Re: Configuration vs. compat hints [was Re: [Qemu-devel] [PATCHv3 03/13] qemu: add routines to manage PCI capabilities]

[Michael S. Tsirkin]

On Fri, Jun 12, 2009 at 09:43:29AM +0100, Mark McLoughlin wrote:
> = Solution - Separate configuration from compat hints =
> 
> As I suggested before:
> 
>   - Allow the VM manager to dump compat hints; this would be an opaque 
>     file format, more like the savevm format than a config file

Why make it "like the savevm" format then?
If they are opaque anyway, compat hints could be part of savevm format.

>   - Use defaults where compat hints are not available; e.g. if the VM 
>     manager specifies a device config, but no compat hints are 
>     supplied for it, then just use default values
> 
>   - Make the config override compat hints; e.g. if there are compat 
>     hints specified for a device not included in the machine config, 
>     just ignore those hints
> 
> Cheers,
> Mark.

If compat hints are opaque and only editable by qemu, we can get into a
situation where one can't create a specific setup with a new qemu.

-- 
MST