From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754288Ab1E0PB1 (ORCPT ); Fri, 27 May 2011 11:01:27 -0400 Received: from casper.infradead.org ([85.118.1.10]:49116 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753708Ab1E0PB0 (ORCPT ); Fri, 27 May 2011 11:01:26 -0400 Subject: Re: [PATCH 7/7] Intel pci: Indicate 64-bit IOMMU passthrough available From: David Woodhouse To: Mike Travis Cc: Chris Wright , Andrew Morton , Ingo Molnar , Mike Habeck , Jesse Barnes , stable@kernel.org, iommu@lists.linux-foundation.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Dimitri Sivanich Date: Fri, 27 May 2011 16:01:01 +0100 In-Reply-To: <20110527013222.261166889@gulag1.americas.sgi.com> References: <20110527013221.231071058@gulag1.americas.sgi.com> <20110527013222.261166889@gulag1.americas.sgi.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.0.1 (3.0.1-1.fc15) Content-Transfer-Encoding: 7bit Message-ID: <1306508463.2029.123.camel@i7.infradead.org> Mime-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2011-05-26 at 20:32 -0500, Mike Travis wrote: > Prior to these IOMMU patches, the passthrough option > could not be used because it would cause the kernel to > panic. Could not be used on certain hardware? In certain configurations? It wasn't just *completely* broken (unless it got broken in a recent regression). > Provide an indication that a kernel is capable > of handling passthrough mode through the introduction > of a specific variable name. This allows automatic > configuration utilities to set the "iommu=pt" kernel > cmdline option safely. That implies that there is a follow-up patch to somehow export this information to userspace? Where the information in question is just the fact that a certain set of bugs have been fixed? Since these *are* actually bugs, and not new features, I take it we're looking at merging them for 2.6.40? I was planning to ask Linus to pull my tree today, and I'm not entirely happy with merging them at the last minute. So I'll plan to merge them into my tree after the outstanding merge, and then perhaps ask Linus to take them *after* -rc1? Since they're actually bug fixes, I suspect that's the best way to proceed? -- dwmw2