summaryrefslogtreecommitdiff
path: root/src/virt.c
diff options
context:
space:
mode:
authorLennart Poettering <lennart@poettering.net>2011-09-23 17:00:33 +0200
committerLennart Poettering <lennart@poettering.net>2011-09-23 17:00:33 +0200
commitb52aae1d934b006830e7d575e56e2a98b0765ad3 (patch)
treee1ab1148d400ce6234e106f05420bb4b3bec83c5 /src/virt.c
parentf2b33002cd5747ebf288d20a352655307f97aac5 (diff)
util: move virtualization detection into its own files, and extend return codes
Diffstat (limited to 'src/virt.c')
-rw-r--r--src/virt.c314
1 files changed, 314 insertions, 0 deletions
diff --git a/src/virt.c b/src/virt.c
new file mode 100644
index 0000000000..380fabded2
--- /dev/null
+++ b/src/virt.c
@@ -0,0 +1,314 @@
+/*-*- 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 General Public License as published by
+ the Free Software Foundation; either version 2 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
+ General Public License for more details.
+
+ You should have received a copy of the GNU 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) {
+ FILE *f;
+
+ /* 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;
+ }
+
+ f = fopen("/proc/1/environ", "re");
+ if (f) {
+ bool done = false;
+
+ do {
+ char line[LINE_MAX];
+ unsigned i;
+
+ for (i = 0; i < sizeof(line)-1; i++) {
+ int c;
+
+ c = getc(f);
+ if (_unlikely_(c == EOF)) {
+ done = true;
+ break;
+ } else if (c == 0)
+ break;
+
+ line[i] = c;
+ }
+ line[i] = 0;
+
+ if (streq(line, "container=lxc")) {
+ fclose(f);
+
+ if (id)
+ *id = "lxc";
+ return 1;
+
+ } else if (streq(line, "container=systemd-nspawn")) {
+ fclose(f);
+
+ if (id)
+ *id = "systemd-nspawn";
+ return 1;
+
+ } else if (startswith(line, "container=")) {
+ fclose(f);
+
+ if (id)
+ *id = "other";
+ return 1;
+ }
+
+ } while (!done);
+
+ fclose(f);
+ }
+
+ f = fopen("/proc/self/cgroup", "re");
+ if (f) {
+
+ for (;;) {
+ char line[LINE_MAX], *p;
+
+ if (!fgets(line, sizeof(line), f))
+ break;
+
+ p = strchr(strstrip(line), ':');
+ if (!p)
+ continue;
+
+ if (strncmp(p, ":ns:", 4))
+ continue;
+
+ if (!streq(p, ":ns:/")) {
+ fclose(f);
+
+ if (id)
+ *id = "pidns";
+
+ return 1;
+ }
+ }
+
+ fclose(f);
+ }
+
+ return 0;
+}
+
+/* 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;
+}