From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49069) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eMFZj-0007Ap-3c for qemu-devel@nongnu.org; Tue, 05 Dec 2017 10:56:03 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eMFZf-0006vl-US for qemu-devel@nongnu.org; Tue, 05 Dec 2017 10:56:03 -0500 Received: from mx1.redhat.com ([209.132.183.28]:45990) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eMFZf-0006vU-Nl for qemu-devel@nongnu.org; Tue, 05 Dec 2017 10:55:59 -0500 Date: Tue, 5 Dec 2017 17:55:45 +0200 From: "Michael S. Tsirkin" Message-ID: <20171205174833-mutt-send-email-mst@kernel.org> References: <1512444796-30615-1-git-send-email-wei.w.wang@intel.com> <1512444796-30615-3-git-send-email-wei.w.wang@intel.com> <20171205145950.GF31150@stefanha-x1.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171205145950.GF31150@stefanha-x1.localdomain> Subject: Re: [Qemu-devel] [virtio-dev] [PATCH v3 2/7] vhost-pci-net: add vhost-pci-net List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Hajnoczi Cc: Wei Wang , virtio-dev@lists.oasis-open.org, qemu-devel@nongnu.org, marcandre.lureau@redhat.com, jasowang@redhat.com, pbonzini@redhat.com, jan.kiszka@siemens.com, avi.cohen@huawei.com, zhiyong.yang@intel.com On Tue, Dec 05, 2017 at 02:59:50PM +0000, Stefan Hajnoczi wrote: > On Tue, Dec 05, 2017 at 11:33:11AM +0800, Wei Wang wrote: > > Add the vhost-pci-net device emulation. The device uses bar 2 to expose > > the remote VM's memory to the guest. The first 4KB of the the bar area > > stores the metadata which describes the remote memory and vring info. > > This device looks like the beginning of a new "vhost-pci" virtio device > type. There are layering violations: > > 1. This has nothing to do with virtio-net or networking, it's purely > vhost-pci. Why is it called vhost-pci-net instead of vhost-pci? > > 2. VirtIODevice does not know about PCI. It should work over virtio-ccw > or virtio-mmio. This patch talks about BARs inside a VirtIODevice so > there is a problem here. I think the point is how memory is exposed to another guest. This device exposes it as a pci bar. I don't think e.g. ccw can do this, it's all hypercall-based. > I'm concerned that there is no clear architecture and elements of the > virtio architecture are being mixed up with no justification. > > Can you explain what you're trying to do? > > Please post a specification for the vhost-pci device so the operation of > the device can be discussed and is clear to reviewers. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: virtio-dev-return-2757-cohuck=redhat.com@lists.oasis-open.org Sender: List-Post: List-Help: List-Unsubscribe: List-Subscribe: Received: from lists.oasis-open.org (oasis-open.org [66.179.20.138]) by lists.oasis-open.org (Postfix) with ESMTP id 506335818F45 for ; Tue, 5 Dec 2017 07:56:01 -0800 (PST) Date: Tue, 5 Dec 2017 17:55:45 +0200 From: "Michael S. Tsirkin" Message-ID: <20171205174833-mutt-send-email-mst@kernel.org> References: <1512444796-30615-1-git-send-email-wei.w.wang@intel.com> <1512444796-30615-3-git-send-email-wei.w.wang@intel.com> <20171205145950.GF31150@stefanha-x1.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171205145950.GF31150@stefanha-x1.localdomain> Subject: Re: [virtio-dev] [PATCH v3 2/7] vhost-pci-net: add vhost-pci-net To: Stefan Hajnoczi Cc: Wei Wang , virtio-dev@lists.oasis-open.org, qemu-devel@nongnu.org, marcandre.lureau@redhat.com, jasowang@redhat.com, pbonzini@redhat.com, jan.kiszka@siemens.com, avi.cohen@huawei.com, zhiyong.yang@intel.com List-ID: On Tue, Dec 05, 2017 at 02:59:50PM +0000, Stefan Hajnoczi wrote: > On Tue, Dec 05, 2017 at 11:33:11AM +0800, Wei Wang wrote: > > Add the vhost-pci-net device emulation. The device uses bar 2 to expose > > the remote VM's memory to the guest. The first 4KB of the the bar area > > stores the metadata which describes the remote memory and vring info. > > This device looks like the beginning of a new "vhost-pci" virtio device > type. There are layering violations: > > 1. This has nothing to do with virtio-net or networking, it's purely > vhost-pci. Why is it called vhost-pci-net instead of vhost-pci? > > 2. VirtIODevice does not know about PCI. It should work over virtio-ccw > or virtio-mmio. This patch talks about BARs inside a VirtIODevice so > there is a problem here. I think the point is how memory is exposed to another guest. This device exposes it as a pci bar. I don't think e.g. ccw can do this, it's all hypercall-based. > I'm concerned that there is no clear architecture and elements of the > virtio architecture are being mixed up with no justification. > > Can you explain what you're trying to do? > > Please post a specification for the vhost-pci device so the operation of > the device can be discussed and is clear to reviewers. --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org