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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 1880DC282CB for ; Tue, 5 Feb 2019 23:57:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DA1672073D for ; Tue, 5 Feb 2019 23:57:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726558AbfBEX5A (ORCPT ); Tue, 5 Feb 2019 18:57:00 -0500 Received: from mga17.intel.com ([192.55.52.151]:2258 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727524AbfBEX5A (ORCPT ); Tue, 5 Feb 2019 18:57:00 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 05 Feb 2019 15:56:59 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.58,337,1544515200"; d="scan'208";a="131860291" Received: from jacob-builder.jf.intel.com (HELO jacob-builder) ([10.7.199.155]) by orsmga002.jf.intel.com with ESMTP; 05 Feb 2019 15:56:59 -0800 Date: Tue, 5 Feb 2019 15:58:59 -0800 From: Jacob Pan To: Logan Gunthorpe Cc: Joerg Roedel , Allen Hubbe , Dave Jiang , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Serge Semin , Eric Pilmore , iommu@lists.linux-foundation.org, linux-kselftest@vger.kernel.org, Bjorn Helgaas , linux-ntb@googlegroups.com, David Woodhouse , jacob.jun.pan@linux.intel.com Subject: Re: [PATCH 1/9] iommu/vt-d: Allow interrupts from the entire bus for aliased devices Message-ID: <20190205155859.0e96dd4f@jacob-builder> In-Reply-To: References: <20190131185656.17972-1-logang@deltatee.com> <20190131185656.17972-2-logang@deltatee.com> <20190201164401.GT32526@8bytes.org> <398e6a0a-9cbd-c218-e20e-ed91f74a653d@deltatee.com> <20190205111939.6f91739e@jacob-builder> Organization: OTC X-Mailer: Claws Mail 3.13.2 (GTK+ 2.24.30; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Tue, 5 Feb 2019 13:40:36 -0700 Logan Gunthorpe wrote: > On 2019-02-05 12:19 p.m., Jacob Pan wrote: > > On Fri, 1 Feb 2019 10:27:29 -0700 > > Logan Gunthorpe wrote: > > > >> On 2019-02-01 9:44 a.m., Joerg Roedel wrote: > >>> On Thu, Jan 31, 2019 at 11:56:48AM -0700, Logan Gunthorpe > >>> wrote: > >>>> @@ -394,6 +402,10 @@ static int set_msi_sid(struct irte *irte, > >>>> struct pci_dev *dev) set_irte_sid(irte, SVT_VERIFY_BUS, > >>>> SQ_ALL_16, PCI_DEVID(PCI_BUS_NUM(data.alias), > >>>> dev->bus->number)); > > I guess devfn can be removed also. but that is separate cleanup. > > Actually, no, I've dug into this and we *do* need the devfn here but > it's needlessly confusing. We should not be using PCI_DEVID() as we > aren't actually representing a DEVID in this case... > > According to the Intel VT-D spec, when using SVT_VERIFY_BUS, the MSB > of the SID field represents the starting bus number and the LSB > represents the end bus number. The requester id's bus number must > then be within that range. The PCI_DEVID macro matches these > semantics if you assume the devfn is the end bus, but doesn't really > make sense here and just confuses the issue. > > So the code was correct, I'll just try to clean it up to make it less > confusing. > you are right, thanks for explaining. > Thanks, > > Logan