From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:39489) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TDpjQ-0001rj-87 for qemu-devel@nongnu.org; Tue, 18 Sep 2012 00:48:21 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TDpjO-0007nk-T3 for qemu-devel@nongnu.org; Tue, 18 Sep 2012 00:48:20 -0400 Received: from mailout1.w1.samsung.com ([210.118.77.11]:65404) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TDpjO-0007nX-Mv for qemu-devel@nongnu.org; Tue, 18 Sep 2012 00:48:18 -0400 Received: from eusync3.samsung.com (mailout1.w1.samsung.com [210.118.77.11]) by mailout1.w1.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0MAJ00CGJ413D980@mailout1.w1.samsung.com> for qemu-devel@nongnu.org; Tue, 18 Sep 2012 05:48:39 +0100 (BST) Received: from [106.109.8.14] by eusync3.samsung.com (Oracle Communications Messaging Server 7u4-23.01(7.0.4.23.0) 64bit (built Aug 10 2011)) with ESMTPA id <0MAJ009BK40DD220@eusync3.samsung.com> for qemu-devel@nongnu.org; Tue, 18 Sep 2012 05:48:14 +0100 (BST) Message-id: <5057FD0D.7080004@samsung.com> Date: Tue, 18 Sep 2012 08:48:13 +0400 From: Evgeny Voevodin MIME-version: 1.0 References: <1347876042-22609-1-git-send-email-e.voevodin@samsung.com> <1347876042-22609-5-git-send-email-e.voevodin@samsung.com> <50571AA0.4070503@redhat.com> In-reply-to: <50571AA0.4070503@redhat.com> Content-type: text/plain; charset=ISO-8859-1; format=flowed Content-transfer-encoding: 7bit Subject: Re: [Qemu-devel] [RFC v2 04/12] hw/qdev-properties.c: Add "transport" property. List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: peter.maydell@linaro.org, kyungmin.park@samsung.com, qemu-devel@nongnu.org, aliguori@us.ibm.com On 09/17/2012 04:42 PM, Paolo Bonzini wrote: > Il 17/09/2012 12:00, Evgeny Voevodin ha scritto: >> Virtio back-end devices can be plugged into both transports: >> VIRTIO_PCI and VIRTIO_MMIO. In order to choose the desired >> transport we have a property "transport" in every back-end >> state struct. By specifying -device virtio-blk-pci user chooses >> VIRTIO_PCI transport and "transport" property is set automatically. >> But in order to provide full control to user we need to have >> "transport" property available to be set through command line: >> >> -device virtio-pci,id=virtio-pci.0 >> -device virtio-blk,transport=virtio-pci.0,... > What's the difference between this and "bus"? i.e. > > -device virtio-pci,id=virtio-pci-0 > -device virtio-blk,bus=virtio-pci-0.0,... > > Paolo > The difference is that with "transport" I used a linked list like, say, bdrv_states in block.c. It's much simpler then use buses. Also I was planning to use a . In this approach buses are used only to reflect hierarchy of devices in emulator manager. And yes, cover letter contains quite misleading information because attach to transport is based on a list of links, not on buses. Sorry, I forgot that when wrote the cover. -- Kind regards, Evgeny Voevodin, Technical Leader, Mobile Group, Samsung Moscow Research Center, e-mail: e.voevodin@samsung.com