Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751091AbaLEKaN (ORCPT ); Fri, 5 Dec 2014 05:30:13 -0500 Received: from smtp02.citrix.com ([66.165.176.63]:46876 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750724AbaLEKaL (ORCPT ); Fri, 5 Dec 2014 05:30:11 -0500 X-IronPort-AV: E=Sophos;i="5.07,521,1413244800"; d="scan'208";a="200646006" Message-ID: <54818929.5000008@citrix.com> Date: Fri, 5 Dec 2014 10:30:01 +0000 From: David Vrabel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.2.0 MIME-Version: 1.0 To: Alex Williamson , Sander Eikelenboom CC: , Konrad Rzeszutek Wilk , , Boris Ostrovsky , , Subject: Re: [Xen-devel] [PATCH v5 9/9] xen/pciback: Implement PCI reset slot or bus with 'do_flr' SysFS attribute References: <201412041206.sB4C6XVQ009497@userz7022.oracle.com> <5480528F.8010106@citrix.com> <1107877503.20141204141054@eikelenboom.it> <548064EA.8090905@citrix.com> <308719815.20141204150909@eikelenboom.it> <5480702F.2060004@citrix.com> <1578910783.20141204155025@eikelenboom.it> <1417707546.15750.100.camel@bling.home> In-Reply-To: <1417707546.15750.100.camel@bling.home> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-DLP: MIA1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/12/14 15:39, Alex Williamson wrote: > > I don't know what workaround you're talking about. As devices are > released from the user, vfio-pci attempts to reset them. If > pci_reset_function() returns success we mark the device clean, otherwise > it gets marked dirty. Each time a device is released, if there are > dirty devices we test whether we can try a bus/slot reset to clean them. > In the case of assigning a GPU this typically means that the GPU or > audio function come through first, there's no reset mechanism so it gets > marked dirty, the next device comes through and we manage to try a bus > reset. vfio-pci does not have any device specific resets, all > functionality is added to the PCI-core, thank-you-very-much. I even > posted a generic PCI quirk patch recently that marks AMD VGA PM reset as > bad so that pci_reset_function() won't claim that worked. All VGA > access quirks are done in QEMU, the kernel doesn't have any business in > remapping config space over MMIO regions or trapping other config space > backdoors. Thanks for the info Alex, I hadn't got around to actually looking and the vfio-pci code and was just going to what Sander said. We probably do need to have a more in depth look at now PCI devices and handled by both the toolstack and pciback but in the short term I would like a simple solution that does not extend the ABI. David -- 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/