Fix included in qemu-kvm-0.12.1.2-2.498.el6

Reproduce this bug
Host version:
             qemu-kvm-0.12.1.2-2.496.el6.x86_64
             kernel-2.6.32-680.el6.x86_64
guest:kernel-2.6.32-680.el6.x86_64

Following is the details
a. repeat virtio-balloon driver increases
1. Boot guest with following cmd
/usr/libexec/qemu-kvm \
-M pc \
-cpu Nehalem,enforce \
-m 4G \
-name rhel6.9 \
-uuid 2fd41914-5019-4d17-a6cc-fa653ba516f5 \
-boot menu=on  \
-qmp tcp:0:4444,server,nowait \
-monitor stdio \
-vga qxl \
-usbdevice mouse \
-usbdevice tablet \
-nodefaults \
-rtc base=utc \
-smp 2,sockets=2,cores=1,threads=1 \
-enable-kvm \
-smbios type=1,manufacturer='Red Hat',product='RHEV Hypervisor',version=el6,serial=koTUXQrb,uuid=feebc8fd-f8b0-4e75-abc3-e63fcdb67170 \
-serial unix:/tmp/console,server,nowait \
-bios /usr/share/seabios/bios.bin \
-chardev file,path=/home/seabios.log,id=seabios \
-device isa-debugcon,chardev=seabios,iobase=0x402 \
-spice port=5932,disable-ticketing \
-drive file=/home/bug1392520/test.qcow2,if=none,id=drive-virtio-disk0,format=qcow2,cache=none,werror=stop,rerror=stop \
-device virtio-blk-pci,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1 \
-device virtio-balloon-pci,id=virtio-balloon0 \
-usbdevice tablet \
-netdev tap,id=hostnet1 \
-device virtio-net-pci,netdev=hostnet1,id=net1,mac=54:52:00:B6:40:22 \

2. In guest, repeat following operation
  for n in $(seq 200); do
    echo $n
    modprobe -r virtio-balloon
    modprobe virtio-balloon
  done

Test results:
guest will be shutdown and qemu quit with "qemu-kvm: Virtqueue size exceeded"

b.reboot guest 
1.Boot guest through libvirt
2.reboot guest through following scripts
#!/bin/bash
for i in  $(seq 129);
do    
	echo $i
        virsh qemu-monitor-command generic --hmp "system_reset"
        sleep 30
done

Test results:
guest shutdown when repeat 128 times
129
error: Requested operation is not valid: domain is not running
-------------------------------------------------------------------
Verify this bug on "qemu-kvm-0.12.1.2-2.499.el6.x86_64" as same steps above.
a.
Test results:
guest normal work and qemu not quit.
b.
Test results:
guest not shutdown when repeat 128 times

Conclusion：
  According to result above,this bug has been fixed.

Verify this bug 
Host version:
             qemu-kvm-0.12.1.2-2.499.el6.x86_64
             kernel-2.6.32-680.el6.x86_64
guest:kernel-2.6.32-680.el6.x86_64

Following is the details
a. repeat virtio-balloon driver increases
1. Boot guest with following cmd
/usr/libexec/qemu-kvm \
-name rhel6.9 \
-M pc \
-cpu SandyBridge,enforce  \
-m 2G \
-smp 1,sockets=1,cores=1,threads=1 \
-uuid 87a8008b-d8bd-42ce-b1b8-d329116c174c \
-nodefaults \
-rtc base=utc,driftfix=slew \
-drive file=/home/bz1392520/rhel6.9.qcow2,if=none,id=drive-virtio-disk0,format=qcow2 \
-device virtio-blk-pci,scsi=off,bus=pci.0,addr=0x7,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1 \
-netdev tap,id=hostnet0,vhost=on \
-device virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:cb:b4:5e,bus=pci.0,addr=0x3 \
-spice port=5930,disable-ticketing \
-monitor stdio \
-usbdevice tablet \
-vga qxl \
-device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x8 \
-device virtio-scsi-pci,id=scsi0,bus=pci.0,addr=0x4 \
-drive file=/home/bz1392520/data.qcow2,if=none,id=drive-scsi0-0-0-0,format=qcow2 \
-device scsi-hd,bus=scsi0.0,channel=0,scsi-id=0,lun=0,drive=drive-scsi0-0-0-0,id=scsi0-0-0-0,bootindex=3 \
-object rng-random,filename=/dev/urandom,id=rng0 \
-device virtio-rng-pci,rng=rng0 \
-device virtio-serial-pci,id=virtio-serial0 \
-chardev socket,id=channel1,path=/tmp/helloworld1,server,nowait \
-device virtserialport,chardev=channel1,name=port1,bus=virtio-serial0.0,id=port1 \
-device virtio-serial-pci,id=virtio-serial1 \
-chardev pty,id=console0 \
-device virtconsole,chardev=console0,id=console0 \

2. In guest, repeat following operation
  for n in $(seq 200); do
    echo $n
    modprobe -r virtio-balloon
    modprobe virtio-balloon
  done

Test results:
guest normal work and qemu not quit.

b.reboot guest 
1.Boot guest through libvirt
2.reboot guest through following scripts
#!/bin/bash
for i in  $(seq 129);
do    
	echo $i
        virsh qemu-monitor-command generic --hmp "system_reset"
        sleep 30
done

Test results:
guest not shutdown when repeat 128 times,guest normal work.

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHSA-2017-0621.html