I tried live migration with multifd enabled. The guest on the source side hangs there when it is migrated with the setting multifd-channels = 16.  It works well when set multifd-channels as 2,4, 8. 

Qemu version: qemu-6.0.50: 

Latest commit:  commit c313e52e6459de2e9064767083a0c949c476e32b

Qemu command line: 

source side: 

qemu-system-x86_64 --machine pc,accel=kvm,usb=off,dump-guest-core=off -smp 40 -m 1024 --nographic \
    -device pci-bridge,id=pci_bridge1,bus=pci.0,chassis_nr=1 \
    -drive file=./CentOS.raw,if=none,id=drive-virtio-disk0,format=raw,cache=none,aio=native \
    -device virtio-blk-pci,scsi=off,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=0 \
    -serial telnet:localhost:4444,server,nowait

Destination side: 

qemu-system-x86_64  --machine pc,accel=kvm,usb=off,dump-guest-core=off -smp 40 -m 1024 --nographic \
    -device pci-bridge,id=pci_bridge1,bus=pci.0,chassis_nr=1 \
    -drive file=./CentOS.raw,if=none,id=drive-virtio-disk0,format=raw,cache=none,aio=native \
    -device virtio-blk-pci,scsi=off,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=0 \
    -serial telnet:localhost:4444,server,nowait \
    -incoming tcp:10.43.16.29:4446,server,wait

Setting of migration: 

# migrate_set_capability multifd on
# migrate_set_parameter multifd-channels 16
# migrate_set_parameter max-bandwidth 4G

 

Any ideas? 

Thanks

Li