Re: [PATCH 001/104] KVM: Fix *nopage() in kvm_main.c

Avi Kivity
2007-09-17T18:19:23Z

Nick Piggin wrote:
>>
>> I should mention that the converting to use ->fault() is a 15-minute
>> change; the tricky part is adding backwards compatibility for the
>> external module package.
>>
>
> It should be mostly possible to ifdef a nopage() handler, which is
> just a wrapper function to translate arguments then call your new
> ->fault() handler. With luck, fault would mostly inline into nopage,
> and do some constant folding to make it cheaper...
>
> I'm planning to go through and convert the rest of the in-tree users
> at some point soon, so if you do get a chance to convert your
> upstream code before I try, it would nice ;)
>
>

In kvm I don't add compatibility #ifdefs to mainline, instead I have an
awk script that massages the sources into something that all kernels can
grok.

It isn't pretty but it works.

--
Do not meddle in the internals of kernels, for they are subtle and quick to panic.