From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gregory Haskins Subject: Re: [PATCH 0/7] AlacrityVM guest drivers Reply-To: Date: Fri, 07 Aug 2009 08:14:20 -0400 Message-ID: <4A7C1A9C.9000600@gmail.com> References: <20090803171030.17268.26962.stgit@dev.haskins.net> <4A7AE150.7040009@redhat.com> <4A7AAB1A0200005A00051BED@sinclair.provo.novell.com> <200908061740.04276.arnd@arndb.de> <20090806154543.GA11944@redhat.com> <1295ed070908060928s7b02e8bbtaf2b9b5c35679c0d@mail.gmail.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig29316DD0C8D47A592CD78F0A" Cc: kvm@vger.kernel.org, alacrityvm-devel@lists.sourceforge.net To: Pantelis Koukousoulas Return-path: Received: from qw-out-2122.google.com ([74.125.92.26]:24212 "EHLO qw-out-2122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753737AbZHGMOX (ORCPT ); Fri, 7 Aug 2009 08:14:23 -0400 Received: by qw-out-2122.google.com with SMTP id 8so612197qwh.37 for ; Fri, 07 Aug 2009 05:14:23 -0700 (PDT) In-Reply-To: <1295ed070908060928s7b02e8bbtaf2b9b5c35679c0d@mail.gmail.com> Sender: kvm-owner@vger.kernel.org List-ID: This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig29316DD0C8D47A592CD78F0A Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable [not sure if it was intentional, but you dropped the CC list. Therefore, I didn't see this until I caught up on my kvm@vger reading] Pantelis Koukousoulas wrote: > How hard would it be to implement virtio over vbus and perhaps the > virtio-net backend? It should be relatively trivial. I have already written the transport (called virtio-vbus) that would allow the existing front-end (virtio-net) to work without modification. http://lkml.org/lkml/2009/4/21/427 All that is needed is to take venet-tap as an example and port it to something virtio compatible (via that patch I posted) on the backend. I have proposed this as an alternative to venet, but so far I have not had any takers to help with this effort. Likewise, I am too busy with the infrastructure to take this on myself. >=20 > This would leave only one variable in the comparison, clear misconcepti= ons and > make evaluation easier by judging each of vbus, venet etc separately on= its own > merits. >=20 > The way things are now, it is unclear exactly where those performance > improvements are coming from (or how much each component contributes) > because there are too many variables. >=20 > Replacing virtio-net by venet would be a hard proposition if only becau= se > virtio-net has (closed source) windows drivers available. There has to = be > shown that venet by itself does something significantly better that > virtio-net can't be modified to do comparably well. I am not proposing anyone replace virtio-net. It will continue to work fine despite the existence of an alternative, and KVM can continue to standardize on it if that is what KVM wants to do. >=20 > Having venet in addition to virtio-net is also difficult, given that ha= ving only > one set of paravirtual drivers in the kernel was the whole point behind= virtio. As it stands right now, virtio-net fails to meet my performance goals, and venet meets them (or at least, gets much closer, but I will not rest..). So, at least for AlacrityVM, I will continue to use and promote it when performance matters. If at some time in the future I can get virtio-net to work in my environment in a comparable and satisfactory way, I will consider migrating to it and deprecating venet. Until then, having two drivers is ok, and no-one has to use the one they don't like. I certainly do not think having more than one driver that speaks 802.x ethernet in the kernel tree is without precedent. ;) Kind Regards, -Greg --------------enig29316DD0C8D47A592CD78F0A Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG/MacGPG2 v2.0.11 (Darwin) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAkp8GpwACgkQP5K2CMvXmqHpFQCeN22gqi3QeirJV3VNlIHxtEek 9XsAn3o+HTv0M8DZrbTvMa/cDSDfqJ3o =rvfs -----END PGP SIGNATURE----- --------------enig29316DD0C8D47A592CD78F0A--