From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ian Campbell Subject: Re: [PATCH v4 07/17] xen/arm: ITS: Add virtual ITS commands support Date: Fri, 17 Jul 2015 16:34:34 +0100 Message-ID: <1437147274.32371.353.camel@citrix.com> References: <1436514172-3263-1-git-send-email-vijay.kilari@gmail.com> <1436514172-3263-8-git-send-email-vijay.kilari@gmail.com> <55A658A5.4000605@citrix.com> <55A91C15.5030202@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <55A91C15.5030202@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Julien Grall Cc: Vijay Kilari , Stefano Stabellini , Prasun Kapoor , Vijaya Kumar K , Tim Deegan , "xen-devel@lists.xen.org" , Stefano Stabellini , manish.jaggi@caviumnetworks.com List-Id: xen-devel@lists.xenproject.org On Fri, 2015-07-17 at 16:15 +0100, Julien Grall wrote: > >> > >> Also, you have to translate the col_id into to a VCPU ID. > > > > This is virtual collection id which itself is vcpu id. isn't it? > > No. A collection can move between CPU, so you will end up to have vCPUID > != vCID. Specifically it is a TA (TargetAddress) and not a collection which is equal to a VCPU ID (in our implementation, because we have chosen to implement GITS_TYPER.PTA==0). A collection is mapped onto a TA by MAPC command. Thus some sort of record of which collection is mapped to which TA(==vcpuid) is required. > Your MAPC command is correctly storing the mapping in collections, so > please use it to retrieve the correct vCPU. Indeed.