From 8458bf94b0399cd1bca6c437366bcafb29c230c5 Mon Sep 17 00:00:00 2001 From: Tom Lendacky Date: Mon, 17 Jul 2017 16:10:30 -0500 Subject: x86/mm: Use proper encryption attributes with /dev/mem MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When accessing memory using /dev/mem (or /dev/kmem) use the proper encryption attributes when mapping the memory. To insure the proper attributes are applied when reading or writing /dev/mem, update the xlate_dev_mem_ptr() function to use memremap() which will essentially perform the same steps of applying __va for RAM or using ioremap() if not RAM. To insure the proper attributes are applied when mmapping /dev/mem, update the phys_mem_access_prot() to call phys_mem_access_encrypted(), a new function which will check if the memory should be mapped encrypted or not. If it is not to be mapped encrypted then the VMA protection value is updated to remove the encryption bit. Signed-off-by: Tom Lendacky Reviewed-by: Thomas Gleixner Reviewed-by: Borislav Petkov 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/c917f403ab9f61cbfd455ad6425ed8429a5e7b54.1500319216.git.thomas.lendacky@amd.com Signed-off-by: Ingo Molnar --- arch/x86/include/asm/io.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'arch/x86/include/asm/io.h') diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h index 09c5557b1454..e080a39b2108 100644 --- a/arch/x86/include/asm/io.h +++ b/arch/x86/include/asm/io.h @@ -386,4 +386,7 @@ extern bool arch_memremap_can_ram_remap(resource_size_t offset, unsigned long flags); #define arch_memremap_can_ram_remap arch_memremap_can_ram_remap +extern bool phys_mem_access_encrypted(unsigned long phys_addr, + unsigned long size); + #endif /* _ASM_X86_IO_H */ -- cgit v1.2.3