Re: [PATCH v17 007/116] KVM: TDX: Make TDX VM type supported

[Sagi Shahar <sagis@google.com>]

On Tue, Nov 7, 2023 at 6:57 AM <isaku.yamahata@intel.com> wrote:
>
> From: Isaku Yamahata <isaku.yamahata@intel.com>
>
> NOTE: This patch is in position of the patch series for developers to be
> able to test codes during the middle of the patch series although this
> patch series doesn't provide functional features until the all the patches
> of this patch series.  When merging this patch series, this patch can be
> moved to the end.
>
> As first step TDX VM support, return that TDX VM type supported to device
> model, e.g. qemu.  The callback to create guest TD is vm_init callback for
> KVM_CREATE_VM.
>
> Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
> ---
>  arch/x86/kvm/vmx/main.c    | 18 ++++++++++++++++--
>  arch/x86/kvm/vmx/tdx.c     |  6 ++++++
>  arch/x86/kvm/vmx/vmx.c     |  6 ------
>  arch/x86/kvm/vmx/x86_ops.h |  3 ++-
>  4 files changed, 24 insertions(+), 9 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
> index 2b805bb95b9e..73a1c4b64819 100644
> --- a/arch/x86/kvm/vmx/main.c
> +++ b/arch/x86/kvm/vmx/main.c
> @@ -10,6 +10,12 @@
>  static bool enable_tdx __ro_after_init;
>  module_param_named(tdx, enable_tdx, bool, 0444);
>
> +static bool vt_is_vm_type_supported(unsigned long type)
> +{
> +       return __kvm_is_vm_type_supported(type) ||
> +               (enable_tdx && tdx_is_vm_type_supported(type));
> +}
> +
>  static int vt_hardware_enable(void)
>  {
>         int ret;
> @@ -37,6 +43,14 @@ static __init int vt_hardware_setup(void)
>         return 0;
>  }
>
> +static int vt_vm_init(struct kvm *kvm)
> +{
> +       if (is_td(kvm))
> +               return -EOPNOTSUPP;     /* Not ready to create guest TD yet. */
> +
> +       return vmx_vm_init(kvm);
> +}
> +
>  #define VMX_REQUIRED_APICV_INHIBITS                            \
>         (BIT(APICV_INHIBIT_REASON_DISABLE)|                     \
>          BIT(APICV_INHIBIT_REASON_ABSENT) |                     \
> @@ -57,9 +71,9 @@ struct kvm_x86_ops vt_x86_ops __initdata = {
>         .hardware_disable = vmx_hardware_disable,
>         .has_emulated_msr = vmx_has_emulated_msr,
>
> -       .is_vm_type_supported = vmx_is_vm_type_supported,
> +       .is_vm_type_supported = vt_is_vm_type_supported,

I don't see is_vm_type_supported defined at HEAD.
I could only find it here:
https://lore.kernel.org/lkml/ab9d8654bd98ae24de05788a2ecaa4bea6c0c44b.1689893403.git.isaku.yamahata@intel.com/#r
Is [RFC PATCH v4 00/10] KVM: guest_memfd(), X86: Common base ..." a
dependency for this patch series?

>         .vm_size = sizeof(struct kvm_vmx),
> -       .vm_init = vmx_vm_init,
> +       .vm_init = vt_vm_init,
>         .vm_destroy = vmx_vm_destroy,
>
>         .vcpu_precreate = vmx_vcpu_precreate,
> diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
> index 1c9884164566..9d3f593eacb8 100644
> --- a/arch/x86/kvm/vmx/tdx.c
> +++ b/arch/x86/kvm/vmx/tdx.c
> @@ -24,6 +24,12 @@ static int __init tdx_module_setup(void)
>         return 0;
>  }
>
> +bool tdx_is_vm_type_supported(unsigned long type)
> +{
> +       /* enable_tdx check is done by the caller. */
> +       return type == KVM_X86_TDX_VM;
> +}
> +
>  struct vmx_tdx_enabled {
>         cpumask_var_t vmx_enabled;
>         atomic_t err;
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index 34165a3c99fa..83b0b62cab6c 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -7532,12 +7532,6 @@ int vmx_vcpu_create(struct kvm_vcpu *vcpu)
>         return err;
>  }
>
> -bool vmx_is_vm_type_supported(unsigned long type)
> -{
> -       /* TODO: Check if TDX is supported. */
> -       return __kvm_is_vm_type_supported(type);
> -}
> -
>  #define L1TF_MSG_SMT "L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1tf.html for details.\n"
>  #define L1TF_MSG_L1D "L1TF CPU bug present and virtualization mitigation disabled, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1tf.html for details.\n"
>
> diff --git a/arch/x86/kvm/vmx/x86_ops.h b/arch/x86/kvm/vmx/x86_ops.h
> index 86c8ee6954e5..ed9147f7b958 100644
> --- a/arch/x86/kvm/vmx/x86_ops.h
> +++ b/arch/x86/kvm/vmx/x86_ops.h
> @@ -28,7 +28,6 @@ void vmx_hardware_unsetup(void);
>  int vmx_check_processor_compat(void);
>  int vmx_hardware_enable(void);
>  void vmx_hardware_disable(void);
> -bool vmx_is_vm_type_supported(unsigned long type);
>  int vmx_vm_init(struct kvm *kvm);
>  void vmx_vm_destroy(struct kvm *kvm);
>  int vmx_vcpu_precreate(struct kvm *kvm);
> @@ -137,8 +136,10 @@ void vmx_setup_mce(struct kvm_vcpu *vcpu);
>
>  #ifdef CONFIG_INTEL_TDX_HOST
>  int __init tdx_hardware_setup(struct kvm_x86_ops *x86_ops);
> +bool tdx_is_vm_type_supported(unsigned long type);
>  #else
>  static inline int tdx_hardware_setup(struct kvm_x86_ops *x86_ops) { return -EOPNOTSUPP; }
> +static inline bool tdx_is_vm_type_supported(unsigned long type) { return false; }
>  #endif
>
>  #endif /* __KVM_X86_VMX_X86_OPS_H */
> --
> 2.25.1
>