[PATCH] Fix bug in iommu_context_addr: Always get pointer to lower extended-context-table

From: Xiao, Nan (Nan@HPS Performance, Beijing)
Date: Mon Aug 24 2015 - 02:26:59 EST


Hi David & joerg,

In iommu_context_addr() function, we always use lower extended-context-table
even though upper-half of the extended root-entry is present.

Signed-off-by: Nan Xiao <nan.xiao@xxxxxx>
---
drivers/iommu/intel-iommu.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 0649b94..4213598 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -759,10 +759,11 @@ static inline struct context_entry *iommu_context_addr(struct intel_iommu *iommu
if (devfn >= 0x80) {
devfn -= 0x80;
entry = &root->hi;
- }
+ } else
+ entry = &root->lo;
devfn *= 2;
- }
- entry = &root->lo;
+ } else
+ entry = &root->lo;
if (*entry & 1)
context = phys_to_virt(*entry & VTD_PAGE_MASK);
else {
--
2.4.3

Best Regards
Nan Xiao

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