On Wed, May 16, 2007 at 12:28:00PM -0500, Anthony Liguori wrote: > Eric Van Hensbergen wrote: > > On 5/11/07, Anthony Liguori <[EMAIL PROTECTED]> wrote: > >> > >> There's definitely a conversation to have here. There are going to be a > >> lot of small devices that would benefit from a common transport > >> mechanism. Someone mentioned a PV entropy device on LKML. A > >> host=>guest filesystem is another consumer of such an interface. > >> > >> I'm inclined to think though that the abstraction point should be the > >> transport and not the actual protocol. My concern with standardizing on > >> a protocol like 9p would be that one would lose some potential > >> optimizations (like passing PFN's directly between guest and host). > >> > > > > I think that there are two layers - having a standard, well defined, > > simple shared memory transport between partitions (or between > > emulators and the host system) is certainly a prerequisite. There are > > lots of different decisions to made here: > > What do you think about a socket interface? I'm not sure how discovery > would work yet, but there are a few PV socket implementations for Xen at > the moment.
As a userspace apps service, I'd very much like to see a common sockets interface for inter-VM communication that is portable across virt systems like Xen & KVM. I'd see it as similar to UNIX domain sockets in style. So basically any app which could do UNIX domain sockets, could be ported to inter-VM sockets by just changing PF_UNIX to say, PF_VIRT Lots of interesting details around impl & security (what VMs are allowed to talk to each other, whether this policy should be controlled by the host, or allow VMs to decide for themselves). > > a) does it communicate with userspace, kernelspace, or both? > > sockets are usable for both userspace/kernespace. For userspace, it would be very easy to adapt existing sockets based apps using IP or UNIX sockets to use inter-VM sockets, which is a big positive. > > d) can all of these parameters be something controllable from userspace? > > e) I'm sure there are many others that I can't be bothered to think > > of on a Friday > > The biggest point of contention would probably be what goes in the > sockaddr structure. Keeping it very simple would be some arbitrary 'path', similar to UNIX domain sockets in the abstract namespace ? Regards, Dan. -- |=- Red Hat, Engineering, Emerging Technologies, Boston. +1 978 392 2496 -=| |=- Perl modules: http://search.cpan.org/~danberr/ -=| |=- Projects: http://freshmeat.net/~danielpb/ -=| |=- GnuPG: 7D3B9505 F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 -=| ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
