I just downloaded Debian Squeeze and installed Xen
      from packages, following the instructions here: http://wiki.debian.org/Xen
      I am able to get PV guests up and running easily, but HVM
        guests will not even boot.
      
      
      The HVM I am currently trying to run is Debian sarge, which I
        installed into a disk image and configured using qemu.
      I am running on an HP Proliant ML150G6, which has Intel-VT
        hardware virtualization. One strange thing that I noticed is
        both
      
      
      grep vmx /proc/cpuinfo
      grep svm /proc/cpuinfo
      
      
      return nothing, although according to the BIOS settings the
        Intel-VT extensions are enabled.
    
    
      On trying to boot my HVM guest (xm create sarge.cfg), several
        different things would happen. At I fiddled with the
        configuration file for the VM a bit in attempts to get things
        working, it seems to have settled on the following. It prints
      
      
      Using config file "./sarge.cfg"
      
      
      and then hangs for a looong time, at least one minute. After
        waiting a bit, it prints 
      
      
      Error: Domain 'sarge' does not exist.
      
      
      and quits.
      
      
      I would really appreciate any advice or insight into this
        problem and possible solutions! I am including the configuration
        file for the VM in question, please let me know if more
        information would be useful:
      
      
      
      
      
        import os, re
        arch = os.uname()[4]
        if re.search('64', arch):
                arch_libdir = 'lib64'
        else:
                arch_libdir = 'lib'
        
        
        device_model = '/usr/' + arch_libdir +
          '/xen-4.0/bin/qemu-dm'
        
        
        name = 'sarge'
        kernel = '/usr/lib/xen-default/boot/hvmloader'
        
          builder = 'hvm'
        memory = 256
        shadow_memory = 16
        vcpus = 1
        disk  = [
        
         
           ]
        vif = [ 'type=ioemu, bridge=xenbr0' ]
        
        
        
        
        
        boot="cda"
        
        
        sdl=0
        vnc=1
        vncconsole=1
        vncunused=1
        stdvga=0
        serial='pty'