Re: [PATCH v14 03/22] KVM: selftests: Initialize the TDX VM

[Peter Fang]

On Wed, Jul 22, 2026 at 11:13:08PM +0000, Lisa Wang wrote:
> From: Sagi Shahar <sagis@xxxxxxxxxx>
> 
> Add tdx_init_vm() to handle the mandatory VM-level initialization
> sequence required for Intel TDX.
> 
> For TDX, the guest's CPUID configuration must be "sealed" during
> KVM_TDX_INIT_VM before any vCPUs are created. This is necessary because
> the TDX hardware directly virtualizes CPUID and includes the
> configuration in the guest's initial security measurement.
> 
> The helper calculates the required CPUID values by filtering the host-
> supported bits (kvm_get_supported_cpuid) against the "directly
> configurable" bits reported by KVM_TDX_CAPABILITIES, ensuring
> compliance with the strict requirements of the TDH.MNG.INIT SEAMCALL.
> 

[ ... ]

> +
> +/*
> + * Filter CPUID based on TDX supported capabilities
> + *
> + * Input Args:
> + *   vm - Virtual Machine
> + *   cpuid_data - CPUID fields to filter
> + *
> + * Output Args: None
> + *
> + * Return: None
> + *
> + * For each CPUID leaf, filter out unsupported bits based on the capabilities
> + * reported by the TDX module
> + */
> +static void tdx_filter_cpuid(struct kvm_vm *vm,
> +			     struct kvm_cpuid2 *cpuid_data)
> +{
> +	struct kvm_tdx_capabilities *tdx_cap;
> +	const struct kvm_cpuid_entry2 *config;

Nit: reverse fir tree order i.e. declaring "config" first?

> +	struct kvm_cpuid_entry2 *e;
> +	int i;
> +