On Tue, 1 Feb 2022 09:06:25 +0000 Daniel P. Berrangé <berra...@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 <kra...@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
