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=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 21390C433DB for ; Fri, 22 Jan 2021 03:33:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E548B23899 for ; Fri, 22 Jan 2021 03:33:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726623AbhAVDdr (ORCPT ); Thu, 21 Jan 2021 22:33:47 -0500 Received: from foss.arm.com ([217.140.110.172]:55122 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726492AbhAVDdZ (ORCPT ); Thu, 21 Jan 2021 22:33:25 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6862E11D4; Thu, 21 Jan 2021 19:32:39 -0800 (PST) Received: from [192.168.0.130] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 774FC3F68F; Thu, 21 Jan 2021 19:32:32 -0800 (PST) Subject: Re: [PATCH RFC] virtio-mem: check against memhp_get_pluggable_range() which memory we can hotplug To: David Hildenbrand , linux-mm@kvack.org, akpm@linux-foundation.org, hca@linux.ibm.com, catalin.marinas@arm.com Cc: Oscar Salvador , Vasily Gorbik , Will Deacon , Ard Biesheuvel , Mark Rutland , linux-arm-kernel@lists.infradead.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, "Michael S. Tsirkin" , Jason Wang , Pankaj Gupta , Michal Hocko , Wei Yang , teawater , Pankaj Gupta , Jonathan Cameron References: <1610975582-12646-1-git-send-email-anshuman.khandual@arm.com> <1610975582-12646-5-git-send-email-anshuman.khandual@arm.com> <36a10a6f-a2c7-b108-5054-5e4f3e1a1daf@redhat.com> From: Anshuman Khandual Message-ID: <99c20d27-b759-73b3-c8a0-68365a3ef943@arm.com> Date: Fri, 22 Jan 2021 09:02:51 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <36a10a6f-a2c7-b108-5054-5e4f3e1a1daf@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/21/21 3:27 PM, David Hildenbrand wrote: > On 18.01.21 14:21, Anshuman Khandual wrote: >> >> >> On 1/18/21 6:43 PM, Anshuman Khandual wrote: >>> From: David Hildenbrand >>> >>> Right now, we only check against MAX_PHYSMEM_BITS - but turns out there >>> are more restrictions of which memory we can actually hotplug, especially >>> om arm64 or s390x once we support them: we might receive something like >>> -E2BIG or -ERANGE from add_memory_driver_managed(), stopping device >>> operation. >>> >>> So, check right when initializing the device which memory we can add, >>> warning the user. Try only adding actually pluggable ranges: in the worst >>> case, no memory provided by our device is pluggable. >>> >>> In the usual case, we expect all device memory to be pluggable, and in >>> corner cases only some memory at the end of the device-managed memory >>> region to not be pluggable. >>> >>> Cc: "Michael S. Tsirkin" >>> Cc: Jason Wang >>> Cc: Pankaj Gupta >>> Cc: Michal Hocko >>> Cc: Oscar Salvador >>> Cc: Wei Yang >>> Cc: Andrew Morton >>> Cc: catalin.marinas@arm.com >>> Cc: teawater >>> Cc: Anshuman Khandual >>> Cc: Pankaj Gupta >>> Cc: Jonathan Cameron >>> Cc: hca@linux.ibm.com >>> Cc: Vasily Gorbik >>> Cc: Will Deacon >>> Cc: Ard Biesheuvel >>> Cc: Mark Rutland >>> Cc: Heiko Carstens >>> Cc: Michal Hocko >>> Signed-off-by: David Hildenbrand >>> Signed-off-by: Anshuman Khandual >> >> Hello David, >> >> As your original patch was in the RFC state, I have just maintained >> the same here as well. But once you test this patch along with the >> new series, please do let me know if this needs to be converted to >> a normal PATCH instead. Thank you. > > Yes, you can drop the RFC part. I assume you'll send another revision, > I'll do another test there, thanks! Sure, will drop the RFC in next version.