/* SPDX-License-Identifier: LGPL-2.1+ */
/***
- This file is part of systemd.
-
Copyright 2011 Lennart Poettering
***/
if (__get_cpuid(1, &eax, &ebx, &ecx, &edx) == 0)
return VIRTUALIZATION_NONE;
- hypervisor = !!(ecx & 0x80000000U);
+ hypervisor = ecx & 0x80000000U;
if (hypervisor) {
union {
/* Returns a short identifier for the various VM implementations */
int detect_vm(void) {
static thread_local int cached_found = _VIRTUALIZATION_INVALID;
- int r, dmi;
bool other = false;
+ int r, dmi;
if (cached_found >= 0)
return cached_found;
/* We have to use the correct order here:
*
- * -> First try to detect Oracle Virtualbox, even if it uses KVM.
- * -> Second try to detect from cpuid, this will report KVM for
- * whatever software is used even if info in dmi is overwritten.
- * -> Third try to detect from dmi. */
+ * → First, try to detect Oracle Virtualbox, even if it uses KVM, as well as Xen even if it cloaks as Microsoft
+ * Hyper-V.
+ *
+ * → Second, try to detect from CPUID, this will report KVM for whatever software is used even if info in DMI is
+ * overwritten.
+ *
+ * → Third, try to detect from DMI. */
dmi = detect_vm_dmi();
- if (dmi == VIRTUALIZATION_ORACLE) {
+ if (IN_SET(dmi, VIRTUALIZATION_ORACLE, VIRTUALIZATION_XEN)) {
r = dmi;
goto finish;
}
r = detect_vm_cpuid();
if (r < 0)
return r;
- if (r != VIRTUALIZATION_NONE) {
- if (r == VIRTUALIZATION_VM_OTHER)
- other = true;
- else
- goto finish;
- }
+ if (r == VIRTUALIZATION_VM_OTHER)
+ other = true;
+ else if (r != VIRTUALIZATION_NONE)
+ goto finish;
- r = dmi;
- if (r < 0)
- return r;
- if (r != VIRTUALIZATION_NONE) {
- if (r == VIRTUALIZATION_VM_OTHER)
- other = true;
- else
- goto finish;
+ /* Now, let's get back to DMI */
+ if (dmi < 0)
+ return dmi;
+ if (dmi == VIRTUALIZATION_VM_OTHER)
+ other = true;
+ else if (dmi != VIRTUALIZATION_NONE) {
+ r = dmi;
+ goto finish;
}
/* x86 xen will most likely be detected by cpuid. If not (most likely
r = detect_vm_xen();
if (r < 0)
return r;
- if (r != VIRTUALIZATION_NONE) {
- if (r == VIRTUALIZATION_VM_OTHER)
- other = true;
- else
- goto finish;
- }
+ if (r == VIRTUALIZATION_VM_OTHER)
+ other = true;
+ else if (r != VIRTUALIZATION_NONE)
+ goto finish;
r = detect_vm_hypervisor();
if (r < 0)
return r;
- if (r != VIRTUALIZATION_NONE) {
- if (r == VIRTUALIZATION_VM_OTHER)
- other = true;
- else
- goto finish;
- }
+ if (r == VIRTUALIZATION_VM_OTHER)
+ other = true;
+ else if (r != VIRTUALIZATION_NONE)
+ goto finish;
r = detect_vm_device_tree();
if (r < 0)
return r;
- if (r != VIRTUALIZATION_NONE) {
- if (r == VIRTUALIZATION_VM_OTHER)
- other = true;
- else
- goto finish;
- }
+ if (r == VIRTUALIZATION_VM_OTHER)
+ other = true;
+ else if (r != VIRTUALIZATION_NONE)
+ goto finish;
r = detect_vm_uml();
if (r < 0)
return r;
- if (r != VIRTUALIZATION_NONE) {
- if (r == VIRTUALIZATION_VM_OTHER)
- other = true;
- else
- goto finish;
- }
+ if (r == VIRTUALIZATION_VM_OTHER)
+ other = true;
+ else if (r != VIRTUALIZATION_NONE)
+ goto finish;
r = detect_vm_zvm();
if (r < 0)
* In order to detect the Dom0 as not virtualization we need to
* double-check it */
if (r == VIRTUALIZATION_XEN) {
- int ret = detect_vm_xen_dom0();
- if (ret < 0)
- return ret;
- if (ret > 0)
+ int dom0;
+
+ dom0 = detect_vm_xen_dom0();
+ if (dom0 < 0)
+ return dom0;
+ if (dom0 > 0)
r = VIRTUALIZATION_NONE;
} else if (r == VIRTUALIZATION_NONE && other)
r = VIRTUALIZATION_VM_OTHER;