在 2020/6/5 下午5:08, David Hildenbrand 写道:
> Please use the virtio-mem-v4 branch for now, v5 is still under
> construction (and might be scrapped completely if v4 goes upstream as is).
>
> Looks like a DMA issue. Your're hotplugging 1GB, which should not really
> eat too much memory. There was a similar issue reported by Hui in [1],
> which boiled down to wrong usage of the swiotlb parameter.
I have no swiotbl=noforce set, and sometime no swiotlb error reported, like
(qemu) [ 41.591308] e1000 0000:00:03.0: dma_direct_map_page: overflow
0x000000011fd470da+54 of device mask ffffffff
[ 41.592431] e1000 0000:00:03.0: TX DMA map failed
[ 41.593031] e1000 0000:00:03.0: dma_direct_map_page: overflow
0x000000011fd474da+54 of device mask ffffff
...
[ 63.049464] ata_piix 0000:00:01.1: dma_direct_map_sg: overflow
0x0000000107db2000+4096 of device mask ffffffff
[ 63.068297] ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x0
[ 63.069057] ata1.00: failed command: READ DMA
[ 63.069580] ata1.00: cmd c8/00:20:40:bd:d2/00:00:00:00:00/e0 tag 0 dma 16384
in
[ 63.069580] res 50/00:00:3f:30:80/00:00:00:00:00/a0 Emask 0x40
(internal error)
>
> In such cases you should always try to reproduce with hotplug of a
> sam-sized DIMM. E.g., hotplugging a 1GB DIMM should result in the same
> issue.
>
> What does your .config specify for CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE?
Yes, it's set.
I had tried the v2/v4 version, which has the same issue.
Is this related with virtio-mem start address too low?
Thanks a lot!
>
> I'll try to reproduce with v4 briefly.
>
> [1]
> https://lkml.kernel.org/r/9708f43a-9bd2-4377-8ee8-7fb1d95c6...@linux.alibaba.com
