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=-7.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,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 36252C433E1 for ; Tue, 9 Jun 2020 03:06:15 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id CB8DD2078C for ; Tue, 9 Jun 2020 03:06:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CB8DD2078C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 25C466B0002; Mon, 8 Jun 2020 23:06:14 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 20DA26B0005; Mon, 8 Jun 2020 23:06:14 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0FBD86B0006; Mon, 8 Jun 2020 23:06:14 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0180.hostedemail.com [216.40.44.180]) by kanga.kvack.org (Postfix) with ESMTP id EA1C26B0002 for ; Mon, 8 Jun 2020 23:06:13 -0400 (EDT) Received: from smtpin27.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id AD11F3572 for ; Tue, 9 Jun 2020 03:06:13 +0000 (UTC) X-FDA: 76908184626.27.alarm41_560ce2026dbf Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin27.hostedemail.com (Postfix) with ESMTP id 7BBF714C23 for ; Tue, 9 Jun 2020 03:06:13 +0000 (UTC) X-HE-Tag: alarm41_560ce2026dbf X-Filterd-Recvd-Size: 4247 Received: from out30-131.freemail.mail.aliyun.com (out30-131.freemail.mail.aliyun.com [115.124.30.131]) by imf29.hostedemail.com (Postfix) with ESMTP for ; Tue, 9 Jun 2020 03:06:10 +0000 (UTC) X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R781e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e07425;MF=alex.shi@linux.alibaba.com;NM=1;PH=DS;RN=39;SR=0;TI=SMTPD_---0U.29n7._1591671962; Received: from IT-FVFX43SYHV2H.local(mailfrom:alex.shi@linux.alibaba.com fp:SMTPD_---0U.29n7._1591671962) by smtp.aliyun-inc.com(127.0.0.1); Tue, 09 Jun 2020 11:06:03 +0800 Subject: Re: [PATCH RFC v4 00/13] virtio-mem: paravirtualized memory To: David Hildenbrand , linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, virtio-dev@lists.oasis-open.org, virtualization@lists.linux-foundation.org, kvm@vger.kernel.org, Michal Hocko , Andrew Morton , "Michael S . Tsirkin" , Sebastien Boeuf , Samuel Ortiz , Robert Bradford , Luiz Capitulino , Alexander Duyck , Alexander Potapenko , Alexander Viro , Anshuman Khandual , Anthony Yznaga , Dan Williams , Dave Young , Igor Mammedov , Jason Wang , Johannes Weiner , Juergen Gross , Konrad Rzeszutek Wilk , Len Brown , Mel Gorman , Michal Hocko , Mike Rapoport , Oscar Salvador , Oscar Salvador , Pavel Tatashin , Pavel Tatashin , Pingfan Liu , Qian Cai , "Rafael J. Wysocki" , Stefan Hajnoczi , Vlastimil Babka , Wei Yang References: <20191212171137.13872-1-david@redhat.com> <9acc5d04-c8e9-ef53-85e4-709030997ca6@redhat.com> <1cfa9edb-47ea-1495-4e28-4cf391eab44c@linux.alibaba.com> <6b4724bf-84b5-9880-5464-1908425d106d@redhat.com> <95c6ef21-23e0-c768-999d-3af7f69d02d3@linux.alibaba.com> From: Alex Shi Message-ID: Date: Tue, 9 Jun 2020 11:05:50 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 X-Rspamd-Queue-Id: 7BBF714C23 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam01 Content-Transfer-Encoding: quoted-printable 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: =E5=9C=A8 2020/6/5 =E4=B8=8B=E5=8D=888:18, David Hildenbrand =E5=86=99=E9= =81=93: > On 05.06.20 12:46, Alex Shi wrote: >> >> >> =E5=9C=A8 2020/6/5 =E4=B8=8B=E5=8D=886:05, David Hildenbrand =E5=86=99= =E9=81=93: >>>> I guess I know what's happening here. In case we only have DMA memor= y >>>> when booting, we don't reserve swiotlb buffers. Once we hotplug memo= ry >>>> and online ZONE_NORMAL, we don't have any swiotlb DMA bounce buffers= to >>>> map such PFNs (total 0 (slots), used 0 (slots)). >>>> >>>> Can you try with "swiotlb=3Dforce" on the kernel cmdline? >>> Alternative, looks like you can specify "-m 2G,maxmem=3D16G,slots=3D1= ", to >>> create proper ACPI tables that indicate hotpluggable memory. (I'll ha= ve >>> to look into QEMU to figure out to always indicate hotpluggable memor= y >>> that way). >>> >> >> >> That works too. Yes, better resolved in qemu, maybe. :) >> >=20 > You can checkout >=20 > git@github.com:davidhildenbrand/qemu.git virtio-mem-v4 yes, it works for me. Thanks! >=20 > (prone to change before officially sent), which will create srat tables > also if no "slots" parameter was defined (and no -numa config was > specified). >=20 > Your original example should work with that. >=20