Re: [PATCH v19 125/130] KVM: TDX: Add methods to ignore virtual apic related operation

[Binbin Wu]

On 2/26/2024 4:27 PM, isaku.yamahata@xxxxxxxxx wrote:
> From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
>
> TDX protects TDX guest APIC state from VMM.  Implement access methods of
> TDX guest vAPIC state to ignore them or return zero.
>
> Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
> ---
>   arch/x86/kvm/vmx/main.c    | 61 ++++++++++++++++++++++++++++++++++----
>   arch/x86/kvm/vmx/tdx.c     |  6 ++++
>   arch/x86/kvm/vmx/x86_ops.h |  3 ++
>   3 files changed, 64 insertions(+), 6 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
> index fae5a3668361..c46c860be0f2 100644
> --- a/arch/x86/kvm/vmx/main.c
> +++ b/arch/x86/kvm/vmx/main.c
> @@ -352,6 +352,14 @@ static bool vt_apic_init_signal_blocked(struct kvm_vcpu *vcpu)
>   	return vmx_apic_init_signal_blocked(vcpu);
>   }
>   
> +static void vt_set_virtual_apic_mode(struct kvm_vcpu *vcpu)
> +{
> +	if (is_td_vcpu(vcpu))
> +		return tdx_set_virtual_apic_mode(vcpu);
Can open code this function...

> +
> +	return vmx_set_virtual_apic_mode(vcpu);
> +}
> +
[...]
>   
> +void tdx_set_virtual_apic_mode(struct kvm_vcpu *vcpu)
> +{
> +	/* Only x2APIC mode is supported for TD. */
> +	WARN_ON_ONCE(kvm_get_apic_mode(vcpu) != LAPIC_MODE_X2APIC);
> +}
> +