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

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

[Zhen Lei]

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@huawei.com>
---
 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

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

[Leizhen (ThunderTown)]

Hi Joerg:
  Can you take a look at it?


On 2018/6/6 10:18, Zhen Lei wrote:
> 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-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
> ---
>  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
> 
> 
> 
> .
> 

-- 
Thanks!
BestRegards

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

[Joerg Roedel]

On Wed, Jun 06, 2018 at 10:18:46AM +0800, Zhen Lei wrote:
> 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@huawei.com>
> ---
>  drivers/iommu/amd_iommu.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Applied, thanks.