Re: [PATCH] KVM: nVMX: Remove outdated comments in nested_vmx_setup_ctls_msrs().

From: Sean Christopherson
Date: Thu Dec 15 2022 - 13:23:27 EST


On Thu, Dec 15, 2022, Yu Zhang wrote:
> nested_vmx_setup_ctls_msrs() initializes the vmcs_conf.nested,
> which stores the global VMX MSR configurations when nested is
> supported, regardless of any particular CPUID settings for one
> VM.
>
> Commit 6defc591846d ("KVM: nVMX: include conditional controls
> in /dev/kvm KVM_GET_MSRS") added the some feature flags for
> secondary proc-based controls, so that those features can be
> available in KVM_GET_MSRS. Yet this commit did not remove the
> obsolete comments in nested_vmx_setup_ctls_msrs().
>
> Just fix the comments, and no functional change intended.
>
> Fixes: 6defc591846d ("KVM: nVMX: include conditional controls in /dev/kvm KVM_GET_MSRS")
> Reported-by: Sean Christopherson <seanjc@xxxxxxxxxx>

I appreciate the nod, but you found this, not me :-)

> Signed-off-by: Yu Zhang <yu.c.zhang@xxxxxxxxxxxxxxx>
> ---
> arch/x86/kvm/vmx/nested.c | 6 +-----
> 1 file changed, 1 insertion(+), 5 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
> index b6f4411b613e..76cca5d5aa6b 100644
> --- a/arch/x86/kvm/vmx/nested.c
> +++ b/arch/x86/kvm/vmx/nested.c
> @@ -6854,11 +6854,7 @@ void nested_vmx_setup_ctls_msrs(struct vmcs_config *vmcs_conf, u32 ept_caps)
> msrs->procbased_ctls_low &=
> ~(CPU_BASED_CR3_LOAD_EXITING | CPU_BASED_CR3_STORE_EXITING);
>
> - /*
> - * secondary cpu-based controls. Do not include those that
> - * depend on CPUID bits, they are added later by
> - * vmx_vcpu_after_set_cpuid.
> - */
> + /* secondary cpu-based controls */

Eh, just drop the comment. Pretty obvious this is for secondary execution controls.

> msrs->secondary_ctls_low = 0;
>
> msrs->secondary_ctls_high = vmcs_conf->cpu_based_2nd_exec_ctrl;
> --
> 2.17.1
>