[PATCH 1/1] iommu/amd: make sure TLB to be flushed before IOVA freed

From: Zhen Lei
Date: Tue Jun 05 2018 - 22:20:53 EST


Although the mapping has already been removed in the page table, it maybe
still exist in TLB. Suppose the freed IOVAs is reused by others before the
flush operation completed, the new user can not correctly access to its
meomory.

Signed-off-by: Zhen Lei <thunder.leizhen@xxxxxxxxxx>
---
drivers/iommu/amd_iommu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 8fb8c73..93aa389 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -2402,9 +2402,9 @@ static void __unmap_single(struct dma_ops_domain *dma_dom,
}

if (amd_iommu_unmap_flush) {
- dma_ops_free_iova(dma_dom, dma_addr, pages);
domain_flush_tlb(&dma_dom->domain);
domain_flush_complete(&dma_dom->domain);
+ dma_ops_free_iova(dma_dom, dma_addr, pages);
} else {
pages = __roundup_pow_of_two(pages);
queue_iova(&dma_dom->iovad, dma_addr >> PAGE_SHIFT, pages, 0);
--
1.8.3