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Message-ID: <0d8141b7-804c-40e4-b9f8-ac0ebc0a84cb@intel.com>
Date: Mon, 6 May 2024 17:31:04 +0800
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH v10 00/27] Enable CET Virtualization
To: Sean Christopherson <seanjc@google.com>
CC: <pbonzini@redhat.com>, <dave.hansen@intel.com>, <x86@kernel.org>,
	<kvm@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
	<peterz@infradead.org>, <chao.gao@intel.com>, <rick.p.edgecombe@intel.com>,
	<mlevitsk@redhat.com>, <john.allen@amd.com>
References: <20240219074733.122080-1-weijiang.yang@intel.com>
 <ZjLP8jLWGOWnNnau@google.com>
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From: "Yang, Weijiang" <weijiang.yang@intel.com>
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On 5/2/2024 7:27 AM, Sean Christopherson wrote:
> On Sun, Feb 18, 2024, Yang Weijiang wrote:
>> Sean Christopherson (4):
>>    x86/fpu/xstate: Always preserve non-user xfeatures/flags in
>>      __state_perm
>>    KVM: x86: Rework cpuid_get_supported_xcr0() to operate on vCPU data
>>    KVM: x86: Report XSS as to-be-saved if there are supported features
>>    KVM: x86: Load guest FPU state when access XSAVE-managed MSRs
>>
>> Yang Weijiang (23):
>>    x86/fpu/xstate: Refine CET user xstate bit enabling
>>    x86/fpu/xstate: Add CET supervisor mode state support
>>    x86/fpu/xstate: Introduce XFEATURE_MASK_KERNEL_DYNAMIC xfeature set
>>    x86/fpu/xstate: Introduce fpu_guest_cfg for guest FPU configuration
>>    x86/fpu/xstate: Create guest fpstate with guest specific config
>>    x86/fpu/xstate: Warn if kernel dynamic xfeatures detected in normal
>>      fpstate
>>    KVM: x86: Rename kvm_{g,s}et_msr()* to menifest emulation operations
>>    KVM: x86: Refine xsave-managed guest register/MSR reset handling
>>    KVM: x86: Add kvm_msr_{read,write}() helpers
>>    KVM: x86: Refresh CPUID on write to guest MSR_IA32_XSS
>>    KVM: x86: Initialize kvm_caps.supported_xss
>>    KVM: x86: Add fault checks for guest CR4.CET setting
>>    KVM: x86: Report KVM supported CET MSRs as to-be-saved
>>    KVM: VMX: Introduce CET VMCS fields and control bits
>>    KVM: x86: Use KVM-governed feature framework to track "SHSTK/IBT
>>      enabled"
>>    KVM: VMX: Emulate read and write to CET MSRs
>>    KVM: x86: Save and reload SSP to/from SMRAM
>>    KVM: VMX: Set up interception for CET MSRs
>>    KVM: VMX: Set host constant supervisor states to VMCS fields
>>    KVM: x86: Enable CET virtualization for VMX and advertise to userspace
>>    KVM: nVMX: Introduce new VMX_BASIC bit for event error_code delivery
>>      to L1
>>    KVM: nVMX: Enable CET support for nested guest
>>    KVM: x86: Don't emulate instructions guarded by CET
> A decent number of comments, but almost all of them are quite minor.  The big
> open is how to handle save/restore of SSP from userspace.
>
> Instead of spinning a full v10, maybe send an RFC for KVM_{G,S}ET_ONE_REG idea?

OK, I'll send an RFC patch after relevant discussion is settled.

> That will make it easier to review, and if you delay v11 a bit, I should be able
> to get various series applied that have minor conflicts/dependencies, e.g. the
> MSR access and the kvm_host series.
I can wait until the series landed in x86-kvm tree.
Appreciated for your review and comments!