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X-CSE-ConnectionGUID: 04bTr26eR5StJQFa5YMmWg== X-CSE-MsgGUID: Q5IOQKJ4Q02Pp5dwUgfWkw== X-IronPort-AV: E=McAfee;i="6800,10657,11483"; a="65227621" X-IronPort-AV: E=Sophos;i="6.16,284,1744095600"; d="scan'208";a="65227621" Received: from fmviesa005.fm.intel.com ([10.60.135.145]) by fmvoesa104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Jul 2025 07:25:28 -0700 X-CSE-ConnectionGUID: JItw5yr/RkahzZ5oOWeQww== X-CSE-MsgGUID: NS3z1/klQ6iL4U4vUpkkrA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.16,284,1744095600"; d="scan'208";a="158661873" Received: from puneetse-mobl.amr.corp.intel.com (HELO [10.125.110.13]) ([10.125.110.13]) by fmviesa005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Jul 2025 07:25:26 -0700 Message-ID: <4bce6d90-c0d4-4f0d-bcb7-4a58fa9643e3@intel.com> Date: Thu, 3 Jul 2025 07:25:25 -0700 Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/2] x86/tdx: Skip clearing reclaimed pages unless X86_BUG_TDX_PW_MCE is present To: Adrian Hunter , Dave Hansen , pbonzini@redhat.com, seanjc@google.com, vannapurve@google.com Cc: Tony Luck , Borislav Petkov , Thomas Gleixner , Ingo Molnar , x86@kernel.org, H Peter Anvin , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, rick.p.edgecombe@intel.com, kirill.shutemov@linux.intel.com, kai.huang@intel.com, reinette.chatre@intel.com, xiaoyao.li@intel.com, tony.lindgren@linux.intel.com, binbin.wu@linux.intel.com, isaku.yamahata@intel.com, yan.y.zhao@intel.com, chao.gao@intel.com References: <20250703114038.99270-1-adrian.hunter@intel.com> <20250703114038.99270-3-adrian.hunter@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 7/3/25 04:40, Adrian Hunter wrote: > @@ -642,6 +642,15 @@ static void reset_tdx_pages(unsigned long base, unsigned long size) > const void *zero_page = (const void *)page_address(ZERO_PAGE(0)); > unsigned long phys, end; If the only possible use for reset_tdx_pages() is for the erratum, then it needs to be in the function name. > + /* > + * Linux uses only KeyID 0 which can read or write pages > + * that were formerly TDX private pages, without poisoning > + * memory. However on platforms with the partial-write errata, > + * poisoning still happens for partial writes. > + */ > + if (!boot_cpu_has_bug(X86_BUG_TDX_PW_MCE)) > + return; Would this be more clear? /* * Typically, any write to the page will convert it from TDX * private back to normal kernel memory. Systems with the * erratum need to do the conversion explicitly. */