Messages in this thread Patch in this message | | | From | Sven Peter <> | Subject | [PATCH v2 1/8] iommu/dma: Align size for untrusted devs to IOVA granule | Date | Sat, 28 Aug 2021 17:36:35 +0200 |
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Up until now PAGE_SIZE was always a multiple of iovad->granule such that adjacent pages were never exposed to untrusted devices due to allocations done as part of the coherent DMA API. With PAGE_SIZE < iovad->granule however all these allocations must also be aligned to iovad->granule.
Signed-off-by: Sven Peter <sven@svenpeter.dev> --- drivers/iommu/dma-iommu.c | 40 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 39 insertions(+), 1 deletion(-)
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index d0bc8c06e1a4..e8eae34e9e4f 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -735,10 +735,16 @@ static void *iommu_dma_alloc_remap(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t gfp, pgprot_t prot, unsigned long attrs) { + struct iommu_domain *domain = iommu_get_dma_domain(dev); + struct iommu_dma_cookie *cookie = domain->iova_cookie; + struct iova_domain *iovad = &cookie->iovad; struct page **pages; struct sg_table sgt; void *vaddr; + if (dev_is_untrusted(dev)) + size = iova_align(iovad, size); + pages = __iommu_dma_alloc_noncontiguous(dev, size, &sgt, gfp, prot, attrs); if (!pages) @@ -762,12 +768,18 @@ static struct sg_table *iommu_dma_alloc_noncontiguous(struct device *dev, size_t size, enum dma_data_direction dir, gfp_t gfp, unsigned long attrs) { + struct iommu_domain *domain = iommu_get_dma_domain(dev); + struct iommu_dma_cookie *cookie = domain->iova_cookie; + struct iova_domain *iovad = &cookie->iovad; struct dma_sgt_handle *sh; sh = kmalloc(sizeof(*sh), gfp); if (!sh) return NULL; + if (dev_is_untrusted(dev)) + size = iova_align(iovad, size); + sh->pages = __iommu_dma_alloc_noncontiguous(dev, size, &sh->sgt, gfp, PAGE_KERNEL, attrs); if (!sh->pages) { @@ -780,8 +792,15 @@ static struct sg_table *iommu_dma_alloc_noncontiguous(struct device *dev, static void iommu_dma_free_noncontiguous(struct device *dev, size_t size, struct sg_table *sgt, enum dma_data_direction dir) { + struct iommu_domain *domain = iommu_get_dma_domain(dev); + struct iommu_dma_cookie *cookie = domain->iova_cookie; + struct iova_domain *iovad = &cookie->iovad; struct dma_sgt_handle *sh = sgt_handle(sgt); + + if (dev_is_untrusted(dev)) + size = iova_align(iovad, size); + __iommu_dma_unmap(dev, sgt->sgl->dma_address, size); __iommu_dma_free_pages(sh->pages, PAGE_ALIGN(size) >> PAGE_SHIFT); sg_free_table(&sh->sgt); @@ -1127,10 +1146,17 @@ static void iommu_dma_unmap_resource(struct device *dev, dma_addr_t handle, static void __iommu_dma_free(struct device *dev, size_t size, void *cpu_addr) { + struct iommu_domain *domain = iommu_get_dma_domain(dev); + struct iommu_dma_cookie *cookie = domain->iova_cookie; + struct iova_domain *iovad = &cookie->iovad; size_t alloc_size = PAGE_ALIGN(size); - int count = alloc_size >> PAGE_SHIFT; + int count; struct page *page = NULL, **pages = NULL; + if (dev_is_untrusted(dev)) + alloc_size = iova_align(iovad, alloc_size); + count = alloc_size >> PAGE_SHIFT; + /* Non-coherent atomic allocation? Easy */ if (IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) && dma_free_from_pool(dev, cpu_addr, alloc_size)) @@ -1166,12 +1192,18 @@ static void iommu_dma_free(struct device *dev, size_t size, void *cpu_addr, static void *iommu_dma_alloc_pages(struct device *dev, size_t size, struct page **pagep, gfp_t gfp, unsigned long attrs) { + struct iommu_domain *domain = iommu_get_dma_domain(dev); + struct iommu_dma_cookie *cookie = domain->iova_cookie; + struct iova_domain *iovad = &cookie->iovad; bool coherent = dev_is_dma_coherent(dev); size_t alloc_size = PAGE_ALIGN(size); int node = dev_to_node(dev); struct page *page = NULL; void *cpu_addr; + if (dev_is_untrusted(dev)) + alloc_size = iova_align(iovad, alloc_size); + page = dma_alloc_contiguous(dev, alloc_size, gfp); if (!page) page = alloc_pages_node(node, gfp, get_order(alloc_size)); @@ -1203,6 +1235,9 @@ static void *iommu_dma_alloc_pages(struct device *dev, size_t size, static void *iommu_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp, unsigned long attrs) { + struct iommu_domain *domain = iommu_get_dma_domain(dev); + struct iommu_dma_cookie *cookie = domain->iova_cookie; + struct iova_domain *iovad = &cookie->iovad; bool coherent = dev_is_dma_coherent(dev); int ioprot = dma_info_to_prot(DMA_BIDIRECTIONAL, coherent, attrs); struct page *page = NULL; @@ -1216,6 +1251,9 @@ static void *iommu_dma_alloc(struct device *dev, size_t size, dma_pgprot(dev, PAGE_KERNEL, attrs), attrs); } + if (dev_is_untrusted(dev)) + size = iova_align(iovad, size); + if (IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) && !gfpflags_allow_blocking(gfp) && !coherent) page = dma_alloc_from_pool(dev, PAGE_ALIGN(size), &cpu_addr, -- 2.25.1
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