From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: [Qemu-devel] [PATCH 2/6] PCI DMA API (v2) Date: Sun, 06 Apr 2008 10:22:19 -0500 Message-ID: <47F8EAAB.2080806@codemonkey.ws> References: <1207368175-19476-1-git-send-email-aliguori@us.ibm.com> <1207368175-19476-2-git-send-email-aliguori@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel@lists.sourceforge.net, Marcelo Tosatti , qemu-devel@nongnu.org, Aurelien Jarno , Paul Brook To: Blue Swirl Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces@lists.sourceforge.net Errors-To: kvm-devel-bounces@lists.sourceforge.net List-Id: kvm.vger.kernel.org Blue Swirl wrote: > On 4/5/08, Anthony Liguori wrote: > >> This patch introduces a PCI DMA API and some generic code to support other DMA >> APIs. It introduces a IOVector type that contains physical address/length >> pairs. These vectors can be translated by the PCI layer and passed either to >> generic copying functions or directly to the block or network subsystems. >> > > But cpu_map_physical_page can't be the correct function for > translation for every case. cpu_map_physical_page is the last function you call after you have already translated the IOVector however many times you need to. It's only used within the IO infrastructure (net, block) which are passed fully translated IOVectors. > To support Sparc IOMMU and DMA controller > I need a way to call a series of different translation functions > depending on the bus where we are. For the byte swapping case the > memcpy functions must be dynamic as well. > Does DMA really byte-swap? I know PCI controllers byte swap within the configuration space but I didn't think they byte-swapped DMA transfers. I'm not even sure how that would work. Regards, Anthony Liguori > ------------------------------------------------------------------------- > This SF.net email is sponsored by the 2008 JavaOne(SM) Conference > Register now and save $200. Hurry, offer ends at 11:59 p.m., > Monday, April 7! Use priority code J8TLD2. > http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone > _______________________________________________ > kvm-devel mailing list > kvm-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/kvm-devel > ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Register now and save $200. Hurry, offer ends at 11:59 p.m., Monday, April 7! Use priority code J8TLD2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone