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 CD7A2C433EF for ; Fri, 1 Apr 2022 17:33:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350150AbiDARfj (ORCPT ); Fri, 1 Apr 2022 13:35:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36444 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350165AbiDARfb (ORCPT ); Fri, 1 Apr 2022 13:35:31 -0400 Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 39AE125280 for ; Fri, 1 Apr 2022 10:33:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1648834421; x=1680370421; h=message-id:date:mime-version:to:cc:references:from: subject:in-reply-to:content-transfer-encoding; bh=Prr3OHQFQtCFSdwCOz3twIgyEvMuZhH+9u/SrFurkRA=; b=LYRKIq3+kEva+sU1MFFJmf1WgZAxyvwFJhAgvfwqLCyK6lMo949IrIHz hTJO33Cx2x2f1eMLQvOyHoT4hCND4fGvYxJraY+07+ExuARquTIQf33yX cTUDcya4cjJ5FzGpBoOYlfKnxg1R4pHhbHyeZxmOFY2L4JUsHqYeuRKVC /NvvGPNcVh4dNQTe/t4WW0CkTVNkr1crPyM68/kwWT2/O8hFg2pdTDF2h qzgeOnw4QwGhdxfTN9YupZI/6M81tFmja6P/8NJZdEbgVPv3xlJX5kkxG Vy+iuYvVoNJIzoAhKZrxdasfSiXTIWpkDgZ+rUNBBRBkpUVBnX3a5r3ud w==; X-IronPort-AV: E=McAfee;i="6200,9189,10304"; a="320891334" X-IronPort-AV: E=Sophos;i="5.90,228,1643702400"; d="scan'208";a="320891334" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Apr 2022 10:33:39 -0700 X-IronPort-AV: E=Sophos;i="5.90,228,1643702400"; d="scan'208";a="567663407" Received: from dajones-mobl.amr.corp.intel.com (HELO [10.212.134.9]) ([10.212.134.9]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Apr 2022 10:33:39 -0700 Message-ID: Date: Fri, 1 Apr 2022 10:33:39 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.7.0 Content-Language: en-US To: "Kirill A. Shutemov" Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, luto@kernel.org, peterz@infradead.org, sathyanarayanan.kuppuswamy@linux.intel.com, aarcange@redhat.com, ak@linux.intel.com, dan.j.williams@intel.com, david@redhat.com, hpa@zytor.com, jgross@suse.com, jmattson@google.com, joro@8bytes.org, jpoimboe@redhat.com, knsathya@kernel.org, pbonzini@redhat.com, sdeep@vmware.com, seanjc@google.com, tony.luck@intel.com, vkuznets@redhat.com, wanpengli@tencent.com, thomas.lendacky@amd.com, brijesh.singh@amd.com, x86@kernel.org, linux-kernel@vger.kernel.org, Sean Christopherson , "Rafael J . Wysocki" References: <20220318153048.51177-1-kirill.shutemov@linux.intel.com> <20220318153048.51177-22-kirill.shutemov@linux.intel.com> <2847763c-6202-9e2a-54c5-44c761b59a63@intel.com> <20220324152415.grt6xvhblmd4uccu@black.fi.intel.com> <4c0c05a8-08f2-7d5d-6746-a92d0d3c5ef0@intel.com> <20220330231609.ymxekzgdp2pd7gfy@black.fi.intel.com> <9e84cdea-754c-1864-4c54-66beeba7f921@intel.com> <20220331015239.h7bihbfjq4xfrhyj@black.fi.intel.com> From: Dave Hansen Subject: Re: [PATCHv7 21/30] x86/acpi, x86/boot: Add multiprocessor wake-up support In-Reply-To: <20220331015239.h7bihbfjq4xfrhyj@black.fi.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 3/30/22 18:52, Kirill A. Shutemov wrote: > >>>From ab320371f9ef8d24722394ec2505089e68737527 Mon Sep 17 00:00:00 2001 > From: Kuppuswamy Sathyanarayanan > Date: Thu, 15 Apr 2021 10:31:38 -0700 > Subject: [PATCH] x86/acpi, x86/boot: Add multiprocessor wake-up support > > Secondary CPU startup is currently performed with something called > the "INIT/SIPI protocol". This protocol requires assistance from > VMMs to boot guests. As should be a familiar story by now, that > support can not be provded to TDX guests because TDX VMMs are > not trusted by guests. > > To remedy this situation a new[1] "Multiprocessor Wakeup Structure" > has been added to to an existing ACPI table (MADT). This structure > provides the physical address of a "mailbox". A write to the mailbox > then steers the secondary CPU to the boot code. > > Add ACPI MADT wake structure parsing support and wake support. Use > this support to wake CPUs whenever it is present instead of INIT/SIPI. > > While this structure can theoretically be used on 32-bit kernels, > there are no 32-bit TDX guest kernels. It has not been tested and > can not practically *be* tested on 32-bit. Make it 64-bit only. > > 1. Details about the new structure can be found in ACPI v6.4, in the > "Multiprocessor Wakeup Structure" section. > > Co-developed-by: Sean Christopherson > Signed-off-by: Sean Christopherson > Reviewed-by: Andi Kleen > Reviewed-by: Rafael J. Wysocki > Signed-off-by: Kuppuswamy Sathyanarayanan > Signed-off-by: Kirill A. Shutemov Looks good. I'm glad you were able to get rid of the extra-wakeup checks too. Reviewed-by: Dave Hansen