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charset=UTF-8 Content-Transfer-Encoding: 7bit On 11/21/25 04:54, Xu Yilun wrote: ... > For now, TDX Module Extensions consume quite large amount of memory > (12800 pages), print this readout value on TDX Module Extentions > initialization. Overall, the description is looking better, thanks! A few more nits, though. Please don't talk about things in terms of number of pages. Just give the usage in megabytes. >>> --- a/arch/x86/virt/vmx/tdx/tdx.h >>> +++ b/arch/x86/virt/vmx/tdx/tdx.h >>> @@ -46,6 +46,7 @@ >>> #define TDH_PHYMEM_PAGE_WBINVD 41 >>> #define TDH_VP_WR 43 >>> #define TDH_SYS_CONFIG 45 >>> +#define TDH_SYS_CONFIG_V1 (TDH_SYS_CONFIG | (1ULL << TDX_VERSION_SHIFT)) >>> >>> And if a SEAMCALL needs export, add new tdh_foobar() helper. Anyway >>> the parameter list should be different. >> >> I'd need quite a bit of convincing that this is the right way. >> >> What is the scenario where there's a: >> >> TDH_SYS_CONFIG_V1 >> and >> TDH_SYS_CONFIG_V2 >> >> in the tree at the same time? > > I assume you mean TDH_SYS_CONFIG & TDH_SYS_CONFIG_V1. Sure. But I wasn't being that literal about it. My point was whether we need two macros for two simultaneous uses of the same seamcall. > If you want to enable optional features via this seamcall, you must use > v1, otherwise v0 & v1 are all good. Mm... I suddenly don't see usecase > they must co-exist. Unconditionally use v1 is fine. So does TDH_VP_INIT. > > Does that mean we don't have to keep versions, always use the latest is > good? (Proper Macro to be used...) > > -#define TDH_SYS_CONFIG 45 > +#define TDH_SYS_CONFIG (45 | (1ULL << TDX_VERSION_SHIFT)) That's my theory: we don't need to keep versions. >> Second, does it hurt to pass the version along with other calls, like >> ... (naming a random one) ... TDH_PHYMEM_PAGE_WBINVD ? > > I see no runtime hurt, just an extra zero parameter passed around. > > And version change always goes with more parameters, if we add version > parameter, it looks like: > > u64 tdh_phymem_page_wbinvd_tdr(int version, struct tdx_td *td, int new_param1, int new_param2); > > For readability, I prefer the following, they provide clear definitions: > > u64 tdh_phymem_page_wbinvd_tdr(struct tdx_td *td); > u64 tdh_phymem_page_wbinvd_tdr_1(struct tdx_td *td, int new_param1, int new_param2); > > But I hope eventually we don't have to keep versions, then we don't have to choose: > > u64 tdh_phymem_page_wbinvd_tdr(struct tdx_td *td, int new_param1, int new_param2); Sure, but that's not happening today. So for TDX_FEATURES0_TDXCONNECT at least, config_tdx_module() doesn't change. > The TDX Module can only accept one root page (i.e. 512 HPAs at most), while > struct tdx_page_array contains the whole EXT memory (12800 pages). So we > can't populate all pages into one root page then tell TDX Module. We need to > populate one batch, tell tdx module, then populate the next batch, tell > tdx module... That is, indeed, the information that I was looking for. Can you please ensure that makes it into code comments?