Messages in this thread | | | Subject | Re: [PATCH v2 00/10] iommu/vt-d: Bounce buffer for untrusted devices | From | Lu Baolu <> | Date | Thu, 28 Mar 2019 14:33:04 +0800 |
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Hi,
On 3/27/19 2:48 PM, Christoph Hellwig wrote: > On Wed, Mar 27, 2019 at 02:34:56PM +0800, Lu Baolu wrote: >> - During the v1 review cycle, we discussed the possibility >> of reusing swiotlb code to avoid code dumplication, but >> we found the swiotlb implementations are not ready for the >> use of bounce page pool. >> https://lkml.org/lkml/2019/3/19/259 > > So make it ready. You too can contribute to common code. Robin > also explicitly asked to make the bounce policy iommu-subsystem wide. >
Sure. I am glad to make the code common. I will try to make it with a new version.
For the swiotlb APIs, I am thinking about keeping current APIs untouched and adding below new ones for bounce page.
/** * swiotlb_bounce_page_map - create a bounce page mapping * @dev: the device * @phys: the physical address of the buffer requiring bounce * @size: the size of the buffer * @align: IOMMU page align * @dir: DMA direction * @attrs: DMA attributions * * This creates a swiotlb bounce page mapping for the buffer at @phys, * and in case of DMAing to the device copy the data into it as well. * Return the tlb addr on success, otherwise DMA_MAPPING_ERROR. */ dma_addr_t swiotlb_bounce_page_map(struct device *dev, phys_addr_t phys, size_t size, unsigned long align, enum dma_data_direction dir, unsigned long attrs) { return 0; }
/** * swiotlb_bounce_page_unmap - destroy a bounce page mapping * @dev: the device * @tlb_addr: the tlb address of the buffer requiring bounce * @size: the size of the buffer * @align: IOMMU page align * @dir: DMA direction * @attrs: DMA attributions * * This destroys a swiotlb bounce page mapping for the buffer at @tlb_addr, * and in case of DMAing from the device copy the data from it as well. */ void swiotlb_bounce_page_unmap(struct device *dev, phys_addr_t tlb_addr, size_t size, unsigned long align, enum dma_data_direction dir, unsigned long attrs) { }
/** * swiotlb_bounce_page_sync - sync bounce page mapping * @dev: the device * @tlb_addr: the tlb address of the buffer requiring bounce * @size: the size of the buffer * @align: IOMMU page align * @dir: DMA direction * @attrs: DMA attributions * * This syncs a swiotlb bounce page mapping for the buffer at @tlb_addr. */ void swiotlb_bounce_page_sync(struct device *dev, phys_addr_t tlb_addr, size_t size, unsigned long align, enum dma_data_direction dir, unsigned long attrs) { }
Any comments?
Best regards, Lu Baolu
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