From owner-svn-src-projects@FreeBSD.ORG Mon Nov 21 19:03:10 2011 Return-Path: Delivered-To: svn-src-projects@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 14776106566C; Mon, 21 Nov 2011 19:03:10 +0000 (UTC) (envelope-from grehan@freebsd.org) Received: from alto.onthenet.com.au (alto.OntheNet.com.au [203.13.68.12]) by mx1.freebsd.org (Postfix) with ESMTP id C19BF8FC36; Mon, 21 Nov 2011 19:03:09 +0000 (UTC) Received: from dommail.onthenet.com.au (dommail.OntheNet.com.au [203.13.70.57]) by alto.onthenet.com.au (Postfix) with ESMTPS id E83C611DBB; Tue, 22 Nov 2011 05:03:07 +1000 (EST) Received: from Peter-Grehans-MacBook-Pro.local (c-67-161-203-10.hsd1.co.comcast.net [67.161.203.10]) by dommail.onthenet.com.au (MOS 4.2.4-GA) with ESMTP id BAL29681 (AUTH peterg@ptree32.com.au); Tue, 22 Nov 2011 05:03:05 +1000 Message-ID: <4ECAA067.7060906@freebsd.org> Date: Mon, 21 Nov 2011 12:03:03 -0700 From: Peter Grehan User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.2.24) Gecko/20111103 Thunderbird/3.1.16 MIME-Version: 1.0 To: Nathan Whitehorn References: <201111202147.pAKLlR0i010700@svn.freebsd.org> <4EC98E99.9000601@freebsd.org> <4EC9D65C.6050106@freebsd.org> In-Reply-To: <4EC9D65C.6050106@freebsd.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Junkmail-Info: RCVD_IN_PBL,RCVD_IN_SORBS_DUL,RDNS_DYNAMIC,SPF_SOFTFAIL X-Junkmail-Status: score=29/51, host=dommail.onthenet.com.au Cc: svn-src-projects@freebsd.org, src-committers@freebsd.org, bv Subject: Re: svn commit: r227772 - in projects/pseries: amd64/amd64 amd64/conf amd64/ia32 amd64/include amd64/linux32 arm/arm arm/at91 arm/conf arm/econa arm/include arm/mv arm/sa11x0 arm/xscale/i80321 arm/xsca... X-BeenThere: svn-src-projects@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "SVN commit messages for the src " projects" tree" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 21 Nov 2011 19:03:10 -0000 Hi Nathan, (cc'ing Bryan, virtio author) >> One thing to look out for is that the virtio spec has PCI register >> access in host-order, so you may need to switch in big-endian bus ops. ... > Is it worth making some generic way to avoid regular bus accessors? It > also needs to avoid regular bus dma calls, since the spec indicates > finger-of-God accesses that bypass any emulated IOMMU that busdma would > ordinarily try to use. The PCI interface for virtio specifies i/o space for device register access - that still needs bus space on x86 to get the right instructions issued. But, there's also a recent proposal to have additional BARs accessed via MMIO and not i/o. At least on x86 this still fits in fine with the standard PCI driver model. Is the p-series i/f a memory-mapped local-bus style of access, or is it via a pseudo PCI bus ? later, Peter.