From: Sean Christopherson <[email protected]> When the CPU supports SGX, check that the BIOS has enabled SGX and SGX1 opcodes are available. Otherwise, all the SGX related capabilities.
In addition, clear X86_FEATURE_SGX_LC also in the case when the launch enclave are read-only. This way the feature bit reflects the level that Linux supports the launch control. Signed-off-by: Sean Christopherson <[email protected]> Co-developed-by: Jarkko Sakkinen <[email protected]> Signed-off-by: Jarkko Sakkinen <[email protected]> --- arch/x86/kernel/cpu/intel.c | 39 +++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index 8d6d92ebeb54..777ea63b4f85 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -623,6 +623,42 @@ static void detect_tme(struct cpuinfo_x86 *c) c->x86_phys_bits -= keyid_bits; } +static void __maybe_unused detect_sgx(struct cpuinfo_x86 *c) +{ + unsigned long long fc; + + rdmsrl(MSR_IA32_FEATURE_CONTROL, fc); + if (!(fc & FEATURE_CONTROL_LOCKED)) { + pr_err_once("sgx: The feature control MSR is not locked\n"); + goto err_unsupported; + } + + if (!(fc & FEATURE_CONTROL_SGX_ENABLE)) { + pr_err_once("sgx: SGX is not enabled in IA32_FEATURE_CONTROL MSR\n"); + goto err_unsupported; + } + + if (!cpu_has(c, X86_FEATURE_SGX1)) { + pr_err_once("sgx: SGX1 instruction set is not supported\n"); + goto err_unsupported; + } + + if (!(fc & FEATURE_CONTROL_SGX_LE_WR)) { + pr_info_once("sgx: The launch control MSRs are not writable\n"); + goto err_msrs_rdonly; + } + + return; + +err_unsupported: + setup_clear_cpu_cap(X86_FEATURE_SGX); + setup_clear_cpu_cap(X86_FEATURE_SGX1); + setup_clear_cpu_cap(X86_FEATURE_SGX2); + +err_msrs_rdonly: + setup_clear_cpu_cap(X86_FEATURE_SGX_LC); +} + static void init_cpuid_fault(struct cpuinfo_x86 *c) { u64 msr; @@ -760,6 +796,9 @@ static void init_intel(struct cpuinfo_x86 *c) if (cpu_has(c, X86_FEATURE_TME)) detect_tme(c); + if (IS_ENABLED(CONFIG_INTEL_SGX) && cpu_has(c, X86_FEATURE_SGX)) + detect_sgx(c); + init_intel_misc_features(c); } -- 2.20.1
