Re: A set of "standard" virtual devices?

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

Jeremy Fitzhardinge wrote:
> 
> So, what you're saying is:
> 
>    1. assuming there's going to be a vast number of miscellaneous devices
>    2. it would be best if there were one per device rather than one per
>       hypervisor per device
>    3. so we'd have one linux device driver
> 
> But this implies that the work is just pushed off into all the
> hypervisors to support this new device over the generic interface;
> there's no overall reduction of code or complexity, other than making
> "wc" on the kernel source smaller.
> 

Sure there is, assuming you deal about heterogenous clients.  I'm not 
sure Xen is (although that is, as far as I understand, being remedied), 
which might explain your different perspective.

Consider that this may not even be about Linux -- having these standard 
devices would enable, say, 'doze device drivers to be written and shared.

> That said, something like USB is probably the best bet for this kind of
> low-performance device.  I think.  Not that I really know anything about
> USB.

USB is evil in the extreme for this kind of stuff.  Although in theory 
you can have any HCI you want, in practice the ones that are implemented 
requires a very complex framework for full compatiblity.

	-hpa