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=-10.4 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=ham 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 E76EEC433E0 for ; Mon, 18 Jan 2021 13:21:19 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 94A4C206F9 for ; Mon, 18 Jan 2021 13:21:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 94A4C206F9 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 115E08D0002; Mon, 18 Jan 2021 08:21:19 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 09EEF6B0271; Mon, 18 Jan 2021 08:21:19 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EA9148D0002; Mon, 18 Jan 2021 08:21:18 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0142.hostedemail.com [216.40.44.142]) by kanga.kvack.org (Postfix) with ESMTP id CE2176B0270 for ; Mon, 18 Jan 2021 08:21:18 -0500 (EST) Received: from smtpin13.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 8728A3637 for ; Mon, 18 Jan 2021 13:21:18 +0000 (UTC) X-FDA: 77718957036.13.car62_450741027549 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin13.hostedemail.com (Postfix) with ESMTP id 6D93318140B89 for ; Mon, 18 Jan 2021 13:21:18 +0000 (UTC) X-HE-Tag: car62_450741027549 X-Filterd-Recvd-Size: 3979 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf49.hostedemail.com (Postfix) with ESMTP for ; Mon, 18 Jan 2021 13:21:17 +0000 (UTC) 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 5609D31B; Mon, 18 Jan 2021 05:21:17 -0800 (PST) Received: from [10.163.89.163] (unknown [10.163.89.163]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B70BB3F719; Mon, 18 Jan 2021 05:21:09 -0800 (PST) Subject: Re: [PATCH RFC] virtio-mem: check against memhp_get_pluggable_range() which memory we can hotplug To: linux-mm@kvack.org, akpm@linux-foundation.org, david@redhat.com, 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> From: Anshuman Khandual Message-ID: Date: Mon, 18 Jan 2021 18:51:30 +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: <1610975582-12646-5-git-send-email-anshuman.khandual@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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. - Anshuman