iommu/vt-d: Fix missing IOTLB flush in intel_iommu_unmap()

Based on commit ea8ea460c9ace60bbb5ac6e5521d637d5c15293d upstream

This missing IOTLB flush was added as a minor, inconsequential bug-fix
in commit ea8ea460c ("iommu/vt-d: Clean up and fix page table clear/free
behaviour") in 3.15. It wasn't originally intended for -stable but a
couple of users have reported issues which turn out to be fixed by
adding the missing flush.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index a22c86c..40f6b47 100644 (file)
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -4075,7 +4075,7 @@ static size_t intel_iommu_unmap(struct iommu_domain *domain,
                             unsigned long iova, size_t size)
 {
        struct dmar_domain *dmar_domain = domain->priv;
-       int order;
+       int order, iommu_id;
 
        order = dma_pte_clear_range(dmar_domain, iova >> VTD_PAGE_SHIFT,
                            (iova + size - 1) >> VTD_PAGE_SHIFT);
@@ -4083,6 +4083,22 @@ static size_t intel_iommu_unmap(struct iommu_domain *domain,
        if (dmar_domain->max_addr == iova + size)
                dmar_domain->max_addr = iova;
 
+       for_each_set_bit(iommu_id, dmar_domain->iommu_bmp, g_num_of_iommus) {
+               struct intel_iommu *iommu = g_iommus[iommu_id];
+               int num, ndomains;
+
+               /*
+                * find bit position of dmar_domain
+                */
+               ndomains = cap_ndoms(iommu->cap);
+               for_each_set_bit(num, iommu->domain_ids, ndomains) {
+                       if (iommu->domains[num] == dmar_domain)
+                               iommu_flush_iotlb_psi(iommu, num,
+                                                     iova >> VTD_PAGE_SHIFT,
+                                                     1 << order, 0);
+               }
+       }
+
        return PAGE_SIZE << order;
 }