Xen HVM

check HVM capabilities : 

[root@localhost]# xm info|grep xen_caps
xen_caps               : xen-3.0-x86_32p hvm-3.0-x86_32 hvm-3.0-x86_32p

[root@localhost]# xm dmesg | grep -i hvm
(XEN) HVM: VMX enabled

VNC on HVM guests

Enable following options in configuration file /etc/xen/xen-config.sxp

(network-script network-bridge)
(vnc-listen '127.0.0.1')
(vncpasswd '...')

VNC password is created with /usr/bin/vncpasswd


 virsh # dumpxml firewall
<domain type='xen' id='1'>
  <name>firewall</name>
  <uuid>e816f20f-1ada-0c43-5323-91fbed2a1c27</uuid>
  <memory>524288</memory>
  <currentMemory>524288</currentMemory>
  <vcpu>1</vcpu>
  <os>
    <type>hvm</type>
    <loader>/usr/lib/xen/boot/hvmloader</loader>
    <boot dev='hd'/>
  </os>
  <features>
    <acpi/>
    <apic/>
    <pae/>
  </features>
  <clock offset='utc'/>
  <on_poweroff>destroy</on_poweroff>
  <on_reboot>restart</on_reboot>
  <on_crash>restart</on_crash>
  <devices>
    <emulator>/usr/lib/xen/bin/qemu-dm</emulator>
    <disk type='file' device='disk'>
      <driver name='file'/>
      <source file='/vm/firewall.img'/>
      <target dev='hda' bus='ide'/>
    </disk>
    <disk type='file' device='cdrom'>
      <target dev='hdc' bus='ide'/>
      <readonly/>
    </disk>
    <interface type='bridge'>
      <mac address='00:16:36:1d:26:bf'/>
      <source bridge='xenbr0'/>
      <script path='vif-bridge'/>
      <target dev='vif1.0'/>
    </interface>
    <serial type='pty'>
      <source path='/dev/pts/1'/>
      <target port='0'/>
    </serial>
    <console type='pty' tty='/dev/pts/1'>
      <source path='/dev/pts/1'/>
      <target port='0'/>
    </console>
  </devices>
</domain>

sample : 

name = "rhel4u4-x86_64"
builder = "hvm"
memory = "500"
disk = [ 'file:/var/lib/xen/images/rhel4u4-x86_64.dsk,hda,w', ]
vif = [ 'type=ioemu, mac=00:16:3e:09:f0:12, bridge=xenbr0', 'type=ioemu, 
mac=00:16:3e:09:f0:13, bridge=xenbr1' ]
uuid = "b10372f9-91d7-a05f-12ff-372100c99af5"
device_model = "/usr/lib64/xen/bin/qemu-dm"
kernel = "/usr/lib/xen/boot/hvmloader"
vnc=1
vncunused=1
apic=1
acpi=1
pae=1
vcpus=1
serial = "pty" # enable serial console
on_reboot   = 'restart'