diff options
| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2021-12-06 16:55:05 +0300 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2021-12-08 16:49:53 +0100 |
| commit | 20f07a044a76aebaaa0603038857229b5c460d69 (patch) | |
| tree | a980d1c7ab87780047ed90648275683adfa7588e /arch/x86/Kconfig | |
| parent | dbca5e1a04f8b30aea4e2c91e5045ee6e7c3ef43 (diff) | |
x86/sev: Move common memory encryption code to mem_encrypt.c
SEV and TDX both protect guest memory from host accesses. They both use
guest physical address bits to communicate to the hardware which pages
receive protection or not. SEV and TDX both assume that all I/O (real
devices and virtio) must be performed to pages *without* protection.
To add this support, AMD SEV code forces force_dma_unencrypted() to
decrypt DMA pages when DMA pages were allocated for I/O. It also uses
swiotlb_update_mem_attributes() to update decryption bits in SWIOTLB DMA
buffers.
Since TDX also uses a similar memory sharing design, all the above
mentioned changes can be reused. So move force_dma_unencrypted(),
SWIOTLB update code and virtio changes out of mem_encrypt_amd.c to
mem_encrypt.c.
Introduce a new config option X86_MEM_ENCRYPT that can be selected by
platforms which use x86 memory encryption features (needed in both AMD
SEV and Intel TDX guest platforms).
Since the code is moved from mem_encrypt_amd.c, inherit the same make
flags.
This is preparation for enabling TDX memory encryption support and it
has no functional changes.
Co-developed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Tested-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20211206135505.75045-4-kirill.shutemov@linux.intel.com
Diffstat (limited to 'arch/x86/Kconfig')
| -rw-r--r-- | arch/x86/Kconfig | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 95dd1ee01546..793e9b42ace0 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1523,16 +1523,20 @@ config X86_CPA_STATISTICS helps to determine the effectiveness of preserving large and huge page mappings when mapping protections are changed. +config X86_MEM_ENCRYPT + select ARCH_HAS_FORCE_DMA_UNENCRYPTED + select DYNAMIC_PHYSICAL_MASK + select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS + def_bool n + config AMD_MEM_ENCRYPT bool "AMD Secure Memory Encryption (SME) support" depends on X86_64 && CPU_SUP_AMD select DMA_COHERENT_POOL - select DYNAMIC_PHYSICAL_MASK select ARCH_USE_MEMREMAP_PROT - select ARCH_HAS_FORCE_DMA_UNENCRYPTED select INSTRUCTION_DECODER - select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS select ARCH_HAS_CC_PLATFORM + select X86_MEM_ENCRYPT help Say yes to enable support for the encryption of system memory. This requires an AMD processor that supports Secure Memory |