> +static int __init mem_encrypt_snp_init(void) > +{ > + if (!boot_cpu_has(X86_FEATURE_SEV_SNP)) > + return 1; > + > + if (rmptable_init()) { > + setup_clear_cpu_cap(X86_FEATURE_SEV_SNP); > + return 1; > + } > + > + static_branch_enable(&snp_enable_key); > + > + return 0; > +}
Could you explain a bit why 'snp_enable_key' is needed in addition to X86_FEATURE_SEV_SNP? For a lot of features, we just use cpu_feature_enabled(), which does both compile-time and static_cpu_has(). This whole series seems to lack compile-time disables for the code that it adds, like the code it adds to arch/x86/mm/fault.c or even mm/memory.c.