From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 897A4C00140 for ; Wed, 10 Aug 2022 23:09:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232815AbiHJXJF (ORCPT ); Wed, 10 Aug 2022 19:09:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34982 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231550AbiHJXJD (ORCPT ); Wed, 10 Aug 2022 19:09:03 -0400 Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ABB0573338 for ; Wed, 10 Aug 2022 16:09:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1660172942; x=1691708942; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=q4SxPdLSzVBG3OLsteoyYJUs7wpKwN1B3yE/EJ6LQ24=; b=gHfzq4v0C/yUvHguq+0thQ3ojv690zmYrfqX6cYvMMBRLWb/Fp9HM+N2 /qFx9LRfjde2uW4Foho5QRSmTBsxptM8Kx2nhY1y26krsL0oo0p3off9s D/kBXTpYxZZmrTIrMgQj86esoMlmzksaH+bwchaB4Q75D8fbOzyjUzjsf QhlI48CnOs8O4P/5LbFSpy/hZPl8TNLln87796KRPH0rjUezs44Bb4d1q bcRblHcsMyIL8lLV+ZA4EUUjTEdlps3IMMH5jwijlwbrtyQuLBNjO8hs3 dAWez3ShLsP6zt0qZ4xzvz0AbeOE7FbvfNZKgaiGKOhLNrEdy13G+ljeH g==; X-IronPort-AV: E=McAfee;i="6400,9594,10435"; a="271599704" X-IronPort-AV: E=Sophos;i="5.93,228,1654585200"; d="scan'208";a="271599704" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Aug 2022 16:09:02 -0700 X-IronPort-AV: E=Sophos;i="5.93,228,1654585200"; d="scan'208";a="781398405" Received: from snedunga-mobl2.amr.corp.intel.com (HELO [10.212.234.47]) ([10.212.234.47]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Aug 2022 16:09:01 -0700 Message-ID: Date: Wed, 10 Aug 2022 16:09:02 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Subject: Re: [PATCH] x86/apic: Don't disable x2APIC if locked Content-Language: en-US To: Daniel Sneddon , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "Shutemov, Kirill" , "Huang, Kai" Cc: "H. Peter Anvin" , linux-kernel@vger.kernel.org, "Gomez Iglesias, Antonio" , Pawan Gupta References: <20220809234000.783284-1-daniel.sneddon@linux.intel.com> <238ea612-5a25-9323-b31f-0a14493db2f7@linux.intel.com> <341ea6e9-d8f3-ee7a-6794-67408abbf047@linux.intel.com> <87r11nu52l.ffs@tglx> <83a0d220-1872-caba-4e7e-b6a366655cf2@linux.intel.com> From: Dave Hansen In-Reply-To: <83a0d220-1872-caba-4e7e-b6a366655cf2@linux.intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/10/22 16:03, Daniel Sneddon wrote: > On 8/10/22 15:06, Thomas Gleixner wrote: >> So this affects already deployed systems and we have to >> >> - backport the x2apic lock changes >> >> - provide proper diagnostics >> >> - make SGX and TDX depend on X2APIC support > I'll add the comments Dave mentioned earlier, and will make SGX and TDX depend > on X2APIC since that makes sense regardless of what hw ends up with this change. > Unless we want to get rid of CONFIG_X86_X2APIC like Dave mentioned? The TDX guest support in the kernel isn't _actually_ related to this*. It's the host-side support that matters and that isn't merged yet. I've cc'd Kai so he doesn't forget to do this. I agree on the SGX side, though. * TDX guest support already has this dependency, but it's for unrelated reasons: config INTEL_TDX_GUEST bool "Intel TDX (Trust Domain Extensions) - Guest Support" depends on X86_64 && CPU_SUP_INTEL depends on X86_X2APIC