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 X-Spam-Level: X-Spam-Status: No, score=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2D7B9C3A5A9 for ; Mon, 4 May 2020 19:03:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1152B206B8 for ; Mon, 4 May 2020 19:03:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="CRsaquWQ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727768AbgEDTDC (ORCPT ); Mon, 4 May 2020 15:03:02 -0400 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:25928 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726469AbgEDTDB (ORCPT ); Mon, 4 May 2020 15:03:01 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1588618979; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=mP9q+4tMTUFFbHWKmZ6XyIVd8J3nRNyyGmILxDAp3rM=; b=CRsaquWQerzl88VxeMXNnQceRzPXubJFUokrLQGGSy00uU8wvaw3oXVk94RKbjU06/cx9A hUrTEjPr83CRV54k1UutbyXLjsDof1n4KTHyqNo1Wrx4q40xArHpkBYfuO5ZGcSWqg9SHc 6jbTXUAlFGa7wfyHeubXAsY4eQT+EcE= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-282-NZ081FhiM1eWnMh_6FGHpA-1; Mon, 04 May 2020 15:02:51 -0400 X-MC-Unique: NZ081FhiM1eWnMh_6FGHpA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A42CB107ACCD; Mon, 4 May 2020 19:02:48 +0000 (UTC) Received: from t480s.redhat.com (ovpn-114-235.ams2.redhat.com [10.36.114.235]) by smtp.corp.redhat.com (Postfix) with ESMTP id B21522B4AF; Mon, 4 May 2020 19:02:42 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, linux-nvdimm@lists.01.org, kexec@lists.infradead.org, Vishal Verma , Dave Jiang , Pavel Tatashin , David Hildenbrand , Andrew Morton , Baoquan He , Dan Williams , Dave Hansen , Eric Biederman , Michal Hocko , Pankaj Gupta , Wei Yang Subject: [PATCH v3 0/3] mm/memory_hotplug: Interface to add driver-managed system ram Date: Mon, 4 May 2020 21:02:24 +0200 Message-Id: <20200504190227.18269-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Content-Transfer-Encoding: quoted-printable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Third time is the charm? Let's see ... :) This is the follow up of [1]: [PATCH v1 0/3] mm/memory_hotplug: Make virtio-mem play nicely with kexec-tools and [2]: [PATCH v2 0/3] mm/memory_hotplug: Allow to not create firmware memmap entries kexec (via kexec_load()) can currently not properly handle memory added v= ia dax/kmem, and will have similar issues with virtio-mem. kexec-tools will currently add all memory to the fixed-up initial firmware memmap. In case of dax/kmem, this means that - in contrast to a proper reboot - how that persistent memory will be used can no longer be configured by the kexec'd kernel. In case of virtio-mem it will be harmful, because that memory might contain inaccessible pieces that require coordination with hypervis= or first. In both cases, we want to let the driver in the kexec'd kernel handle detecting and adding the memory, like during an ordinary reboot. Introduce add_memory_driver_managed(). More on the samentics are in patch #1. In the future, we might want to make this behavior configurable for dax/kmem- either by configuring it in the kernel (which would then also allow to configure kexec_file_load()) or in kexec-tools by also adding "System RAM (kmem)" memory from /proc/iomem to the fixed-up initial firmware memmap. More on the motivation can be found in [1] and [2]. v2 -> v3: - Don't use flags for add_memory() and friends, provide add_memory_driver_managed() instead. - Flag memory resources via IORESOURCE_MEM_DRIVER_MANAGED and handle them in kexec. - Name memory resources "System RAM ($DRIVER)", visible via /proc/iomem - Added more details to the patch descriptions, especially regarding the history of /sys/firmware/memmap - Add a comment to the device-dax change. Dropped Dave's Ack as the v1 -> v2: - Don't change the resource name - Rename the flag to MHP_NO_FIRMWARE_MEMMAP to reflect what it is doing - Rephrase subjects/descriptions - Use the flag for dax/kmem [1] https://lkml.kernel.org/r/20200429160803.109056-1-david@redhat.com [2] https://lkml.kernel.org/r/20200430102908.10107-1-david@redhat.com David Hildenbrand (3): mm/memory_hotplug: Introduce add_memory_device_managed() kexec_file: Don't place kexec images on IORESOURCE_MEM_DRIVER_MANAGED device-dax: Add memory via add_memory_driver_managed() drivers/dax/kmem.c | 8 ++++- include/linux/ioport.h | 1 + include/linux/memory_hotplug.h | 2 ++ kernel/kexec_file.c | 5 +++ mm/memory_hotplug.c | 62 +++++++++++++++++++++++++++++++--- 5 files changed, 73 insertions(+), 5 deletions(-) --=20 2.25.3