qemu: set clocksource to acpi_pm when kvm is not present

tsc is not reliable in this case, especially if hyperd runs inside
a virtual machine itself, as in the hykins use case.

Signed-off-by: Peng Tao <[email protected]>

Author: bergwolf

hypervisor/qemu/qemu_amd64.go

@@ -38,11 +38,13 @@ func (qc *QemuContext) arguments(ctx *hypervisor.VmContext) []string {
 		cpuParams = strconv.Itoa(boot.CPU)
 	}
 
+	cmdline := "console=ttyS0 panic=1 no_timer_check"
 	params := []string{
 		"-machine", machineClass + ",accel=kvm,usb=off", "-global", "kvm-pit.lost_tick_policy=discard", "-cpu", "host"}
 	if _, err := os.Stat("/dev/kvm"); os.IsNotExist(err) {
 		glog.V(1).Info("kvm not exist change to no kvm mode")
 		params = []string{"-machine", machineClass + ",usb=off", "-cpu", "core2duo"}
+		cmdline += " clocksource=acpi_pm notsc"
 	}
 
 	if boot.Bios != "" && boot.Cbfs != "" {
@@ -52,13 +54,13 @@ func (qc *QemuContext) arguments(ctx *hypervisor.VmContext) []string {
 	} else if boot.Bios != "" {
 		params = append(params,
 			"-bios", boot.Bios,
-			"-kernel", boot.Kernel, "-initrd", boot.Initrd, "-append", "console=ttyS0 panic=1 no_timer_check")
+			"-kernel", boot.Kernel, "-initrd", boot.Initrd, "-append", cmdline)
 	} else if boot.Cbfs != "" {
 		params = append(params,
 			"-drive", fmt.Sprintf("if=pflash,file=%s,readonly=on", boot.Cbfs))
 	} else {
 		params = append(params,
-			"-kernel", boot.Kernel, "-initrd", boot.Initrd, "-append", "console=ttyS0 panic=1 no_timer_check")
+			"-kernel", boot.Kernel, "-initrd", boot.Initrd, "-append", cmdline)
 	}
 
 	params = append(params,