and ofc shortly after submitting this series I realized this doesn't quite work yet: swiotlb_tbl_map_single can return a 16KB buffer that's only aligned to a 4KB boundary. v3 will need at least another change to ensure that the result will be aligned to a 16KB boundary as well.
Sven On Sat, Aug 28, 2021, at 17:36, Sven Peter wrote: > If swiotlb is enabled we should never try to create any mappings that > would expose more memory than requested to the device. > WARN_ON and refuse those mappings just in case. > > Signed-off-by: Sven Peter <s...@svenpeter.dev> > --- > drivers/iommu/dma-iommu.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c > index e8eae34e9e4f..d6e273ec3de6 100644 > --- a/drivers/iommu/dma-iommu.c > +++ b/drivers/iommu/dma-iommu.c > @@ -534,13 +534,20 @@ static dma_addr_t __iommu_dma_map(struct device > *dev, phys_addr_t phys, > struct iommu_dma_cookie *cookie = domain->iova_cookie; > struct iova_domain *iovad = &cookie->iovad; > size_t iova_off = iova_offset(iovad, phys); > + size_t size_aligned = iova_align(iovad, size + iova_off); > dma_addr_t iova; > > if (static_branch_unlikely(&iommu_deferred_attach_enabled) && > iommu_deferred_attach(dev, domain)) > return DMA_MAPPING_ERROR; > > - size = iova_align(iovad, size + iova_off); > + if (IS_ENABLED(CONFIG_SWIOTLB) && dev_is_untrusted(dev)) { > + if (WARN_ON(iova_off)) > + return DMA_MAPPING_ERROR; > + if (WARN_ON(size_aligned != size)) > + return DMA_MAPPING_ERROR; > + } > + size = size_aligned; > > iova = iommu_dma_alloc_iova(domain, size, dma_mask, dev); > if (!iova) > -- > 2.25.1 > > -- Sven Peter _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu