From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965716AbdGTWTK (ORCPT ); Thu, 20 Jul 2017 18:19:10 -0400 Received: from mx1.redhat.com ([209.132.183.28]:46190 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934851AbdGTWTI (ORCPT ); Thu, 20 Jul 2017 18:19:08 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 53203C04D2B4 Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=alex.williamson@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 53203C04D2B4 Date: Thu, 20 Jul 2017 16:19:05 -0600 From: Alex Williamson To: Feng Kan Cc: "linux-kernel@vger.kernel.org" , linux-pci@vger.kernel.org, Bjorn Helgaas , "Jonglih (Daniel) Yu" , "jcm@redhat.com" Subject: Re: [PATCH] pci: quirk: Apply APM ACS quirk to XGene devices Message-ID: <20170720161905.24e300eb@ul30vt.home> In-Reply-To: References: <1500338752-30576-1-git-send-email-fkan@apm.com> <20170717202324.105e993c@w520.home> <20170718121618.6eea460f@w520.home> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Thu, 20 Jul 2017 22:19:08 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 18 Jul 2017 22:37:00 -0700 Feng Kan wrote: > > > > I don't know what that means, does the hardware support an equivalent > > to source validation or not? > > Yes, source validation is done through the smmu. The SMMU does a context lookup based on the bdf, but if the root port does not support SV, what is it that prevents the device from spoofing a different bdf? How does the smmu intercept this? Thanks, Alex > What's the response of the root port if > > the downstream device issues a transaction spoofing devices not within > > the bus number ranges of the bridge? > HW guys informs me there is way to disable transactions between root port. > I will confirm later. > > > > >> Alex, the goal here is to enable virtualization to work correctly. > >> Please let me know if the > >> above is sufficient. Much thanks. > > > > Of course, but that means that the hardware vendor is vouching that > > this device provides the equivalent isolation for each of the missing > > components of ACS. Claiming to have isolation capabilities that don't > > exist would be irresponsible and put users of that hardware at risk. > Agreed, I believe we do have isolation in our case based on the conference > we had today. > > > Thanks, > > > > Alex