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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9D872C02198 for ; Sun, 9 Feb 2025 03:09:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To: Content-Transfer-Encoding:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=j31g1VoN7O4XuCmDiX3R+x/Ync3MiakZ5YN14frwoaw=; b=m9BRx9+wLDrO4BzctsPeaE81aB vihZK73AHHLWzHfnTGxkE2YGH4RqQUarxByxR4bW639dQUdjB/F9Im90KUrjgbgI8/kpNAlKqa95R aHCU8Up6zoHTxJ7izP4eceCmrJHrzCVGitFHCMy3veNZhuyOnt19RMu9XbZcyR9Gx1pfPj5aY+v6s YxZffhg1hYheyH8Q+XS1XxA/mJcERXOC/530hrsqQJ5hu9oZUIwmJ+XkT2I+vwuRjIPVPUwueoPe/ 64x4wQ4TolGNW5C9YAfvchFUG0EhfAVTEcAf8RJFrJPO61TMn9v0YNBC2S4WbCfE7gJ0PrqoV9AXx DY6vadkg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tgxhX-0000000Dx7Y-2eR8; Sun, 09 Feb 2025 03:09:43 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tgxg7-0000000Dwyq-3K2Z for linux-arm-kernel@lists.infradead.org; Sun, 09 Feb 2025 03:08:17 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1739070494; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=j31g1VoN7O4XuCmDiX3R+x/Ync3MiakZ5YN14frwoaw=; b=AYv6noQO8jAZ4JAxcYIjX9TbwGDzUHg4SLFhgZx1wCzjktDLoxe+GIFRQ1K4n0Ql39o4fd TMWy+C9+ssZPanATfaM4XoawgeGV/3++l1ybaZ1DN11pHhnSKKEdkx7xWw7hrD4ro63o/b F/jOFWt1iwYMhuX4dxVYJiUEmnidv3M= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-527--0UWXAPWP4aY9sz5uQfGng-1; Sat, 08 Feb 2025 22:08:10 -0500 X-MC-Unique: -0UWXAPWP4aY9sz5uQfGng-1 X-Mimecast-MFC-AGG-ID: -0UWXAPWP4aY9sz5uQfGng Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id CC58C1800360; Sun, 9 Feb 2025 03:08:03 +0000 (UTC) Received: from localhost (unknown [10.72.112.28]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 48D321800265; Sun, 9 Feb 2025 03:08:00 +0000 (UTC) Date: Sun, 9 Feb 2025 11:07:53 +0800 From: Baoquan He To: Pasha Tatashin Cc: Andrew Morton , Mike Rapoport , linux-kernel@vger.kernel.org, Alexander Graf , Andy Lutomirski , Anthony Yznaga , Arnd Bergmann , Ashish Kalra , Benjamin Herrenschmidt , Borislav Petkov , Catalin Marinas , Dave Hansen , David Woodhouse , Eric Biederman , Ingo Molnar , James Gowans , Jonathan Corbet , Krzysztof Kozlowski , Mark Rutland , Paolo Bonzini , "H. Peter Anvin" , Peter Zijlstra , Pratyush Yadav , Rob Herring , Rob Herring , Saravana Kannan , Stanislav Kinsburskii , Steven Rostedt , Thomas Gleixner , Tom Lendacky , Usama Arif , Will Deacon , devicetree@vger.kernel.org, kexec@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org, changyuanl@google.com Subject: Re: [PATCH v4 00/14] kexec: introduce Kexec HandOver (KHO) Message-ID: References: <20250206132754.2596694-1-rppt@kernel.org> <20250206162939.a1f86fb835f1eeb7ed73ff1c@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250208_190815_977469_C3C5FDBB X-CRM114-Status: GOOD ( 36.86 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 02/08/25 at 07:23pm, Pasha Tatashin wrote: > On Fri, Feb 7, 2025 at 8:38 PM Baoquan He wrote: > > > > On 02/06/25 at 08:28pm, Pasha Tatashin wrote: > > > On Thu, Feb 6, 2025 at 7:29 PM Andrew Morton wrote: > > > > > > > > On Thu, 6 Feb 2025 15:27:40 +0200 Mike Rapoport wrote: > > > > > > > > > This a next version of Alex's "kexec: Allow preservation of ftrace buffers" > > > > > series (https://lore.kernel.org/all/20240117144704.602-1-graf@amazon.com), > > > > > just to make things simpler instead of ftrace we decided to preserve > > > > > "reserve_mem" regions. > > > > > > > > > > The patches are also available in git: > > > > > https://git.kernel.org/rppt/h/kho/v4 > > > > > > > > > > > > > > > Kexec today considers itself purely a boot loader: When we enter the new > > > > > kernel, any state the previous kernel left behind is irrelevant and the > > > > > new kernel reinitializes the system. > > > > > > > > I tossed this into mm.git for some testing and exposure. > > > > > > > > What merge path are you anticipating? > > > > > > > > Review activity seems pretty thin thus far? > > > > > > KHO is going to be discussed at the upcoming lsfmm, we are also > > > planning to send v5 of this patch series (discussed with Mike > > > Rapoport) in a couple of weeks. It will include enhancements needed > > > for the hypervisor live update scenario: > > > > So is this V4 still a RFC if v5 will be sent by plan? Should we hold the > > reviewing until v5? Or this series is a infrustructure building, v5 will > > add more details as you listed as below. I am a little confused. > > We will modify the existing patches and send as v5 because some > interfaces are going to be changed*. > > Otherwise, v5 will make KHO a lot more flexible as it will allow to > use the tree all the time while the system is running instead of only > once during the activation phase. > > * Changing interfaces is optional, but decision whether to change > will be discussed at Hypervisor Live Update on Feb 10th: > https://lore.kernel.org/all/26a4b7ca-93a6-30e2-923b-f551ced03d62@google.com/ Ah, this is what I would like to know about the difference between v4 and v5. Thanks for the information, and looking forward to seeing the v5 update. > > > > > > > > > 1. Allow nodes to be added to the KHO tree at any time > > > 2. Remove "activate" (I will also send a live update framework that > > > provides the activate functionality). > > > 3. Allow serialization during shutdown. > > > 4. Decouple KHO from kexec_file_load(), as kexec_file_load() should > > > not be used during live update blackout time. > > > 5. Enable multithreaded serialization by using hash-table as an > > > intermediate step before conversion to FDT. > > >