From: Jarkko Sakkinen <jarkko@kernel.org>
To: Kai Huang <kai.huang@intel.com>
Cc: linux-sgx@vger.kernel.org, kvm@vger.kernel.org, x86@kernel.org,
seanjc@google.com, luto@kernel.org, dave.hansen@intel.com,
haitao.huang@intel.com, pbonzini@redhat.com, bp@alien8.de,
tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com,
jethro@fortanix.com, b.thiel@posteo.de
Subject: Re: [RFC PATCH v3 07/27] x86/cpu/intel: Allow SGX virtualization without Launch Control support
Date: Sat, 30 Jan 2021 16:42:56 +0200 [thread overview]
Message-ID: <YBVwcJ0KrWmXkcjL@kernel.org> (raw)
In-Reply-To: <ae05882235e61fd8e7a56e37b0d9c044781bd767.1611634586.git.kai.huang@intel.com>
On Tue, Jan 26, 2021 at 10:30:54PM +1300, Kai Huang wrote:
> From: Sean Christopherson <sean.j.christopherson@intel.com>
>
> The kernel will currently disable all SGX support if the hardware does
> not support launch control. Make it more permissive to allow SGX
> virtualization on systems without Launch Control support. This will
> allow KVM to expose SGX to guests that have less-strict requirements on
> the availability of flexible launch control.
>
> Improve error message to distinguish between three cases. There are two
> cases where SGX support is completely disabled:
> 1) SGX has been disabled completely by the BIOS
> 2) SGX LC is locked by the BIOS. Bare-metal support is disabled because
> of LC unavailability. SGX virtualization is unavailable (because of
> Kconfig).
> One where it is partially available:
> 3) SGX LC is locked by the BIOS. Bare-metal support is disabled because
> of LC unavailability. SGX virtualization is supported.
>
> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
> Co-developed-by: Kai Huang <kai.huang@intel.com>
> Signed-off-by: Kai Huang <kai.huang@intel.com>
> ---
> v2->v3:
>
> - Added to use 'enable_sgx_any', per Dave.
> - Changed to call clear_cpu_cap() directly, rather than using clear_sgx_caps()
> and clear_sgx_lc().
> - Changed to use CONFIG_X86_SGX_KVM, instead of CONFIG_X86_SGX_VIRTUALIZATION.
>
> v1->v2:
>
> - Refined commit message per Dave's comments.
> - Added check to only enable SGX virtualization when VMX is supported, per
> Dave's comment.
> - Refined error msg print to explicitly call out SGX virtualization will be
> supported when LC is locked by BIOS, per Dave's comment.
>
> ---
> arch/x86/kernel/cpu/feat_ctl.c | 58 ++++++++++++++++++++++++++--------
> 1 file changed, 45 insertions(+), 13 deletions(-)
>
> diff --git a/arch/x86/kernel/cpu/feat_ctl.c b/arch/x86/kernel/cpu/feat_ctl.c
> index 27533a6e04fa..0fc202550fcc 100644
> --- a/arch/x86/kernel/cpu/feat_ctl.c
> +++ b/arch/x86/kernel/cpu/feat_ctl.c
> @@ -105,7 +105,8 @@ early_param("nosgx", nosgx);
> void init_ia32_feat_ctl(struct cpuinfo_x86 *c)
> {
> bool tboot = tboot_enabled();
> - bool enable_sgx;
> + bool enable_vmx;
> + bool enable_sgx_any, enable_sgx_kvm, enable_sgx_driver;
Move the declaration first (reverse christmas tree).
> u64 msr;
>
> if (rdmsrl_safe(MSR_IA32_FEAT_CTL, &msr)) {
> @@ -114,13 +115,22 @@ void init_ia32_feat_ctl(struct cpuinfo_x86 *c)
> return;
> }
>
> + enable_vmx = cpu_has(c, X86_FEATURE_VMX) &&
> + IS_ENABLED(CONFIG_KVM_INTEL);
> +
> /*
> - * 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.
> + * Enable SGX if and only if the kernel supports SGX. Require Launch
> + * Control support if SGX virtualization is *not* supported, i.e.
> + * disable SGX if the LE hash MSRs can't be written and SGX can't be
> + * exposed to a KVM guest (which might support non-LC configurations).
> */
> - enable_sgx = cpu_has(c, X86_FEATURE_SGX) &&
> - cpu_has(c, X86_FEATURE_SGX_LC) &&
> - IS_ENABLED(CONFIG_X86_SGX);
> + enable_sgx_any = cpu_has(c, X86_FEATURE_SGX) &&
> + cpu_has(c, X86_FEATURE_SGX1) &&
> + IS_ENABLED(CONFIG_X86_SGX);
> + enable_sgx_driver = enable_sgx_any &&
> + cpu_has(c, X86_FEATURE_SGX_LC);
> + enable_sgx_kvm = enable_sgx_any && enable_vmx &&
> + IS_ENABLED(CONFIG_X86_SGX_KVM);
>
> if (msr & FEAT_CTL_LOCKED)
> goto update_caps;
> @@ -136,15 +146,18 @@ void init_ia32_feat_ctl(struct cpuinfo_x86 *c)
> * i.e. KVM is enabled, to avoid unnecessarily adding an attack vector
> * for the kernel, e.g. using VMX to hide malicious code.
> */
> - if (cpu_has(c, X86_FEATURE_VMX) && IS_ENABLED(CONFIG_KVM_INTEL)) {
> + if (enable_vmx) {
> msr |= FEAT_CTL_VMX_ENABLED_OUTSIDE_SMX;
>
> if (tboot)
> msr |= FEAT_CTL_VMX_ENABLED_INSIDE_SMX;
> }
>
> - if (enable_sgx)
> - msr |= FEAT_CTL_SGX_ENABLED | FEAT_CTL_SGX_LC_ENABLED;
> + if (enable_sgx_kvm || enable_sgx_driver) {
> + msr |= FEAT_CTL_SGX_ENABLED;
> + if (enable_sgx_driver)
> + msr |= FEAT_CTL_SGX_LC_ENABLED;
> + }
>
> wrmsrl(MSR_IA32_FEAT_CTL, msr);
>
> @@ -167,10 +180,29 @@ void init_ia32_feat_ctl(struct cpuinfo_x86 *c)
> }
>
> update_sgx:
> - if (!(msr & FEAT_CTL_SGX_ENABLED) ||
> - !(msr & FEAT_CTL_SGX_LC_ENABLED) || !enable_sgx) {
> - if (enable_sgx)
> - pr_err_once("SGX disabled by BIOS\n");
> + if (!(msr & FEAT_CTL_SGX_ENABLED)) {
> + if (enable_sgx_kvm || enable_sgx_driver)
> + pr_err_once("SGX disabled by BIOS.\n");
> clear_cpu_cap(c, X86_FEATURE_SGX);
> + return;
> + }
> +
> + /*
> + * VMX feature bit may be cleared due to being disabled in BIOS,
> + * in which case SGX virtualization cannot be supported either.
> + */
> + if (!cpu_has(c, X86_FEATURE_VMX) && enable_sgx_kvm) {
> + pr_err_once("SGX virtualization disabled due to lack of VMX.\n");
> + enable_sgx_kvm = 0;
> + }
> +
> + if (!(msr & FEAT_CTL_SGX_LC_ENABLED) && enable_sgx_driver) {
> + if (!enable_sgx_kvm) {
> + pr_err_once("SGX Launch Control is locked. Disable SGX.\n");
> + clear_cpu_cap(c, X86_FEATURE_SGX);
> + } else {
> + pr_err_once("SGX Launch Control is locked. Support SGX virtualization only.\n");
> + clear_cpu_cap(c, X86_FEATURE_SGX_LC);
> + }
> }
> }
> --
> 2.29.2
>
>
/Jarkko
next prev parent reply other threads:[~2021-01-30 15:31 UTC|newest]
Thread overview: 156+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-26 10:10 [RFC PATCH v3 00/27] KVM SGX virtualization support Kai Huang
2021-01-26 9:29 ` Kai Huang
2021-01-26 9:30 ` [RFC PATCH v3 01/27] x86/cpufeatures: Add SGX1 and SGX2 sub-features Kai Huang
2021-01-26 15:34 ` Dave Hansen
2021-01-26 23:18 ` Kai Huang
2021-01-30 13:20 ` Jarkko Sakkinen
2021-02-01 0:01 ` Kai Huang
2021-02-02 17:17 ` Jarkko Sakkinen
2021-02-03 1:09 ` Kai Huang
2021-02-02 17:56 ` Paolo Bonzini
2021-02-02 18:00 ` Dave Hansen
2021-02-02 18:03 ` Paolo Bonzini
2021-02-02 18:42 ` Sean Christopherson
2021-02-03 1:05 ` Kai Huang
2021-01-30 13:11 ` Jarkko Sakkinen
2021-01-26 9:30 ` [RFC PATCH v3 02/27] x86/cpufeatures: Make SGX_LC feature bit depend on SGX bit Kai Huang
2021-01-26 15:35 ` Dave Hansen
2021-01-30 13:22 ` Jarkko Sakkinen
2021-02-01 0:08 ` Kai Huang
2021-01-26 9:30 ` [RFC PATCH v3 03/27] x86/sgx: Remove a warn from sgx_free_epc_page() Kai Huang
2021-01-26 15:39 ` Dave Hansen
2021-01-26 16:30 ` Sean Christopherson
2021-01-27 1:08 ` Kai Huang
2021-01-27 1:12 ` Dave Hansen
2021-01-27 1:26 ` Kai Huang
2021-02-01 0:11 ` Kai Huang
2021-02-03 10:03 ` Jarkko Sakkinen
2021-01-26 9:30 ` [RFC PATCH v3 04/27] x86/sgx: Wipe out EREMOVE " Kai Huang
2021-01-26 16:04 ` Dave Hansen
2021-01-27 1:25 ` Kai Huang
2021-02-02 18:00 ` Paolo Bonzini
2021-02-02 19:25 ` Kai Huang
2021-02-02 19:02 ` Dave Hansen
2021-01-26 9:30 ` [RFC PATCH v3 05/27] x86/sgx: Add SGX_CHILD_PRESENT hardware error code Kai Huang
2021-01-26 15:49 ` Dave Hansen
2021-01-27 0:00 ` Kai Huang
2021-01-27 0:21 ` Dave Hansen
2021-01-27 0:52 ` Kai Huang
2021-01-26 9:30 ` [RFC PATCH v3 06/27] x86/sgx: Introduce virtual EPC for use by KVM guests Kai Huang
2021-01-26 16:19 ` Dave Hansen
2021-01-27 0:16 ` Kai Huang
2021-01-27 0:27 ` Dave Hansen
2021-01-27 0:48 ` Kai Huang
2021-01-30 14:41 ` Jarkko Sakkinen
2021-01-26 9:30 ` [RFC PATCH v3 07/27] x86/cpu/intel: Allow SGX virtualization without Launch Control support Kai Huang
2021-01-26 16:26 ` Dave Hansen
2021-01-26 17:00 ` Sean Christopherson
2021-01-26 23:54 ` Kai Huang
2021-01-26 23:56 ` Kai Huang
2021-01-27 0:18 ` Dave Hansen
2021-01-27 2:02 ` Kai Huang
2021-01-27 17:13 ` Sean Christopherson
2021-01-30 14:42 ` Jarkko Sakkinen [this message]
2021-02-01 5:38 ` Kai Huang
2021-01-26 9:31 ` [RFC PATCH v3 08/27] x86/sgx: Initialize virtual EPC driver even when SGX driver is disabled Kai Huang
2021-01-26 17:03 ` Dave Hansen
2021-01-26 18:10 ` Andy Lutomirski
2021-01-26 23:25 ` Kai Huang
2021-01-30 14:45 ` Jarkko Sakkinen
2021-02-01 5:40 ` Kai Huang
2021-02-01 15:25 ` Dave Hansen
2021-02-01 17:23 ` Sean Christopherson
2021-02-02 0:12 ` Kai Huang
2021-02-02 23:10 ` Jarkko Sakkinen
2021-02-02 23:07 ` Jarkko Sakkinen
2021-02-02 17:32 ` Jarkko Sakkinen
2021-02-02 18:20 ` Sean Christopherson
2021-02-02 23:16 ` Jarkko Sakkinen
2021-02-03 0:49 ` Kai Huang
2021-02-03 22:02 ` Jarkko Sakkinen
2021-02-03 22:59 ` Sean Christopherson
2021-02-04 1:39 ` Jarkko Sakkinen
2021-02-04 2:59 ` Kai Huang
2021-02-04 3:05 ` Jarkko Sakkinen
2021-02-04 3:09 ` Jarkko Sakkinen
2021-02-04 3:20 ` Kai Huang
2021-02-04 14:51 ` Jarkko Sakkinen
2021-02-04 22:41 ` Dave Hansen
2021-02-04 22:56 ` Kai Huang
2021-02-05 2:08 ` Jarkko Sakkinen
2021-02-05 3:00 ` Huang, Kai
2021-02-02 18:49 ` Kai Huang
2021-02-02 23:17 ` Jarkko Sakkinen
2021-01-26 9:31 ` [RFC PATCH v3 09/27] x86/sgx: Expose SGX architectural definitions to the kernel Kai Huang
2021-01-30 14:46 ` Jarkko Sakkinen
2021-01-26 9:31 ` [RFC PATCH v3 10/27] x86/sgx: Move ENCLS leaf definitions to sgx_arch.h Kai Huang
2021-01-26 9:31 ` [RFC PATCH v3 11/27] x86/sgx: Add SGX2 ENCLS leaf definitions (EAUG, EMODPR and EMODT) Kai Huang
2021-01-26 9:31 ` [RFC PATCH v3 12/27] x86/sgx: Add encls_faulted() helper Kai Huang
2021-01-30 14:48 ` Jarkko Sakkinen
2021-01-26 9:31 ` [RFC PATCH v3 13/27] x86/sgx: Add helper to update SGX_LEPUBKEYHASHn MSRs Kai Huang
2021-01-30 14:49 ` Jarkko Sakkinen
2021-02-01 1:17 ` Kai Huang
2021-02-01 21:22 ` Dave Hansen
2021-01-26 9:31 ` [RFC PATCH v3 14/27] x86/sgx: Add helpers to expose ECREATE and EINIT to KVM Kai Huang
2021-01-30 14:51 ` Jarkko Sakkinen
2021-02-01 0:17 ` Kai Huang
2021-02-02 17:20 ` Jarkko Sakkinen
2021-02-02 20:35 ` Kai Huang
2021-02-04 3:53 ` Kai Huang
2021-02-05 0:32 ` Sean Christopherson
2021-02-05 1:39 ` Huang, Kai
2021-01-26 9:31 ` [RFC PATCH v3 15/27] x86/sgx: Move provisioning device creation out of SGX driver Kai Huang
2021-01-30 14:52 ` Jarkko Sakkinen
2021-01-26 9:31 ` [RFC PATCH v3 16/27] KVM: VMX: Convert vcpu_vmx.exit_reason to a union Kai Huang
2021-01-30 15:00 ` Jarkko Sakkinen
2021-02-01 0:32 ` Kai Huang
2021-02-02 17:24 ` Jarkko Sakkinen
2021-02-02 19:23 ` Kai Huang
2021-02-02 22:41 ` Jarkko Sakkinen
2021-02-03 0:42 ` Kai Huang
2021-02-01 17:12 ` Sean Christopherson
2021-02-02 22:38 ` Jarkko Sakkinen
2021-01-26 9:31 ` [RFC PATCH v3 17/27] KVM: x86: Export kvm_mmu_gva_to_gpa_{read,write}() for SGX (VMX) Kai Huang
2021-01-26 9:31 ` [RFC PATCH v3 18/27] KVM: x86: Define new #PF SGX error code bit Kai Huang
2021-01-26 9:31 ` [RFC PATCH v3 19/27] KVM: x86: Add support for reverse CPUID lookup of scattered features Kai Huang
2021-01-26 9:31 ` [RFC PATCH v3 20/27] KVM: x86: Add reverse-CPUID lookup support for scattered SGX features Kai Huang
2021-01-26 9:31 ` [RFC PATCH v3 21/27] KVM: VMX: Add basic handling of VM-Exit from SGX enclave Kai Huang
2021-01-26 9:31 ` [RFC PATCH v3 22/27] KVM: VMX: Frame in ENCLS handler for SGX virtualization Kai Huang
2021-01-26 9:31 ` [RFC PATCH v3 23/27] KVM: VMX: Add SGX ENCLS[ECREATE] handler to enforce CPUID restrictions Kai Huang
2021-02-03 0:52 ` Edgecombe, Rick P
2021-02-03 1:36 ` Sean Christopherson
2021-02-03 9:11 ` Kai Huang
2021-02-03 17:07 ` Sean Christopherson
2021-02-03 23:11 ` Kai Huang
2021-02-03 18:47 ` Edgecombe, Rick P
2021-02-03 19:36 ` Sean Christopherson
2021-02-03 23:29 ` Kai Huang
2021-02-03 23:36 ` Sean Christopherson
2021-02-03 23:45 ` Kai Huang
2021-02-03 23:59 ` Sean Christopherson
2021-02-04 0:11 ` Kai Huang
2021-02-04 2:01 ` Sean Christopherson
2021-01-26 9:31 ` [RFC PATCH v3 24/27] KVM: VMX: Add emulation of SGX Launch Control LE hash MSRs Kai Huang
2021-01-26 9:31 ` [RFC PATCH v3 25/27] KVM: VMX: Add ENCLS[EINIT] handler to support SGX Launch Control (LC) Kai Huang
2021-01-26 9:31 ` [RFC PATCH v3 26/27] KVM: VMX: Enable SGX virtualization for SGX1, SGX2 and LC Kai Huang
2021-01-26 9:32 ` [RFC PATCH v3 27/27] KVM: x86: Add capability to grant VM access to privileged SGX attribute Kai Huang
2021-02-02 22:21 ` [RFC PATCH v3 00/27] KVM SGX virtualization support Edgecombe, Rick P
2021-02-02 22:33 ` Sean Christopherson
2021-02-02 23:21 ` Dave Hansen
2021-02-02 23:56 ` Sean Christopherson
2021-02-03 0:43 ` Dave Hansen
2021-02-03 15:10 ` Dave Hansen
2021-02-03 17:36 ` Sean Christopherson
2021-02-03 17:43 ` Paolo Bonzini
2021-02-03 17:46 ` Dave Hansen
2021-02-03 23:09 ` Kai Huang
2021-02-03 23:32 ` Sean Christopherson
2021-02-03 23:37 ` Dave Hansen
2021-02-04 0:04 ` Kai Huang
2021-02-04 0:28 ` Sean Christopherson
2021-02-04 3:18 ` Kai Huang
2021-02-04 16:28 ` Sean Christopherson
2021-02-04 16:48 ` Dave Hansen
2021-02-05 12:32 ` Kai Huang
2021-02-05 16:51 ` Sean Christopherson
2021-02-02 22:36 ` Dave Hansen
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