Commit "59ce0515cdaf iommu/vt-d: Update DRHD/RMRR/ATSR device scope
caches when PCI hotplug happens" introduces a bug, which fails to
match PCI devices with DMAR device scope entries if PCI path array
in the entry has more than one level.
For example, it fails to handle
[1D2h 0466 1] Device Scope Entry Type : 01
[1D3h 0467 1] Entry Length : 0A
[1D4h 0468 2] Reserved : 0000
[1D6h 0470 1] Enumeration ID : 00
[1D7h 0471 1] PCI Bus Number : 00
[1D8h 0472 2] PCI Path : 1C,04
[1DAh 0474 2] PCI Path : 00,02
And cause DMA failure on HP DL980 as:
DMAR:[fault reason 02] Present bit in context entry is clear
dmar: DRHD: handling fault status reg 602
dmar: DMAR:[DMA Read] Request device [02:00.2] fault addr 7f61e000
Reported-and-tested-by: Davidlohr Bueso <davidlohr@xxxxxx>
Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx>
---
Hi David and Davidlohr,
I have made minor syntax change to the patch, but there should be no
functional change.
Thanks!
Gerry
---
drivers/iommu/dmar.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index f445c10df8df..39f8b717fe84 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -152,7 +152,8 @@ dmar_alloc_pci_notify_info(struct pci_dev *dev, unsigned long event)
info->seg = pci_domain_nr(dev->bus);
info->level = level;
if (event == BUS_NOTIFY_ADD_DEVICE) {
- for (tmp = dev, level--; tmp; tmp = tmp->bus->self) {
+ for (tmp = dev; tmp; tmp = tmp->bus->self) {
+ level--;
info->path[level].device = PCI_SLOT(tmp->devfn);
info->path[level].function = PCI_FUNC(tmp->devfn);
if (pci_is_root_bus(tmp->bus))
--
1.7.10.4
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