Re: [PATCH v10 00/27] Enable CET Virtualization

[Yang, Weijiang]

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!