Re: [PATCH 3/4] x86 paravirt_ops: implementation of paravirt_ops

Jeremy Fitzhardinge
2006-08-07T05:56:24Z

Andi Kleen wrote:
> On Monday 07 August 2006 06:47, Rusty Russell wrote:
>
>> This patch does the dumbest possible replacement of paravirtualized
>> instructions: calls through a "paravirt_ops" structure. Currently
>> these are function implementations of native hardware: hypervisors
>> will override the ops structure with their own variants.
>>
>
> You should call it HAL - that would make it clearer what it is.
>

I've always found the term "HAL" to be vague to the point of
meaningless. What would it mean in this case: "hypervisor abstraction
layer"? It certainly doesn't attempt abstract all hardware.

> I think I would prefer to patch always. Is there a particular
> reason you can't do that?
>

Some calls just don't need patching; an indirect call is fast enough,
and simple. But I can't think of a good reason to not patch patchable
calls, other than for debugging perhaps (easier to place one breakpoint
than one per inline site).

J