[Libvir] Re: support for hvm guests

[Jim Fehlig]

Daniel Veillard wrote:

>On Fri, Apr 07, 2006 at 04:10:36PM -0600, Jim Fehlig wrote:
>  
>
>>Daniel,
>>
>>FYI, I'm working on a patch to support hvm guests.
>>    
>>
[snip]

>>Calling "virsh dumpxml some_hvm_guest" will (almost) 
>>correctly dump xml config info on hvm guests.  Needs to handle 
>>"type=ioemu" component of VIF specification.  Currently in the XML there 
>>is a type attribute for the interface element that specifies bridge, 
>>route, etc.  How would you like to structure the interface element and 
>>its children to account for hvm guests?
>>    
>>
>
>  Well <interface type='iommu'> and then as sub elements the extra
>informations needed, sounds the closer to the existing format. But
>is that making sense from a logical point of view ?
>  
>

Type 'bridge' can be valid for hvm guests.  Perhaps it is better to not 
expose ioemu in the XML for now as there will probably be changes in 
this area anyway.  We know the domain is type hvm, so just add 'ioemu:' 
where necessary when talking to xend/xenstore.  I'm currently thinking 
about the following XML for OS element when type is hvm:

<os>
    <type>hvm</type>
    <kernel>/usr/lib/xen/boot/hvmloader</kernel>
    <device_model>/usr/lib/xen/bin/qemu-dm</device_model>
    <boot dev='c'>
    <graphics type='vnc'>
    <cdrom dev='/dev/hdd'>
</os>
 
boot, graphics, and cdrom elements are optional.
 - boot: The device from which the guest should boot.  If not specified 
the guest will
             be booted from hard disk.  'a' = floppy, 'c' = hard disk, 
'd' = cdrom
 - graphics: Graphics model to use for the guest.  Valid type attribute 
values are 'vnc'
                   and 'sdl'.  If not specified the guest will be 
launched with sdl.
 - cdrom: The cdrom device, e.g. '/dev/hdd', '/path/to/iso/plan9.iso'

The patch I'm currently working on assumes this XML format.  What do you 
think?

Regards,
Jim