[PATCH AUTOSEL 4.18 018/136] iommu/amd: make sure TLB to be flushed before IOVA freed

From: Sasha Levin
Date: Sun Sep 16 2018 - 23:37:07 EST


From: Zhen Lei <thunder.leizhen@xxxxxxxxxx>

[ Upstream commit 3c120143f584360a13614787e23ae2cdcb5e5ccd ]

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>
Fixes: b1516a14657a ('iommu/amd: Implement flush queue')
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
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 596b95c50051..d77c97fe4a23 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -2405,9 +2405,9 @@ 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);
--
2.17.1