From 5ae0566a0fffa09a77ac5996e3854fe91cd87167 Mon Sep 17 00:00:00 2001 From: Jiang Liu Date: Tue, 15 Apr 2014 10:35:35 +0800 Subject: [PATCH] iommu/vt-d: fix bug in matching PCI devices with DRHD/RMRR descriptors 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 Signed-off-by: Jiang Liu Signed-off-by: David Woodhouse --- 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)) -- 2.20.1