From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH 2/2] vhost_net: a kernel-level virtio server Date: Thu, 13 Aug 2009 16:53:46 +0200 Message-ID: <200908131653.47029.arnd@arndb.de> References: <200908131548.35199.arnd@arndb.de> <20090813144129.GB5080@redhat.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Cc: virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, "Ira W. Snyder" , linux-kernel@vger.kernel.org, kvm@vger.kernel.org To: "Michael S. Tsirkin" Return-path: In-Reply-To: <20090813144129.GB5080@redhat.com> Sender: kvm-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Thursday 13 August 2009, Michael S. Tsirkin wrote: > The best way to do this IMO would be to add zero copy support to raw > sockets, vhost will then get it basically for free. Yes, that would be nice. I wonder if that could lead to security problems on TX though. I guess It will only bring significant performance improvements if we leave the data writable in the user space or guest during the operation. If the user finds the right timing, it could modify the frame headers after they have been checked using netfilter, or while the frames are being consumed in the kernel (e.g. an NFS server running in a guest). Ardn <><