From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Monjalon Subject: Re: [PATCH v4 02/15] mem: introduce IOVA type Date: Mon, 06 Nov 2017 10:08:24 +0100 Message-ID: <1658152.eYkLdl3WOf@xps> References: <20170814151537.29454-1-santosh.shukla@caviumnetworks.com> <3304743.b7VfCBXbgQ@xps> <020f79b0-8d81-7e5f-fd28-089f38e27723@caviumnetworks.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Cc: olivier.matz@6wind.com, sergio.gonzalez.monroy@intel.com, anatoly.burakov@intel.com, dev@dpdk.org To: santosh Return-path: Received: from out4-smtp.messagingengine.com (out4-smtp.messagingengine.com [66.111.4.28]) by dpdk.org (Postfix) with ESMTP id 1B33F1B2A1 for ; Mon, 6 Nov 2017 10:08:26 +0100 (CET) In-Reply-To: <020f79b0-8d81-7e5f-fd28-089f38e27723@caviumnetworks.com> List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" 06/11/2017 09:51, santosh: > > On Monday 06 November 2017 02:07 PM, Thomas Monjalon wrote: > > 06/11/2017 06:38, santosh: > >> On Monday 06 November 2017 07:11 AM, Thomas Monjalon wrote: > >>> The IO virtual addresses may be used instead of physical addresses. > >>> As IOVA is more generic, it should be used in most places instead > >>> of physical address wording. > >>> > >>> Signed-off-by: Thomas Monjalon > >>> --- > >>> +/** > >>> + * IO virtual address type. > >>> + * When the physical addressing mode is in use, > >>> + * the translation from a virtual address to a physical address > >>> + * is a direct mapping, i.e. the same value. > >>> + */ > >> I guess - that description applicable for iova=va mode > >> and for iova=pa mode - Need to do explicit virt2phy translation. > >> I believe you mis-wrote - s/physical addressing mode/virtual addressing mode. > > Not sure to understand your comment. > > Let me reword the description to be less ambiguous: > > > > * When the physical addressing mode (IOVA as PA) is in use, > > * the translation from an IO virtual address (IOVA) to a physical address > > * is a direct mapping, i.e. the same value. > > * Otherwise, in virtual mode (IOVA as VA), an IOMMU may do the translation. > > > > Is this description correct? > > > Yes. Good, so I can change the description with this one and add your ack, right?