Re: [PATCH v3 3/6] x86/virt/tdx: Add extra memory to TDX module for the extensions

[Xu Yilun]

On Fri, Oct 09, 2026 at 06:58:44PM +0000, Edgecombe, Rick P wrote:
> On Tue, 2026-10-06 at 01:41 +0800, Xu Yilun wrote:
> > +static __init int tdx_ext_mem_setup(void)
> > +{
> > +	unsigned int required_pages, added_pages;
> > +	struct tdx_sys_info_ext sysinfo_ext;
> > +	struct tdx_hpa_list *hpa_list;
> > +	struct page *page;
> > +	int ret;
> > +
> > +	ret = get_tdx_sys_info_ext(&sysinfo_ext);
> > +	if (ret)
> > +		return ret;
> > +
> > +	required_pages = sysinfo_ext.memory_pool_required_pages;
> > +
> > +	/*
> > +	 * Skip the memory setup if no memory is required. This may happen when
> > +	 * no add-on features requiring TDX module extensions are configured
> > +	 * via TDH.SYS.CONFIG.
> > +	 */
> > +	if (!required_pages)
> > +		return 0;
> 
> Marshaling this through the struct just to get a set it to required_pages seems
> a bit silly. But I see required_pages is needed for line length.
> 
> Two options:
> 
> Make the get_tdx_sys_info_ext() just take an unsigned int pointer arg. When
> Chao's metadata reading stuff lands, we can keep the struct internal to the
> helper, to still re-use the macro struct mapper stuff.

struct tdx_sys_info_handoff is an existing example so I don't want to
make it different.

> 
> Rename memory_pool_required_pages to required_pages to shorten the lines to
> something manageable and use it directly below.

I prefer the 2nd one. I also want to rename the sysinfo_ext to ext, to
make the field short enough for direct usage everywhere.

  struct tdx_sys_info ext ext;

  ret = get_tdx_sys_info_ext(&ext);
  if (ret)
	return ret;

  if (!ext.required_pages)
	return 0;

  ...