From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49466) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZpXZ0-0008Bv-VX for qemu-devel@nongnu.org; Fri, 23 Oct 2015 04:19:04 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZpXYx-0006zu-5y for qemu-devel@nongnu.org; Fri, 23 Oct 2015 04:19:02 -0400 Received: from mx1.redhat.com ([209.132.183.28]:39193) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZpXYx-0006zZ-0P for qemu-devel@nongnu.org; Fri, 23 Oct 2015 04:18:59 -0400 Date: Fri, 23 Oct 2015 09:18:54 +0100 From: "Daniel P. Berrange" Message-ID: <20151023081853.GA19259@redhat.com> References: <1444952643-5033-1-git-send-email-valerio@aimale.com> <87h9lrkz56.fsf@blackfin.pond.sub.org> <56210A17.6080401@aimale.com> <87io63xpke.fsf@blackfin.pond.sub.org> <56250035.40805@aimale.com> <87twpkqyow.fsf@blackfin.pond.sub.org> <20151022191203.GC3736@thinpad.lan.raisama.net> <877fmeqeho.fsf@blackfin.pond.sub.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <877fmeqeho.fsf@blackfin.pond.sub.org> Subject: Re: [Qemu-devel] QEMU patch to allow VM introspection via libvmi Reply-To: "Daniel P. Berrange" List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Markus Armbruster Cc: lcapitulino@redhat.com, Eduardo Habkost , Valerio Aimale , qemu-devel@nongnu.org On Fri, Oct 23, 2015 at 08:35:15AM +0200, Markus Armbruster wrote: > Eduardo Habkost writes: > > > On Wed, Oct 21, 2015 at 12:54:23PM +0200, Markus Armbruster wrote: > >> Valerio Aimale writes: > > [...] > >> > There's also a similar patch, floating around the internet, the uses > >> > shared memory, instead of sockets, as inter-process communication > >> > between libvmi and QEMU. I've never used that. > >> > >> By the time you built a working IPC mechanism on top of shared memory, > >> you're often no better off than with AF_LOCAL sockets. > >> > >> Crazy idea: can we allocate guest memory in a way that support sharing > >> it with another process? Eduardo, can -mem-path do such wild things? > > > > It can't today, but just because it creates a temporary file inside > > mem-path and unlinks it immediately after opening a file descriptor. We > > could make memory-backend-file also accept a full filename as argument, > > or add a mechanism to let QEMU send the open file descriptor to a QMP > > client. > > Valerio, would an command line option to share guest memory suffice, or > does it have to be a monitor command? If the latter, why? IIUC, libvmi wants to be able to connect to arbitrary pre-existing running KVM instances on the host. As such I think it cannot assume anything about the way they have been started, so requiring they be booted with a special command line arg looks impractical for this scenario. Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|