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 28DACE95A91 for ; Mon, 9 Oct 2023 14:14:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1377605AbjJIOO0 (ORCPT ); Mon, 9 Oct 2023 10:14:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57122 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1376918AbjJIOOX (ORCPT ); Mon, 9 Oct 2023 10:14:23 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 006548E for ; Mon, 9 Oct 2023 07:13:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1696860816; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=TtAr6vMHSkU1o8N9xFJERXPEAH/eUDbPVOnY1/d3q0M=; b=O+60ygEICjNQViaOD+wfaarkAu6PEPJWpVq3f7GIvHghyuIoAg1fxvofr6N8EwaQyFpX2g DVloX+Q5I1/WS/VaWJeDE/Ja24GqUqfVETB5bkarVo4zjoIToy76YiMethp4FnoOgRbYNn FQBk5NfM1c+Wkz7OrfikfICLnJIOTLE= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-641-1ORgyTEpN9-o7KLkB5trKw-1; Mon, 09 Oct 2023 10:13:15 -0400 X-MC-Unique: 1ORgyTEpN9-o7KLkB5trKw-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id DDD5881D787; Mon, 9 Oct 2023 14:13:14 +0000 (UTC) Received: from localhost (unknown [10.72.112.74]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 1498240C6EBF; Mon, 9 Oct 2023 14:13:13 +0000 (UTC) Date: Mon, 9 Oct 2023 22:13:10 +0800 From: Baoquan He To: "Kirill A. Shutemov" Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "Rafael J. Wysocki" , Peter Zijlstra , Adrian Hunter , Kuppuswamy Sathyanarayanan , Elena Reshetova , Jun Nakajima , Rick Edgecombe , Tom Lendacky , kexec@lists.infradead.org, linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH 00/13] x86/tdx: Add kexec support Message-ID: References: <20231005131402.14611-1-kirill.shutemov@linux.intel.com> <20231009133655.3aqi4kwx7wtqgqtm@box.shutemov.name> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231009133655.3aqi4kwx7wtqgqtm@box.shutemov.name> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.2 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/09/23 at 04:36pm, Kirill A. Shutemov wrote: > On Mon, Oct 09, 2023 at 07:49:35AM +0800, Baoquan He wrote: > > On 10/05/23 at 04:13pm, Kirill A. Shutemov wrote: > > > The patchset adds bits and pieces to get kexec (and crashkernel) work on > > > TDX guest. > > > > > > They bring kexec support to the point when we can start the new kernel, > > > but it will only be able to use single CPU. It should be enough to cover > > > the most common case: crashkernel. > > > > Not sure if this question has been raised and answered in the past. Please > > forgive my bad memory if it has. The one cpu is fine to kdump kernel most > > of time, while we enable all CPUs by default when kexec rebooting. And kdump > > kernel with multiple cpu is allowed too. Wondering if there's plan to > > support the multiple cpu on TDX in the future. > > Sorry, I didn't update this part of cover letter properly, but the last > patch of the patchset makes possible to kexec with multiple CPUs and the > 2nd kernel will see them all. It requires support on BIOS side, otherwise > we fallback to single CPU kexec. Oops, I didn't read them carefully. You have mentioned that in the last paragraph of cover letter. That's a great news, thanks.