From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1MDk6T-0001cw-NL for qemu-devel@nongnu.org; Mon, 08 Jun 2009 15:01:53 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1MDk6P-0001bW-2G for qemu-devel@nongnu.org; Mon, 08 Jun 2009 15:01:53 -0400 Received: from [199.232.76.173] (port=45999 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1MDk6O-0001bT-Tk for qemu-devel@nongnu.org; Mon, 08 Jun 2009 15:01:48 -0400 Received: from mail-px0-f190.google.com ([209.85.216.190]:43904) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1MDk6O-00056m-B5 for qemu-devel@nongnu.org; Mon, 08 Jun 2009 15:01:48 -0400 Received: by pxi28 with SMTP id 28so42808pxi.4 for ; Mon, 08 Jun 2009 12:01:47 -0700 (PDT) MIME-Version: 1.0 Sender: alex.l.williamson@gmail.com In-Reply-To: <20090606204845.GC26877@redhat.com> References: <20090605204647.3355.81929.stgit@kvm.aw> <20090605204718.3355.28647.stgit@kvm.aw> <20090606204845.GC26877@redhat.com> Date: Mon, 8 Jun 2009 13:01:39 -0600 Message-ID: <7162ab20906081201y4c598899mdfd5d42c42e17038@mail.gmail.com> Subject: Re: [Qemu-devel] [PATCH 6/7] virtio-net: Add new RX filter controls From: Alex Williamson Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: qemu-devel@nongnu.org On Sat, Jun 6, 2009 at 2:48 PM, Michael S. Tsirkin wrote: > On Fri, Jun 05, 2009 at 02:47:18PM -0600, Alex Williamson wrote: >> Add a few new RX modes to better control the receive_filter. =C2=A0These >> are all fairly obvious features that hardware could provide. > > Could you add a bit more detail on motivation for these > features please? Sure, e1000 offers RX controls which separate unicast and multicast promiscuous, these are replicated with allmulti, which has a direct mapping for Linux, and thus already exists, and alluni, to accept all unicast packets. With these we could actually do away with promiscuous, but since we have to dig into the header to determine the type of packet, I chose to leave promiscuous separate. Promiscuous also filters before vlan filtering, so has a slightly different meaning (maybe all-multi/uni should too?). e1000 also allows the driver to selectively enable/disable RX of packets to the broadcast address. This is replicated with the all/no-bcast options. Finally, there may be cases where we want to receive only unicast or only multicast address for special purpose network devices. This is provided by the nouni and nomulti options. A proprietary guest know as DMX intends to make use of these extra modes. Are there any other interesting, useful and lightweight packet filters we could implement? Thanks, Alex