From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCHv5 3/3] vhost_net: a kernel-level virtio server Date: Tue, 15 Sep 2009 15:32:38 +0300 Message-ID: <4AAF8966.3040602@redhat.com> References: <20090827160750.GD23722@redhat.com> <20090903183945.GF28651@ovro.caltech.edu> <20090907101537.GH3031@redhat.com> <20090908172035.GB319@ovro.caltech.edu> <4AAA7415.5080204@gmail.com> <20090913120140.GA31218@redhat.com> <4AAE6A97.7090808@gmail.com> <20090914164750.GB3745@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Gregory Haskins , "Ira W. Snyder" , netdev@vger.kernel.org, virtualization@lists.linux-foundation.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, mingo@elte.hu, linux-mm@kvack.org, akpm@linux-foundation.org, hpa@zytor.com, Rusty Russell , s.hetze@linux-ag.com To: "Michael S. Tsirkin" Return-path: In-Reply-To: <20090914164750.GB3745@redhat.com> Sender: owner-linux-mm@kvack.org List-Id: netdev.vger.kernel.org On 09/14/2009 07:47 PM, Michael S. Tsirkin wrote: > On Mon, Sep 14, 2009 at 12:08:55PM -0400, Gregory Haskins wrote: > >> For Ira's example, the addresses would represent a physical address on >> the PCI boards, and would follow any kind of relevant rules for >> converting a "GPA" to a host accessible address (even if indirectly, via >> a dma controller). >> > I don't think limiting addresses to PCI physical addresses will work > well. From what I rememeber, Ira's x86 can not initiate burst > transactions on PCI, and it's the ppc that initiates all DMA. > vhost-net would run on the PPC then. >>> But we can't let the guest specify physical addresses. >>> >> Agreed. Neither your proposal nor mine operate this way afaict. >> > But this seems to be what Ira needs. > In Ira's scenario, the "guest" (x86 host) specifies x86 physical addresses, and the ppc dmas to them. It's the virtio model without any change. A normal guest also specifis physical addresses. -- error compiling committee.c: too many arguments to function -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org