On 1/25/22 07:20, Kirill A. Shutemov wrote:
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>
Acked-by: Tom Lendacky <thomas.lenda...@amd.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,
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
