Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752807AbaBNVno (ORCPT ); Fri, 14 Feb 2014 16:43:44 -0500 Received: from mail-ie0-f169.google.com ([209.85.223.169]:37974 "EHLO mail-ie0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752487AbaBNVnm (ORCPT ); Fri, 14 Feb 2014 16:43:42 -0500 MIME-Version: 1.0 In-Reply-To: <20140203212216.8607.68273.stgit@bling.home> References: <20140203212216.8607.68273.stgit@bling.home> From: Bjorn Helgaas Date: Fri, 14 Feb 2014 14:43:20 -0700 Message-ID: Subject: Re: [PATCH v2 0/3] Quirk Intel PCH root ports for ACS-like features To: Alex Williamson Cc: "linux-pci@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Don Dugger Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [+cc Don] On Mon, Feb 03, 2014 at 02:27:27PM -0700, Alex Williamson wrote: > v2: > - Remove bus #0 bug in filtering matching > - Add 2/3 introducing PCI_DEV_FLAGS_ACS_ENABLED_QUIRK, this gives > is better tracking and addresses the theoretical hotplug issue > - Update 3/3 for PCI_DEV_FLAGS_ACS_ENABLED_QUIRK > - Add dev_info to print regardless of whether we changes bits > - Add Intel cc > > As described in 3/3 many Intel root ports lack PCIe ACS capabilities > which results in excessively large IOMMU groups. Many of these root > ports do provide isolation capabilities, we just need to use device > specific mechanisms to enable and verify. Long term, I hope we can > round out this list (particularly to include X79 root ports) and > more importantly, encourage proper PCIe ACS support in future > products. I'm really hoping we can get this in during the 3.14 cycle. > Thanks, > > Alex > --- > > Alex Williamson (3): > pci: Add device specific PCI ACS enable > pci: Add pci_dev_flag for ACS enable quirks > pci/quirks: Enable quirks for PCIe ACS on Intel PCH root ports I applied these (with Don's ack for 3/3) to pci/virtualization. I tried to figure out how to handle post-merge window patches. Per Documentation/development-process/2.Process, "[after -rc1], only patches which fix problems should be submitted to the mainline," so one might conclude that a fix for any sort of problem is allowed. However, Documentation/networking/netdev-FAQ.txt says "No new features get mainlined after this [-rc1] -- only fixes to the rc1 content are expected," which is how I've been operating. In any case, these patches look more like new functionality (enabling a non-standard ACS feature) than a bug fix to me, so my preference is to merge them during the v3.15 merge window. I understand the desire for v3.14, namely, "lots of Intel devices don't support ACS, and that makes it hard for users to expose devices to userspace with fine granularity, and waiting for v3.15 will mean another two months." But this problem is really of Intel's own making: if they'd used standard ACS, or if they'd documented their non-standard mechanism, this wouldn't be an issue. Bjorn -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/