Add Hypervisor Vendor (#147)

* fix: vendor id mapping for KVM

Last few bytes are ascii null characters: "KVMKVMKVM\0\0\0". When parsed by `valAsString` this shows up as just "KVMKVMKVM".

Tested manually in a QEMU VM with KVM using https://github.com/numtide/nixos-facter.

* 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
 )
 
@@ -296,20 +302,22 @@ const (
 
 // CPUInfo contains information about the detected system CPU.
 type CPUInfo struct {
-	BrandName      string  // Brand name reported by the CPU
-	VendorID       Vendor  // Comparable CPU vendor ID
-	VendorString   string  // Raw vendor string.
-	featureSet     flagSet // Features of the CPU
-	PhysicalCores  int     // Number of physical processor cores in your CPU. Will be 0 if undetectable.
-	ThreadsPerCore int     // Number of threads per physical core. Will be 1 if undetectable.
-	LogicalCores   int     // Number of physical cores times threads that can run on each core through the use of hyperthreading. Will be 0 if undetectable.
-	Family         int     // CPU family number
-	Model          int     // CPU model number
-	Stepping       int     // CPU stepping info
-	CacheLine      int     // Cache line size in bytes. Will be 0 if undetectable.
-	Hz             int64   // Clock speed, if known, 0 otherwise. Will attempt to contain base clock speed.
-	BoostFreq      int64   // Max clock speed, if known, 0 otherwise
-	Cache          struct {
+	BrandName              string  // Brand name reported by the CPU
+	VendorID               Vendor  // Comparable CPU vendor ID
+	VendorString           string  // Raw vendor string.
+	HypervisorVendorID     Vendor  // Hypervisor vendor
+	HypervisorVendorString string  // Raw hypervisor vendor string
+	featureSet             flagSet // Features of the CPU
+	PhysicalCores          int     // Number of physical processor cores in your CPU. Will be 0 if undetectable.
+	ThreadsPerCore         int     // Number of threads per physical core. Will be 1 if undetectable.
+	LogicalCores           int     // Number of physical cores times threads that can run on each core through the use of hyperthreading. Will be 0 if undetectable.
+	Family                 int     // CPU family number
+	Model                  int     // CPU model number
+	Stepping               int     // CPU stepping info
+	CacheLine              int     // Cache line size in bytes. Will be 0 if undetectable.
+	Hz                     int64   // Clock speed, if known, 0 otherwise. Will attempt to contain base clock speed.
+	BoostFreq              int64   // Max clock speed, if known, 0 otherwise
+	Cache                  struct {
 		L1I int // L1 Instruction Cache (per core or shared). Will be -1 if undetected
 		L1D int // L1 Data Cache (per core or shared). Will be -1 if undetected
 		L2  int // L2 Cache (per core or shared). Will be -1 if undetected
@@ -318,8 +326,9 @@ type CPUInfo struct {
 	SGX              SGXSupport
 	AMDMemEncryption AMDMemEncryptionSupport
 	AVX10Level       uint8
-	maxFunc          uint32
-	maxExFunc        uint32
+
+	maxFunc   uint32
+	maxExFunc uint32
 }
 
 var cpuid func(op uint32) (eax, ebx, ecx, edx uint32)
@@ -886,7 +895,9 @@ var vendorMapping = map[string]Vendor{
 	"GenuineTMx86": Transmeta,
 	"Geode by NSC": NSC,
 	"VIA VIA VIA ": VIA,
-	"KVMKVMKVMKVM": KVM,
+	"KVMKVMKVM":    KVM,
+	"Linux KVM Hv": KVM,
+	"TCGTCGTCGTCG": QEMU,
 	"Microsoft Hv": MSVM,
 	"VMwareVMware": VMware,
 	"XenVMMXenVMM": XenHVM,
@@ -896,6 +907,10 @@ 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) {
@@ -908,6 +923,17 @@ 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 {