Re: [PATCH RFC 1/7] x86/virt/tdx: Add SEAMCALL wrapper to enter/exit TDX guest

[Dave Hansen]

On 12/11/24 10:43, Adrian Hunter wrote:
...
> -	size = tdvmcall_a0_read(vcpu);
> -	write = tdvmcall_a1_read(vcpu);
> -	port = tdvmcall_a2_read(vcpu);
> +	size  = tdx->vp_enter_out.io_size;
> +	write = tdx->vp_enter_out.io_direction == TDX_WRITE;
> +	port  = tdx->vp_enter_out.io_port;
...> +	case TDVMCALL_IO:
> +		out->io_size		= args.r12;
> +		out->io_direction	= args.r13 ? TDX_WRITE : TDX_READ;
> +		out->io_port		= args.r14;
> +		out->io_value		= args.r15;
> +		break;

I honestly don't understand the need for the abstracted structure to sit
in the middle. It doesn't get stored or serialized or anything, right?
So why have _another_ structure?

Why can't this just be (for instance):

	size = tdx->foo.r12;

?

Basically, you hand around the raw arguments until you need to use them.