[PATCH 4.2 114/134] iommu/vt-d: Really use upper context table when necessary

Greg Kroah-Hartman
2015-09-26T22:01:34Z

From: Joerg Roedel <jroedel@suse.de>

commit 4df4eab168c1c4058603be55a3169d4a45779cc0 upstream.

There is a bug in iommu_context_addr() which will always use
the lower context table, even when the upper context table
needs to be used. Fix this issue.

Fixes: 03ecc32c5274 ("iommu/vt-d: support extended root and context entries")
Reported-by: Xiao, Nan <nan.xiao@hp.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/iommu/intel-iommu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -755,6 +755,7 @@ static inline struct context_entry *iomm
struct context_entry *context;
u64 *entry;

+ entry = &root->lo;
if (ecs_enabled(iommu)) {
if (devfn >= 0x80) {
devfn -= 0x80;
@@ -762,7 +763,6 @@ static inline struct context_entry *iomm
}
devfn *= 2;
}
- entry = &root->lo;
if (*entry & 1)
context = phys_to_virt(*entry & VTD_PAGE_MASK);
else {