From: Greg KH Subject: Re: [PATCH 0/16 v6] PCI: Linux kernel SR-IOV support Date: Thu, 6 Nov 2008 22:19:52 -0800 Message-ID: <20081107061952.GF3860@kroah.com> References: <20081106154351.GA30459@kroah.com> <894107.30288.qm@web45108.mail.sp1.yahoo.com> <20081106164919.GA4099@kroah.com> <0199E0D51A61344794750DC57738F58E5E26F996C4@GVW1118EXC.americas.hpqcorp.net> <20081106183630.GD11773@parisc-linux.org> <491371F0.7020805@codemonkey.ws> <20081106225854.GA15439@parisc-linux.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Anthony Liguori , "Fischer, Anna" , H L , "randy.dunlap@oracle.com" , "grundler@parisc-linux.org" , "Chiang, Alexander" , "linux-pci@vger.kernel.org" , "rdreier@cisco.com" , "linux-kernel@vger.kernel.org" , "jbarnes@virtuousgeek.org" , "virtualization@lists.linux-foundation.org" , "kvm@vger.kernel.org" , "mingo@elte.hu" To: Matthew Wilcox Return-path: Content-Disposition: inline In-Reply-To: <20081106225854.GA15439@parisc-linux.org> Sender: linux-pci-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On Thu, Nov 06, 2008 at 03:58:54PM -0700, Matthew Wilcox wrote: > > What we would rather do in KVM, is have the VFs appear in the host as > > standard network devices. We would then like to back our existing PV > > driver to this VF directly bypassing the host networking stack. A key > > feature here is being able to fill the VF's receive queue with guest > > memory instead of host kernel memory so that you can get zero-copy > > receive traffic. This will perform just as well as doing passthrough > > (at least) and avoid all that ugliness of dealing with SR-IOV in the guest. > > This argues for ignoring the SR-IOV mess completely. Just have the > host driver expose multiple 'ethN' devices. That would work, but do we want to do that for every different type of driver? thanks, greg k-h