1 files changed, 223 insertions, 0 deletions
diff --git a/pkg/cpuid/cpuid_test.go b/pkg/cpuid/cpuid_test.go
new file mode 100644
index 000000000..02f732f85
--- /dev/null
+++ b/pkg/cpuid/cpuid_test.go
@@ -0,0 +1,223 @@
+// Copyright 2018 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package cpuid
+
+import (
+	"testing"
+)
+
+var justFPU = &FeatureSet{
+	Set: map[Feature]bool{
+		X86FeatureFPU: true,
+	}}
+
+var justFPUandPAE = &FeatureSet{
+	Set: map[Feature]bool{
+		X86FeatureFPU: true,
+		X86FeaturePAE: true,
+	}}
+
+func TestIsSubset(t *testing.T) {
+	if !justFPU.IsSubset(justFPUandPAE) {
+		t.Errorf("Got %v is not subset of %v, want IsSubset being true", justFPU, justFPUandPAE)
+	}
+
+	if justFPUandPAE.IsSubset(justFPU) {
+		t.Errorf("Got %v is a subset of %v, want IsSubset being false", justFPU, justFPUandPAE)
+	}
+}
+
+func TestTakeFeatureIntersection(t *testing.T) {
+	testFeatures := HostFeatureSet()
+	testFeatures.TakeFeatureIntersection(justFPU)
+	if !testFeatures.IsSubset(justFPU) {
+		t.Errorf("Got more features than expected after intersecting host features with justFPU: %v, want %v", testFeatures.Set, justFPU.Set)
+	}
+	if !testFeatures.HasFeature(X86FeatureFPU) {
+		t.Errorf("Got no features in testFeatures after intersecting, want %v", X86FeatureFPU)
+	}
+}
+
+// TODO: Run this test on a very old platform, and make sure more
+// bits are enabled than just FPU and PAE. This test currently may not detect
+// if HostFeatureSet gives back junk bits.
+func TestHostFeatureSet(t *testing.T) {
+	hostFeatures := HostFeatureSet()
+	if !justFPUandPAE.IsSubset(hostFeatures) {
+		t.Errorf("Got invalid feature set %v from HostFeatureSet()", hostFeatures)
+	}
+}
+
+func TestHasFeature(t *testing.T) {
+	if !justFPU.HasFeature(X86FeatureFPU) {
+		t.Errorf("HasFeature failed, %v should contain %v", justFPU, X86FeatureFPU)
+	}
+
+	if justFPU.HasFeature(X86FeatureAVX) {
+		t.Errorf("HasFeature failed, %v should not contain %v", justFPU, X86FeatureAVX)
+	}
+}
+
+// Note: these tests are aware of and abuse internal details of FeatureSets.
+// Users of FeatureSets should not depend on this.
+func TestAdd(t *testing.T) {
+	// Test a basic insertion into the FeatureSet.
+	testFeatures := newEmptyFeatureSet()
+	testFeatures.Add(X86FeatureCLFSH)
+	if len(testFeatures.Set) != 1 {
+		t.Errorf("Got length %v want 1", len(testFeatures.Set))
+	}
+
+	if !testFeatures.HasFeature(X86FeatureCLFSH) {
+		t.Errorf("Add failed, got %v want set with %v", testFeatures, X86FeatureCLFSH)
+	}
+
+	// Test that duplicates are ignored.
+	testFeatures.Add(X86FeatureCLFSH)
+	if len(testFeatures.Set) != 1 {
+		t.Errorf("Got length %v, want 1", len(testFeatures.Set))
+	}
+}
+
+func TestRemove(t *testing.T) {
+	// Try removing the last feature.
+	testFeatures := newEmptyFeatureSet()
+	testFeatures.Add(X86FeatureFPU)
+	testFeatures.Add(X86FeaturePAE)
+	testFeatures.Remove(X86FeaturePAE)
+	if !testFeatures.HasFeature(X86FeatureFPU) || len(testFeatures.Set) != 1 || testFeatures.HasFeature(X86FeaturePAE) {
+		t.Errorf("Remove failed, got %v want %v", testFeatures, justFPU)
+	}
+
+	// Try removing a feature not in the set.
+	testFeatures.Remove(X86FeatureRDRAND)
+	if !testFeatures.HasFeature(X86FeatureFPU) || len(testFeatures.Set) != 1 {
+		t.Errorf("Remove failed, got %v want %v", testFeatures, justFPU)
+	}
+}
+
+func TestFeatureFromString(t *testing.T) {
+	f, ok := FeatureFromString("avx")
+	if f != X86FeatureAVX || !ok {
+		t.Errorf("got %v want avx", f)
+	}
+
+	f, ok = FeatureFromString("bad")
+	if ok {
+		t.Errorf("got %v want nothing", f)
+	}
+}
+
+// This tests function 0 (eax=0), which returns the vendor ID and highest cpuid
+// function reported to be available.
+func TestEmulateIDVendorAndLength(t *testing.T) {
+	testFeatures := newEmptyFeatureSet()
+
+	ax, bx, cx, dx := testFeatures.EmulateID(0, 0)
+	wantEax := uint32(0xd) // Highest supported cpuid function.
+
+	// These magical constants are the characters of "GenuineIntel".
+	// See Intel AN485 for a reference on why they are laid out like this.
+	wantEbx := uint32(0x756e6547)
+	wantEcx := uint32(0x6c65746e)
+	wantEdx := uint32(0x49656e69)
+	if wantEax != ax {
+		t.Errorf("highest function failed, got %x want %x", ax, wantEax)
+	}
+
+	if wantEbx != bx || wantEcx != cx || wantEdx != dx {
+		t.Errorf("vendor string emulation failed, bx:cx:dx, got %x:%x:%x want %x:%x:%x", bx, cx, dx, wantEbx, wantEcx, wantEdx)
+	}
+}
+
+func TestEmulateIDBasicFeatures(t *testing.T) {
+	// Make a minimal test feature set.
+	testFeatures := newEmptyFeatureSet()
+	testFeatures.Add(X86FeatureCLFSH)
+	testFeatures.Add(X86FeatureAVX)
+
+	ax, bx, cx, dx := testFeatures.EmulateID(1, 0)
+	ECXAVXBit := uint32(1 << uint(X86FeatureAVX))
+	EDXCLFlushBit := uint32(1 << uint(X86FeatureCLFSH-32)) // We adjust by 32 since it's in block 1.
+
+	if EDXCLFlushBit&dx == 0 || dx&^EDXCLFlushBit != 0 {
+		t.Errorf("EmulateID failed, got feature bits %x want %x", dx, testFeatures.blockMask(1))
+	}
+
+	if ECXAVXBit&cx == 0 || cx&^ECXAVXBit != 0 {
+		t.Errorf("EmulateID failed, got feature bits %x want %x", cx, testFeatures.blockMask(0))
+	}
+
+	// Default signature bits, based on values for i7/Xeon.
+	// See Intel AN485 for information on stepping/model bits.
+	defaultSignature := uint32(0x000106a0)
+	if defaultSignature != ax {
+		t.Errorf("EmulateID stepping emulation failed, got %x want %x", ax, defaultSignature)
+	}
+
+	clflushSizeInfo := uint32(8 << 8)
+	if clflushSizeInfo != bx {
+		t.Errorf("EmulateID bx emulation failed, got %x want %x", bx, clflushSizeInfo)
+	}
+}
+
+func TestEmulateIDExtendedFeatures(t *testing.T) {
+	// Make a minimal test feature set, one bit in each extended feature word.
+	testFeatures := newEmptyFeatureSet()
+	testFeatures.Add(X86FeatureSMEP)
+	testFeatures.Add(X86FeatureAVX512VBMI)
+
+	ax, bx, cx, dx := testFeatures.EmulateID(7, 0)
+	EBXSMEPBit := uint32(1 << uint(X86FeatureSMEP-2*32))      // Adjust by 2*32 since SMEP is a block 2 feature.
+	ECXAVXBit := uint32(1 << uint(X86FeatureAVX512VBMI-3*32)) // We adjust by 3*32 since it's a block 3 feature.
+
+	// Test that the desired bit is set and no other bits are set.
+	if EBXSMEPBit&bx == 0 || bx&^EBXSMEPBit != 0 {
+		t.Errorf("extended feature emulation failed, got feature bits %x want %x", bx, testFeatures.blockMask(2))
+	}
+
+	if ECXAVXBit&cx == 0 || cx&^ECXAVXBit != 0 {
+		t.Errorf("extended feature emulation failed, got feature bits %x want %x", cx, testFeatures.blockMask(3))
+	}
+
+	if ax != 0 || dx != 0 {
+		t.Errorf("extended feature emulation failed, ax:dx, got %x:%x want 0:0", ax, dx)
+	}
+
+	// Check that no subleaves other than 0 do anything.
+	ax, bx, cx, dx = testFeatures.EmulateID(7, 1)
+	if ax != 0 || bx != 0 || cx != 0 || dx != 0 {
+		t.Errorf("extended feature emulation failed, got %x:%x:%x:%x want 0:0", ax, bx, cx, dx)
+	}
+
+}
+
+// Checks that the expected extended features are available via cpuid functions
+// 0x80000000 and up.
+func TestEmulateIDExtended(t *testing.T) {
+	testFeatures := newEmptyFeatureSet()
+	testFeatures.Add(X86FeatureSYSCALL)
+	EDXSYSCALLBit := uint32(1 << uint(X86FeatureSYSCALL-6*32)) // Adjust by 6*32 since SYSCALL is a block 6 feature.
+
+	ax, bx, cx, dx := testFeatures.EmulateID(0x80000000, 0)
+	if ax != 0x80000001 || bx != 0 || cx != 0 || dx != 0 {
+		t.Errorf("EmulateID extended emulation failed, ax:bx:cx:dx, got %x:%x:%x:%x want 0x80000001:0:0:0", ax, bx, cx, dx)
+	}
+
+	_, _, _, dx = testFeatures.EmulateID(0x80000001, 0)
+	if EDXSYSCALLBit&dx == 0 || dx&^EDXSYSCALLBit != 0 {
+		t.Errorf("extended feature emulation failed, got feature bits %x want %x", dx, testFeatures.blockMask(6))
+	}
+}