Bug 1260464

Description of problem:
The spapr vscsi disks for lun id '9-31' and channel id '4-7' could not be recognized inside a power pc guest

Version-Release number of selected component (if applicable):
Host kernel: 3.10.0-306.0.1.el7.ppc64le
Guest kernel: 3.10.0-306.0.1.el7.ppc64le
Qemu-kvm-rhev: qemu-kvm-rhev-2.3.0-22.el7.ppc64le

How reproducible:
100%

Steps to Reproduce:
1. Open a host terminal, change the open files limit to 3072:
# ulimit - n 3072
# ulimit -a

2. Boot up a guest with following qemu cmd in the same host terminal:

/usr/libexec/qemu-kvm -name virtioblk-0828-le -machine pseries,accel=kvm,usb=off -m 256000M -realtime mlock=off -smp 152,sockets=1,cores=20,threads=8 -uuid 95346a10-1828-403a-a610-ac5a52a29414 -no-user-config -nodefaults -monitor stdio -rtc base=utc,clock=host -no-shutdown -boot strict=on -device nec-usb-xhci,id=xhci,addr=0x1 -device spapr-vscsi,id=scsi0,reg=0x1000 -drive id=drive_image1,if=none,cache=none,snapshot=off,aio=native,format=qcow2,file=/home/virtioblk-0828-le -device virtio-blk-pci,id=image1,drive=drive_image1,bus=pci.0,addr=04,bootindex=1 -netdev tap,id=hostnet0,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown -device spapr-vlan,netdev=hostnet0,id=net0,mac=52:54:00:c4:e7:14,reg=0x2000 -chardev pty,id=charserial0 -device spapr-vty,chardev=charserial0,reg=0x30000000 -device usb-kbd,id=input0 -device usb-mouse,id=input1 -device usb-tablet,id=input2 -vnc 0:04 -device VGA,id=video0,bus=pci.0,addr=0x8 -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3 -object rng-random,id=rng0,filename=/dev/random -device virtio-rng-pci,rng=rng0,max-bytes=1234,period=2000,bus=pci.0,addr=0x5 -msg timestamp=on -device virtio-scsi-pci,id=scsi1,bus=pci.0,addr=0x9 -monitor unix:/tmp/monitor2,server,nowait

3. Use following shell script to hot plug the lun id '0-8' and channel id '0-3' spapr vscsi disks and make sure they can be found with hmp cmd 'info block':

#!/bin/bash
j=0
k=0
l=0
for j in {0..63}
do
for k in {0..8}
do
for l in {0..3}
do
qemu-img create -f qcow2 /home/disk-spapr/s$j-l$k-c$l 10M
echo "__com.redhat_drive_add file=/home/disk-spapr/s$j-l$k-c$l,format=qcow2,media=disk,id=s$j-l$k-c$l" | nc -U /tmp/monitor2
echo "device_add scsi-hd,bus=scsi0.0,drive=s$j-l$k-c$l,scsi-id=$j,lun=$k,channel=$l,id=hds$j-l$k-c$l" | nc -U /tmp/monitor2
l=$(($l+1))
done
k=$(($k+1))
done
j=$(($j+1))
done

4. After the hotpluging operation finished in step3, reboot the guest and check the spapr-vscsi disks number inside the guest with following cmd:
# ll /dev/sd* | wc -l

5. Hot unplug above disks with following script:

#!/bin/bash
j=0
k=0
l=0
for j in {0..63}
do
for k in {0..8}
do
for l in {0..3}
do
echo "device_del hds$j-l$k-c$l" | nc -U /tmp/monitor2
l=$(($l+1))
done
k=$(($k+1))
done
j=$(($j+1))
done

6. Reboot guest after the operation in step5 finished

7. Repeat steps 3-6 for the lun id '0-8' and channel id '4-7' spapr vscsi disks

8. Repeat steps 3-6 for the lun id '0-8' and channel id '3-7' spapr vscsi disks

9. Repeat steps 3-6 for the lun id '9-17' and channel id '0-3' spapr vscsi disks

10. Repeat steps 3-6 for the lun id '8-17' and channel id '0-3' spapr vscsi disks

11. Repeat steps 3-6 for the lun id '18-26' and channel id '0-3' spapr vscsi disks

12. Repeat steps 3-6 for the lun id '27-31' and channel id '0-3' spapr vscsi disks


Actual results:
In step4, 2304(64*9*4) disks were found inside the guest
In step7, 0 disk was found inside the guest
In step8, 576(64*8*1) disks were found
In step9, 0 disk was found
In step10, 256(64*1*4) disks were found
In steps 11/12, 0 disk was found
As a conclusion, the lun id '9-31' and channel id '4-7' spapr vscsi disks could not be found inside the guest

Expected results:
The lun id '9-31' and channel id '4-7' spapr vscsi disks could not be found inside the guest as the lun id '0-8' and channel id '0-3' ones

Additional info: