From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [PATCH for 4.6 13/13] xen/iommu: smmu: Add Xen specific code to be able to use the driver Date: Wed, 18 Feb 2015 18:22:20 +0000 Message-ID: <54E4D85C.6090600@linaro.org> References: <1418760534-18163-1-git-send-email-julien.grall@linaro.org> <1418760534-18163-14-git-send-email-julien.grall@linaro.org> <54E3E49D.7000109@caviumnetworks.com> <54E47BE2.5030908@linaro.org>, <54E47D60.7010608@linaro.org> <1424280633785.32004@caviumnetworks.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta4.messagelabs.com ([85.158.143.247]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1YO9GR-0007oS-Rq for xen-devel@lists.xenproject.org; Wed, 18 Feb 2015 18:22:23 +0000 Received: by mail-wi0-f181.google.com with SMTP id r20so4134281wiv.2 for ; Wed, 18 Feb 2015 10:22:22 -0800 (PST) In-Reply-To: <1424280633785.32004@caviumnetworks.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: "Jaggi, Manish" , "xen-devel@lists.xenproject.org" Cc: "stefano.stabellini@citrix.com" , "tim@xen.org" , "ian.campbell@citrix.com" List-Id: xen-devel@lists.xenproject.org On 18/02/2015 17:30, Jaggi, Manish wrote: > [manish] There are general comments on the data structures > (a) I don't see a use case where for same domain (VM) there would be different context banks , so linked list may not be required. I guess you mean the list in arm_smmu_xen_domain? All the devices pass-through to a domain may not be protected by the same SMMU. Therefore the context banks are different. Also, for now a context is allocated per-device. It should be rework to share the context between multiple device protected by the same SMMU and pass-through to the same domain. > (b) Also iommu group may not be relevant for the same reason. > I am curious to find the use cases. The iommu_group is used to store the configuration of the device protected by an SMMU (i.e the stream ids associated to this domain). I'm a bit surprised that you think they are not useful... Regards, -- Julien Grall