From 1c387188c60f53b338c20eee32db055dfe022a9b Mon Sep 17 00:00:00 2001 From: Ashok Raj Date: Fri, 21 Oct 2016 15:32:05 -0700 Subject: [PATCH] iommu/vt-d: Fix IOMMU lookup for SR-IOV Virtual Functions MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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. Cc: stable@vger.kernel.org Signed-off-by: Sainath Grandhi Signed-off-by: Ashok Raj Signed-off-by: David Woodhouse --- drivers/iommu/dmar.c | 4 +++- drivers/iommu/intel-iommu.c | 13 +++++++++++++ 2 files changed, 16 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c index 58470f5ced04..8c53748a769d 100644 --- a/drivers/iommu/dmar.c +++ b/drivers/iommu/dmar.c @@ -338,7 +338,9 @@ static int dmar_pci_bus_notifier(struct notifier_block *nb, 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 && diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index a4407eabf0e6..2723090a0d54 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -892,7 +892,13 @@ static struct intel_iommu *device_to_iommu(struct device *dev, u8 *bus, u8 *devf 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 (has_acpi_companion(dev)) dev = &ACPI_COMPANION(dev)->dev; @@ -905,6 +911,13 @@ static struct intel_iommu *device_to_iommu(struct device *dev, u8 *bus, u8 *devf 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; -- 2.20.1