linux-kernel - Re: [RFC PATCH v2 03/23] x86/tdx: Enhance tdh_phymem_page_wbinvd

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Message-ID: <745d70bf-feec-46d5-b3f7-2bb86cd8bbb1@intel.com>
Date: Thu, 13 Nov 2025 07:26:43 -0800
From: Dave Hansen <dave.hansen@...el.com>
To: "Huang, Kai" <kai.huang@...el.com>, "Zhao, Yan Y" <yan.y.zhao@...el.com>
Cc: "Du, Fan" <fan.du@...el.com>, "Li, Xiaoyao" <xiaoyao.li@...el.com>,
 "kvm@...r.kernel.org" <kvm@...r.kernel.org>,
 "david@...hat.com" <david@...hat.com>,
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 "kas@...nel.org" <kas@...nel.org>,
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 "Weiny, Ira" <ira.weiny@...el.com>, "Peng, Chao P" <chao.p.peng@...el.com>,
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Subject: Re: [RFC PATCH v2 03/23] x86/tdx: Enhance
 tdh_phymem_page_wbinvd_hkid() to invalidate huge pages

On 11/12/25 23:37, Huang, Kai wrote:
> Sure.  But it seems you will need to wait all patches that you mentioned to
> be merged to safely use 'page++' for pages in a folio?
> 
> And if you do:
> 
> 	for (i = 0; i < npages; i++)
> 	{
> 		struct page *p = folio_page(folio, start_idx + i);
> 		struct tdx_module_args args = {};
> 
> 		args.rcx = mk_keyed_paddr(hkid, p);
> 		...
> 	}
> 
> It should work w/o any dependency?
> 
> Anyway, I don't have any strong opinion, as long as it works.  You may
> choose what you want. 🙂

Folks, I'll make it easy: Do what Kai suggested above. It works
universally and it's obvious. Saving an "i" variable only makes the code
harder to read.

If anyone thinks that:

	while (npages--)

Is easier to understand than the most common C idiom on the planet:

	for (i = 0; i < npages; i++)

... then I don't know what to tell them.