From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54535) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gX4wI-0005wB-Ic for qemu-devel@nongnu.org; Wed, 12 Dec 2018 08:52:43 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gX4w5-00044J-N6 for qemu-devel@nongnu.org; Wed, 12 Dec 2018 08:52:35 -0500 Received: from mx1.redhat.com ([209.132.183.28]:41284) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gX4w3-00042V-Lc for qemu-devel@nongnu.org; Wed, 12 Dec 2018 08:52:25 -0500 Date: Wed, 12 Dec 2018 13:52:03 +0000 From: "Dr. David Alan Gilbert" Message-ID: <20181212135203.GD2370@work-vm> References: <20181210173151.16629-1-dgilbert@redhat.com> <20181212123059.GD31033@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20181212123059.GD31033@redhat.com> Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [RFC PATCH 0/7] virtio-fs: shared file system for virtual machines3 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Daniel =?iso-8859-1?Q?P=2E_Berrang=E9?= Cc: qemu-devel@nongnu.org, sweil@redhat.com, swhiteho@redhat.com, stefanha@redhat.com, vgoyal@redhat.com, miklos@szeredi.hu * Daniel P. Berrang=E9 (berrange@redhat.com) wrote: > On Mon, Dec 10, 2018 at 05:31:44PM +0000, Dr. David Alan Gilbert (git) = wrote: > > From: "Dr. David Alan Gilbert" > >=20 > > Hi, > > This is the first RFC for the QEMU side of 'virtio-fs'; > > a new mechanism for mounting host directories into the guest > > in a fast, consistent and secure manner. Our primary use > > case is kata containers, but it should be usable in other scenarios > > as well. > >=20 > > There are corresponding patches being posted to Linux kernel, > > libfuse and kata lists. > >=20 > > For a fuller design description, and benchmark numbers, please see > > Vivek's posting of the kernel set here: > >=20 > > https://marc.info/?l=3Dlinux-kernel&m=3D154446243024251&w=3D2 > >=20 > > We've got a small website with instructions on how to use it, here: > >=20 > > https://virtio-fs.gitlab.io/ > >=20 > > and all the code is available on gitlab at: > >=20 > > https://gitlab.com/virtio-fs > >=20 > > QEMU's changes > > -------------- > >=20 > > The QEMU changes are pretty small;=20 > >=20 > > There's a new vhost-user device, which is used to carry a stream of > > FUSE messages to an external daemon that actually performs > > all the file IO. The FUSE daemon is an external process in order to > > achieve better isolation for security and resource control (e.g. numb= er > > of file descriptors) and also because it's cleaner than trying to > > integrate libfuse into QEMU. >=20 > Overall I like the virtio-fs architecture more than the virtio-vsock+NF= S > approach, as virtio-fs feels simpler and closer to virtio-9p with the > latter's proxy backends. >=20 > I never really liked the idea of having to mess around with the host > NFS server to exposed filesystems to guests, as that's systemwide > service. The ability to have an isolated virtio-fs backend process > per filesystem share per guest is simpler from a mgmt pov. >=20 > One think I would like to see though is a general purpose, production > quality backend impl that is shipped by the QEMU project. It is fine > if projects like Kata want to write a custom impl tailored to their > specific needs, but I think QEMU should have something as standard that > isn't just demoware.=20 Our patches sent to libfuse may provide that - after we tidy them up a bit more; but it is the result of adding the fuse example code to qemu's contrib vhost-user example code. Given that this is the intersection of so many projects I'm not sure I care which project distributes a working implementation. Dave > Regards, > Daniel > --=20 > |: https://berrange.com -o- https://www.flickr.com/photos/dberr= ange :| > |: https://libvirt.org -o- https://fstop138.berrange= .com :| > |: https://entangle-photo.org -o- https://www.instagram.com/dberr= ange :| -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK