Re: [PATCH v3 06/26] x86/virt/tdx: Prepare to support P-SEAMLDR SEAMCALLs

[Xu Yilun]

> >  static __always_inline int sc_retry_prerr(sc_func_t func,
> >  					  sc_err_func_t err_func,
> >  					  u64 fn, struct tdx_module_args *args)
> > @@ -96,4 +119,7 @@ static __always_inline int sc_retry_prerr(sc_func_t func,
> >  #define seamcall_prerr_ret(__fn, __args)					\
> >  	sc_retry_prerr(__seamcall_ret, seamcall_err_ret, (__fn), (__args))
> >  
> > +#define seamldr_prerr(__fn, __args)						\
> > +	sc_retry_prerr(__seamcall, seamldr_err, (__fn), (__args))
> > +
> >  #endif
> 
> So, honestly, for me, it's a NAK for this whole patch.
> 
> Go change the P-SEAMLDR to use the same error code as the TDX module,
> and fix the documentation. No kernel changes, please.

I'm thinking of ways to avoid a new pseamldr version.

Could we just ask for a unified error code space for both SEAMCALL &
SEAMLDR CALL, eliminating overlaps. There is no overlap now, so this is
just another documentation fix.

Then with all the doc fixes, we only need minor code change:


@@ -127,7 +127,8 @@ static __always_inline u64 sc_retry(sc_func_t func, u64 fn,
                preempt_disable();
                ret = __seamcall_dirty_cache(func, fn, args);
                preempt_enable();
-       } while (ret == TDX_RND_NO_ENTROPY && --retry);
+       } while ((ret == TDX_RND_NO_ENTROPY ||
+                 ret == SEAMLDR_RND_NO_ENTROPY) && --retry);


I think this is a balance. The existing error code philosophy for SEAM
is as informative as possible, e.g. all kinds of xxx_INVALID,
SEAMLDR_RND_NO_ENTROPY is not that evil among 200+ other error codes.