For larger TDX VM, memset() after set_memory_decrypted() in swiotlb_update_mem_attributes() takes substantial portion of boot time.
Zeroing doesn't serve any functional purpose. Malicious VMM can mess with decrypted/shared buffer at any point. Remove the memset(). Signed-off-by: Kirill A. Shutemov <kirill.shute...@linux.intel.com> --- kernel/dma/swiotlb.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index f1e7ea160b43..9390b38d2897 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -207,8 +207,6 @@ void __init swiotlb_update_mem_attributes(void) mem->vaddr = swiotlb_mem_remap(mem, bytes); if (!mem->vaddr) mem->vaddr = vaddr; - - memset(mem->vaddr, 0, bytes); } static void swiotlb_init_io_tlb_mem(struct io_tlb_mem *mem, phys_addr_t start, -- 2.34.1 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu