Received-SPF: pass (google.com: domain of linux-kernel+bounces-210040-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45d1:ec00::1 as permitted sender) client-ip=2604:1380:45d1:ec00::1;
Precedence: bulk
MIME-Version: 1.0
References: <cover.1708933498.git.isaku.yamahata@intel.com>
 <9c4547ea234a2ba09ebe05219f180f08ac6fc2e3.1708933498.git.isaku.yamahata@intel.com>
 <ZiJ3Krs_HoqdfyWN@google.com> <aefee0c0-6931-4677-932e-e61db73b63a2@linux.intel.com>
In-Reply-To: <aefee0c0-6931-4677-932e-e61db73b63a2@linux.intel.com>
From: Paolo Bonzini <pbonzini@redhat.com>
Date: Tue, 11 Jun 2024 16:11:23 +0200
Message-ID: <CABgObfb9DC744cQeaDeP5hbKhgVisCvxBew=pCP5JB6U1=oz-A@mail.gmail.com>
Subject: Re: [PATCH v19 116/130] KVM: TDX: Silently discard SMI request
To: Binbin Wu <binbin.wu@linux.intel.com>
Cc: Sean Christopherson <seanjc@google.com>, isaku.yamahata@intel.com, kvm@vger.kernel.org, 
	linux-kernel@vger.kernel.org, isaku.yamahata@gmail.com, erdemaktas@google.com, 
	Sagi Shahar <sagis@google.com>, Kai Huang <kai.huang@intel.com>, chen.bo@intel.com, 
	hang.yuan@intel.com, tina.zhang@intel.com
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

On Tue, Jun 11, 2024 at 3:18=E2=80=AFPM Binbin Wu <binbin.wu@linux.intel.co=
m> wrote:
> >>   }
> >>
> >> diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
> >> index ed46e7e57c18..4f3b872cd401 100644
> >> --- a/arch/x86/kvm/vmx/main.c
> >> +++ b/arch/x86/kvm/vmx/main.c
> >> @@ -283,6 +283,43 @@ static void vt_msr_filter_changed(struct kvm_vcpu=
 *vcpu)
> >>      vmx_msr_filter_changed(vcpu);
> >>   }
> >>
> >> +#ifdef CONFIG_KVM_SMM
> >> +static int vt_smi_allowed(struct kvm_vcpu *vcpu, bool for_injection)
> >> +{
> >> +    if (is_td_vcpu(vcpu))
> >> +            return tdx_smi_allowed(vcpu, for_injection);
> > Adding stubs for something that TDX will never support is silly.  Bug t=
he VM and
> > return an error.
> >
> >       if (KVM_BUG_ON(is_td_vcpu(vcpu)))
> >               return -EIO;
>
> is_td_vcpu() is defined in tdx.h.
> Do you mind using open code to check whether the VM is TD in vmx.c?
> "vcpu->kvm->arch.vm_type =3D=3D KVM_X86_TDX_VM"

I'd move it to some place that main.c can see. Or vmx.c as Sean says
below, but I am not sure I like the idea too much.

Paolo

> > And I wouldn't even bother with vt_* wrappers, just put that right in v=
mx_*().
> > Same thing for everything below.

If it's a KVM_BUG_ON()