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X-CSE-ConnectionGUID: p4BFgT4tSVuemnGw/1x2HQ== X-CSE-MsgGUID: ILp2R5j5STSxAQC0/tQfRQ== X-IronPort-AV: E=McAfee;i="6800,10657,11631"; a="70406368" X-IronPort-AV: E=Sophos;i="6.20,246,1758610800"; d="scan'208";a="70406368" Received: from fmviesa002.fm.intel.com ([10.60.135.142]) by orvoesa107.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Dec 2025 10:21:39 -0800 X-CSE-ConnectionGUID: KfJAwDywRvqmhtBPH+NDJw== X-CSE-MsgGUID: N1lxkKoSRSaAz8clhTgEDg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.20,246,1758610800"; d="scan'208";a="218098705" Received: from tslove-mobl4.amr.corp.intel.com (HELO [10.125.108.18]) ([10.125.108.18]) by fmviesa002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Dec 2025 10:21:38 -0800 Message-ID: <474f5ace-e237-4c01-b0bc-d3e68ecc937b@intel.com> Date: Wed, 3 Dec 2025 10:21:37 -0800 Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 07/16] x86/virt/tdx: Add tdx_alloc/free_page() helpers To: "Edgecombe, Rick P" , "nik.borisov@suse.com" , "kas@kernel.org" Cc: "kvm@vger.kernel.org" , "linux-coco@lists.linux.dev" , "Huang, Kai" , "Li, Xiaoyao" , "Zhao, Yan Y" , "Wu, Binbin" , "linux-kernel@vger.kernel.org" , "seanjc@google.com" , "mingo@redhat.com" , "pbonzini@redhat.com" , "tglx@linutronix.de" , "Yamahata, Isaku" , "Annapurve, Vishal" , "Gao, Chao" , "bp@alien8.de" , "x86@kernel.org" References: <20251121005125.417831-1-rick.p.edgecombe@intel.com> <20251121005125.417831-8-rick.p.edgecombe@intel.com> <730de4be289ed7e3550d40170ea7d67e5d37458f.camel@intel.com> <0274cee22d90cbfd2b26c52b864cde6dba04fc60.camel@intel.com> <7xbqq2uplwkc36q6jyorxe6u3fboka3snwar6parado5ysz25o@qrstyzh3okgh> <89d5876f-625b-43a6-bcad-d8caa4cbda2b@suse.com> <04c51f1d-b79b-4ff8-b141-5888407a318e@intel.com> From: Dave Hansen Content-Language: en-US Autocrypt: addr=dave.hansen@intel.com; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 12/3/25 10:15, Edgecombe, Rick P wrote: > On Wed, 2025-12-03 at 07:41 -0800, Dave Hansen wrote: >> It's fixed at a "page pair" in the ABI documentation, no? >> >> If Intel wants anything else, it should have documented that as the ABI. >> So, as far as the code goes, it's a "page pair" now and forever. Linux >> does not need to go out of its way to make it inflexible, but there's no >> need to add complexity now for some future that may never come. >> >> I agree with Nikolay: KISS. > Thanks Dave. Yes, let's stick to the spec. I'm going to try to pull the loops > out too because we can get rid of the union array thing too. Also, I honestly don't see the problem with just allocating an order-1 page for this. Yeah, the TDX modules doesn't need physically contiguous pages, but it's easier for _us_ to lug them around if they are physically contiguous. Plus, if you permanently allocate 2 order-0 pages, you are _probably_ going to permanently destroy 2 potential future 2MB pages. The order-1 allocation will only destroy 1.