introduce basic fact collection

client/vendor/github.com/zcalusic/sysinfo/hypervisor.go

@@ -0,0 +1,65 @@
+// Copyright © 2016 Zlatko Čalušić
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file.
+
+package sysinfo
+
+import (
+	"strings"
+	"unsafe"
+
+	"github.com/zcalusic/sysinfo/cpuid"
+)
+
+// https://en.wikipedia.org/wiki/CPUID#EAX.3D0:_Get_vendor_ID
+var hvmap = map[string]string{
+	"bhyve bhyve ": "bhyve",
+	"KVMKVMKVM":    "kvm",
+	"Microsoft Hv": "hyperv",
+	" lrpepyh vr":  "parallels",
+	"VMwareVMware": "vmware",
+	"XenVMMXenVMM": "xenhvm",
+}
+
+func isHypervisorActive() bool {
+	var info [4]uint32
+	cpuid.CPUID(&info, 0x1)
+	return info[2]&(1<<31) != 0
+}
+
+func getHypervisorCpuid(ax uint32) string {
+	var info [4]uint32
+	cpuid.CPUID(&info, ax)
+	return hvmap[strings.TrimRight(string((*[12]byte)(unsafe.Pointer(&info[1]))[:]), "\000")]
+}
+
+func (si *SysInfo) getHypervisor() {
+	if !isHypervisorActive() {
+		if hypervisorType := slurpFile("/sys/hypervisor/type"); hypervisorType != "" {
+			if hypervisorType == "xen" {
+				si.Node.Hypervisor = "xenpv"
+			}
+		}
+		return
+	}
+
+	// KVM has been caught to move its real signature to this leaf, and put something completely different in the
+	// standard location. So this leaf must be checked first.
+	if hv := getHypervisorCpuid(0x40000100); hv != "" {
+		si.Node.Hypervisor = hv
+		return
+	}
+
+	if hv := getHypervisorCpuid(0x40000000); hv != "" {
+		si.Node.Hypervisor = hv
+		return
+	}
+
+	// getBIOSInfo() must have run first, to detect BIOS vendor
+	if si.BIOS.Vendor == "Bochs" {
+		si.Node.Hypervisor = "bochs"
+		return
+	}
+
+	si.Node.Hypervisor = "unknown"
+}