feat: hypervisor vendor

Read hypervisor vendor as per https://lwn.net/Articles/301888/.

cpuid.go

@@ -55,6 +55,12 @@ const (
 	Qualcomm
 	Marvell
 
+	QEMU
+	QNX
+	ACRN
+	SRE
+	Apple
+
 	lastVendor
 )
 
@@ -881,6 +887,8 @@ var vendorMapping = map[string]Vendor{
 	"Geode by NSC": NSC,
 	"VIA VIA VIA ": VIA,
 	"KVMKVMKVM":    KVM,
+	"Linux KVM Hv": KVM,
+	"TCGTCGTCGTCG": QEMU,
 	"Microsoft Hv": MSVM,
 	"VMwareVMware": VMware,
 	"XenVMMXenVMM": XenHVM,
@@ -890,6 +898,10 @@ var vendorMapping = map[string]Vendor{
 	"SiS SiS SiS ": SiS,
 	"RiseRiseRise": SiS,
 	"Genuine  RDC": RDC,
+	"QNXQVMBSQG":   QNX,
+	"ACRNACRNACRN": ACRN,
+	"SRESRESRESRE": SRE,
+	"Apple VZ":     Apple,
 }
 
 func vendorID() (Vendor, string) {
@@ -902,6 +914,17 @@ func vendorID() (Vendor, string) {
 	return vend, v
 }
 
+func hypervisorVendorID() (Vendor, string) {
+	// https://lwn.net/Articles/301888/
+	_, b, c, d := cpuid(0x40000000)
+	v := string(valAsString(b, c, d))
+	vend, ok := vendorMapping[v]
+	if !ok {
+		return VendorUnknown, v
+	}
+	return vend, v
+}
+
 func cacheLine() int {
 	if maxFunctionID() < 0x1 {
 		return 0

detect_x86.go

@@ -32,6 +32,7 @@ func addInfo(c *CPUInfo, safe bool) {
 	c.LogicalCores = logicalCores()
 	c.PhysicalCores = physicalCores()
 	c.VendorID, c.VendorString = vendorID()
+	c.HypervisorVendorID, c.HypervisorVendorString = hypervisorVendorID()
 	c.AVX10Level = c.supportAVX10()
 	c.cacheSize()
 	c.frequencies()

mockcpu_test.go

@@ -98,7 +98,7 @@ func mockCPU(def []byte) func() {
 	}(idfuncs{cpuid: cpuid, cpuidex: cpuidex, xgetbv: xgetbv})
 
 	cpuid = func(op uint32) (eax, ebx, ecx, edx uint32) {
-		if op == 0x80000000 || op == 0 || op == 0x4000000c {
+		if op == 0x80000000 || op == 0 || op == 0x4000000c || op == 0x40000000 {
 			var ok bool
 			_, ok = fakeID[op]
 			if !ok {