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From: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>
To: "peterz@infradead.org" <peterz@infradead.org>,
	"Yang, Weijiang" <weijiang.yang@intel.com>,
	"pbonzini@redhat.com" <pbonzini@redhat.com>, "Christopherson,,
	Sean" <seanjc@google.com>,
	"john.allen@amd.com" <john.allen@amd.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>
Subject: Re: [PATCH v2 21/21] KVM:x86: Support CET supervisor shadow stack MSR access
Date: Wed, 3 May 2023 17:07:15 +0000	[thread overview]
Message-ID: <175c826d59f1ac77fa588908d3768ffc2e79268e.camel@intel.com> (raw)
In-Reply-To: <20230421134615.62539-22-weijiang.yang@intel.com>

On Fri, 2023-04-21 at 09:46 -0400, Yang Weijiang wrote:
> +
> +       incpt = !is_cet_state_supported(vcpu,
> XFEATURE_MASK_CET_KERNEL);
> +       incpt |= !guest_cpuid_has(vcpu, X86_FEATURE_SHSTK);
> +
> +       vmx_set_intercept_for_msr(vcpu, MSR_IA32_INT_SSP_TAB,
> MSR_TYPE_RW, incpt);
> +       vmx_set_intercept_for_msr(vcpu, MSR_IA32_PL0_SSP,
> MSR_TYPE_RW, incpt);
> +       vmx_set_intercept_for_msr(vcpu, MSR_IA32_PL1_SSP,
> MSR_TYPE_RW, incpt);
> +       vmx_set_intercept_for_msr(vcpu, MSR_IA32_PL2_SSP,
> MSR_TYPE_RW, incpt);
>  }

Why is this tied to XFEATURE_MASK_CET_KERNEL? I don't know how the SVM
side works, but the host kernel doesn't use this xfeature. Just not
clear on what the intention is. Why not use
kvm_cet_kernel_shstk_supported() again?

  parent reply	other threads:[~2023-05-03 17:10 UTC|newest]

Thread overview: 50+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-04-21 13:45 [PATCH v2 00/21] Enable CET Virtualization Yang Weijiang
2023-04-21 13:45 ` [PATCH v2 01/21] x86/shstk: Add Kconfig option for shadow stack Yang Weijiang
2023-04-21 13:45 ` [PATCH v2 02/21] x86/cpufeatures: Add CPU feature flags for shadow stacks Yang Weijiang
2023-04-21 13:45 ` [PATCH v2 03/21] x86/cpufeatures: Enable CET CR4 bit for shadow stack Yang Weijiang
2023-04-21 13:45 ` [PATCH v2 04/21] x86/fpu/xstate: Introduce CET MSR and XSAVES supervisor states Yang Weijiang
2023-04-21 13:45 ` [PATCH v2 05/21] x86/fpu: Add helper for modifying xstate Yang Weijiang
2023-04-21 13:46 ` [PATCH v2 06/21] KVM:x86: Report XSS as to-be-saved if there are supported features Yang Weijiang
2023-04-21 13:46 ` [PATCH v2 07/21] KVM:x86: Refresh CPUID on write to guest MSR_IA32_XSS Yang Weijiang
2023-04-24  1:38   ` Binbin Wu
2023-04-24  6:15     ` Yang, Weijiang
2023-04-21 13:46 ` [PATCH v2 08/21] KVM:x86: Init kvm_caps.supported_xss with supported feature bits Yang Weijiang
2023-04-21 13:46 ` [PATCH v2 09/21] KVM:x86: Load guest FPU state when accessing xsaves-managed MSRs Yang Weijiang
2023-04-27  3:46   ` Binbin Wu
2023-04-27 15:57     ` Yang, Weijiang
2023-04-21 13:46 ` [PATCH v2 10/21] KVM:x86: Add #CP support in guest exception classification Yang Weijiang
2023-04-28  6:09   ` Binbin Wu
2023-05-04  3:41     ` Yang, Weijiang
2023-05-04  5:36       ` Binbin Wu
2023-05-04  6:59         ` Yang, Weijiang
2023-04-21 13:46 ` [PATCH v2 11/21] KVM:VMX: Introduce CET VMCS fields and control bits Yang Weijiang
2023-05-05  2:18   ` Binbin Wu
2023-05-05  2:22   ` Binbin Wu
2023-05-05  7:07     ` Yang, Weijiang
2023-04-21 13:46 ` [PATCH v2 12/21] KVM:x86: Add fault checks for guest CR4.CET setting Yang Weijiang
2023-05-05  5:01   ` Binbin Wu
2023-05-05  7:24     ` Yang, Weijiang
2023-04-21 13:46 ` [PATCH v2 13/21] KVM:VMX: Emulate reads and writes to CET MSRs Yang Weijiang
2023-04-21 13:46 ` [PATCH v2 14/21] KVM:VMX: Add a synthetic MSR to allow userspace VMM to access GUEST_SSP Yang Weijiang
2023-05-03 17:08   ` Edgecombe, Rick P
2023-05-04  1:30     ` Yang, Weijiang
2023-04-21 13:46 ` [PATCH v2 15/21] KVM:x86: Report CET MSRs as to-be-saved if CET is supported Yang Weijiang
2023-04-21 13:46 ` [PATCH v2 16/21] KVM:x86: Save/Restore GUEST_SSP to/from SMM state save area Yang Weijiang
2023-04-21 13:46 ` [PATCH v2 17/21] KVM:VMX: Pass through user CET MSRs to the guest Yang Weijiang
2023-04-21 13:46 ` [PATCH v2 18/21] KVM:x86: Enable CET virtualization for VMX and advertise to userspace Yang Weijiang
2023-04-21 13:46 ` [PATCH v2 19/21] KVM:nVMX: Enable user CET support for nested VMX Yang Weijiang
2023-04-21 13:46 ` [PATCH v2 20/21] KVM:x86: Enable supervisor IBT support for guest Yang Weijiang
2023-04-21 13:46 ` [PATCH v2 21/21] KVM:x86: Support CET supervisor shadow stack MSR access Yang Weijiang
2023-05-03 17:06   ` Edgecombe, Rick P
2023-05-04  1:11     ` Yang, Weijiang
2023-05-03 17:07   ` Edgecombe, Rick P [this message]
2023-05-04  1:20     ` Yang, Weijiang
2023-05-04  4:17       ` Edgecombe, Rick P
2023-05-04  6:51         ` Yang, Weijiang
2023-04-21 21:54 ` [PATCH v2 00/21] Enable CET Virtualization Mike Rapoport
2023-04-23  5:37   ` Yang, Weijiang
2023-04-24 18:22   ` John Allen
2023-04-22 13:02 ` Peter Zijlstra
2023-04-23  6:12   ` Yang, Weijiang
2023-04-23  8:30 ` Binbin Wu
2023-04-24  6:12   ` Yang, Weijiang

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