On 11/21/22 6:39 AM, Borislav Petkov wrote: > On Fri, Nov 18, 2022 at 02:55:32AM +0000, Michael Kelley (LINUX) wrote: >> But I had not thought about TDX. In the TDX case, it appears that >> sme_postprocess_startup() will not decrypt the bss_decrypted section. >> The corresponding mem_encrypt_free_decrypted_mem() is a no-op unless >> CONFIG_AMD_MEM_ENCRYPT is set. But maybe if someone builds a >> kernel image that supports both TDX and AMD encryption, it could break > > sme_me_mask better be 0 on a kernel with both built in and running as a > TDX guest. > Yes. It will be 0 in TDX. In sme_enable(), AMD code checks for CPUID support before updating the sme_me_mask. -- Sathyanarayanan Kuppuswamy Linux Kernel Developer
