1 /* SPDX-License-Identifier: LGPL-2.1+ */
3 #if defined(__i386__) || defined(__x86_64__)
12 #include "alloc-util.h"
13 #include "dirent-util.h"
18 #include "process-util.h"
19 #include "stat-util.h"
20 #include "string-table.h"
21 #include "string-util.h"
24 #if 0 /// UNNEEDED by elogind
25 static int detect_vm_cpuid(void) {
27 /* CPUID is an x86 specific interface. */
28 #if defined(__i386__) || defined(__x86_64__)
33 } cpuid_vendor_table[] = {
34 { "XenVMMXenVMM", VIRTUALIZATION_XEN },
35 { "KVMKVMKVM", VIRTUALIZATION_KVM },
36 { "TCGTCGTCGTCG", VIRTUALIZATION_QEMU },
37 /* http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1009458 */
38 { "VMwareVMware", VIRTUALIZATION_VMWARE },
39 /* https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/reference/tlfs */
40 { "Microsoft Hv", VIRTUALIZATION_MICROSOFT },
41 /* https://wiki.freebsd.org/bhyve */
42 { "bhyve bhyve ", VIRTUALIZATION_BHYVE },
43 { "QNXQVMBSQG", VIRTUALIZATION_QNX },
46 uint32_t eax, ebx, ecx, edx;
49 /* http://lwn.net/Articles/301888/ */
51 /* First detect whether there is a hypervisor */
52 if (__get_cpuid(1, &eax, &ebx, &ecx, &edx) == 0)
53 return VIRTUALIZATION_NONE;
55 hypervisor = ecx & 0x80000000U;
64 /* There is a hypervisor, see what it is */
65 __cpuid(0x40000000U, eax, ebx, ecx, edx);
71 log_debug("Virtualization found, CPUID=%s", sig.text);
73 for (j = 0; j < ELEMENTSOF(cpuid_vendor_table); j ++)
74 if (streq(sig.text, cpuid_vendor_table[j].cpuid))
75 return cpuid_vendor_table[j].id;
77 return VIRTUALIZATION_VM_OTHER;
80 log_debug("No virtualization found in CPUID");
82 return VIRTUALIZATION_NONE;
85 static int detect_vm_device_tree(void) {
86 #if defined(__arm__) || defined(__aarch64__) || defined(__powerpc__) || defined(__powerpc64__)
87 _cleanup_free_ char *hvtype = NULL;
90 r = read_one_line_file("/proc/device-tree/hypervisor/compatible", &hvtype);
92 _cleanup_closedir_ DIR *dir = NULL;
95 dir = opendir("/proc/device-tree");
97 if (errno == ENOENT) {
98 log_debug_errno(errno, "/proc/device-tree: %m");
99 return VIRTUALIZATION_NONE;
104 FOREACH_DIRENT(dent, dir, return -errno)
105 if (strstr(dent->d_name, "fw-cfg")) {
106 log_debug("Virtualization QEMU: \"fw-cfg\" present in /proc/device-tree/%s", dent->d_name);
107 return VIRTUALIZATION_QEMU;
110 log_debug("No virtualization found in /proc/device-tree/*");
111 return VIRTUALIZATION_NONE;
115 log_debug("Virtualization %s found in /proc/device-tree/hypervisor/compatible", hvtype);
116 if (streq(hvtype, "linux,kvm"))
117 return VIRTUALIZATION_KVM;
118 else if (strstr(hvtype, "xen"))
119 return VIRTUALIZATION_XEN;
121 return VIRTUALIZATION_VM_OTHER;
123 log_debug("This platform does not support /proc/device-tree");
124 return VIRTUALIZATION_NONE;
128 static int detect_vm_dmi(void) {
129 #if defined(__i386__) || defined(__x86_64__) || defined(__arm__) || defined(__aarch64__)
131 static const char *const dmi_vendors[] = {
132 "/sys/class/dmi/id/product_name", /* Test this before sys_vendor to detect KVM over QEMU */
133 "/sys/class/dmi/id/sys_vendor",
134 "/sys/class/dmi/id/board_vendor",
135 "/sys/class/dmi/id/bios_vendor"
138 static const struct {
141 } dmi_vendor_table[] = {
142 { "KVM", VIRTUALIZATION_KVM },
143 { "QEMU", VIRTUALIZATION_QEMU },
144 /* http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1009458 */
145 { "VMware", VIRTUALIZATION_VMWARE },
146 { "VMW", VIRTUALIZATION_VMWARE },
147 { "innotek GmbH", VIRTUALIZATION_ORACLE },
148 { "Xen", VIRTUALIZATION_XEN },
149 { "Bochs", VIRTUALIZATION_BOCHS },
150 { "Parallels", VIRTUALIZATION_PARALLELS },
151 /* https://wiki.freebsd.org/bhyve */
152 { "BHYVE", VIRTUALIZATION_BHYVE },
157 for (i = 0; i < ELEMENTSOF(dmi_vendors); i++) {
158 _cleanup_free_ char *s = NULL;
161 r = read_one_line_file(dmi_vendors[i], &s);
169 for (j = 0; j < ELEMENTSOF(dmi_vendor_table); j++)
170 if (startswith(s, dmi_vendor_table[j].vendor)) {
171 log_debug("Virtualization %s found in DMI (%s)", s, dmi_vendors[i]);
172 return dmi_vendor_table[j].id;
177 log_debug("No virtualization found in DMI");
179 return VIRTUALIZATION_NONE;
182 static int detect_vm_xen(void) {
184 /* Check for Dom0 will be executed later in detect_vm_xen_dom0
185 The presence of /proc/xen indicates some form of a Xen domain */
186 if (access("/proc/xen", F_OK) < 0) {
187 log_debug("Virtualization XEN not found, /proc/xen does not exist");
188 return VIRTUALIZATION_NONE;
191 log_debug("Virtualization XEN found (/proc/xen exists)");
192 return VIRTUALIZATION_XEN;
195 #define XENFEAT_dom0 11 /* xen/include/public/features.h */
196 #define PATH_FEATURES "/sys/hypervisor/properties/features"
197 /* Returns -errno, or 0 for domU, or 1 for dom0 */
198 static int detect_vm_xen_dom0(void) {
199 _cleanup_free_ char *domcap = NULL;
203 r = read_one_line_file(PATH_FEATURES, &domcap);
204 if (r < 0 && r != -ENOENT)
207 unsigned long features;
209 /* Here, we need to use sscanf() instead of safe_atoul()
210 * as the string lacks the leading "0x". */
211 r = sscanf(domcap, "%lx", &features);
213 r = !!(features & (1U << XENFEAT_dom0));
214 log_debug("Virtualization XEN, found %s with value %08lx, "
215 "XENFEAT_dom0 (indicating the 'hardware domain') is%s set.",
216 PATH_FEATURES, features, r ? "" : " not");
219 log_debug("Virtualization XEN, found %s, unhandled content '%s'",
220 PATH_FEATURES, domcap);
223 r = read_one_line_file("/proc/xen/capabilities", &domcap);
225 log_debug("Virtualization XEN because /proc/xen/capabilities does not exist");
232 while ((cap = strsep(&i, ",")))
233 if (streq(cap, "control_d"))
236 log_debug("Virtualization XEN DomU found (/proc/xen/capabilites)");
240 log_debug("Virtualization XEN Dom0 ignored (/proc/xen/capabilities)");
244 static int detect_vm_hypervisor(void) {
245 _cleanup_free_ char *hvtype = NULL;
248 r = read_one_line_file("/sys/hypervisor/type", &hvtype);
250 return VIRTUALIZATION_NONE;
254 log_debug("Virtualization %s found in /sys/hypervisor/type", hvtype);
256 if (streq(hvtype, "xen"))
257 return VIRTUALIZATION_XEN;
259 return VIRTUALIZATION_VM_OTHER;
262 static int detect_vm_uml(void) {
263 _cleanup_free_ char *cpuinfo_contents = NULL;
266 /* Detect User-Mode Linux by reading /proc/cpuinfo */
267 r = read_full_file("/proc/cpuinfo", &cpuinfo_contents, NULL);
269 log_debug("/proc/cpuinfo not found, assuming no UML virtualization.");
270 return VIRTUALIZATION_NONE;
275 if (strstr(cpuinfo_contents, "\nvendor_id\t: User Mode Linux\n")) {
276 log_debug("UML virtualization found in /proc/cpuinfo");
277 return VIRTUALIZATION_UML;
280 log_debug("UML virtualization not found in /proc/cpuinfo.");
281 return VIRTUALIZATION_NONE;
284 static int detect_vm_zvm(void) {
286 #if defined(__s390__)
287 _cleanup_free_ char *t = NULL;
290 r = get_proc_field("/proc/sysinfo", "VM00 Control Program", WHITESPACE, &t);
292 return VIRTUALIZATION_NONE;
296 log_debug("Virtualization %s found in /proc/sysinfo", t);
297 if (streq(t, "z/VM"))
298 return VIRTUALIZATION_ZVM;
300 return VIRTUALIZATION_KVM;
302 log_debug("This platform does not support /proc/sysinfo");
303 return VIRTUALIZATION_NONE;
307 /* Returns a short identifier for the various VM implementations */
308 int detect_vm(void) {
309 static thread_local int cached_found = _VIRTUALIZATION_INVALID;
313 if (cached_found >= 0)
316 /* We have to use the correct order here:
318 * → First, try to detect Oracle Virtualbox, even if it uses KVM, as well as Xen even if it cloaks as Microsoft
321 * → Second, try to detect from CPUID, this will report KVM for whatever software is used even if info in DMI is
324 * → Third, try to detect from DMI. */
326 dmi = detect_vm_dmi();
327 if (IN_SET(dmi, VIRTUALIZATION_ORACLE, VIRTUALIZATION_XEN)) {
332 r = detect_vm_cpuid();
335 if (r == VIRTUALIZATION_VM_OTHER)
337 else if (r != VIRTUALIZATION_NONE)
340 /* Now, let's get back to DMI */
343 if (dmi == VIRTUALIZATION_VM_OTHER)
345 else if (dmi != VIRTUALIZATION_NONE) {
350 /* x86 xen will most likely be detected by cpuid. If not (most likely
351 * because we're not an x86 guest), then we should try the /proc/xen
352 * directory next. If that's not found, then we check for the high-level
353 * hypervisor sysfs file.
359 if (r == VIRTUALIZATION_VM_OTHER)
361 else if (r != VIRTUALIZATION_NONE)
364 r = detect_vm_hypervisor();
367 if (r == VIRTUALIZATION_VM_OTHER)
369 else if (r != VIRTUALIZATION_NONE)
372 r = detect_vm_device_tree();
375 if (r == VIRTUALIZATION_VM_OTHER)
377 else if (r != VIRTUALIZATION_NONE)
383 if (r == VIRTUALIZATION_VM_OTHER)
385 else if (r != VIRTUALIZATION_NONE)
393 /* x86 xen Dom0 is detected as XEN in hypervisor and maybe others.
394 * In order to detect the Dom0 as not virtualization we need to
396 if (r == VIRTUALIZATION_XEN) {
399 dom0 = detect_vm_xen_dom0();
403 r = VIRTUALIZATION_NONE;
404 } else if (r == VIRTUALIZATION_NONE && other)
405 r = VIRTUALIZATION_VM_OTHER;
408 log_debug("Found VM virtualization %s", virtualization_to_string(r));
413 int detect_container(void) {
415 static const struct {
419 { "lxc", VIRTUALIZATION_LXC },
420 { "lxc-libvirt", VIRTUALIZATION_LXC_LIBVIRT },
421 { "systemd-nspawn", VIRTUALIZATION_SYSTEMD_NSPAWN },
422 { "docker", VIRTUALIZATION_DOCKER },
423 { "rkt", VIRTUALIZATION_RKT },
426 static thread_local int cached_found = _VIRTUALIZATION_INVALID;
427 _cleanup_free_ char *m = NULL;
428 const char *e = NULL;
432 if (cached_found >= 0)
435 /* /proc/vz exists in container and outside of the container, /proc/bc only outside of the container. */
436 if (access("/proc/vz", F_OK) >= 0 &&
437 access("/proc/bc", F_OK) < 0) {
438 r = VIRTUALIZATION_OPENVZ;
442 if (getpid_cached() == 1) {
443 /* If we are PID 1 we can just check our own environment variable, and that's authoritative. */
445 e = getenv("container");
447 r = VIRTUALIZATION_NONE;
454 /* Otherwise, PID 1 might have dropped this information into a file in /run. This is better than accessing
455 * /proc/1/environ, since we don't need CAP_SYS_PTRACE for that. */
456 r = read_one_line_file("/run/systemd/container", &m);
462 return log_debug_errno(r, "Failed to read /run/systemd/container: %m");
464 /* Fallback for cases where PID 1 was not systemd (for example, cases where init=/bin/sh is used. */
465 r = getenv_for_pid(1, "container", &m);
470 if (r < 0) /* This only works if we have CAP_SYS_PTRACE, hence let's better ignore failures here */
471 log_debug_errno(r, "Failed to read $container of PID 1, ignoring: %m");
473 /* Interestingly /proc/1/sched actually shows the host's PID for what we see as PID 1. Hence, if the PID shown
474 * there is not 1, we know we are in a PID namespace. and hence a container. */
475 r = read_one_line_file("/proc/1/sched", &m);
483 if (!startswith(t, "(1,")) {
484 r = VIRTUALIZATION_CONTAINER_OTHER;
487 } else if (r != -ENOENT)
490 /* If that didn't work, give up, assume no container manager. */
491 r = VIRTUALIZATION_NONE;
495 for (j = 0; j < ELEMENTSOF(value_table); j++)
496 if (streq(e, value_table[j].value)) {
497 r = value_table[j].id;
501 r = VIRTUALIZATION_CONTAINER_OTHER;
504 log_debug("Found container virtualization %s.", virtualization_to_string(r));
509 #if 0 /// UNNEEDED by elogind
510 int detect_virtualization(void) {
513 r = detect_container();
520 static int userns_has_mapping(const char *name) {
521 _cleanup_fclose_ FILE *f = NULL;
522 _cleanup_free_ char *buf = NULL;
523 size_t n_allocated = 0;
528 f = fopen(name, "re");
530 log_debug_errno(errno, "Failed to open %s: %m", name);
531 return errno == ENOENT ? false : -errno;
534 n = getline(&buf, &n_allocated, f);
537 log_debug("%s is empty, we're in an uninitialized user namespace", name);
541 return log_debug_errno(errno, "Failed to read %s: %m", name);
544 r = sscanf(buf, "%"PRIu32" %"PRIu32" %"PRIu32, &a, &b, &c);
546 return log_debug_errno(errno, "Failed to parse %s: %m", name);
548 if (a == 0 && b == 0 && c == UINT32_MAX) {
549 /* The kernel calls mappings_overlap() and does not allow overlaps */
550 log_debug("%s has a full 1:1 mapping", name);
554 /* Anything else implies that we are in a user namespace */
555 log_debug("Mapping found in %s, we're in a user namespace", name);
559 int running_in_userns(void) {
560 _cleanup_free_ char *line = NULL;
563 r = userns_has_mapping("/proc/self/uid_map");
567 r = userns_has_mapping("/proc/self/gid_map");
571 /* "setgroups" file was added in kernel v3.18-rc6-15-g9cc46516dd. It is also
572 * possible to compile a kernel without CONFIG_USER_NS, in which case "setgroups"
573 * also does not exist. We cannot distinguish those two cases, so assume that
574 * we're running on a stripped-down recent kernel, rather than on an old one,
575 * and if the file is not found, return false.
577 r = read_one_line_file("/proc/self/setgroups", &line);
579 log_debug_errno(r, "/proc/self/setgroups: %m");
580 return r == -ENOENT ? false : r;
584 r = streq(line, "deny");
585 /* See user_namespaces(7) for a description of this "setgroups" contents. */
586 log_debug("/proc/self/setgroups contains \"%s\", %s user namespace", line, r ? "in" : "not in");
591 int running_in_chroot(void) {
594 #if 0 /// elogind does not allow to ignore chroots, we are never init!
595 if (getenv_bool("SYSTEMD_IGNORE_CHROOT") > 0)
599 r = files_same("/proc/1/root", "/", 0);
606 static const char *const virtualization_table[_VIRTUALIZATION_MAX] = {
607 [VIRTUALIZATION_NONE] = "none",
608 [VIRTUALIZATION_KVM] = "kvm",
609 [VIRTUALIZATION_QEMU] = "qemu",
610 [VIRTUALIZATION_BOCHS] = "bochs",
611 [VIRTUALIZATION_XEN] = "xen",
612 [VIRTUALIZATION_UML] = "uml",
613 [VIRTUALIZATION_VMWARE] = "vmware",
614 [VIRTUALIZATION_ORACLE] = "oracle",
615 [VIRTUALIZATION_MICROSOFT] = "microsoft",
616 [VIRTUALIZATION_ZVM] = "zvm",
617 [VIRTUALIZATION_PARALLELS] = "parallels",
618 [VIRTUALIZATION_BHYVE] = "bhyve",
619 [VIRTUALIZATION_QNX] = "qnx",
620 [VIRTUALIZATION_VM_OTHER] = "vm-other",
622 [VIRTUALIZATION_SYSTEMD_NSPAWN] = "systemd-nspawn",
623 [VIRTUALIZATION_LXC_LIBVIRT] = "lxc-libvirt",
624 [VIRTUALIZATION_LXC] = "lxc",
625 [VIRTUALIZATION_OPENVZ] = "openvz",
626 [VIRTUALIZATION_DOCKER] = "docker",
627 [VIRTUALIZATION_RKT] = "rkt",
628 [VIRTUALIZATION_CONTAINER_OTHER] = "container-other",
631 DEFINE_STRING_TABLE_LOOKUP(virtualization, int);