Re: [PATCH v3 16/25] KVM: VMX: Move CPU_BASED_CR8_{LOAD,STORE}_EXITING filtering out of setup_vmcs_config()

Maxim Levitsky
2022-07-12T11:57:33Z

On Fri, 2022-07-08 at 16:42 +0200, Vitaly Kuznetsov wrote:
> As a preparation to reusing the result of setup_vmcs_config() in
> nested VMX MSR setup, move CPU_BASED_CR8_{LOAD,STORE}_EXITING filtering
> to vmx_exec_control().
>
> No functional change intended.
>
> Reviewed-by: Jim Mattson <jmattson@google.com>
> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
> ---
>  arch/x86/kvm/vmx/vmx.c | 13 ++++++-------
>  1 file changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index 93ca9ff8e641..d7170990f469 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -2479,11 +2479,6 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf,
>                                 MSR_IA32_VMX_PROCBASED_CTLS,
>                                 &_cpu_based_exec_control) < 0)
>                 return -EIO;
> -#ifdef CONFIG_X86_64
> -       if (_cpu_based_exec_control & CPU_BASED_TPR_SHADOW)
> -               _cpu_based_exec_control &= ~CPU_BASED_CR8_LOAD_EXITING &
> -                                          ~CPU_BASED_CR8_STORE_EXITING;
> -#endif
>         if (_cpu_based_exec_control & CPU_BASED_ACTIVATE_SECONDARY_CONTROLS) {
>                 if (adjust_vmx_controls(KVM_REQ_VMX_SECONDARY_VM_EXEC_CONTROL,
>                                         KVM_OPT_VMX_SECONDARY_VM_EXEC_CONTROL,
> @@ -4248,13 +4243,17 @@ static u32 vmx_exec_control(struct vcpu_vmx *vmx)
>         if (vmx->vcpu.arch.switch_db_regs & KVM_DEBUGREG_WONT_EXIT)
>                 exec_control &= ~CPU_BASED_MOV_DR_EXITING;
>
> -       if (!cpu_need_tpr_shadow(&vmx->vcpu)) {
> +       if (!cpu_need_tpr_shadow(&vmx->vcpu))
>                 exec_control &= ~CPU_BASED_TPR_SHADOW;
> +
>  #ifdef CONFIG_X86_64
> +       if (exec_control & CPU_BASED_TPR_SHADOW)
> +               exec_control &= ~(CPU_BASED_CR8_LOAD_EXITING |
> +                                 CPU_BASED_CR8_STORE_EXITING);
> +       else
>                 exec_control |= CPU_BASED_CR8_STORE_EXITING |
>                                 CPU_BASED_CR8_LOAD_EXITING;
>  #endif
> -       }
>         if (!enable_ept)
>                 exec_control |= CPU_BASED_CR3_STORE_EXITING |
>                                 CPU_BASED_CR3_LOAD_EXITING  |

Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>

Best regards,
Maxim Levitsky