Re: [PATCH v13 004/113] KVM: TDX: Initialize logical processor when onlined

From: Huang, Kai
Date: Wed Mar 15 2023 - 05:59:29 EST


On Sun, 2023-03-12 at 10:55 -0700, isaku.yamahata@xxxxxxxxx wrote:
> From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
>
> TDX requires to call a TDX initialization function per logical processor
> (LP) before the LP uses TDX. When CPU is onlined, call the TDX LP
> initialization API when cpu is onlined.  
>

Double "when CPU is onlined".

> If it failed refuse onlininig of
> the cpu for simplicity instead of TDX avoiding the LP.

Sorry cannot understand this sentence, particularly, the "instead ..." part.

>
> Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
> ---
> arch/x86/kvm/vmx/main.c | 15 ++++++++++++++-
> arch/x86/kvm/vmx/tdx.c | 5 +++++
> arch/x86/kvm/vmx/x86_ops.h | 2 ++
> 3 files changed, 21 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
> index 5c9f5e00b3c4..d1c9c7f55050 100644
> --- a/arch/x86/kvm/vmx/main.c
> +++ b/arch/x86/kvm/vmx/main.c
> @@ -9,6 +9,19 @@
> static bool enable_tdx __ro_after_init;
> module_param_named(tdx, enable_tdx, bool, 0444);
>
> +static int vt_hardware_enable(void)
> +{
> + int ret;
> +
> + ret = vmx_hardware_enable();
> + if (!ret && enable_tdx) {
> + ret = tdx_hardware_enable();
> + if (ret)
> + vmx_hardware_disable();
> + }
> + return ret;
> +}
> +
> static __init int vt_hardware_setup(void)
> {
> int ret;
> @@ -40,7 +53,7 @@ struct kvm_x86_ops vt_x86_ops __initdata = {
>
> .hardware_unsetup = vmx_hardware_unsetup,
>
> - .hardware_enable = vmx_hardware_enable,
> + .hardware_enable = vt_hardware_enable,
> .hardware_disable = vmx_hardware_disable,
> .has_emulated_msr = vmx_has_emulated_msr,
>
> diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
> index f3eb0138b60b..e51314bbb439 100644
> --- a/arch/x86/kvm/vmx/tdx.c
> +++ b/arch/x86/kvm/vmx/tdx.c
> @@ -10,6 +10,11 @@
> #undef pr_fmt
> #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
>
> +int tdx_hardware_enable(void)
> +{
> + return tdx_cpu_enable();
> +}
> +
> static int __init tdx_module_setup(void)
> {
> int ret;
> diff --git a/arch/x86/kvm/vmx/x86_ops.h b/arch/x86/kvm/vmx/x86_ops.h
> index 0f200aead411..010d02c86ba4 100644
> --- a/arch/x86/kvm/vmx/x86_ops.h
> +++ b/arch/x86/kvm/vmx/x86_ops.h
> @@ -139,8 +139,10 @@ void vmx_setup_mce(struct kvm_vcpu *vcpu);
>
> #ifdef CONFIG_INTEL_TDX_HOST
> int __init tdx_hardware_setup(struct kvm_x86_ops *x86_ops);
> +int tdx_hardware_enable(void);
> #else
> static inline int tdx_hardware_setup(struct kvm_x86_ops *x86_ops) { return -ENOSYS; }
> +static inline int tdx_hardware_enable(void) { return -EOPNOTSUPP; }
> #endif
>
> #endif /* __KVM_X86_VMX_X86_OPS_H */