On 13/12/24 18:16, Dave Hansen wrote:
> 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.
That sounds like what we have at present? That is:
u64 tdh_vp_enter(u64 tdvpr, struct tdx_module_args *args)
{
args->rcx = tdvpr;
return __seamcall_saved_ret(TDH_VP_ENTER, args);
}
And then either add Rick's struct tdx_vp? Like so:
u64 tdh_vp_enter(struct tdx_vp *vp, struct tdx_module_args *args)
{
args->rcx = tdx_tdvpr_pa(vp);
return __seamcall_saved_ret(TDH_VP_ENTER, args);
}
Or leave it to the caller:
u64 tdh_vp_enter(struct tdx_module_args *args)
{
return __seamcall_saved_ret(TDH_VP_ENTER, args);
}
Or forget the wrapper altogether, and let KVM call
__seamcall_saved_ret() ?
