Re: [Qemu-devel] linux-user: enabling binfmt P flag

[Joakim Tjernlund]

Riku Voipio <address@hidden> wrote on 2014/08/25 16:49:17:
> 
> On Mon, Aug 25, 2014 at 04:30:40PM +0200, Joakim Tjernlund wrote:
> > Riku Voipio <address@hidden> wrote on 2014/08/25 15:55:55:
> > > 
> > > Hi,
> > > 
> > > On Mon, Aug 25, 2014 at 03:39:19PM +0200, Joakim Tjernlund wrote:
> > > > Then consider when you run a LXC without P flag. 
> > > 
> > > Please remember that your usecase of running Qemu in LXC is a new 
> > feature,
> > > never before supported. Adding new features is always nice. However, 
it 
> > must
> > > not happen with expense of regressing already working features
> > > (traditional chroot).
> 
> > OK, but traditional chroot is unaffected with my patch. Only binfmt
> > users which uses the binfmt flag O will have to change to PO. How
> > many is that? 
> 
> Traditional chroot is with binfmt_misc. Debian and ubuntu packages of

Sorry, I figured you meant plain chroot 

> Qemu enable OC flags, so at least all debian/ubuntu users who use qemu
> linux-user in chroots are affected. 
> 
> Using OC seems quite typical:
> 
> 
http://sources.gentoo.org/cgi-bin/viewvc.cgi/gentoo-x86/app-emulation/qemu/files/qemu-binfmt.initd-r1?view=markup

> 
http://rwmj.wordpress.com/2013/12/22/how-to-run-aarch64-binaries-on-an-x86-64-host-using-qemu-userspace-emulation/#content

> 
> Others, like Suse, scratchbox use the P flag and wrapper binary.

Yes, but I meant those not using the dist. default as dists will update
their binfmt scripts when upgrading QEMU.

Basically this will only be a potential problem for DIYs QEMU users.

 Jocke