Re: A set of "standard" virtual devices?

["H. Peter Anvin" <hpa@zytor.com>]

Arnd Bergmann wrote:
> 
>> That being said, on platforms which are PCI-centric, such as x86, this 
>> of course makes it a lot easier to produce virtual devices which work 
>> across hypervisors, since the device model, of *any* operating system is 
>> set up to handle them.
> 
> Yes, as I said there are two separate problems. I really think that
> a standardized virtual driver interface should be modeled after
> kernel <-> user interfaces, not hardware <-> kernel interfaces.
> 
> Once we know what operations we want (e.g. read, write and SIGIO,
> or some other set of primitives), it will be good to provide a
> virtual PCI device that can be used as one transport mechanism
> below it. Using PCI device IDs to tell what functionality is
> provided by the device would provide a reasonable method for
> autoprobing.
> 

That seems like a reasonable approach.  I *do* care about 
hardware-equivalent interfaces, because they, too, keep getting 
reinvented, but it seems reasonable to approach it in a layered fashion 
like you describe.

	-hpa