> index 43c88626a1f3..edc84a00b9f9 100644 > --- a/kernel/dma/swiotlb.c > +++ b/kernel/dma/swiotlb.c > @@ -35,6 +35,7 @@ > #include <linux/scatterlist.h> > #include <linux/mem_encrypt.h> > #include <linux/set_memory.h> > +#include <linux/pci.h> > #ifdef CONFIG_DEBUG_FS > #include <linux/debugfs.h> > #endif > @@ -562,6 +563,11 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, > */ > for (i = 0; i < nslots; i++) > io_tlb_orig_addr[index+i] = orig_addr + (i << IO_TLB_SHIFT); > + > + /* Zero out the bounce buffer if the consumer is untrusted. */ > + if (dev_is_untrusted(hwdev)) > + memset(phys_to_virt(tlb_addr), 0, alloc_size);
Hmm. Maybe we need to move the untrusted flag to struct device? Directly poking into the pci_dev from swiotlb is a bit of a layering violation. > + > if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC) && > (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)) > swiotlb_bounce(orig_addr, tlb_addr, mapping_size, > DMA_TO_DEVICE); Also for the case where we bounce here we only need to zero the padding (if there is any), so I think we could optimize this a bit.
