From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757753AbcK3O0z (ORCPT ); Wed, 30 Nov 2016 09:26:55 -0500 Received: from 8bytes.org ([81.169.241.247]:49241 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755681AbcK3O0t (ORCPT ); Wed, 30 Nov 2016 09:26:49 -0500 Date: Wed, 30 Nov 2016 15:26:43 +0100 From: Joerg Roedel To: Baoquan He Cc: xlpang@redhat.com, Don Brace , Myron Stowe , kexec@lists.infradead.org, LKML , iommu@lists.linux-foundation.org, Myron Stowe , Dave Young , David Woodhouse Subject: Re: [PATCH] iommu/vt-d: Flush old iotlb for kdump when the device gets context mapped Message-ID: <20161130142642.GJ2078@8bytes.org> References: <1479286950-21885-1-git-send-email-xlpang@redhat.com> <582C232F.6080205@redhat.com> <582D1A40.409@redhat.com> <20161129143547.GG2078@8bytes.org> <583E8A9B.7070906@redhat.com> <20161130090327.GA4192@x1> <20161130095334.GB4192@x1> <20161130102334.GC4192@x1> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161130102334.GC4192@x1> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 30, 2016 at 06:23:34PM +0800, Baoquan He wrote: > OK, talked with Xunlei. The old cache could be entry with present bit > set. -EPARSE Anyway, what I was trying to say is, that the IOMMU TLB is tagged with domain-ids, and that there is also a context-cache which maps device-ids to domain-ids. If we update the context entry then we need to flush only the context entry, as it will point to a new domain-id then and future IOTLB lookups in the IOMMU will be using the new domain-id and do not match the old entries. Joerg