Messages in this thread | ![/](/images/icornerl.gif) | | From | "Huang, Kai" <> | Subject | Re: [PATCH v11 10/20] x86/virt/tdx: Add placeholder to construct TDMRs to cover all TDX memory regions | Date | Thu, 8 Jun 2023 10:18:31 +0000 |
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On Wed, 2023-06-07 at 08:57 -0700, Dave Hansen wrote: > On 6/4/23 07:27, Kai Huang wrote: > > +struct tdmr_info_list { > > + void *tdmrs; /* Flexible array to hold 'tdmr_info's */ > > + int nr_consumed_tdmrs; /* How many 'tdmr_info's are in use */ > > I'm looking back here after seeing the weird cast in the next patch. > > Why is this a void* instead of a _real_ type?
I followed your suggestion in v8:
https://lore.kernel.org/linux-mm/725de6e9-e468-48ef-3bae-1e8a1b7ef0f7@intel.com/
I quoted the relevant part here:
> +/* Get the TDMR from the list at the given index. */ > +static struct tdmr_info *tdmr_entry(struct tdmr_info_list *tdmr_list, > + int idx) > +{ > + return (struct tdmr_info *)((unsigned long)tdmr_list->first_tdmr + > + tdmr_list->tdmr_sz * idx); > +}
I think that's more complicated and has more casting than necessary. This looks nicer:
int tdmr_info_offset = tdmr_list->tdmr_sz * idx;
return (void *)tdmr_list->first_tdmr + tdmr_info_offset;
Also, it might even be worth keeping ->first_tdmr as a void*. It isn't a real C array and keeping it as void* would keep anyone from doing:
tdmr_foo = tdmr_list->first_tdmr[foo];
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