busybox_fs.xml

<domain type="kvm" xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0'>
        <name>busybox_fs</name>
        <memory>512000</memory>
        <currentMemory>512000</currentMemory>
        <vcpu>2</vcpu>

        <os>
                <type arch='x86_64' machine='pc'>hvm</type>
                <kernel>/home/osboxes/code/linux-4.4.60/arch/x86_64/boot/bzImage</kernel>
                <!--
                <cmdline>console=ttyS0,115200 root=/dev/sda rootfs=ext4 rw</cmdline>
                --> 
                <cmdline>console=ttyS0,115200 root=/dev/vda rootfs=ext4 rw</cmdline>
                <boot dev='hd'/>
        </os>

        <features>
                <acpi/>
                <apic/>
                <pae/>
        </features>

        <clock offset='localtime'/>
        <on_poweroff>destroy</on_poweroff>
        <on_reboot>restart</on_reboot>
        <on_crash>destroy</on_crash>

        <devices>
                <emulator>/usr/bin/kvm</emulator>
                <disk type='file' device='disk'>
                        <!--
                        <driver name='qemu' type='qcow2'/>
                        <source file='/home/osboxes/code/image/busybox_fs.qcow2'/>
                        -->
                        <driver name='qemu' type='raw'/>
                        <source file='/home/osboxes/code/image/busybox_fs.raw'/>

                        <!-- 
                        <target dev='hda' bus='ide'/>
                        -->  
                        <target dev='vda' bus='virtio'/>
                </disk>

                <!--
                <disk type='file' device='cdrom'>
                        <source file='/home/zhangpeng/centos.iso'/>
                        <target dev='hdb' bus='ide'/>
                </disk>
                <graphics type='vnc' port='-1' autoport='yes' listen='0.0.0.0' keymap='en-us'/>
                -->

                <interface type='bridge'>
                        <source bridge='br0'/>
                        <mac address="00:16:3e:5d:aa:22"/>
                        <model type="virtio"/>
                </interface>

                <input type='mouse' bus='ps2'/>
                <serial type="pty">
                    <target port="0" />
                </serial>
                <console type="pty">
                    <target type="serial" port="0" />
                </console>
        </devices>
        <qemu:commandline>
            <qemu:arg value="-s"/>
            <!--
                <qemu:arg value="-gdb"/>
                <qemu:arg value="tcp:1234"/>
            -->
        </qemu:commandline>
</domain>