On Thu, Jun 29, 2023 at 09:15:39AM +0000, Huang, Kai wrote: > Sure. How about below? > > + /* > + * TDH.SYS.INFO writes the TDSYSINFO_STRUCT and the CMR array > + * to the buffers provided by the kernel (via RCX and R8 > + * respectively). The buffer size of the TDSYSINFO_STRUCT > + * (via RDX) and the maximum entries of the CMR array (via R9) > + * passed to this SEAMCALL must be at least the size of > + * TDSYSINFO_STRUCT and MAX_CMRS respectively. > + * > + * Upon a successful return, R9 contains the actual entries > + * written to the CMR array. > + */ > sysinfo_pa = __pa(sysinfo); > cmr_array_pa = __pa(cmr_array); > ret = seamcall(TDH_SYS_INFO, sysinfo_pa, TDSYSINFO_STRUCT_SIZE, > Or should I just repeat the spec like below? > + /* > + * TDH.SYS.INFO writes the TDSYSINFO_STRUCT and the CMR array > + * to the buffers provided by the kernel: > + * > + * Input: > + * - RCX: The buffer of TDSYSINFO_STRUCT > + * - RDX: The size of the TDSYSINFO_STRUCT buffer, must be at > + * at least the size of TDSYSINFO_STRUCT > + * - R8: The buffer of the CMR array > + * - R9: The entry number of the array, must be at least > + * MAX_CMRS. > + * > + * Output (successful): > + * - RDX: The actual bytes written to the TDSYSINFO_STRUCT > + * buffer > + * - R9: The actual entries written to the CMR array. > + */ > sysinfo_pa = __pa(sysinfo); > cmr_array_pa = __pa(cmr_array); > ret = seamcall(TDH_SYS_INFO, sysinfo_pa, TDSYSINFO_STRUCT_SIZE, Either of them work for me, thanks! > > SDM doesn't seem to be the place. That doesn't > > even list TDCALL/SEAMCALL in Volume 2 :-( Let alone describe the magic > > values. > > > > TDX has it's own specs at here: > > https://www.intel.com/content/www/us/en/developer/articles/technical/intel-trust-domain-extensions.html > > For this one you can find it in here: > > https://cdrdv2.intel.com/v1/dl/getContent/733568 Yeah, eventually found it. I still think both TDCALL and SEAMCALL should be listed in SDM Vol.2 instruction listing -- every valid instruction should be found there IMO. I also feel strongly that a global ABI should be decided upon for them and the SDM would be a good place to mention that. leaving this to individual calls like now is a giant pain in the rear. As is, we have TDCALL leaf-0 with a giant regset but every other leaf has (c,d,8,9) for input and +(10,11) for output. Lets fix that in stone. Obviously I also very strongly feel any such ABI must not confict with pre-existing calling conventions -- IOW, using BP is out, must not happen.
