On Mon, 17 Jul 2017, Tom Lendacky wrote: > This patch series provides support for AMD's new Secure Memory Encryption (SME) > feature. > > SME can be used to mark individual pages of memory as encrypted through the > page tables. A page of memory that is marked encrypted will be automatically > decrypted when read from DRAM and will be automatically encrypted when > written to DRAM. Details on SME can found in the links below. > > The SME feature is identified through a CPUID function and enabled through > the SYSCFG MSR. Once enabled, page table entries will determine how the > memory is accessed. If a page table entry has the memory encryption mask set, > then that memory will be accessed as encrypted memory. The memory encryption > mask (as well as other related information) is determined from settings > returned through the same CPUID function that identifies the presence of the > feature. > > The approach that this patch series takes is to encrypt everything possible > starting early in the boot where the kernel is encrypted. Using the page > table macros the encryption mask can be incorporated into all page table > entries and page allocations. By updating the protection map, userspace > allocations are also marked encrypted. Certain data must be accounted for > as having been placed in memory before SME was enabled (EFI, initrd, etc.) > and accessed accordingly. > > This patch series is a pre-cursor to another AMD processor feature called > Secure Encrypted Virtualization (SEV). The support for SEV will build upon > the SME support and will be submitted later. Details on SEV can be found > in the links below. Well done series. Thanks to all people involved, especially Tom and Boris! It was a pleasure to review that. Reviewed-by: Thomas Gleixner <tglx at linutronix.de>
