From: Peter Zijlstra <peterz@infradead.org>
To: Yang Weijiang <weijiang.yang@intel.com>
Cc: pbonzini@redhat.com, seanjc@google.com, x86@kernel.org,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
rick.p.edgecombe@intel.com, Yu-cheng Yu <yu-cheng.yu@intel.com>,
Kees Cook <keescook@chromium.org>
Subject: Re: [PATCH 03/19] x86/cpufeatures: Enable CET CR4 bit for shadow stack
Date: Thu, 16 Jun 2022 12:25:37 +0200 [thread overview]
Message-ID: <YqsFIRDPvaEKMqIh@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20220616084643.19564-4-weijiang.yang@intel.com>
On Thu, Jun 16, 2022 at 04:46:27AM -0400, Yang Weijiang wrote:
> static __always_inline void setup_cet(struct cpuinfo_x86 *c)
> {
> + bool kernel_ibt = HAS_KERNEL_IBT && cpu_feature_enabled(X86_FEATURE_IBT);
> u64 msr = CET_ENDBR_EN;
>
> + if (kernel_ibt)
> + wrmsrl(MSR_IA32_S_CET, msr);
>
> + if (kernel_ibt || cpu_feature_enabled(X86_FEATURE_SHSTK))
> + cr4_set_bits(X86_CR4_CET);
Does flipping the CR4 and S_CET MSR write not result in simpler code?
>
> + if (kernel_ibt && !ibt_selftest()) {
> pr_err("IBT selftest: Failed!\n");
> setup_clear_cpu_cap(X86_FEATURE_IBT);
Looking at this error path; I think I forgot to clear S_CET here.
> return;
> }
> }
next prev parent reply other threads:[~2022-06-16 10:25 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-16 8:46 [PATCH 00/19] Refresh queued CET virtualization series Yang Weijiang
2022-06-16 8:46 ` [PATCH 01/19] x86/cet/shstk: Add Kconfig option for Shadow Stack Yang Weijiang
2022-06-16 8:46 ` [PATCH 02/19] x86/cpufeatures: Add CPU feature flags for shadow stacks Yang Weijiang
2022-06-16 8:46 ` [PATCH 03/19] x86/cpufeatures: Enable CET CR4 bit for shadow stack Yang Weijiang
2022-06-16 10:24 ` Peter Zijlstra
2022-06-16 17:12 ` Edgecombe, Rick P
2022-06-17 11:38 ` Peter Zijlstra
2022-06-17 21:18 ` Edgecombe, Rick P
2022-06-16 10:25 ` Peter Zijlstra [this message]
2022-06-16 17:36 ` Edgecombe, Rick P
2022-06-16 8:46 ` [PATCH 04/19] x86/fpu/xstate: Introduce CET MSR and XSAVES supervisor states Yang Weijiang
2022-06-16 10:27 ` Peter Zijlstra
2022-06-16 17:12 ` Edgecombe, Rick P
2022-06-16 8:46 ` [PATCH 05/19] x86/fpu: Add helper for modifying xstate Yang Weijiang
2022-06-16 8:46 ` [PATCH 06/19] KVM: x86: Report XSS as an MSR to be saved if there are supported features Yang Weijiang
2022-06-16 8:46 ` [PATCH 07/19] KVM: x86: Refresh CPUID on writes to MSR_IA32_XSS Yang Weijiang
2022-06-16 8:46 ` [PATCH 08/19] KVM: x86: Load guest fpu state when accessing MSRs managed by XSAVES Yang Weijiang
2022-06-16 8:46 ` [PATCH 09/19] KVM: x86: Add #CP support in guest exception classification Yang Weijiang
2022-06-16 8:46 ` [PATCH 10/19] KVM: VMX: Introduce CET VMCS fields and flags Yang Weijiang
2022-06-16 8:46 ` [PATCH 11/19] KVM: x86: Add fault checks for CR4.CET Yang Weijiang
2022-06-16 8:46 ` [PATCH 12/19] KVM: VMX: Emulate reads and writes to CET MSRs Yang Weijiang
2022-06-16 8:46 ` [PATCH 13/19] KVM: VMX: Add a synthetic MSR to allow userspace VMM to access GUEST_SSP Yang Weijiang
2022-06-16 8:46 ` [PATCH 14/19] KVM: x86: Report CET MSRs as to-be-saved if CET is supported Yang Weijiang
2022-06-16 8:46 ` [PATCH 15/19] KVM: x86: Save/Restore GUEST_SSP to/from SMM state save area Yang Weijiang
2022-06-16 8:46 ` [PATCH 16/19] KVM: x86: Enable CET virtualization for VMX and advertise CET to userspace Yang Weijiang
2022-06-16 10:59 ` Peter Zijlstra
2022-06-16 15:27 ` Yang, Weijiang
2022-06-25 6:55 ` Yang, Weijiang
2022-06-16 8:46 ` [PATCH 17/19] KVM: VMX: Pass through CET MSRs to the guest when supported Yang Weijiang
2022-06-16 8:46 ` [PATCH 18/19] KVM: nVMX: Enable CET support for nested VMX Yang Weijiang
2022-06-16 8:46 ` [PATCH 19/19] KVM: x86: Enable supervisor IBT support for guest Yang Weijiang
2022-06-16 11:05 ` Peter Zijlstra
2022-06-16 11:19 ` Peter Zijlstra
2022-06-16 15:56 ` Yang, Weijiang
2022-06-16 9:10 ` [PATCH 00/19] Refresh queued CET virtualization series Christoph Hellwig
2022-06-16 11:25 ` Peter Zijlstra
2022-06-16 10:12 ` Peter Zijlstra
2022-06-16 10:21 ` Paolo Bonzini
2022-06-16 14:18 ` Peter Zijlstra
2022-06-16 15:06 ` Yang, Weijiang
2022-06-16 15:28 ` Paolo Bonzini
2022-06-18 6:43 ` Yang, Weijiang
2022-07-14 19:36 ` Sean Christopherson
2022-07-15 15:04 ` Yang, Weijiang
2022-07-15 15:58 ` Sean Christopherson
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