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Re: [Qemu-devel] [RFC PATCH 0/7] virtio-fs: shared file system for virtu
From: |
Dr. David Alan Gilbert |
Subject: |
Re: [Qemu-devel] [RFC PATCH 0/7] virtio-fs: shared file system for virtual machines3 |
Date: |
Wed, 12 Dec 2018 13:52:03 +0000 |
User-agent: |
Mutt/1.10.1 (2018-07-13) |
* Daniel P. Berrangé (address@hidden) wrote:
> On Mon, Dec 10, 2018 at 05:31:44PM +0000, Dr. David Alan Gilbert (git) wrote:
> > From: "Dr. David Alan Gilbert" <address@hidden>
> >
> > 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.
> >
> > There are corresponding patches being posted to Linux kernel,
> > libfuse and kata lists.
> >
> > For a fuller design description, and benchmark numbers, please see
> > Vivek's posting of the kernel set here:
> >
> > https://marc.info/?l=linux-kernel&m=154446243024251&w=2
> >
> > We've got a small website with instructions on how to use it, here:
> >
> > https://virtio-fs.gitlab.io/
> >
> > and all the code is available on gitlab at:
> >
> > https://gitlab.com/virtio-fs
> >
> > QEMU's changes
> > --------------
> >
> > The QEMU changes are pretty small;
> >
> > 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. number
> > of file descriptors) and also because it's cleaner than trying to
> > integrate libfuse into QEMU.
>
> Overall I like the virtio-fs architecture more than the virtio-vsock+NFS
> approach, as virtio-fs feels simpler and closer to virtio-9p with the
> latter's proxy backends.
>
> 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.
>
> 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.
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
> --
> |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :|
> |: https://libvirt.org -o- https://fstop138.berrange.com :|
> |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK
- [Qemu-devel] [RFC PATCH 2/7] virtio: add vhost-user-fs-pci device, (continued)
- [Qemu-devel] [RFC PATCH 2/7] virtio: add vhost-user-fs-pci device, Dr. David Alan Gilbert (git), 2018/12/10
- [Qemu-devel] [RFC PATCH 5/7] virtio-fs: Fill in slave commands for mapping, Dr. David Alan Gilbert (git), 2018/12/10
- [Qemu-devel] [RFC PATCH 7/7] virtio-fs: Allow mapping of journal, Dr. David Alan Gilbert (git), 2018/12/10
- [Qemu-devel] [RFC PATCH 4/7] virtio-fs: Add vhost-user slave commands for mapping, Dr. David Alan Gilbert (git), 2018/12/10
- [Qemu-devel] [RFC PATCH 6/7] virtio-fs: Allow mapping of meta data version table, Dr. David Alan Gilbert (git), 2018/12/10
- Re: [Qemu-devel] [RFC PATCH 0/7] virtio-fs: shared file system for virtual machines3, no-reply, 2018/12/10
- Re: [Qemu-devel] [RFC PATCH 0/7] virtio-fs: shared file system for virtual machines3, Stefan Hajnoczi, 2018/12/11
- Re: [Qemu-devel] [RFC PATCH 0/7] virtio-fs: shared file system for virtual machines3, Daniel P . Berrangé, 2018/12/12
- Re: [Qemu-devel] [RFC PATCH 0/7] virtio-fs: shared file system for virtual machines3,
Dr. David Alan Gilbert <=
- Re: [Qemu-devel] [RFC PATCH 0/7] virtio-fs: shared file system for virtual machines3, jiangyiwen, 2018/12/22