From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753718AbdBOXKO (ORCPT ); Wed, 15 Feb 2017 18:10:14 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:53697 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753112AbdBOXKL (ORCPT ); Wed, 15 Feb 2017 18:10:11 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Sainath Grandhi" , "David Woodhouse" , "Ashok Raj" Date: Wed, 15 Feb 2017 22:41:40 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 189/306] iommu/vt-d: Fix IOMMU lookup for SR-IOV Virtual Functions In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.40-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Ashok Raj commit 1c387188c60f53b338c20eee32db055dfe022a9b upstream. The VT-d specification (§8.3.3) says: ‘Virtual Functions’ of a ‘Physical Function’ are under the scope of the same remapping unit as the ‘Physical Function’. The BIOS is not required to list all the possible VFs in the scope tables, and arguably *shouldn't* make any attempt to do so, since there could be a huge number of them. This has been broken basically for ever — the VF is never going to match against a specific unit's scope, so it ends up being assigned to the INCLUDE_ALL IOMMU. Which was always actually correct by coincidence, but now we're looking at Root-Complex integrated devices with SR-IOV support it's going to start being wrong. Fix it to simply use pci_physfn() before doing the lookup for PCI devices. Signed-off-by: Sainath Grandhi Signed-off-by: Ashok Raj Signed-off-by: David Woodhouse Signed-off-by: Ben Hutchings --- drivers/iommu/dmar.c | 4 +++- drivers/iommu/intel-iommu.c | 13 +++++++++++++ 2 files changed, 16 insertions(+), 1 deletion(-) --- a/drivers/iommu/dmar.c +++ b/drivers/iommu/dmar.c @@ -299,7 +299,9 @@ static int dmar_pci_bus_notifier(struct struct pci_dev *pdev = to_pci_dev(data); struct dmar_pci_notify_info *info; - /* Only care about add/remove events for physical functions */ + /* Only care about add/remove events for physical functions. + * For VFs we actually do the lookup based on the corresponding + * PF in device_to_iommu() anyway. */ if (pdev->is_virtfn) return NOTIFY_DONE; if (action != BUS_NOTIFY_ADD_DEVICE && action != BUS_NOTIFY_DEL_DEVICE) --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -684,7 +684,13 @@ static struct intel_iommu *device_to_iom return NULL; if (dev_is_pci(dev)) { + struct pci_dev *pf_pdev; + pdev = to_pci_dev(dev); + /* VFs aren't listed in scope tables; we need to look up + * the PF instead to find the IOMMU. */ + pf_pdev = pci_physfn(pdev); + dev = &pf_pdev->dev; segment = pci_domain_nr(pdev->bus); } else if (ACPI_COMPANION(dev)) dev = &ACPI_COMPANION(dev)->dev; @@ -697,6 +703,13 @@ static struct intel_iommu *device_to_iom for_each_active_dev_scope(drhd->devices, drhd->devices_cnt, i, tmp) { if (tmp == dev) { + /* For a VF use its original BDF# not that of the PF + * which we used for the IOMMU lookup. Strictly speaking + * we could do this for all PCI devices; we only need to + * get the BDF# from the scope table for ACPI matches. */ + if (pdev->is_virtfn) + goto got_pdev; + *bus = drhd->devices[i].bus; *devfn = drhd->devices[i].devfn; goto out;