Hi Tom, On 02/16/17 at 09:41am, Tom Lendacky wrote: > This RFC 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. > > The following links provide additional detail: > > AMD Memory Encryption whitepaper: > http://amd-dev.wpengine.netdna-cdn.com/wordpress/media/2013/12/AMD_Memory_Encryption_Whitepaper_v7-Public.pdf > > AMD64 Architecture Programmer's Manual: > http://support.amd.com/TechDocs/24593.pdf > SME is section 7.10 > SEV is section 15.34 > > This patch series is based off of the master branch of tip. > Commit a27cb9e1b2b4 ("Merge branch 'WIP.sched/core'") > > --- > > Still to do: IOMMU enablement support > > Changes since v3: > - Broke out some of the patches into smaller individual patches > - Updated Documentation > - Added a message to indicate why the IOMMU was disabled > - Updated CPU feature support for SME by taking into account whether > BIOS has enabled SME > - Eliminated redundant functions > - Added some warning messages for DMA usage of bounce buffers when SME > is active > - Added support for persistent memory > - Added support to determine when setup data is being mapped and be sure > to map it un-encrypted > - Added CONFIG support to set the default action of whether to activate > SME if it is supported/enabled > - Added support for (re)booting with kexec Could you please add kexec list in cc when you updating the patches so that kexec/kdump people do not miss them? > > Changes since v2: > - Updated Documentation > - Make the encryption mask available outside of arch/x86 through a > standard include file > - Conversion of assembler routines to C where possible (not everything > could be converted, e.g. the routine that does the actual encryption > needs to be copied into a safe location and it is difficult to > determine the actual length of the function in order to copy it) > - Fix SME feature use of scattered CPUID feature > - Creation of SME specific functions for things like encrypting > the setup data, ramdisk, etc. > - New take on early_memremap / memremap encryption support > - Additional support for accessing video buffers (fbdev/gpu) as > un-encrypted > - Disable IOMMU for now - need to investigate further in relation to > how it needs to be programmed relative to accessing physical memory > > Changes since v1: > - Added Documentation. > - Removed AMD vendor check for setting the PAT write protect mode > - Updated naming of trampoline flag for SME as well as moving of the > SME check to before paging is enabled. > - Change to early_memremap to identify the data being mapped as either > boot data or kernel data. The idea being that boot data will have > been placed in memory as un-encrypted data and would need to be accessed > as such. > - Updated debugfs support for the bootparams to access the data properly. > - Do not set the SYSCFG[MEME] bit, only check it. The setting of the > MemEncryptionModeEn bit results in a reduction of physical address size > of the processor. It is possible that BIOS could have configured resources > resources into a range that will now not be addressable. To prevent this, > rely on BIOS to set the SYSCFG[MEME] bit and only then enable memory > encryption support in the kernel. > > Tom Lendacky (28): > x86: Documentation for AMD Secure Memory Encryption (SME) > x86: Set the write-protect cache mode for full PAT support > x86: Add the Secure Memory Encryption CPU feature > x86: Handle reduction in physical address size with SME > x86: Add Secure Memory Encryption (SME) support > x86: Add support to enable SME during early boot processing > x86: Provide general kernel support for memory encryption > x86: Extend the early_memremap support with additional attrs > x86: Add support for early encryption/decryption of memory > x86: Insure that boot memory areas are mapped properly > x86: Add support to determine the E820 type of an address > efi: Add an EFI table address match function > efi: Update efi_mem_type() to return defined EFI mem types > Add support to access boot related data in the clear > Add support to access persistent memory in the clear > x86: Add support for changing memory encryption attribute > x86: Decrypt trampoline area if memory encryption is active > x86: DMA support for memory encryption > swiotlb: Add warnings for use of bounce buffers with SME > iommu/amd: Disable AMD IOMMU if memory encryption is active > x86: Check for memory encryption on the APs > x86: Do not specify encrypted memory for video mappings > x86/kvm: Enable Secure Memory Encryption of nested page tables > x86: Access the setup data through debugfs decrypted > x86: Access the setup data through sysfs decrypted > x86: Allow kexec to be used with SME > x86: Add support to encrypt the kernel in-place > x86: Add support to make use of Secure Memory Encryption > > > Documentation/admin-guide/kernel-parameters.txt | 11 + > Documentation/x86/amd-memory-encryption.txt | 57 ++++ > arch/x86/Kconfig | 26 ++ > arch/x86/boot/compressed/pagetable.c | 7 + > arch/x86/include/asm/cacheflush.h | 5 > arch/x86/include/asm/cpufeature.h | 7 - > arch/x86/include/asm/cpufeatures.h | 5 > arch/x86/include/asm/disabled-features.h | 3 > arch/x86/include/asm/dma-mapping.h | 5 > arch/x86/include/asm/e820/api.h | 2 > arch/x86/include/asm/e820/types.h | 2 > arch/x86/include/asm/fixmap.h | 20 + > arch/x86/include/asm/init.h | 1 > arch/x86/include/asm/io.h | 3 > arch/x86/include/asm/kvm_host.h | 3 > arch/x86/include/asm/mem_encrypt.h | 108 ++++++++ > arch/x86/include/asm/msr-index.h | 2 > arch/x86/include/asm/page.h | 4 > arch/x86/include/asm/pgtable.h | 26 +- > arch/x86/include/asm/pgtable_types.h | 54 +++- > arch/x86/include/asm/processor.h | 3 > arch/x86/include/asm/realmode.h | 12 + > arch/x86/include/asm/required-features.h | 3 > arch/x86/include/asm/setup.h | 8 + > arch/x86/include/asm/vga.h | 13 + > arch/x86/kernel/Makefile | 3 > arch/x86/kernel/cpu/common.c | 23 ++ > arch/x86/kernel/e820.c | 26 ++ > arch/x86/kernel/espfix_64.c | 2 > arch/x86/kernel/head64.c | 46 +++ > arch/x86/kernel/head_64.S | 65 ++++- > arch/x86/kernel/kdebugfs.c | 30 +- > arch/x86/kernel/ksysfs.c | 27 +- > arch/x86/kernel/machine_kexec_64.c | 3 > arch/x86/kernel/mem_encrypt_boot.S | 156 ++++++++++++ > arch/x86/kernel/mem_encrypt_init.c | 310 +++++++++++++++++++++++ > arch/x86/kernel/pci-dma.c | 11 + > arch/x86/kernel/pci-nommu.c | 2 > arch/x86/kernel/pci-swiotlb.c | 8 - > arch/x86/kernel/process.c | 43 +++ > arch/x86/kernel/setup.c | 43 +++ > arch/x86/kernel/smp.c | 4 > arch/x86/kvm/mmu.c | 8 - > arch/x86/kvm/vmx.c | 3 > arch/x86/kvm/x86.c | 3 > arch/x86/mm/Makefile | 1 > arch/x86/mm/ident_map.c | 6 > arch/x86/mm/ioremap.c | 157 ++++++++++++ > arch/x86/mm/kasan_init_64.c | 4 > arch/x86/mm/mem_encrypt.c | 218 ++++++++++++++++ > arch/x86/mm/pageattr.c | 71 +++++ > arch/x86/mm/pat.c | 6 > arch/x86/platform/efi/efi.c | 4 > arch/x86/platform/efi/efi_64.c | 16 + > arch/x86/realmode/init.c | 16 + > arch/x86/realmode/rm/trampoline_64.S | 17 + > drivers/firmware/efi/efi.c | 33 ++ > drivers/gpu/drm/drm_gem.c | 2 > drivers/gpu/drm/drm_vm.c | 4 > drivers/gpu/drm/ttm/ttm_bo_vm.c | 7 - > drivers/gpu/drm/udl/udl_fb.c | 4 > drivers/iommu/amd_iommu_init.c | 7 + > drivers/video/fbdev/core/fbmem.c | 12 + > include/asm-generic/early_ioremap.h | 2 > include/asm-generic/pgtable.h | 8 + > include/linux/dma-mapping.h | 11 + > include/linux/efi.h | 7 + > include/linux/mem_encrypt.h | 53 ++++ > include/linux/swiotlb.h | 1 > init/main.c | 13 + > kernel/kexec_core.c | 24 ++ > kernel/memremap.c | 11 + > lib/swiotlb.c | 59 ++++ > mm/early_ioremap.c | 28 ++ > 74 files changed, 1880 insertions(+), 128 deletions(-) > create mode 100644 Documentation/x86/amd-memory-encryption.txt > create mode 100644 arch/x86/include/asm/mem_encrypt.h > create mode 100644 arch/x86/kernel/mem_encrypt_boot.S > create mode 100644 arch/x86/kernel/mem_encrypt_init.c > create mode 100644 arch/x86/mm/mem_encrypt.c > create mode 100644 include/linux/mem_encrypt.h > > -- > Tom Lendacky > -- > To unsubscribe from this list: send the line "unsubscribe linux-efi" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html Thanks a lot! Dave -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
