From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:22567 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755238Ab3E1Txj (ORCPT ); Tue, 28 May 2013 15:53:39 -0400 Message-ID: <1369770790.2646.272.camel@ul30vt.home> Subject: Re: [PATCH v2 1/2] iommu: Quirked PCIe bridge test and search function From: Alex Williamson To: Stephen Hemminger Cc: iommu@lists.linux-foundation.org, dwmw2@infradead.org, joro@8bytes.org, linux-pci@vger.kernel.org, ddutile@redhat.com Date: Tue, 28 May 2013 13:53:10 -0600 In-Reply-To: <20130528123827.2507c34e@nehalam.linuxnetplumber.net> References: <20130528183527.3318.5365.stgit@bling.home> <20130528184020.3318.7800.stgit@bling.home> <20130528123827.2507c34e@nehalam.linuxnetplumber.net> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Sender: linux-pci-owner@vger.kernel.org List-ID: On Tue, 2013-05-28 at 12:38 -0700, Stephen Hemminger wrote: > On Tue, 28 May 2013 12:40:20 -0600 > Alex Williamson wrote: > > > Some PCIe-to-PCI bridges are not fully compliant with the PCIe spec > > and do not include a PCIe capability. pci_is_pcie() is not useful on > > these devices, making it difficult to determine where we transition > > from a legacy PCI bus to a PCIe link. PCI-core doesn't want a quirked > > bridge test for fear of confusion that a PCIe capability would be > > expected, so implement it in IOMMU code. > > > > Signed-off-by: Alex Williamson > > This won't work for me because I run without IOMMU. > The overhead of IOMMU setup per-packet significantly impacts network performance. You were one of the reporters of this issue: http://www.spinics.net/lists/linux-pci/msg19579.html Does this not work for you or are you saying this is not relevant to you because you no longer attempt to enable the IOMMU? Thanks, Alex