Re: A set of "standard" virtual devices?

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

Jeremy Fitzhardinge wrote:
> 
> Yes, and that's the core of the Xen netfront.  But is there really much
> code which can be shared between different hypervisors?  When you get
> down to it, all the real code is hypervisor-specific stuff for setting
> up ringbuffers and dealing with interrupts.  Like all the other network
> drivers.
> 

One thing, Jeremy, which I think is being a bit misleading here: you're 
focusing on big, performance-critical stuff.  Those things are going to 
be the ones which has the most win to implement in hypervisor-specific 
ways.  Although we can offer models for some hypervisors (and G-d knows 
there are enough implementations out there of virtual disk which are 
almost identical), they're clearly not going to be universal.

However, there are other things; console is some, or my original 
example, which was random number generation.  For those, the benefit of 
unification is proportionally greater, simply because the win of 
anything hypervisor-specific is much smaller.

	-hpa