From: David Stevens <stevensd@chromium.org> To: Robin Murphy <robin.murphy@arm.com>, Christoph Hellwig <hch@lst.de> Cc: Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>, Lu Baolu <baolu.lu@linux.intel.com>, Tom Murphy <murphyt7@tcd.ie>, Rajat Jain <rajatja@google.com>, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, David Stevens <stevensd@chromium.org> Subject: [PATCH v8 2/7] dma-iommu: fix arch_sync_dma for map Date: Wed, 29 Sep 2021 11:32:55 +0900 [thread overview] Message-ID: <20210929023300.335969-3-stevensd@google.com> (raw) In-Reply-To: <20210929023300.335969-1-stevensd@google.com> From: David Stevens <stevensd@chromium.org> When calling arch_sync_dma, we need to pass it the memory that's actually being used for dma. When using swiotlb bounce buffers, this is the bounce buffer. Move arch_sync_dma into the __iommu_dma_map_swiotlb helper, so it can use the bounce buffer address if necessary. Now that iommu_dma_map_sg delegates to a function which takes care of architectural syncing in the untrusted device case, the call to iommu_dma_sync_sg_for_device can be moved so it only occurs for trusted devices. Doing the sync for untrusted devices before mapping never really worked, since it needs to be able to target swiotlb buffers. This also moves the architectural sync to before the call to __iommu_dma_map, to guarantee that untrusted devices can't see stale data they shouldn't see. Fixes: 82612d66d51d ("iommu: Allow the dma-iommu api to use bounce buffers") Signed-off-by: David Stevens <stevensd@chromium.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Robin Murphy <robin.murphy@arm.com> --- drivers/iommu/dma-iommu.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index c4d205b63c58..19bebacbf178 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -593,6 +593,9 @@ static dma_addr_t __iommu_dma_map_swiotlb(struct device *dev, phys_addr_t phys, memset(padding_start, 0, padding_size); } + if (!coherent && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + arch_sync_dma_for_device(phys, org_size, dir); + iova = __iommu_dma_map(dev, phys, aligned_size, prot, dma_mask); if (iova == DMA_MAPPING_ERROR && is_swiotlb_buffer(dev, phys)) swiotlb_tbl_unmap_single(dev, phys, org_size, dir, attrs); @@ -860,14 +863,9 @@ static dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page, { phys_addr_t phys = page_to_phys(page) + offset; bool coherent = dev_is_dma_coherent(dev); - dma_addr_t dma_handle; - dma_handle = __iommu_dma_map_swiotlb(dev, phys, size, dma_get_mask(dev), + return __iommu_dma_map_swiotlb(dev, phys, size, dma_get_mask(dev), coherent, dir, attrs); - if (!coherent && !(attrs & DMA_ATTR_SKIP_CPU_SYNC) && - dma_handle != DMA_MAPPING_ERROR) - arch_sync_dma_for_device(phys, size, dir); - return dma_handle; } static void iommu_dma_unmap_page(struct device *dev, dma_addr_t dma_handle, @@ -1012,12 +1010,12 @@ static int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg, goto out; } - if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) - iommu_dma_sync_sg_for_device(dev, sg, nents, dir); - if (dev_is_untrusted(dev)) return iommu_dma_map_sg_swiotlb(dev, sg, nents, dir, attrs); + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + iommu_dma_sync_sg_for_device(dev, sg, nents, dir); + /* * Work out how much IOVA space we need, and align the segments to * IOVA granules for the IOMMU driver to handle. With some clever -- 2.33.0.685.g46640cef36-goog
WARNING: multiple messages have this Message-ID (diff)
From: David Stevens <stevensd@chromium.org> To: Robin Murphy <robin.murphy@arm.com>, Christoph Hellwig <hch@lst.de> Cc: linux-kernel@vger.kernel.org, Tom Murphy <murphyt7@tcd.ie>, iommu@lists.linux-foundation.org, David Stevens <stevensd@chromium.org>, Rajat Jain <rajatja@google.com>, Will Deacon <will@kernel.org> Subject: [PATCH v8 2/7] dma-iommu: fix arch_sync_dma for map Date: Wed, 29 Sep 2021 11:32:55 +0900 [thread overview] Message-ID: <20210929023300.335969-3-stevensd@google.com> (raw) In-Reply-To: <20210929023300.335969-1-stevensd@google.com> From: David Stevens <stevensd@chromium.org> When calling arch_sync_dma, we need to pass it the memory that's actually being used for dma. When using swiotlb bounce buffers, this is the bounce buffer. Move arch_sync_dma into the __iommu_dma_map_swiotlb helper, so it can use the bounce buffer address if necessary. Now that iommu_dma_map_sg delegates to a function which takes care of architectural syncing in the untrusted device case, the call to iommu_dma_sync_sg_for_device can be moved so it only occurs for trusted devices. Doing the sync for untrusted devices before mapping never really worked, since it needs to be able to target swiotlb buffers. This also moves the architectural sync to before the call to __iommu_dma_map, to guarantee that untrusted devices can't see stale data they shouldn't see. Fixes: 82612d66d51d ("iommu: Allow the dma-iommu api to use bounce buffers") Signed-off-by: David Stevens <stevensd@chromium.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Robin Murphy <robin.murphy@arm.com> --- drivers/iommu/dma-iommu.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index c4d205b63c58..19bebacbf178 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -593,6 +593,9 @@ static dma_addr_t __iommu_dma_map_swiotlb(struct device *dev, phys_addr_t phys, memset(padding_start, 0, padding_size); } + if (!coherent && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + arch_sync_dma_for_device(phys, org_size, dir); + iova = __iommu_dma_map(dev, phys, aligned_size, prot, dma_mask); if (iova == DMA_MAPPING_ERROR && is_swiotlb_buffer(dev, phys)) swiotlb_tbl_unmap_single(dev, phys, org_size, dir, attrs); @@ -860,14 +863,9 @@ static dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page, { phys_addr_t phys = page_to_phys(page) + offset; bool coherent = dev_is_dma_coherent(dev); - dma_addr_t dma_handle; - dma_handle = __iommu_dma_map_swiotlb(dev, phys, size, dma_get_mask(dev), + return __iommu_dma_map_swiotlb(dev, phys, size, dma_get_mask(dev), coherent, dir, attrs); - if (!coherent && !(attrs & DMA_ATTR_SKIP_CPU_SYNC) && - dma_handle != DMA_MAPPING_ERROR) - arch_sync_dma_for_device(phys, size, dir); - return dma_handle; } static void iommu_dma_unmap_page(struct device *dev, dma_addr_t dma_handle, @@ -1012,12 +1010,12 @@ static int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg, goto out; } - if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) - iommu_dma_sync_sg_for_device(dev, sg, nents, dir); - if (dev_is_untrusted(dev)) return iommu_dma_map_sg_swiotlb(dev, sg, nents, dir, attrs); + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + iommu_dma_sync_sg_for_device(dev, sg, nents, dir); + /* * Work out how much IOVA space we need, and align the segments to * IOVA granules for the IOMMU driver to handle. With some clever -- 2.33.0.685.g46640cef36-goog _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
next prev parent reply other threads:[~2021-09-29 2:33 UTC|newest] Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-09-29 2:32 [PATCH v8 0/7] Fixes for dma-iommu swiotlb bounce buffers David Stevens 2021-09-29 2:32 ` David Stevens 2021-09-29 2:32 ` [PATCH v8 1/7] dma-iommu: fix sync_sg with swiotlb David Stevens 2021-09-29 2:32 ` David Stevens 2021-09-29 2:32 ` David Stevens [this message] 2021-09-29 2:32 ` [PATCH v8 2/7] dma-iommu: fix arch_sync_dma for map David Stevens 2021-09-29 2:32 ` [PATCH v8 3/7] dma-iommu: skip extra sync during unmap w/swiotlb David Stevens 2021-09-29 2:32 ` David Stevens 2021-09-29 2:32 ` [PATCH v8 4/7] dma-iommu: fold _swiotlb helpers into callers David Stevens 2021-09-29 2:32 ` David Stevens 2021-09-29 2:32 ` [PATCH v8 5/7] dma-iommu: Check CONFIG_SWIOTLB more broadly David Stevens 2021-09-29 2:32 ` David Stevens 2021-09-29 2:32 ` [PATCH v8 6/7] swiotlb: support aligned swiotlb buffers David Stevens 2021-09-29 2:32 ` David Stevens 2021-09-29 2:33 ` [PATCH v8 7/7] dma-iommu: account for min_align_mask w/swiotlb David Stevens 2021-09-29 2:33 ` David Stevens
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