Re: [PATCH 09/25] KVM: TDX: Get system-wide info about TDX module on initialization

Binbin Wu
2024-08-14T06:18:49Z

On 8/13/2024 6:48 AM, Rick Edgecombe wrote:
> From: Isaku Yamahata <isaku.yamahata@intel.com>
>
> TDX KVM needs system-wide information about the TDX module, store it in
> struct tdx_info. Release the allocated memory on module unloading by
> hardware_unsetup() callback.
>
> Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
> Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
> ---
> uAPI breakout v1:
> - Mention about hardware_unsetup(). (Binbin)
> - Added Reviewed-by. (Binbin)
> - Eliminated tdx_md_read(). (Kai)
> - Include "x86_ops.h" to tdx.c as the patch to initialize TDX module
> doesn't include it anymore.
> - Introduce tdx_vm_ioctl() as the first tdx func in x86_ops.h
>
> v19:
> - Added features0
> - Use tdx_sys_metadata_read()
> - Fix error recovery path by Yuan
>
> Change v18:
> - Newly Added
> ---
> arch/x86/include/uapi/asm/kvm.h | 28 +++++++++++++
> arch/x86/kvm/vmx/tdx.c | 70 +++++++++++++++++++++++++++++++++
> 2 files changed, 98 insertions(+)
>
> diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h
> index d91f1bad800e..47caf508cca7 100644
> --- a/arch/x86/include/uapi/asm/kvm.h
> +++ b/arch/x86/include/uapi/asm/kvm.h
> @@ -952,4 +952,32 @@ struct kvm_tdx_cmd {
> __u64 hw_error;
> };
>
> +#define KVM_TDX_CPUID_NO_SUBLEAF ((__u32)-1)
> +
> +struct kvm_tdx_cpuid_config {
> + __u32 leaf;
> + __u32 sub_leaf;
> + __u32 eax;
> + __u32 ebx;
> + __u32 ecx;
> + __u32 edx;
> +};

I am wondering if there is any specific reason to define a new structure
instead of using 'struct kvm_cpuid_entry2'?

> +
> +/* supported_gpaw */
> +#define TDX_CAP_GPAW_48 (1 << 0)
> +#define TDX_CAP_GPAW_52 (1 << 1)
> +
> +struct kvm_tdx_capabilities {
> + __u64 attrs_fixed0;
> + __u64 attrs_fixed1;
> + __u64 xfam_fixed0;
> + __u64 xfam_fixed1;
> + __u32 supported_gpaw;
> + __u32 padding;
> + __u64 reserved[251];
> +
> + __u32 nr_cpuid_configs;
> + struct kvm_tdx_cpuid_config cpuid_configs[];
> +};
> +