Re: stand-alone kvmtool

From: Claudio Fontana <claudio.fontana@huawei.com>
To: Andre Przywara <andre.przywara@arm.com>,
	Pekka Enberg <penberg@kernel.org>,
	Sasha Levin <sasha.levin@oracle.com>,
	Cyrill Gorcunov <gorcunov@gmail.com>,
	Asias He <asias.hejun@gmail.com>
Cc: "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	Marc Zyngier <Marc.Zyngier@arm.com>,
	Will Deacon <Will.Deacon@arm.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Ronald Minnich <rminnich@google.com>,
	"kvmarm@lists.cs.columbia.edu" <kvmarm@lists.cs.columbia.edu>,
	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>
Subject: Re: stand-alone kvmtool
Date: Fri, 13 Feb 2015 17:36:10 +0100	[thread overview]
Message-ID: <54DE27FA.6070507@huawei.com> (raw)
In-Reply-To: <54DE0CDD.70308@arm.com>

On 13.02.2015 15:40, Andre Przywara wrote:
> Ciao Claudio,
> 
> On 13/02/15 14:30, Claudio Fontana wrote:
>> Hello Andre,
>>
>> On 13.02.2015 11:39, Andre Przywara wrote:
>>> Hi,
>>>
>>> as I found it increasingly inconvenient to use kvmtool[1] as part of a
>>> Linux repository, I decided to give it a go and make it a stand-alone
>>> project. So I filtered all the respective commits, adjusted the paths in
>>> there (while keeping authorship and commit date, of course) and then
>>> added the missing bits to let it compile without a kernel tree nearby.
>>> The result is now available on:
>>>
>>> git://linux-arm.org/kvmtool.git
>>> http://linux-arm.org/kvmtool.git
>>
>> It builds fine on x86_64, but when I tried to crosscompile from x86_64 to AArch64,
>> I get in trouble because of libfdt: I have the aarch64 libs (static and shared), but how do I instruct the build system to get it from the right place?
> 
> You have to install them into your cross-compiler's SYSROOT.
> Get the location of that by executing
> $ ${CROSS_COMPILE}gcc -print-sysroot.
> If it's just for libfdt, it's probably the easiest to copy them
> manually, the header files into $SYSROOT/usr/include, the libraries into
> $SYSROOT/usr/lib/aarch64-linux-gnu
> That fixed it for me ;-)

Thanks!

> 
> For a more robust approach you would use your distribution's packaging
> system to install the aarch64 package into $SYSROOT.
> 
> Cheers,
> Andre.

I still prefer to be forced to understand things so I actually prefer the manual route.

Ciao,

Claudio

>>
>>>
>>> You can simply check it out, type make and use "./lkvm run" for a quick
>>> test. So far I briefly tested x86-64, arm and arm64, the later two were
>>> also cross-compiled. For sure there are rough edges in there (for
>>> instance copying a few non-uapi header files into), but I deem it worthy
>>> enough to get some public comments.
>>> For me that also fixed some nasty warnings about libfdt, which now are
>>> gone due it using your system library version of it.
>>> I also managed to get rid of the libc-i386-dev dependency when compiling
>>> for x86-64, but that still needs to be cleaned up and thus is not in the
>>> current HEAD.
>>> I haven't got around to compile-test the other supported architectures,
>>> but supporting them should be as easy as copying over the uapi kvm.h
>>> header file (see the respective ARM commit). Contributions (and tests!)
>>> are welcome.
>>>
>>> Please give it a go and tell me what you think. I don't want to fork the
>>> project, so I am happy if someone "official" picks it up.
>>>
>>> Cheers,
>>> Andre.
>>>
>>> [1] https://github.com/penberg/linux-kvm/tree/master/tools/kvm
>>> _______________________________________________
>>> kvmarm mailing list
>>> kvmarm@lists.cs.columbia.edu
>>> https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
>>>
>>
>>