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

[Adrian Hunter <adrian.hunter@intel.com>]

On 22/11/24 19:29, Edgecombe, Rick P wrote:
> On Fri, 2024-11-22 at 08:26 -0800, Dave Hansen wrote:
>> On 11/21/24 12:14, Adrian Hunter wrote:
>>> +u64 tdh_vp_enter(u64 tdvpr, struct tdx_module_args *args)
>>> +{
>>> +   args->rcx = tdvpr;
>>> +
>>> +   return __seamcall_saved_ret(TDH_VP_ENTER, args);
>>> +}
>>> +EXPORT_SYMBOL_GPL(tdh_vp_enter);
>>
>> I made a similar comment on another series, but it stands here too: the
>> typing of this wrappers really needs a closer look. Passing u64's around
>> everywhere means zero type safety.
>>
>> Type safety is the reason that we have types like pte_t and pgprot_t in
>> mm code even though they're really just longs (most of the time).
>>
>> I'd suggest keeping the tdx_td_page type as long as possible, probably
>> until (for example) the ->rcx assignment, like this:
>>
>>       args->rcx = td_page.pa;
> 
> Any thoughts on the approach here to the type questions?
> 
> https://lore.kernel.org/kvm/20241115202028.1585487-1-rick.p.edgecombe@intel.com/

For tdh_vp_enter() we will just use the same approach for
tdvpr, whatever that ends up being.