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9c6fd700 GKH |
1 | From 1c387188c60f53b338c20eee32db055dfe022a9b Mon Sep 17 00:00:00 2001 |
2 | From: Ashok Raj <ashok.raj@intel.com> | |
3 | Date: Fri, 21 Oct 2016 15:32:05 -0700 | |
4 | Subject: iommu/vt-d: Fix IOMMU lookup for SR-IOV Virtual Functions | |
5 | MIME-Version: 1.0 | |
6 | Content-Type: text/plain; charset=UTF-8 | |
7 | Content-Transfer-Encoding: 8bit | |
8 | ||
9 | From: Ashok Raj <ashok.raj@intel.com> | |
10 | ||
11 | commit 1c387188c60f53b338c20eee32db055dfe022a9b upstream. | |
12 | ||
13 | The VT-d specification (§8.3.3) says: | |
14 | ‘Virtual Functions’ of a ‘Physical Function’ are under the scope | |
15 | of the same remapping unit as the ‘Physical Function’. | |
16 | ||
17 | The BIOS is not required to list all the possible VFs in the scope | |
18 | tables, and arguably *shouldn't* make any attempt to do so, since there | |
19 | could be a huge number of them. | |
20 | ||
21 | This has been broken basically for ever — the VF is never going to match | |
22 | against a specific unit's scope, so it ends up being assigned to the | |
23 | INCLUDE_ALL IOMMU. Which was always actually correct by coincidence, but | |
24 | now we're looking at Root-Complex integrated devices with SR-IOV support | |
25 | it's going to start being wrong. | |
26 | ||
27 | Fix it to simply use pci_physfn() before doing the lookup for PCI devices. | |
28 | ||
29 | Signed-off-by: Sainath Grandhi <sainath.grandhi@intel.com> | |
30 | Signed-off-by: Ashok Raj <ashok.raj@intel.com> | |
31 | Signed-off-by: David Woodhouse <dwmw2@infradead.org> | |
32 | Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> | |
33 | ||
34 | --- | |
35 | drivers/iommu/dmar.c | 4 +++- | |
36 | drivers/iommu/intel-iommu.c | 13 +++++++++++++ | |
37 | 2 files changed, 16 insertions(+), 1 deletion(-) | |
38 | ||
39 | --- a/drivers/iommu/dmar.c | |
40 | +++ b/drivers/iommu/dmar.c | |
41 | @@ -326,7 +326,9 @@ static int dmar_pci_bus_notifier(struct | |
42 | struct pci_dev *pdev = to_pci_dev(data); | |
43 | struct dmar_pci_notify_info *info; | |
44 | ||
45 | - /* Only care about add/remove events for physical functions */ | |
46 | + /* Only care about add/remove events for physical functions. | |
47 | + * For VFs we actually do the lookup based on the corresponding | |
48 | + * PF in device_to_iommu() anyway. */ | |
49 | if (pdev->is_virtfn) | |
50 | return NOTIFY_DONE; | |
51 | if (action != BUS_NOTIFY_ADD_DEVICE && | |
52 | --- a/drivers/iommu/intel-iommu.c | |
53 | +++ b/drivers/iommu/intel-iommu.c | |
54 | @@ -885,7 +885,13 @@ static struct intel_iommu *device_to_iom | |
55 | return NULL; | |
56 | ||
57 | if (dev_is_pci(dev)) { | |
58 | + struct pci_dev *pf_pdev; | |
59 | + | |
60 | pdev = to_pci_dev(dev); | |
61 | + /* VFs aren't listed in scope tables; we need to look up | |
62 | + * the PF instead to find the IOMMU. */ | |
63 | + pf_pdev = pci_physfn(pdev); | |
64 | + dev = &pf_pdev->dev; | |
65 | segment = pci_domain_nr(pdev->bus); | |
66 | } else if (has_acpi_companion(dev)) | |
67 | dev = &ACPI_COMPANION(dev)->dev; | |
68 | @@ -898,6 +904,13 @@ static struct intel_iommu *device_to_iom | |
69 | for_each_active_dev_scope(drhd->devices, | |
70 | drhd->devices_cnt, i, tmp) { | |
71 | if (tmp == dev) { | |
72 | + /* For a VF use its original BDF# not that of the PF | |
73 | + * which we used for the IOMMU lookup. Strictly speaking | |
74 | + * we could do this for all PCI devices; we only need to | |
75 | + * get the BDF# from the scope table for ACPI matches. */ | |
76 | + if (pdev->is_virtfn) | |
77 | + goto got_pdev; | |
78 | + | |
79 | *bus = drhd->devices[i].bus; | |
80 | *devfn = drhd->devices[i].devfn; | |
81 | goto out; |