[PATCH RFC v4 00/13] virtio-mem: paravirtualized memory

David Hildenbrand
Fri, 05 Jun 2020 12:18:28 -0000

On 05.06.20 12:46, Alex Shi wrote:
>
>
> ? 2020/6/5 ??6:05, David Hildenbrand ??:
>>> 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 at 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