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X-IronPort-AV: E=McAfee;i="6600,9927,10740"; a="421940628" X-IronPort-AV: E=Sophos;i="6.00,239,1681196400"; d="scan'208";a="421940628" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Jun 2023 07:25:51 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10740"; a="705817951" X-IronPort-AV: E=Sophos;i="6.00,239,1681196400"; d="scan'208";a="705817951" Received: from clin147-mobl.amr.corp.intel.com (HELO [10.212.134.227]) ([10.212.134.227]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Jun 2023 07:25:51 -0700 Message-ID: <6fb1ec2f-8713-8191-fd31-751b1a663b0b@intel.com> Date: Tue, 13 Jun 2023 07:25:50 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.11.0 Subject: Re: [PATCH v11 18/20] x86: Handle TDX erratum to reset TDX private memory during kexec() and reboot Content-Language: en-US To: "Huang, Kai" , "kirill.shutemov@linux.intel.com" Cc: "kvm@vger.kernel.org" , "Luck, Tony" , "david@redhat.com" , "bagasdotme@gmail.com" , "ak@linux.intel.com" , "Wysocki, Rafael J" , "linux-kernel@vger.kernel.org" , "Chatre, Reinette" , "Christopherson,, Sean" , "pbonzini@redhat.com" , "tglx@linutronix.de" , "linux-mm@kvack.org" , "Yamahata, Isaku" , "peterz@infradead.org" , "Shahar, Sagi" , "imammedo@redhat.com" , "Gao, Chao" , "Brown, Len" , "sathyanarayanan.kuppuswamy@linux.intel.com" , "Huang, Ying" , "Williams, Dan J" References: <5aa7506d4fedbf625e3fe8ceeb88af3be1ce97ea.1685887183.git.kai.huang@intel.com> <20230609132301.uvvp27yr5kpenl6f@box.shutemov.name> <58f34b4b81b6d6b37d3386dec0f073e6eb7a97ff.camel@intel.com> <20230612075830.jbrdd6ysz4qq7wdf@box.shutemov.name> <4c7effc3abe71aa1cbee41f3bd46b97aed40be26.camel@intel.com> <48d5a29a-878c-665d-6ac2-6f0563bf6f3c@intel.com> <3bbb6b384ba89dfaa13be01654ad27e41d779fba.camel@intel.com> From: Dave Hansen In-Reply-To: <3bbb6b384ba89dfaa13be01654ad27e41d779fba.camel@intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 3B27B1C0006 X-Stat-Signature: hhfxipk91xyhojsmufcuxkfh7eew9jj9 X-Rspam-User: X-HE-Tag: 1686666352-860998 X-HE-Meta: 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 MWsYpAgs V9qRF8t6QYIBZjVZwnezU03tpyQsA7PXz8aXjq8wb5pBG1cImNB5QVA9FpEBQ1IcL1CdoBhBuMcQuNGL5rhJAo7LGqPJ/gAUYBSFmcUVvDM16YUXtW8ykmtyVcVmChWu74eeLrPdQFzvpNE2OSCmYL/8FUApt9N/LLukVr5NwK3KZ57opKoYgOMUngLGaiG8J+JaP X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 6/12/23 17:51, Huang, Kai wrote: > If we introduce a helper to mark a page as TDX private page, Let me get this right: you have working, functional code for a highly-unlikely scenario (kernel bugs or even more rare hardware errors). But, you want to optimize this super-rare case? It's not fast enough? Is there any other motivation here that I'm missing?