zhanghailiang <zhang.zhanghaili...@huawei.com> wrote: > For all NICs(except virtio-net) emulated by qemu, > Such as e1000, rtl8139, pcnet and ne2k_pci, > Qemu can still receive packets when VM is not running. > > If this happened in *migration's* last PAUSE VM stage, but > before the end of the migration, the new receiving packets will possibly dirty > parts of RAM which has been cached in *iovec*(will be sent asynchronously) and > dirty parts of new RAM which will be missed. > This will lead serious network fault in VM. > > To avoid this, we forbid receiving packets in generic net code when > VM is not running. > > Bug reproduction steps: > (1) Start a VM which configured at least one NIC > (2) In VM, open several Terminal and do *Ping IP -i 0.1* > (3) Migrate the VM repeatedly between two Hosts > And the *PING* command in VM will very likely fail with message: > 'Destination HOST Unreachable', the NIC in VM will stay unavailable unless you > run 'service network restart' > > Signed-off-by: zhanghailiang <zhang.zhanghaili...@huawei.com>
Reviewed-by: Juan Quintela <quint...@redhat.com> It fixes the "collateral" issue than info migrate after migration has ended shows a remaining ram != 0. Thanks, Juan.
