1 /* SPDX-License-Identifier: LGPL-2.1+ */
3 This file is part of systemd.
5 Copyright 2011 Lennart Poettering
7 systemd is free software; you can redistribute it and/or modify it
8 under the terms of the GNU Lesser General Public License as published by
9 the Free Software Foundation; either version 2.1 of the License, or
10 (at your option) any later version.
12 systemd is distributed in the hope that it will be useful, but
13 WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 Lesser General Public License for more details.
17 You should have received a copy of the GNU Lesser General Public License
18 along with systemd; If not, see <http://www.gnu.org/licenses/>.
21 #if defined(__i386__) || defined(__x86_64__)
30 #include "alloc-util.h"
31 #include "dirent-util.h"
36 #include "process-util.h"
37 #include "stat-util.h"
38 #include "string-table.h"
39 #include "string-util.h"
42 static int detect_vm_cpuid(void) {
44 /* CPUID is an x86 specific interface. */
45 #if defined(__i386__) || defined(__x86_64__)
50 } cpuid_vendor_table
[] = {
51 { "XenVMMXenVMM", VIRTUALIZATION_XEN
},
52 { "KVMKVMKVM", VIRTUALIZATION_KVM
},
53 { "TCGTCGTCGTCG", VIRTUALIZATION_QEMU
},
54 /* http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1009458 */
55 { "VMwareVMware", VIRTUALIZATION_VMWARE
},
56 /* https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/reference/tlfs */
57 { "Microsoft Hv", VIRTUALIZATION_MICROSOFT
},
58 /* https://wiki.freebsd.org/bhyve */
59 { "bhyve bhyve ", VIRTUALIZATION_BHYVE
},
62 uint32_t eax
, ebx
, ecx
, edx
;
65 /* http://lwn.net/Articles/301888/ */
67 /* First detect whether there is a hypervisor */
68 if (__get_cpuid(1, &eax
, &ebx
, &ecx
, &edx
) == 0)
69 return VIRTUALIZATION_NONE
;
71 hypervisor
= !!(ecx
& 0x80000000U
);
80 /* There is a hypervisor, see what it is */
81 __cpuid(0x40000000U
, eax
, ebx
, ecx
, edx
);
87 log_debug("Virtualization found, CPUID=%s", sig
.text
);
89 for (j
= 0; j
< ELEMENTSOF(cpuid_vendor_table
); j
++)
90 if (streq(sig
.text
, cpuid_vendor_table
[j
].cpuid
))
91 return cpuid_vendor_table
[j
].id
;
93 return VIRTUALIZATION_VM_OTHER
;
96 log_debug("No virtualization found in CPUID");
98 return VIRTUALIZATION_NONE
;
101 static int detect_vm_device_tree(void) {
102 #if defined(__arm__) || defined(__aarch64__) || defined(__powerpc__) || defined(__powerpc64__)
103 _cleanup_free_
char *hvtype
= NULL
;
106 r
= read_one_line_file("/proc/device-tree/hypervisor/compatible", &hvtype
);
108 _cleanup_closedir_
DIR *dir
= NULL
;
111 dir
= opendir("/proc/device-tree");
113 if (errno
== ENOENT
) {
114 log_debug_errno(errno
, "/proc/device-tree: %m");
115 return VIRTUALIZATION_NONE
;
120 FOREACH_DIRENT(dent
, dir
, return -errno
)
121 if (strstr(dent
->d_name
, "fw-cfg")) {
122 log_debug("Virtualization QEMU: \"fw-cfg\" present in /proc/device-tree/%s", dent
->d_name
);
123 return VIRTUALIZATION_QEMU
;
126 log_debug("No virtualization found in /proc/device-tree/*");
127 return VIRTUALIZATION_NONE
;
131 log_debug("Virtualization %s found in /proc/device-tree/hypervisor/compatible", hvtype
);
132 if (streq(hvtype
, "linux,kvm"))
133 return VIRTUALIZATION_KVM
;
134 else if (strstr(hvtype
, "xen"))
135 return VIRTUALIZATION_XEN
;
137 return VIRTUALIZATION_VM_OTHER
;
139 log_debug("This platform does not support /proc/device-tree");
140 return VIRTUALIZATION_NONE
;
144 static int detect_vm_dmi(void) {
145 #if defined(__i386__) || defined(__x86_64__) || defined(__arm__) || defined(__aarch64__)
147 static const char *const dmi_vendors
[] = {
148 "/sys/class/dmi/id/product_name", /* Test this before sys_vendor to detect KVM over QEMU */
149 "/sys/class/dmi/id/sys_vendor",
150 "/sys/class/dmi/id/board_vendor",
151 "/sys/class/dmi/id/bios_vendor"
154 static const struct {
157 } dmi_vendor_table
[] = {
158 { "KVM", VIRTUALIZATION_KVM
},
159 { "QEMU", VIRTUALIZATION_QEMU
},
160 /* http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1009458 */
161 { "VMware", VIRTUALIZATION_VMWARE
},
162 { "VMW", VIRTUALIZATION_VMWARE
},
163 { "innotek GmbH", VIRTUALIZATION_ORACLE
},
164 { "Xen", VIRTUALIZATION_XEN
},
165 { "Bochs", VIRTUALIZATION_BOCHS
},
166 { "Parallels", VIRTUALIZATION_PARALLELS
},
167 /* https://wiki.freebsd.org/bhyve */
168 { "BHYVE", VIRTUALIZATION_BHYVE
},
173 for (i
= 0; i
< ELEMENTSOF(dmi_vendors
); i
++) {
174 _cleanup_free_
char *s
= NULL
;
177 r
= read_one_line_file(dmi_vendors
[i
], &s
);
185 for (j
= 0; j
< ELEMENTSOF(dmi_vendor_table
); j
++)
186 if (startswith(s
, dmi_vendor_table
[j
].vendor
)) {
187 log_debug("Virtualization %s found in DMI (%s)", s
, dmi_vendors
[i
]);
188 return dmi_vendor_table
[j
].id
;
193 log_debug("No virtualization found in DMI");
195 return VIRTUALIZATION_NONE
;
198 static int detect_vm_xen(void) {
200 /* Check for Dom0 will be executed later in detect_vm_xen_dom0
201 The presence of /proc/xen indicates some form of a Xen domain */
202 if (access("/proc/xen", F_OK
) < 0) {
203 log_debug("Virtualization XEN not found, /proc/xen does not exist");
204 return VIRTUALIZATION_NONE
;
207 log_debug("Virtualization XEN found (/proc/xen exists)");
208 return VIRTUALIZATION_XEN
;
211 #define XENFEAT_dom0 11 /* xen/include/public/features.h */
212 #define PATH_FEATURES "/sys/hypervisor/properties/features"
213 /* Returns -errno, or 0 for domU, or 1 for dom0 */
214 static int detect_vm_xen_dom0(void) {
215 _cleanup_free_
char *domcap
= NULL
;
219 r
= read_one_line_file(PATH_FEATURES
, &domcap
);
220 if (r
< 0 && r
!= -ENOENT
)
223 unsigned long features
;
225 r
= sscanf(domcap
, "%lx", &features
);
227 r
= !!(features
& (1U << XENFEAT_dom0
));
228 log_debug("Virtualization XEN, found %s with value %08lx, "
229 "XENFEAT_dom0 (indicating the 'hardware domain') is%s set.",
230 PATH_FEATURES
, features
, r
? "" : " not");
233 log_debug("Virtualization XEN, found %s, unhandled content '%s'",
234 PATH_FEATURES
, domcap
);
237 r
= read_one_line_file("/proc/xen/capabilities", &domcap
);
239 log_debug("Virtualization XEN because /proc/xen/capabilities does not exist");
246 while ((cap
= strsep(&i
, ",")))
247 if (streq(cap
, "control_d"))
250 log_debug("Virtualization XEN DomU found (/proc/xen/capabilites)");
254 log_debug("Virtualization XEN Dom0 ignored (/proc/xen/capabilities)");
258 static int detect_vm_hypervisor(void) {
259 _cleanup_free_
char *hvtype
= NULL
;
262 r
= read_one_line_file("/sys/hypervisor/type", &hvtype
);
264 return VIRTUALIZATION_NONE
;
268 log_debug("Virtualization %s found in /sys/hypervisor/type", hvtype
);
270 if (streq(hvtype
, "xen"))
271 return VIRTUALIZATION_XEN
;
273 return VIRTUALIZATION_VM_OTHER
;
276 static int detect_vm_uml(void) {
277 _cleanup_free_
char *cpuinfo_contents
= NULL
;
280 /* Detect User-Mode Linux by reading /proc/cpuinfo */
281 r
= read_full_file("/proc/cpuinfo", &cpuinfo_contents
, NULL
);
285 if (strstr(cpuinfo_contents
, "\nvendor_id\t: User Mode Linux\n")) {
286 log_debug("UML virtualization found in /proc/cpuinfo");
287 return VIRTUALIZATION_UML
;
290 log_debug("No virtualization found in /proc/cpuinfo.");
291 return VIRTUALIZATION_NONE
;
294 static int detect_vm_zvm(void) {
296 #if defined(__s390__)
297 _cleanup_free_
char *t
= NULL
;
300 r
= get_proc_field("/proc/sysinfo", "VM00 Control Program", WHITESPACE
, &t
);
302 return VIRTUALIZATION_NONE
;
306 log_debug("Virtualization %s found in /proc/sysinfo", t
);
307 if (streq(t
, "z/VM"))
308 return VIRTUALIZATION_ZVM
;
310 return VIRTUALIZATION_KVM
;
312 log_debug("This platform does not support /proc/sysinfo");
313 return VIRTUALIZATION_NONE
;
317 /* Returns a short identifier for the various VM implementations */
318 int detect_vm(void) {
319 static thread_local
int cached_found
= _VIRTUALIZATION_INVALID
;
323 if (cached_found
>= 0)
326 /* We have to use the correct order here:
328 * -> First try to detect Oracle Virtualbox, even if it uses KVM.
329 * -> Second try to detect from cpuid, this will report KVM for
330 * whatever software is used even if info in dmi is overwritten.
331 * -> Third try to detect from dmi. */
333 dmi
= detect_vm_dmi();
334 if (dmi
== VIRTUALIZATION_ORACLE
) {
339 r
= detect_vm_cpuid();
342 if (r
!= VIRTUALIZATION_NONE
) {
343 if (r
== VIRTUALIZATION_VM_OTHER
)
352 if (r
!= VIRTUALIZATION_NONE
) {
353 if (r
== VIRTUALIZATION_VM_OTHER
)
359 /* x86 xen will most likely be detected by cpuid. If not (most likely
360 * because we're not an x86 guest), then we should try the /proc/xen
361 * directory next. If that's not found, then we check for the high-level
362 * hypervisor sysfs file.
368 if (r
!= VIRTUALIZATION_NONE
) {
369 if (r
== VIRTUALIZATION_VM_OTHER
)
375 r
= detect_vm_hypervisor();
378 if (r
!= VIRTUALIZATION_NONE
) {
379 if (r
== VIRTUALIZATION_VM_OTHER
)
385 r
= detect_vm_device_tree();
388 if (r
!= VIRTUALIZATION_NONE
) {
389 if (r
== VIRTUALIZATION_VM_OTHER
)
398 if (r
!= VIRTUALIZATION_NONE
) {
399 if (r
== VIRTUALIZATION_VM_OTHER
)
410 /* x86 xen Dom0 is detected as XEN in hypervisor and maybe others.
411 * In order to detect the Dom0 as not virtualization we need to
413 if (r
== VIRTUALIZATION_XEN
) {
414 int ret
= detect_vm_xen_dom0();
418 r
= VIRTUALIZATION_NONE
;
419 } else if (r
== VIRTUALIZATION_NONE
&& other
)
420 r
= VIRTUALIZATION_VM_OTHER
;
423 log_debug("Found VM virtualization %s", virtualization_to_string(r
));
427 int detect_container(void) {
429 static const struct {
433 { "lxc", VIRTUALIZATION_LXC
},
434 { "lxc-libvirt", VIRTUALIZATION_LXC_LIBVIRT
},
435 { "systemd-nspawn", VIRTUALIZATION_SYSTEMD_NSPAWN
},
436 { "docker", VIRTUALIZATION_DOCKER
},
437 { "rkt", VIRTUALIZATION_RKT
},
440 static thread_local
int cached_found
= _VIRTUALIZATION_INVALID
;
441 _cleanup_free_
char *m
= NULL
;
442 const char *e
= NULL
;
446 if (cached_found
>= 0)
449 /* /proc/vz exists in container and outside of the container, /proc/bc only outside of the container. */
450 if (access("/proc/vz", F_OK
) >= 0 &&
451 access("/proc/bc", F_OK
) < 0) {
452 r
= VIRTUALIZATION_OPENVZ
;
456 if (getpid_cached() == 1) {
457 /* If we are PID 1 we can just check our own environment variable, and that's authoritative. */
459 e
= getenv("container");
461 r
= VIRTUALIZATION_NONE
;
468 /* Otherwise, PID 1 might have dropped this information into a file in /run. This is better than accessing
469 * /proc/1/environ, since we don't need CAP_SYS_PTRACE for that. */
470 r
= read_one_line_file("/run/systemd/container", &m
);
476 return log_debug_errno(r
, "Failed to read /run/systemd/container: %m");
478 /* Fallback for cases where PID 1 was not systemd (for example, cases where init=/bin/sh is used. */
479 r
= getenv_for_pid(1, "container", &m
);
484 if (r
< 0) /* This only works if we have CAP_SYS_PTRACE, hence let's better ignore failures here */
485 log_debug_errno(r
, "Failed to read $container of PID 1, ignoring: %m");
487 /* Interestingly /proc/1/sched actually shows the host's PID for what we see as PID 1. Hence, if the PID shown
488 * there is not 1, we know we are in a PID namespace. and hence a container. */
489 r
= read_one_line_file("/proc/1/sched", &m
);
497 if (!startswith(t
, "(1,")) {
498 r
= VIRTUALIZATION_CONTAINER_OTHER
;
501 } else if (r
!= -ENOENT
)
504 /* If that didn't work, give up, assume no container manager. */
505 r
= VIRTUALIZATION_NONE
;
509 for (j
= 0; j
< ELEMENTSOF(value_table
); j
++)
510 if (streq(e
, value_table
[j
].value
)) {
511 r
= value_table
[j
].id
;
515 r
= VIRTUALIZATION_CONTAINER_OTHER
;
518 log_debug("Found container virtualization %s.", virtualization_to_string(r
));
523 int detect_virtualization(void) {
526 r
= detect_container();
533 static int userns_has_mapping(const char *name
) {
534 _cleanup_fclose_
FILE *f
= NULL
;
535 _cleanup_free_
char *buf
= NULL
;
536 size_t n_allocated
= 0;
541 f
= fopen(name
, "re");
543 log_debug_errno(errno
, "Failed to open %s: %m", name
);
544 return errno
== ENOENT
? false : -errno
;
547 n
= getline(&buf
, &n_allocated
, f
);
550 log_debug("%s is empty, we're in an uninitialized user namespace", name
);
554 return log_debug_errno(errno
, "Failed to read %s: %m", name
);
557 r
= sscanf(buf
, "%"PRIu32
" %"PRIu32
" %"PRIu32
, &a
, &b
, &c
);
559 return log_debug_errno(errno
, "Failed to parse %s: %m", name
);
561 if (a
== 0 && b
== 0 && c
== UINT32_MAX
) {
562 /* The kernel calls mappings_overlap() and does not allow overlaps */
563 log_debug("%s has a full 1:1 mapping", name
);
567 /* Anything else implies that we are in a user namespace */
568 log_debug("Mapping found in %s, we're in a user namespace", name
);
572 int running_in_userns(void) {
573 _cleanup_free_
char *line
= NULL
;
576 r
= userns_has_mapping("/proc/self/uid_map");
580 r
= userns_has_mapping("/proc/self/gid_map");
584 /* "setgroups" file was added in kernel v3.18-rc6-15-g9cc46516dd. It is also
585 * possible to compile a kernel without CONFIG_USER_NS, in which case "setgroups"
586 * also does not exist. We cannot distinguish those two cases, so assume that
587 * we're running on a stripped-down recent kernel, rather than on an old one,
588 * and if the file is not found, return false.
590 r
= read_one_line_file("/proc/self/setgroups", &line
);
592 log_debug_errno(r
, "/proc/self/setgroups: %m");
593 return r
== -ENOENT
? false : r
;
597 r
= streq(line
, "deny");
598 /* See user_namespaces(7) for a description of this "setgroups" contents. */
599 log_debug("/proc/self/setgroups contains \"%s\", %s user namespace", line
, r
? "in" : "not in");
603 int running_in_chroot(void) {
606 if (getenv_bool("SYSTEMD_IGNORE_CHROOT") > 0)
609 ret
= files_same("/proc/1/root", "/", 0);
616 static const char *const virtualization_table
[_VIRTUALIZATION_MAX
] = {
617 [VIRTUALIZATION_NONE
] = "none",
618 [VIRTUALIZATION_KVM
] = "kvm",
619 [VIRTUALIZATION_QEMU
] = "qemu",
620 [VIRTUALIZATION_BOCHS
] = "bochs",
621 [VIRTUALIZATION_XEN
] = "xen",
622 [VIRTUALIZATION_UML
] = "uml",
623 [VIRTUALIZATION_VMWARE
] = "vmware",
624 [VIRTUALIZATION_ORACLE
] = "oracle",
625 [VIRTUALIZATION_MICROSOFT
] = "microsoft",
626 [VIRTUALIZATION_ZVM
] = "zvm",
627 [VIRTUALIZATION_PARALLELS
] = "parallels",
628 [VIRTUALIZATION_BHYVE
] = "bhyve",
629 [VIRTUALIZATION_VM_OTHER
] = "vm-other",
631 [VIRTUALIZATION_SYSTEMD_NSPAWN
] = "systemd-nspawn",
632 [VIRTUALIZATION_LXC_LIBVIRT
] = "lxc-libvirt",
633 [VIRTUALIZATION_LXC
] = "lxc",
634 [VIRTUALIZATION_OPENVZ
] = "openvz",
635 [VIRTUALIZATION_DOCKER
] = "docker",
636 [VIRTUALIZATION_RKT
] = "rkt",
637 [VIRTUALIZATION_CONTAINER_OTHER
] = "container-other",
640 DEFINE_STRING_TABLE_LOOKUP(virtualization
, int);