diff options
Diffstat (limited to 'src/shared/virt.c')
| -rw-r--r-- | src/shared/virt.c | 259 |
1 files changed, 259 insertions, 0 deletions
diff --git a/src/shared/virt.c b/src/shared/virt.c new file mode 100644 index 0000000000..fc62c72328 --- /dev/null +++ b/src/shared/virt.c @@ -0,0 +1,259 @@ +/*-*- 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 */ + + r = running_in_chroot(); + if (r < 0) + return r; + if (r > 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; +} |