From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755510AbcKJLsV (ORCPT ); Thu, 10 Nov 2016 06:48:21 -0500 Received: from 8bytes.org ([81.169.241.247]:58901 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755406AbcKJLsT (ORCPT ); Thu, 10 Nov 2016 06:48:19 -0500 Date: Thu, 10 Nov 2016 12:48:16 +0100 From: Joerg Roedel To: Baoquan He Cc: iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, kexec@lists.infradead.org, Vincent.Wan@amd.com, dyoung@redhat.com, xlpang@redhat.com Subject: Re: [PATCH v6 7/9] iommu/amd: Update domain into to dte entry during device driver init Message-ID: <20161110114816.GE9996@8bytes.org> References: <1476963440-23039-1-git-send-email-bhe@redhat.com> <1476963440-23039-8-git-send-email-bhe@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1476963440-23039-8-git-send-email-bhe@redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 20, 2016 at 07:37:18PM +0800, Baoquan He wrote: > prot = dir2prot(direction); > + if (translation_pre_enabled(iommu) && !dev_data->domain_updated) { > + dev_data->domain_updated = true; > + set_dte_entry(dev_data->devid, domain, dev_data->ats.enabled); > + if (alias != dev_data->devid) > + set_dte_entry(alias, domain, dev_data->ats.enabled); > + device_flush_dte(dev_data); > + } Hmm, I really don't like to have these checks in the fast-path. But to get rid of it I think we need to re-work the way domains are assigned to devices. One way to do this would be to add a 'defered-domain-attach' feature to the iommu-core code. What do you think about this? Joerg