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"
37 #if 0 /// UNNEEDED by elogind
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 { "TCGTCGTCGTCG", VIRTUALIZATION_QEMU },
50 /* http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1009458 */
51 { "VMwareVMware", VIRTUALIZATION_VMWARE },
52 /* https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/reference/tlfs */
53 { "Microsoft Hv", VIRTUALIZATION_MICROSOFT },
54 /* https://wiki.freebsd.org/bhyve */
55 { "bhyve bhyve ", VIRTUALIZATION_BHYVE },
61 /* http://lwn.net/Articles/301888/ */
63 #if defined (__i386__)
66 #elif defined (__amd64__)
71 /* First detect whether there is a hypervisor */
73 __asm__ __volatile__ (
74 /* ebx/rbx is being used for PIC! */
75 " push %%"REG_b" \n\t"
79 : "=a" (eax), "=c" (ecx)
83 hypervisor = !!(ecx & 0x80000000U);
92 /* There is a hypervisor, see what it is */
94 __asm__ __volatile__ (
95 /* ebx/rbx is being used for PIC! */
96 " push %%"REG_b" \n\t"
101 : "=a" (eax), "=r" (sig.sig32[0]), "=c" (sig.sig32[1]), "=d" (sig.sig32[2])
105 log_debug("Virtualization found, CPUID=%s", sig.text);
107 for (j = 0; j < ELEMENTSOF(cpuid_vendor_table); j ++)
108 if (streq(sig.text, cpuid_vendor_table[j].cpuid))
109 return cpuid_vendor_table[j].id;
111 return VIRTUALIZATION_VM_OTHER;
114 log_debug("No virtualization found in CPUID");
116 return VIRTUALIZATION_NONE;
119 static int detect_vm_device_tree(void) {
120 #if defined(__arm__) || defined(__aarch64__) || defined(__powerpc__) || defined(__powerpc64__)
121 _cleanup_free_ char *hvtype = NULL;
124 r = read_one_line_file("/proc/device-tree/hypervisor/compatible", &hvtype);
126 _cleanup_closedir_ DIR *dir = NULL;
129 dir = opendir("/proc/device-tree");
131 if (errno == ENOENT) {
132 log_debug_errno(errno, "/proc/device-tree: %m");
133 return VIRTUALIZATION_NONE;
138 FOREACH_DIRENT(dent, dir, return -errno)
139 if (strstr(dent->d_name, "fw-cfg")) {
140 log_debug("Virtualization QEMU: \"fw-cfg\" present in /proc/device-tree/%s", dent->d_name);
141 return VIRTUALIZATION_QEMU;
144 log_debug("No virtualization found in /proc/device-tree/*");
145 return VIRTUALIZATION_NONE;
149 log_debug("Virtualization %s found in /proc/device-tree/hypervisor/compatible", hvtype);
150 if (streq(hvtype, "linux,kvm"))
151 return VIRTUALIZATION_KVM;
152 else if (strstr(hvtype, "xen"))
153 return VIRTUALIZATION_XEN;
155 return VIRTUALIZATION_VM_OTHER;
157 log_debug("This platform does not support /proc/device-tree");
158 return VIRTUALIZATION_NONE;
162 static int detect_vm_dmi(void) {
163 #if defined(__i386__) || defined(__x86_64__) || defined(__arm__) || defined(__aarch64__)
165 static const char *const dmi_vendors[] = {
166 "/sys/class/dmi/id/product_name", /* Test this before sys_vendor to detect KVM over QEMU */
167 "/sys/class/dmi/id/sys_vendor",
168 "/sys/class/dmi/id/board_vendor",
169 "/sys/class/dmi/id/bios_vendor"
172 static const struct {
175 } dmi_vendor_table[] = {
176 { "KVM", VIRTUALIZATION_KVM },
177 { "QEMU", VIRTUALIZATION_QEMU },
178 /* http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1009458 */
179 { "VMware", VIRTUALIZATION_VMWARE },
180 { "VMW", VIRTUALIZATION_VMWARE },
181 { "innotek GmbH", VIRTUALIZATION_ORACLE },
182 { "Xen", VIRTUALIZATION_XEN },
183 { "Bochs", VIRTUALIZATION_BOCHS },
184 { "Parallels", VIRTUALIZATION_PARALLELS },
185 /* https://wiki.freebsd.org/bhyve */
186 { "BHYVE", VIRTUALIZATION_BHYVE },
191 for (i = 0; i < ELEMENTSOF(dmi_vendors); i++) {
192 _cleanup_free_ char *s = NULL;
195 r = read_one_line_file(dmi_vendors[i], &s);
205 for (j = 0; j < ELEMENTSOF(dmi_vendor_table); j++)
206 if (startswith(s, dmi_vendor_table[j].vendor)) {
207 log_debug("Virtualization %s found in DMI (%s)", s, dmi_vendors[i]);
208 return dmi_vendor_table[j].id;
213 log_debug("No virtualization found in DMI");
215 return VIRTUALIZATION_NONE;
218 static int detect_vm_xen(void) {
219 /* Check for Dom0 will be executed later in detect_vm_xen_dom0
220 Thats why we dont check the content of /proc/xen/capabilities here. */
221 if (access("/proc/xen/capabilities", F_OK) < 0) {
222 log_debug("Virtualization XEN not found, /proc/xen/capabilities does not exist");
223 return VIRTUALIZATION_NONE;
226 log_debug("Virtualization XEN found (/proc/xen/capabilities exists)");
227 return VIRTUALIZATION_XEN;
231 static bool detect_vm_xen_dom0(void) {
232 _cleanup_free_ char *domcap = NULL;
236 r = read_one_line_file("/proc/xen/capabilities", &domcap);
238 log_debug("Virtualization XEN not found, /proc/xen/capabilities does not exist");
245 while ((cap = strsep(&i, ",")))
246 if (streq(cap, "control_d"))
249 log_debug("Virtualization XEN DomU found (/proc/xen/capabilites)");
253 log_debug("Virtualization XEN Dom0 ignored (/proc/xen/capabilities)");
257 static int detect_vm_hypervisor(void) {
258 _cleanup_free_ char *hvtype = NULL;
261 r = read_one_line_file("/sys/hypervisor/type", &hvtype);
263 return VIRTUALIZATION_NONE;
267 log_debug("Virtualization %s found in /sys/hypervisor/type", hvtype);
269 if (streq(hvtype, "xen"))
270 return VIRTUALIZATION_XEN;
272 return VIRTUALIZATION_VM_OTHER;
275 static int detect_vm_uml(void) {
276 _cleanup_free_ char *cpuinfo_contents = NULL;
279 /* Detect User-Mode Linux by reading /proc/cpuinfo */
280 r = read_full_file("/proc/cpuinfo", &cpuinfo_contents, NULL);
284 if (strstr(cpuinfo_contents, "\nvendor_id\t: User Mode Linux\n")) {
285 log_debug("UML virtualization found in /proc/cpuinfo");
286 return VIRTUALIZATION_UML;
289 log_debug("No virtualization found in /proc/cpuinfo.");
290 return VIRTUALIZATION_NONE;
293 static int detect_vm_zvm(void) {
295 #if defined(__s390__)
296 _cleanup_free_ char *t = NULL;
299 r = get_proc_field("/proc/sysinfo", "VM00 Control Program", WHITESPACE, &t);
301 return VIRTUALIZATION_NONE;
305 log_debug("Virtualization %s found in /proc/sysinfo", t);
306 if (streq(t, "z/VM"))
307 return VIRTUALIZATION_ZVM;
309 return VIRTUALIZATION_KVM;
311 log_debug("This platform does not support /proc/sysinfo");
312 return VIRTUALIZATION_NONE;
316 /* Returns a short identifier for the various VM implementations */
317 int detect_vm(void) {
318 static thread_local int cached_found = _VIRTUALIZATION_INVALID;
321 if (cached_found >= 0)
324 /* We have to use the correct order here:
326 * -> First try to detect Oracle Virtualbox, even if it uses KVM.
327 * -> Second try to detect from cpuid, this will report KVM for
328 * whatever software is used even if info in dmi is overwritten.
329 * -> Third try to detect from dmi. */
331 dmi = detect_vm_dmi();
332 if (dmi == VIRTUALIZATION_ORACLE) {
337 r = detect_vm_cpuid();
340 if (r != VIRTUALIZATION_NONE)
346 if (r != VIRTUALIZATION_NONE)
349 /* x86 xen will most likely be detected by cpuid. If not (most likely
350 * because we're not an x86 guest), then we should try the xen capabilities
351 * file next. If that's not found, then we check for the high-level
352 * hypervisor sysfs file:
354 * https://bugs.freedesktop.org/show_bug.cgi?id=77271 */
359 if (r != VIRTUALIZATION_NONE)
362 r = detect_vm_hypervisor();
365 if (r != VIRTUALIZATION_NONE)
368 r = detect_vm_device_tree();
371 if (r != VIRTUALIZATION_NONE)
377 if (r != VIRTUALIZATION_NONE)
385 /* x86 xen Dom0 is detected as XEN in hypervisor and maybe others.
386 * In order to detect the Dom0 as not virtualization we need to
388 if (r == VIRTUALIZATION_XEN && detect_vm_xen_dom0())
389 r = VIRTUALIZATION_NONE;
392 log_debug("Found VM virtualization %s", virtualization_to_string(r));
397 int detect_container(void) {
399 static const struct {
403 { "lxc", VIRTUALIZATION_LXC },
404 { "lxc-libvirt", VIRTUALIZATION_LXC_LIBVIRT },
405 { "systemd-nspawn", VIRTUALIZATION_SYSTEMD_NSPAWN },
406 { "docker", VIRTUALIZATION_DOCKER },
407 { "rkt", VIRTUALIZATION_RKT },
410 static thread_local int cached_found = _VIRTUALIZATION_INVALID;
411 _cleanup_free_ char *m = NULL;
412 const char *e = NULL;
416 if (cached_found >= 0)
419 /* /proc/vz exists in container and outside of the container, /proc/bc only outside of the container. */
420 if (access("/proc/vz", F_OK) >= 0 &&
421 access("/proc/bc", F_OK) < 0) {
422 r = VIRTUALIZATION_OPENVZ;
426 if (getpid_cached() == 1) {
427 /* If we are PID 1 we can just check our own environment variable, and that's authoritative. */
429 e = getenv("container");
431 r = VIRTUALIZATION_NONE;
438 /* Otherwise, PID 1 might have dropped this information into a file in /run. This is better than accessing
439 * /proc/1/environ, since we don't need CAP_SYS_PTRACE for that. */
440 r = read_one_line_file("/run/systemd/container", &m);
446 return log_debug_errno(r, "Failed to read /run/systemd/container: %m");
448 /* Fallback for cases where PID 1 was not systemd (for example, cases where init=/bin/sh is used. */
449 r = getenv_for_pid(1, "container", &m);
454 if (r < 0) /* This only works if we have CAP_SYS_PTRACE, hence let's better ignore failures here */
455 log_debug_errno(r, "Failed to read $container of PID 1, ignoring: %m");
457 /* Interestingly /proc/1/sched actually shows the host's PID for what we see as PID 1. Hence, if the PID shown
458 * there is not 1, we know we are in a PID namespace. and hence a container. */
459 r = read_one_line_file("/proc/1/sched", &m);
467 if (!startswith(t, "(1,")) {
468 r = VIRTUALIZATION_CONTAINER_OTHER;
471 } else if (r != -ENOENT)
474 /* If that didn't work, give up, assume no container manager. */
475 r = VIRTUALIZATION_NONE;
479 for (j = 0; j < ELEMENTSOF(value_table); j++)
480 if (streq(e, value_table[j].value)) {
481 r = value_table[j].id;
485 r = VIRTUALIZATION_CONTAINER_OTHER;
488 log_debug("Found container virtualization %s.", virtualization_to_string(r));
493 #if 0 /// UNNEEDED by elogind
494 int detect_virtualization(void) {
497 r = detect_container();
504 static int userns_has_mapping(const char *name) {
505 _cleanup_fclose_ FILE *f = NULL;
506 _cleanup_free_ char *buf = NULL;
507 size_t n_allocated = 0;
512 f = fopen(name, "re");
514 log_debug_errno(errno, "Failed to open %s: %m", name);
515 return errno == ENOENT ? false : -errno;
518 n = getline(&buf, &n_allocated, f);
521 log_debug("%s is empty, we're in an uninitialized user namespace", name);
525 return log_debug_errno(errno, "Failed to read %s: %m", name);
528 r = sscanf(buf, "%"PRIu32" %"PRIu32" %"PRIu32, &a, &b, &c);
530 return log_debug_errno(errno, "Failed to parse %s: %m", name);
532 if (a == 0 && b == 0 && c == UINT32_MAX) {
533 /* The kernel calls mappings_overlap() and does not allow overlaps */
534 log_debug("%s has a full 1:1 mapping", name);
538 /* Anything else implies that we are in a user namespace */
539 log_debug("Mapping found in %s, we're in a user namespace", name);
543 int running_in_userns(void) {
544 _cleanup_free_ char *line = NULL;
547 r = userns_has_mapping("/proc/self/uid_map");
551 r = userns_has_mapping("/proc/self/gid_map");
555 /* "setgroups" file was added in kernel v3.18-rc6-15-g9cc46516dd. It is also
556 * possible to compile a kernel without CONFIG_USER_NS, in which case "setgroups"
557 * also does not exist. We cannot distinguish those two cases, so assume that
558 * we're running on a stripped-down recent kernel, rather than on an old one,
559 * and if the file is not found, return false.
561 r = read_one_line_file("/proc/self/setgroups", &line);
563 log_debug_errno(r, "/proc/self/setgroups: %m");
564 return r == -ENOENT ? false : r;
568 r = streq(line, "deny");
569 /* See user_namespaces(7) for a description of this "setgroups" contents. */
570 log_debug("/proc/self/setgroups contains \"%s\", %s user namespace", line, r ? "in" : "not in");
575 int running_in_chroot(void) {
578 #if 0 /// elogind does not allow to ignore chroots, we are never init!
579 if (getenv_bool("SYSTEMD_IGNORE_CHROOT") > 0)
583 ret = files_same("/proc/1/root", "/", 0);
590 static const char *const virtualization_table[_VIRTUALIZATION_MAX] = {
591 [VIRTUALIZATION_NONE] = "none",
592 [VIRTUALIZATION_KVM] = "kvm",
593 [VIRTUALIZATION_QEMU] = "qemu",
594 [VIRTUALIZATION_BOCHS] = "bochs",
595 [VIRTUALIZATION_XEN] = "xen",
596 [VIRTUALIZATION_UML] = "uml",
597 [VIRTUALIZATION_VMWARE] = "vmware",
598 [VIRTUALIZATION_ORACLE] = "oracle",
599 [VIRTUALIZATION_MICROSOFT] = "microsoft",
600 [VIRTUALIZATION_ZVM] = "zvm",
601 [VIRTUALIZATION_PARALLELS] = "parallels",
602 [VIRTUALIZATION_BHYVE] = "bhyve",
603 [VIRTUALIZATION_VM_OTHER] = "vm-other",
605 [VIRTUALIZATION_SYSTEMD_NSPAWN] = "systemd-nspawn",
606 [VIRTUALIZATION_LXC_LIBVIRT] = "lxc-libvirt",
607 [VIRTUALIZATION_LXC] = "lxc",
608 [VIRTUALIZATION_OPENVZ] = "openvz",
609 [VIRTUALIZATION_DOCKER] = "docker",
610 [VIRTUALIZATION_RKT] = "rkt",
611 [VIRTUALIZATION_CONTAINER_OTHER] = "container-other",
614 DEFINE_STRING_TABLE_LOOKUP(virtualization, int);