Re: "make check-acceptance" takes way too long

From: Stefano Brivio <sbrivio@redhat.com>
To: "Daniel P. Berrangé" <berrange@redhat.com>
Cc: "Peter Maydell" <peter.maydell@linaro.org>,
	"Thomas Huth" <thuth@redhat.com>,
	"Beraldo Leal" <bleal@redhat.com>,
	"Markus Armbruster" <armbru@redhat.com>,
	"Wainer dos Santos Moschetta" <wainersm@redhat.com>,
	"QEMU Developers" <qemu-devel@nongnu.org>,
	"Gerd Hoffmann" <kraxel@redhat.com>,
	"Cleber Rosa" <crosa@redhat.com>,
	"Alex Bennée" <alex.bennee@linaro.org>,
	"Philippe Mathieu-Daudé" <f4bug@amsat.org>
Subject: Re: "make check-acceptance" takes way too long
Date: Tue, 1 Feb 2022 11:27:20 +0100	[thread overview]
Message-ID: <20220201112720.4ac9b8df@elisabeth> (raw)
In-Reply-To: <Yfj4ERdAvmCF4ZzY@redhat.com>

On Tue, 1 Feb 2022 09:06:25 +0000
Daniel P. Berrangé <berrange@redhat.com> wrote:

> On Tue, Feb 01, 2022 at 07:31:39AM +0100, Stefano Brivio wrote:
> > Hi,
> > 
> > On Tue, 25 Jan 2022 10:20:11 +0100
> > Gerd Hoffmann <kraxel@redhat.com> wrote:
> >   
> > >   Hi,
> > >   
> > > > IMHO the ideal scenario would be for us to have a kernel, initrd
> > > > containing just busybox tools for the key arch targets we care
> > > > about. Those could be used with direct kernel boot or stuffed
> > > > into a disk iamge. Either way, they would boot in ~1 second,
> > > > even with TCG, and would be able to execute simple shell scripts
> > > > to test a decent amount of QEMU functionality.    
> > > 
> > > I have some test images based on buildroot which are essentially that.
> > > https://gitlab.com/kraxel/br-kraxel/
> > > 
> > > Still a significant download, but much smaller than a full fedora or
> > > ubuntu cloud image and it boots much faster too.  Not down to only one
> > > second though.  
> > 
> > I'm not sure you can recycle something from it, but my (ugly) approach
> > to make this fast (for a different purpose -- I'm using qemu to run
> > tests in guests, not testing qemu) is to build an initramfs by copying
> > the host binaries I need (a shell, ip, jq) and recursively sourcing
> > libraries using ldd (I guess I mentioned it's ugly).
> > 
> > No downloads, systemd, dracut, etc., guest boots in half a second
> > (x86_64 on x86_64, KVM -- no idea with TCG). Host kernel with a few
> > modules packed and loaded by a custom init script.  
> 
> That is such a good idea, that it is exactly what I do too :-)
> 
>   https://gitlab.com/berrange/tiny-vm-tools/-/blob/master/make-tiny-image.py
> 
> it works incredibly well for the simple case of host-arch==guest-arch.

Ah-ha, I feel better now. ;)

> It could be made to work for foreign arch easily enough - just need
> to have a foreign chroot lieing around somewhere you can point it
> to.

By the way, stage3 archives from:

	https://www.gentoo.org/downloads/#other-arches

get quite close to it ...no kernel binaries though.

-- 
Stefano