From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> To: linux-kernel@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org Cc: akpm@linux-foundation.org, dave.hansen@intel.com, sean.j.christopherson@intel.com, nhorman@redhat.com, npmccallum@redhat.com, haitao.huang@intel.com, andriy.shevchenko@linux.intel.com, tglx@linutronix.de, kai.svahn@intel.com, bp@alien8.de, josh@joshtriplett.org, luto@kernel.org, kai.huang@intel.com, rientjes@google.com, cedric.xing@intel.com, puiterwijk@redhat.com, Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Subject: [PATCH v28 07/22] x86/cpu/intel: Detect SGX supprt Date: Wed, 4 Mar 2020 01:35:54 +0200 Message-ID: <20200303233609.713348-8-jarkko.sakkinen@linux.intel.com> (raw) In-Reply-To: <20200303233609.713348-1-jarkko.sakkinen@linux.intel.com> From: Sean Christopherson <sean.j.christopherson@intel.com> Configure SGX as part of feature control MSR initialization and update the associated X86_FEATURE flags accordingly. Because the kernel will require the LE hash MSRs to be writable when running native enclaves, disable X86_FEATURE_SGX (and all derivatives) if SGX Launch Control is not (or cannot) be fully enabled via feature control MSR. The check is done for every CPU, not just BSP, in order to verify that MSR_IA32_FEATURE_CONTROL is correctly configured on all CPUs. The other parts of the kernel, like the enclave driver, expect the same configuration from all CPUs. Note, unlike VMX, clear the X86_FEATURE_SGX* flags for all CPUs if any CPU lacks SGX support as the kernel expects SGX to be available on all CPUs. X86_FEATURE_VMX is intentionally cleared only for the current CPU so that KVM can provide additional information if KVM fails to load, e.g. print which CPU doesn't support VMX. KVM/VMX requires additional per-CPU enabling, e.g. to set CR4.VMXE and do VMXON, and so already has the necessary infrastructure to do per-CPU checks. SGX on the other hand doesn't require additional enabling, so clearing the feature flags on all CPUs means the SGX subsystem doesn't need to manually do support checks on a per-CPU basis. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Co-developed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> --- arch/x86/kernel/cpu/feat_ctl.c | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/feat_ctl.c b/arch/x86/kernel/cpu/feat_ctl.c index 0268185bef94..b16b71a6da74 100644 --- a/arch/x86/kernel/cpu/feat_ctl.c +++ b/arch/x86/kernel/cpu/feat_ctl.c @@ -92,6 +92,14 @@ static void init_vmx_capabilities(struct cpuinfo_x86 *c) } #endif /* CONFIG_X86_VMX_FEATURE_NAMES */ +static void clear_sgx_caps(void) +{ + setup_clear_cpu_cap(X86_FEATURE_SGX); + setup_clear_cpu_cap(X86_FEATURE_SGX_LC); + setup_clear_cpu_cap(X86_FEATURE_SGX1); + setup_clear_cpu_cap(X86_FEATURE_SGX2); +} + void init_ia32_feat_ctl(struct cpuinfo_x86 *c) { bool tboot = tboot_enabled(); @@ -99,6 +107,7 @@ void init_ia32_feat_ctl(struct cpuinfo_x86 *c) if (rdmsrl_safe(MSR_IA32_FEAT_CTL, &msr)) { clear_cpu_cap(c, X86_FEATURE_VMX); + clear_sgx_caps(); return; } @@ -123,13 +132,21 @@ void init_ia32_feat_ctl(struct cpuinfo_x86 *c) msr |= FEAT_CTL_VMX_ENABLED_INSIDE_SMX; } + /* + * Enable SGX if and only if the kernel supports SGX and Launch Control + * is supported, i.e. disable SGX if the LE hash MSRs can't be written. + */ + if (cpu_has(c, X86_FEATURE_SGX) && cpu_has(c, X86_FEATURE_SGX_LC) && + IS_ENABLED(CONFIG_INTEL_SGX)) + msr |= FEAT_CTL_SGX_ENABLED | FEAT_CTL_SGX_LC_ENABLED; + wrmsrl(MSR_IA32_FEAT_CTL, msr); update_caps: set_cpu_cap(c, X86_FEATURE_MSR_IA32_FEAT_CTL); if (!cpu_has(c, X86_FEATURE_VMX)) - return; + goto update_sgx; if ( (tboot && !(msr & FEAT_CTL_VMX_ENABLED_INSIDE_SMX)) || (!tboot && !(msr & FEAT_CTL_VMX_ENABLED_OUTSIDE_SMX))) { @@ -142,4 +159,14 @@ void init_ia32_feat_ctl(struct cpuinfo_x86 *c) init_vmx_capabilities(c); #endif } + +update_sgx: + if (!cpu_has(c, X86_FEATURE_SGX) || !cpu_has(c, X86_FEATURE_SGX_LC)) { + clear_sgx_caps(); + } else if (!(msr & FEAT_CTL_SGX_ENABLED) || + !(msr & FEAT_CTL_SGX_LC_ENABLED)) { + if (IS_ENABLED(CONFIG_INTEL_SGX)) + pr_err_once("SGX disabled by BIOS\n"); + clear_sgx_caps(); + } } -- 2.25.0
next prev parent reply index Thread overview: 109+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-03-03 23:35 [PATCH v28 00/22] Intel SGX foundations Jarkko Sakkinen 2020-03-03 23:35 ` [PATCH v28 01/22] x86/sgx: Update MAINTAINERS Jarkko Sakkinen 2020-03-03 23:35 ` [PATCH v28 02/22] x86/cpufeatures: x86/msr: Add Intel SGX hardware bits Jarkko Sakkinen 2020-03-03 23:35 ` [PATCH v28 03/22] x86/cpufeatures: x86/msr: Intel SGX Launch Control " Jarkko Sakkinen 2020-03-03 23:35 ` [PATCH v28 04/22] x86/mm: x86/sgx: Signal SIGSEGV with PF_SGX Jarkko Sakkinen 2020-03-03 23:35 ` [PATCH v28 05/22] x86/sgx: Add SGX microarchitectural data structures Jarkko Sakkinen 2020-03-03 23:35 ` [PATCH v28 06/22] x86/sgx: Add wrappers for ENCLS leaf functions Jarkko Sakkinen 2020-03-09 21:14 ` Sean Christopherson 2020-03-03 23:35 ` Jarkko Sakkinen [this message] 2020-03-09 21:56 ` [PATCH v28 07/22] x86/cpu/intel: Detect SGX supprt Sean Christopherson 2020-03-11 17:03 ` Jarkko Sakkinen 2020-03-03 23:35 ` [PATCH v28 08/22] x86/sgx: Enumerate and track EPC sections Jarkko Sakkinen 2020-03-03 23:35 ` [PATCH v28 09/22] x86/sgx: Add functions to allocate and free EPC pages Jarkko Sakkinen 2020-03-03 23:35 ` [PATCH v28 10/22] mm: Introduce vm_ops->may_mprotect() Jarkko Sakkinen 2020-03-03 23:35 ` [PATCH v28 11/22] x86/sgx: Linux Enclave Driver Jarkko Sakkinen 2020-03-05 17:40 ` Sean Christopherson 2020-03-05 18:24 ` Jethro Beekman 2020-03-05 19:04 ` Sean Christopherson 2020-03-06 19:00 ` Jarkko Sakkinen 2020-03-19 18:22 ` Dr. Greg 2020-03-06 18:58 ` Jarkko Sakkinen 2020-03-03 23:35 ` [PATCH v28 12/22] docs: x86/sgx: Document SGX micro architecture and kernel internals Jarkko Sakkinen 2020-03-03 23:36 ` [PATCH v28 13/22] selftests/x86: Recurse into subdirectories Jarkko Sakkinen 2020-03-03 23:36 ` [PATCH v28 14/22] selftests/x86: Add a selftest for SGX Jarkko Sakkinen 2020-03-04 19:27 ` Nathaniel McCallum 2020-03-05 11:33 ` Jarkko Sakkinen 2020-03-06 15:42 ` Dr. Greg 2020-03-06 19:07 ` Jarkko Sakkinen 2020-03-07 17:42 ` Dr. Greg 2020-03-10 13:08 ` Jarkko Sakkinen 2020-03-11 13:28 ` Jarkko Sakkinen [not found] ` <20200311164047.GG21852@linux.intel.com> 2020-03-13 19:24 ` Jarkko Sakkinen 2020-03-04 19:44 ` Nathaniel McCallum 2020-03-04 19:51 ` Nathaniel McCallum 2020-03-06 5:32 ` Dr. Greg 2020-03-06 19:04 ` Jarkko Sakkinen 2020-03-10 19:29 ` Haitao Huang 2020-03-11 9:13 ` Dr. Greg 2020-03-11 17:15 ` Haitao Huang 2020-03-17 1:07 ` Dr. Greg 2020-03-03 23:36 ` [PATCH v28 15/22] x86/sgx: Add provisioning Jarkko Sakkinen 2020-03-03 23:36 ` [PATCH v28 16/22] x86/sgx: Add a page reclaimer Jarkko Sakkinen 2020-03-05 19:03 ` Sean Christopherson 2020-03-06 18:47 ` Jarkko Sakkinen 2020-03-12 18:38 ` Sean Christopherson 2020-03-15 0:27 ` Jarkko Sakkinen 2020-03-15 1:17 ` Jarkko Sakkinen 2020-03-09 21:16 ` Sean Christopherson 2020-03-03 23:36 ` [PATCH v28 17/22] x86/sgx: ptrace() support for the SGX driver Jarkko Sakkinen 2020-03-03 23:36 ` [PATCH v28 18/22] x86/vdso: Add support for exception fixup in vDSO functions Jarkko Sakkinen 2020-03-03 23:36 ` [PATCH v28 19/22] x86/fault: Add helper function to sanitize error code Jarkko Sakkinen 2020-03-03 23:36 ` [PATCH v28 20/22] x86/traps: Attempt to fixup exceptions in vDSO before signaling Jarkko Sakkinen 2020-03-03 23:36 ` [PATCH v28 21/22] x86/vdso: Implement a vDSO for Intel SGX enclave call Jarkko Sakkinen 2020-03-11 17:30 ` Nathaniel McCallum 2020-03-11 17:38 ` Jethro Beekman 2020-03-11 19:15 ` Nathaniel McCallum 2020-03-13 15:48 ` Nathaniel McCallum 2020-03-13 16:46 ` Sean Christopherson 2020-03-13 18:32 ` Nathaniel McCallum 2020-03-13 18:44 ` Sean Christopherson 2020-03-13 20:14 ` Nathaniel McCallum 2020-03-13 22:08 ` Sean Christopherson 2020-03-14 14:10 ` Nathaniel McCallum 2020-03-18 23:40 ` Sean Christopherson 2020-03-19 0:38 ` Xing, Cedric 2020-03-19 1:03 ` Sean Christopherson 2020-03-20 13:55 ` Nathaniel McCallum 2020-03-15 1:25 ` Jarkko Sakkinen 2020-03-15 17:53 ` Nathaniel McCallum 2020-03-16 13:31 ` Jethro Beekman 2020-03-16 13:57 ` Nathaniel McCallum 2020-03-16 13:59 ` Jethro Beekman 2020-03-16 14:03 ` Nathaniel McCallum 2020-03-16 17:17 ` Sean Christopherson 2020-03-16 21:27 ` Jarkko Sakkinen 2020-03-16 21:29 ` Jarkko Sakkinen 2020-03-16 22:55 ` Sean Christopherson 2020-03-16 23:56 ` Xing, Cedric 2020-03-18 22:01 ` Jarkko Sakkinen 2020-03-18 22:18 ` Jarkko Sakkinen 2020-03-16 13:56 ` Jarkko Sakkinen 2020-03-16 14:01 ` Nathaniel McCallum 2020-03-16 21:38 ` Jarkko Sakkinen 2020-03-16 22:53 ` Sean Christopherson 2020-03-16 23:50 ` Xing, Cedric 2020-03-16 23:59 ` Sean Christopherson 2020-03-17 0:18 ` Xing, Cedric 2020-03-17 0:27 ` Sean Christopherson 2020-03-17 16:37 ` Nathaniel McCallum 2020-03-17 16:50 ` Nathaniel McCallum 2020-03-17 21:40 ` Xing, Cedric 2020-03-17 22:09 ` Sean Christopherson 2020-03-17 22:36 ` Xing, Cedric 2020-03-17 23:57 ` Sean Christopherson 2020-03-17 22:23 ` Xing, Cedric 2020-03-18 13:01 ` Nathaniel McCallum 2020-03-20 15:53 ` Nathaniel McCallum 2020-03-17 16:28 ` Nathaniel McCallum 2020-03-18 22:58 ` Jarkko Sakkinen 2020-03-18 22:39 ` Jarkko Sakkinen 2020-03-11 19:30 ` Nathaniel McCallum 2020-03-13 0:52 ` Sean Christopherson 2020-03-13 16:07 ` Nathaniel McCallum 2020-03-13 16:33 ` Sean Christopherson 2020-03-03 23:36 ` [PATCH v28 22/22] selftests/x86: Add vDSO selftest for SGX Jarkko Sakkinen 2020-03-04 19:24 ` [PATCH v28 00/22] Intel SGX foundations Nathaniel McCallum 2020-03-17 16:00 ` Jordan Hand 2020-03-18 21:56 ` Jarkko Sakkinen 2020-03-19 17:16 ` Dr. Greg
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