From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Hildenbrand Subject: Re: [PATCH RFC v4 00/13] virtio-mem: paravirtualized memory Date: Fri, 5 Jun 2020 14:18:28 +0200 Message-ID: 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> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <95c6ef21-23e0-c768-999d-3af7f69d02d3@linux.alibaba.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Alex Shi , 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 List-Id: virtualization@lists.linuxfoundation.org On 05.06.20 12:46, Alex Shi wrote: > > > 在 2020/6/5 下午6:05, David Hildenbrand 写道: >>> I guess I know what's happening here. In case we only have DMA memory >>> when booting, we don't reserve swiotlb buffers. Once we hotplug memory >>> 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=force" on the kernel cmdline? >> Alternative, looks like you can specify "-m 2G,maxmem=16G,slots=1", to >> create proper ACPI tables that indicate hotpluggable memory. (I'll have >> to look into QEMU to figure out to always indicate hotpluggable memory >> that way). >> > > > That works too. Yes, better resolved in qemu, maybe. :) > You can checkout git@github.com:davidhildenbrand/qemu.git virtio-mem-v4 (prone to change before officially sent), which will create srat tables also if no "slots" parameter was defined (and no -numa config was specified). Your original example should work with that. -- Thanks, David / dhildenb