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X-CSE-ConnectionGUID: 0WYICH1bSdSLSra1U5Al1g== X-CSE-MsgGUID: 4zhPQ155QiCasRpG9DAx6w== X-IronPort-AV: E=McAfee;i="6800,10657,11735"; a="79024063" X-IronPort-AV: E=Sophos;i="6.23,130,1770624000"; d="scan'208";a="79024063" Received: from orviesa005.jf.intel.com ([10.64.159.145]) by fmvoesa106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Mar 2026 10:38:18 -0700 X-CSE-ConnectionGUID: hgi0J7GmReqfDbRWOQfZWg== X-CSE-MsgGUID: qo1T3zduR3WkSNP86jYu6g== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.23,130,1770624000"; d="scan'208";a="228286340" Received: from dnelso2-mobl.amr.corp.intel.com (HELO [10.125.109.109]) ([10.125.109.109]) by orviesa005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Mar 2026 10:38:18 -0700 Message-ID: Date: Fri, 20 Mar 2026 10:38:16 -0700 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 1/2] x86/virt/tdx: Use PFN directly for mapping guest private memory To: "Edgecombe, Rick P" , "kas@kernel.org" Cc: "kvm@vger.kernel.org" , "Li, Xiaoyao" , "Huang, Kai" , "linux-coco@lists.linux.dev" , "Zhao, Yan Y" , "dave.hansen@linux.intel.com" , "linux-kernel@vger.kernel.org" , "mingo@redhat.com" , "seanjc@google.com" , "pbonzini@redhat.com" , "binbin.wu@linux.intel.com" , "Yamahata, Isaku" , "ackerleytng@google.com" , "Annapurve, Vishal" , "sagis@google.com" , "bp@alien8.de" , "tglx@kernel.org" , "yilun.xu@linux.intel.com" , "x86@kernel.org" References: <20260319005605.8965-1-yan.y.zhao@intel.com> <20260319005703.8983-1-yan.y.zhao@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 3/20/26 10:31, Edgecombe, Rick P wrote: > On Fri, 2026-03-20 at 12:59 +0000, Kiryl Shutsemau wrote: >>> I feel like we argued about this before. But it would be more correct to >>> just drop level and make it 4k only until huge pages? Otherwise we are >>> tweaking dead behavior. >> I guess. But you add one more thing on the list to remember when adding >> huge page support. This kind of stuff is easy to miss. > I guess I'm fine either way. I'm not sure Dave will like adding dead branches > though. I suppose huge pages is close enough that we are looking to merge prep > work anyway. Can we add something that will BUG_ON() or fail to compile when the huge page support comes around? I'd much rather have: BUG_ON(level != PG_LEVEL_4K); tdx_clflush_pfn(pfn); That go implementing a level argument to tdx_clflush_pfn() now. Then nobody has to remember. The list to remember is in the code.