Re: kvm userland: Build misses -I <kernel include dir>

[Iain Paton <devnull@darkvoyage.org.uk>]

Ben Bucksch wrote:

> Reason is, as said, that the build assumes that 
> /usr/include/linux/ioctl.h exists, i.e. it just #include <linux/ioctl.h> 

Oh, that's not nice. Certainly for me /usr/include/linux will never point to the kernel I'm building against so that's just a 
problem waiting to happen.

> , but does not pass the kernel dir *that I explicitly passed to 
> configure* to gcc. If I explicitly pass the kernel dir to configure, I 
> expect that to be used, and only that.

Seconded.
Especially when building external modules the only path being used should be the one passed in as the KERNELDIR I want to build 
against. Using /usr/include/linux or something under /lib/modules/$(uname -r)/build is fraught with problems.


> iggy on IRC noted that kernel source and build dir may be separate. 
> That's true - you probably need two configure flags --kernel-source-dir 
> and --kernel-build-dir. The existing --kerneldir could stay and set both 
> to the same value.

That's the issue I found with kvm-74, building the kernel with O= to have seperate source and build dirs fails as the makefile for 
the external kvm modules assumes that isn't an option.

There's a very minimal patch to get that working in this post:
<http://article.gmane.org/gmane.comp.emulators.kvm.devel/21172>

Iain