From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E8142C33C9E for ; Sat, 18 Jan 2020 02:06:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C3E1321D7D for ; Sat, 18 Jan 2020 02:06:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730623AbgARCGX (ORCPT ); Fri, 17 Jan 2020 21:06:23 -0500 Received: from mga11.intel.com ([192.55.52.93]:57680 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727033AbgARCGW (ORCPT ); Fri, 17 Jan 2020 21:06:22 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Jan 2020 18:06:21 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,332,1574150400"; d="scan'208";a="214684983" Received: from allen-box.sh.intel.com (HELO [10.239.159.138]) ([10.239.159.138]) by orsmga007.jf.intel.com with ESMTP; 17 Jan 2020 18:06:19 -0800 Cc: baolu.lu@linux.intel.com, Joerg Roedel , Greg Kroah-Hartman , ashok.raj@intel.com, jacob.jun.pan@intel.com, kevin.tian@intel.com, Christoph Hellwig , Robin Murphy , iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH 2/4] PCI: Add "pci=iommu_passthrough=" parameter for iommu passthrough To: Bjorn Helgaas References: <20200117232403.GA142078@google.com> From: Lu Baolu Message-ID: Date: Sat, 18 Jan 2020 10:04:55 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: <20200117232403.GA142078@google.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Bjorn, On 1/18/20 8:18 AM, Bjorn Helgaas wrote: > On Wed, Jan 01, 2020 at 01:26:46PM +0800, Lu Baolu wrote: >> The new parameter takes a list of devices separated by a semicolon. >> Each device specified will have its iommu_passthrough bit in struct >> device set. This is very similar to the existing 'disable_acs_redir' >> parameter. >> >> Signed-off-by: Lu Baolu >> --- >> .../admin-guide/kernel-parameters.txt | 5 +++ >> drivers/pci/pci.c | 34 +++++++++++++++++++ >> drivers/pci/pci.h | 1 + >> drivers/pci/probe.c | 2 ++ >> 4 files changed, 42 insertions(+) >> >> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt >> index ade4e6ec23e0..d3edc2cb6696 100644 >> --- a/Documentation/admin-guide/kernel-parameters.txt >> +++ b/Documentation/admin-guide/kernel-parameters.txt >> @@ -3583,6 +3583,11 @@ >> may put more devices in an IOMMU group. >> force_floating [S390] Force usage of floating interrupts. >> nomio [S390] Do not use MIO instructions. >> + iommu_passthrough=[; ...] >> + Specify one or more PCI devices (in the format >> + specified above) separated by semicolons. >> + Each device specified will bypass IOMMU DMA >> + translation. >> >> pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power >> Management. >> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c >> index 90dbd7c70371..05bf3f4acc36 100644 >> --- a/drivers/pci/pci.c >> +++ b/drivers/pci/pci.c >> @@ -6401,6 +6401,37 @@ void __weak pci_fixup_cardbus(struct pci_bus *bus) >> } >> EXPORT_SYMBOL(pci_fixup_cardbus); >> >> +static const char *iommu_passthrough_param; >> +bool pci_iommu_passthrough_match(struct pci_dev *dev) >> +{ >> + int ret = 0; >> + const char *p = iommu_passthrough_param; >> + >> + if (!p) >> + return false; >> + >> + while (*p) { >> + ret = pci_dev_str_match(dev, p, &p); >> + if (ret < 0) { >> + pr_info_once("PCI: Can't parse iommu_passthrough parameter: %s\n", >> + iommu_passthrough_param); >> + >> + break; >> + } else if (ret == 1) { >> + pci_info(dev, "PCI: IOMMU passthrough\n"); >> + return true; >> + } >> + >> + if (*p != ';' && *p != ',') { >> + /* End of param or invalid format */ >> + break; >> + } >> + p++; >> + } >> + >> + return false; >> +} > > This duplicates a lot of the code in pci_disable_acs_redir(). That > needs to be factored out somehow so we don't duplicate it. > Sure. I will try to refactor the code in the next version. > Bjorn > Best regards, baolu