Re: linux-next: manual merge of the kvm-ppc tree with the powerpc-merge tree

From: Scott Wood <scottwood@freescale.com>
To: Timur Tabi <B04825@freescale.com>
Cc: Alexander Graf <agraf@suse.de>,
	Stephen Rothwell <sfr@canb.auug.org.au>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	David Howells <dhowells@redhat.com>,
	"linux-next@vger.kernel.org" <linux-next@vger.kernel.org>,
	Paul Mackerras <paulus@samba.org>,
	"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>
Subject: Re: linux-next: manual merge of the kvm-ppc tree with the powerpc-merge tree
Date: Thu, 11 Oct 2012 12:28:56 -0500	[thread overview]
Message-ID: <1349976536.6903.7@snotra> (raw)
In-Reply-To: <507700EB.5090307@freescale.com> (from B04825@freescale.com on Thu Oct 11 12:24:59 2012)

On 10/11/2012 12:24:59 PM, Timur Tabi wrote:
> Scott Wood wrote:
> >> > My concern is that when I think of a user-space header file, I  
> think
> >> > of a
> >> > user-space application that calls ioctls.  I know that KVM guest
> >> > kernels
> >> > run as user-space processes, but that does not seem like a  
> reason to
> >> > combine all of the header files that the KVM guest kernel needs  
> with
> >> > "real" user-space header files.
> 
> > So where should guest headers go?
> 
> I admit that I don't have any answers, especially since this whole  
> thing
> is new to me.  Like I said, I don't know much about KVM internals, so  
> I
> just don't understand why KVM guests need to have access to these  
> kernel
> header files as if they're user header files.  The guests are still  
> Linux
> kernels (or other OSes that think they're running as privileged code).

For hypercalls and other paravirt.  That's the point -- they're not  
kernel headers.  They're guest API headers.

-scott