From c7753208a94c73d5beb1e4bd843081d6dc7d4678 Mon Sep 17 00:00:00 2001 From: Tom Lendacky Date: Mon, 17 Jul 2017 16:10:21 -0500 Subject: x86, swiotlb: Add memory encryption support MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Since DMA addresses will effectively look like 48-bit addresses when the memory encryption mask is set, SWIOTLB is needed if the DMA mask of the device performing the DMA does not support 48-bits. SWIOTLB will be initialized to create decrypted bounce buffers for use by these devices. Signed-off-by: Tom Lendacky Reviewed-by: Thomas Gleixner Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Andy Lutomirski Cc: Arnd Bergmann Cc: Borislav Petkov Cc: Brijesh Singh Cc: Dave Young Cc: Dmitry Vyukov Cc: Jonathan Corbet Cc: Konrad Rzeszutek Wilk Cc: Larry Woodman Cc: Linus Torvalds Cc: Matt Fleming Cc: Michael S. Tsirkin Cc: Paolo Bonzini Cc: Peter Zijlstra Cc: Radim Krčmář Cc: Rik van Riel Cc: Toshimitsu Kani Cc: kasan-dev@googlegroups.com Cc: kvm@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-doc@vger.kernel.org Cc: linux-efi@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/aa2d29b78ae7d508db8881e46a3215231b9327a7.1500319216.git.thomas.lendacky@amd.com Signed-off-by: Ingo Molnar --- init/main.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'init') diff --git a/init/main.c b/init/main.c index 052481fbe363..9789ab7fe85e 100644 --- a/init/main.c +++ b/init/main.c @@ -488,6 +488,8 @@ void __init __weak thread_stack_cache_init(void) } #endif +void __init __weak mem_encrypt_init(void) { } + /* * Set up kernel memory allocators */ @@ -641,6 +643,14 @@ asmlinkage __visible void __init start_kernel(void) */ locking_selftest(); + /* + * This needs to be called before any devices perform DMA + * operations that might use the SWIOTLB bounce buffers. It will + * mark the bounce buffers as decrypted so that their usage will + * not cause "plain-text" data to be decrypted when accessed. + */ + mem_encrypt_init(); + #ifdef CONFIG_BLK_DEV_INITRD if (initrd_start && !initrd_below_start_ok && page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) { -- cgit v1.2.3