qemu: add initrd support

Append initrd image to qemu arguments if configured.

Signed-off-by: Peng Tao <bergwolf@gmail.com>

qemu/qemu.go

@@ -1117,6 +1117,9 @@ type Kernel struct {
 	// Path is the guest kernel path on the host filesystem.
 	Path string
 
+	// InitrdPath is the guest initrd path on the host filesystem.
+	InitrdPath string
+
 	// Params is the kernel parameters string.
 	Params string
 }
@@ -1395,6 +1398,11 @@ func (config *Config) appendKernel() {
 		config.qemuParams = append(config.qemuParams, "-kernel")
 		config.qemuParams = append(config.qemuParams, config.Kernel.Path)
 
+		if config.Kernel.InitrdPath != "" {
+			config.qemuParams = append(config.qemuParams, "-initrd")
+			config.qemuParams = append(config.qemuParams, config.Kernel.InitrdPath)
+		}
+
 		if config.Kernel.Params != "" {
 			config.qemuParams = append(config.qemuParams, "-append")
 			config.qemuParams = append(config.qemuParams, config.Kernel.Params)

qemu/qemu_test.go

@@ -395,12 +395,13 @@ func TestAppendKnobsAllFalse(t *testing.T) {
 	testAppend(knobs, knobsString, t)
 }
 
-var kernelString = "-kernel /opt/vmlinux.container -append root=/dev/pmem0p1 rootflags=dax,data=ordered,errors=remount-ro rw rootfstype=ext4 tsc=reliable"
+var kernelString = "-kernel /opt/vmlinux.container -initrd /opt/initrd.container -append root=/dev/pmem0p1 rootflags=dax,data=ordered,errors=remount-ro rw rootfstype=ext4 tsc=reliable"
 
 func TestAppendKernel(t *testing.T) {
 	kernel := Kernel{
-		Path:   "/opt/vmlinux.container",
-		Params: "root=/dev/pmem0p1 rootflags=dax,data=ordered,errors=remount-ro rw rootfstype=ext4 tsc=reliable",
+		Path:       "/opt/vmlinux.container",
+		InitrdPath: "/opt/initrd.container",
+		Params:     "root=/dev/pmem0p1 rootflags=dax,data=ordered,errors=remount-ro rw rootfstype=ext4 tsc=reliable",
 	}
 
 	testAppend(kernel, kernelString, t)