/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ /*** This file is part of systemd. Copyright 2011 Lennart Poettering systemd is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ #include <string.h> #include <errno.h> #include <unistd.h> #include "util.h" #include "virt.h" /* Returns a short identifier for the various VM implementations */ int detect_vm(const char **id) { #if defined(__i386__) || defined(__x86_64__) /* Both CPUID and DMI are x86 specific interfaces... */ static const char *const dmi_vendors[] = { "/sys/class/dmi/id/sys_vendor", "/sys/class/dmi/id/board_vendor", "/sys/class/dmi/id/bios_vendor" }; static const char dmi_vendor_table[] = "QEMU\0" "qemu\0" /* http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1009458 */ "VMware\0" "vmware\0" "VMW\0" "vmware\0" "Microsoft Corporation\0" "microsoft\0" "innotek GmbH\0" "oracle\0" "Xen\0" "xen\0" "Bochs\0" "bochs\0"; static const char cpuid_vendor_table[] = "XenVMMXenVMM\0" "xen\0" "KVMKVMKVM\0" "kvm\0" /* http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1009458 */ "VMwareVMware\0" "vmware\0" /* http://msdn.microsoft.com/en-us/library/ff542428.aspx */ "Microsoft Hv\0" "microsoft\0"; uint32_t eax, ecx; union { uint32_t sig32[3]; char text[13]; } sig; unsigned i; const char *j, *k; bool hypervisor; /* http://lwn.net/Articles/301888/ */ zero(sig); #if defined (__i386__) #define REG_a "eax" #define REG_b "ebx" #elif defined (__amd64__) #define REG_a "rax" #define REG_b "rbx" #endif /* First detect whether there is a hypervisor */ eax = 1; __asm__ __volatile__ ( /* ebx/rbx is being used for PIC! */ " push %%"REG_b" \n\t" " cpuid \n\t" " pop %%"REG_b" \n\t" : "=a" (eax), "=c" (ecx) : "0" (eax) ); hypervisor = !!(ecx & 0x80000000U); if (hypervisor) { /* There is a hypervisor, see what it is */ eax = 0x40000000U; __asm__ __volatile__ ( /* ebx/rbx is being used for PIC! */ " push %%"REG_b" \n\t" " cpuid \n\t" " mov %%ebx, %1 \n\t" " pop %%"REG_b" \n\t" : "=a" (eax), "=r" (sig.sig32[0]), "=c" (sig.sig32[1]), "=d" (sig.sig32[2]) : "0" (eax) ); NULSTR_FOREACH_PAIR(j, k, cpuid_vendor_table) if (streq(sig.text, j)) { if (id) *id = k; return 1; } } for (i = 0; i < ELEMENTSOF(dmi_vendors); i++) { char *s; int r; const char *found = NULL; if ((r = read_one_line_file(dmi_vendors[i], &s)) < 0) { if (r != -ENOENT) return r; continue; } NULSTR_FOREACH_PAIR(j, k, dmi_vendor_table) if (startswith(s, j)) found = k; free(s); if (found) { if (id) *id = found; return 1; } } if (hypervisor) { if (id) *id = "other"; return 1; } #endif return 0; } int detect_container(const char **id) { char *e = NULL; int r; /* Unfortunately many of these operations require root access * in one way or another */ if (geteuid() != 0) return -EPERM; if (running_in_chroot() > 0) { if (id) *id = "chroot"; return 1; } /* /proc/vz exists in container and outside of the container, * /proc/bc only outside of the container. */ if (access("/proc/vz", F_OK) >= 0 && access("/proc/bc", F_OK) < 0) { if (id) *id = "openvz"; return 1; } r = getenv_for_pid(1, "container", &e); if (r <= 0) return r; /* We only recognize a selected few here, since we want to * enforce a redacted namespace */ if (streq(e, "lxc")) { if (id) *id = "lxc"; } else if (streq(e, "lxc-libvirt")) { if (id) *id = "lxc-libvirt"; } else if (streq(e, "systemd-nspawn")) { if (id) *id = "systemd-nspawn"; } else { if (id) *id = "other"; } free(e); return r; } /* Returns a short identifier for the various VM/container implementations */ Virtualization detect_virtualization(const char **id) { static __thread Virtualization cached_virt = _VIRTUALIZATION_INVALID; static __thread const char *cached_id = NULL; const char *_id; int r; Virtualization v; if (_likely_(cached_virt >= 0)) { if (id && cached_virt > 0) *id = cached_id; return cached_virt; } r = detect_container(&_id); if (r < 0) { v = r; goto finish; } else if (r > 0) { v = VIRTUALIZATION_CONTAINER; goto finish; } r = detect_vm(&_id); if (r < 0) { v = r; goto finish; } else if (r > 0) { v = VIRTUALIZATION_VM; goto finish; } v = VIRTUALIZATION_NONE; finish: if (v > 0) { cached_id = _id; if (id) *id = _id; } if (v >= 0) cached_virt = v; return v; }