iommu/vt-d: Really use upper context table when necessary

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>

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 0649b94f59584ca5b885cd0ecad595a84af0d89d..7553cb90627fc12756af63609906c03d55e5d4c6 100644 (file)
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -755,6 +755,7 @@ static inline struct context_entry *iommu_context_addr(struct intel_iommu *iommu
        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 *iommu_context_addr(struct intel_iommu *iommu
                }
                devfn *= 2;
        }
-       entry = &root->lo;
        if (*entry & 1)
                context = phys_to_virt(*entry & VTD_PAGE_MASK);
        else {