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-9BD2-4377-8EE8-7FB1D95C6F69@xxxxxxxxxxxxxxxxx
