Description of problem:
With bridge e1000, guest network becomes unreachable after hotplug memory 256 times. Virtio-net-pci and rtl8139 works well.


Version-Release number of selected component (if applicable):
kernel: 3.10.0-326.el7.x86_64
qemu-kvm-rhev-2.3.0-31.el7.x86_64

How reproducible:
always

Steps to Reproduce:
1. launch a guest with cmd:
/usr/libexec/qemu-kvm -name rhel72-sn5 -m 1G,slots=256,maxmem=40G \

-numa node -smp 4,sockets=4,cores=1,threads=1 \

-no-user-config -nodefaults -rtc base=utc,driftfix=slew -global kvm-pit.lost_tick_policy=discard -boot menu=on,strict=on \

-object iothread,id=iothread0 -drive file=/home/guest/rhel72-sn5.img,if=none,id=drive-data-disk,format=qcow2,cache=none,aio=native,werror=stop,rerror=stop  -device virtio-blk-pci,drive=drive-data-disk,id=data-disk,iothread=iothread0,bus=pci.0,addr=0x7 \

-netdev tap,id=hostnet1,vhost=on -device e1000,netdev=hostnet1,id=net2,mac=10:1a:4a:42:0a:0b,bus=pci.0,addr=0xa \

-usb -device usb-tablet,id=input0 -vga qxl \

-spice port=5901,addr=0.0.0.0,disable-ticketing,image-compression=off,seamless-migration=on -monitor unix:/tmp/monitor3,server,nowait

2. Hotplug 128M memory to guest 256 times with script:
#!/bin/bash 
i=0 
while [ $i -lt 256 ] 
do 
echo $i 
sleep 3 
echo "object_add memory-backend-ram,id=mem$i,size=128M"|nc -U /tmp/monitor3 
sleep 2 
echo "device_add pc-dimm,id=dimm$i,memdev=mem$i,slot=$i"|nc -U /tmp/monitor3 
i=$(($i+1)) 
done 

3. Ping host inside guest


Actual results:
Destination Host Unreachable.

Expected results:
Can ping host well.

Additional info: