %s", virtualization_to_string(r
));
389 int detect_container(void) {
391 static const struct {
395 { "lxc", VIRTUALIZATION_LXC
},
396 { "lxc-libvirt", VIRTUALIZATION_LXC_LIBVIRT
},
397 { "systemd-nspawn", VIRTUALIZATION_SYSTEMD_NSPAWN
},
398 { "docker", VIRTUALIZATION_DOCKER
},
399 { "rkt", VIRTUALIZATION_RKT
},
402 static thread_local
int cached_found
= _VIRTUALIZATION_INVALID
;
403 _cleanup_free_
char *m
= NULL
;
404 const char *e
= NULL
;
408 if (cached_found
>= 0)
411 /* /proc/vz exists in container and outside of the container,
412 * /proc/bc only outside of the container. */
413 if (access("/proc/vz", F_OK
) >= 0 &&
414 access("/proc/bc", F_OK
) < 0) {
415 r
= VIRTUALIZATION_OPENVZ
;
420 /* If we are PID 1 we can just check our own
421 * environment variable */
423 e
= getenv("container");
425 r
= VIRTUALIZATION_NONE
;
430 /* Otherwise, PID 1 dropped this information into a
431 * file in /run. This is better than accessing
432 * /proc/1/environ, since we don't need CAP_SYS_PTRACE
435 r
= read_one_line_file("/run/systemd/container", &m
);
438 /* Fallback for cases where PID 1 was not
439 * systemd (for example, cases where
440 * init=/bin/sh is used. */
442 r
= getenv_for_pid(1, "container", &m
);
445 /* If that didn't work, give up,
446 * assume no container manager.
448 * Note: This means we still cannot
449 * detect containers if init=/bin/sh
450 * is passed but privileges dropped,
451 * as /proc/1/environ is only readable
452 * with privileges. */
454 r
= VIRTUALIZATION_NONE
;
464 for (j
= 0; j
< ELEMENTSOF(value_table
); j
++)
465 if (streq(e
, value_table
[j
].value
)) {
466 r
= value_table
[j
].id
;
470 r
= VIRTUALIZATION_CONTAINER_OTHER
;
473 log_debug("Found container virtualization %s", virtualization_to_string(r
));
478 int detect_virtualization(void) {
481 r
= detect_container();
488 static int userns_has_mapping(const char *name
) {
489 _cleanup_fclose_
FILE *f
= NULL
;
490 _cleanup_free_
char *buf
= NULL
;
491 size_t n_allocated
= 0;
496 f
= fopen(name
, "re");
498 log_debug_errno(errno
, "Failed to open %s: %m", name
);
499 return errno
== ENOENT
? false : -errno
;
502 n
= getline(&buf
, &n_allocated
, f
);
505 log_debug("%s is empty, we're in an uninitialized user namespace", name
);
509 return log_debug_errno(errno
, "Failed to read %s: %m", name
);
512 r
= sscanf(buf
, "%"PRIu32
" %"PRIu32
" %"PRIu32
, &a
, &b
, &c
);
514 return log_debug_errno(errno
, "Failed to parse %s: %m", name
);
516 if (a
== 0 && b
== 0 && c
== UINT32_MAX
) {
517 /* The kernel calls mappings_overlap() and does not allow overlaps */
518 log_debug("%s has a full 1:1 mapping", name
);
522 /* Anything else implies that we are in a user namespace */
523 log_debug("Mapping found in %s, we're in a user namespace", name
);
527 int running_in_userns(void) {
528 _cleanup_free_
char *line
= NULL
;
531 r
= userns_has_mapping("/proc/self/uid_map");
535 r
= userns_has_mapping("/proc/self/gid_map");
539 /* "setgroups" file was added in kernel v3.18-rc6-15-g9cc46516dd. It is also
540 * possible to compile a kernel without CONFIG_USER_NS, in which case "setgroups"
541 * also does not exist. We cannot distinguish those two cases, so assume that
542 * we're running on a stripped-down recent kernel, rather than on an old one,
543 * and if the file is not found, return false.
545 r
= read_one_line_file("/proc/self/setgroups", &line
);
547 log_debug_errno(r
, "/proc/self/setgroups: %m");
548 return r
== -ENOENT
? false : r
;
552 r
= streq(line
, "deny");
553 /* See user_namespaces(7) for a description of this "setgroups" contents. */
554 log_debug("/proc/self/setgroups contains \"%s\", %s user namespace", line
, r
? "in" : "not in");
558 int running_in_chroot(void) {
561 if (getenv_bool("SYSTEMD_IGNORE_CHROOT") > 0)
564 ret
= files_same("/proc/1/root", "/");
571 static const char *const virtualization_table
[_VIRTUALIZATION_MAX
] = {
572 [VIRTUALIZATION_NONE
] = "none",
573 [VIRTUALIZATION_KVM
] = "kvm",
574 [VIRTUALIZATION_QEMU
] = "qemu",
575 [VIRTUALIZATION_BOCHS
] = "bochs",
576 [VIRTUALIZATION_XEN
] = "xen",
577 [VIRTUALIZATION_UML
] = "uml",
578 [VIRTUALIZATION_VMWARE
] = "vmware",
579 [VIRTUALIZATION_ORACLE
] = "oracle",
580 [VIRTUALIZATION_MICROSOFT
] = "microsoft",
581 [VIRTUALIZATION_ZVM
] = "zvm",
582 [VIRTUALIZATION_PARALLELS
] = "parallels",
583 [VIRTUALIZATION_BHYVE
] = "bhyve",
584 [VIRTUALIZATION_VM_OTHER
] = "vm-other",
586 [VIRTUALIZATION_SYSTEMD_NSPAWN
] = "systemd-nspawn",
587 [VIRTUALIZATION_LXC_LIBVIRT
] = "lxc-libvirt",
588 [VIRTUALIZATION_LXC
] = "lxc",
589 [VIRTUALIZATION_OPENVZ
] = "openvz",
590 [VIRTUALIZATION_DOCKER
] = "docker",
591 [VIRTUALIZATION_RKT
] = "rkt",
592 [VIRTUALIZATION_CONTAINER_OTHER
] = "container-other",
595 DEFINE_STRING_TABLE_LOOKUP(virtualization
, int);