Description of problem:
The guest fail to boot up while the scsi disk with bootindex=0

Version-Release number of selected component (if applicable):
host:3.10.0-656.el7.x86_64
qmeu:qemu-kvm-rhev-2.9.0-1.el


How reproducible:
100%

Steps to Reproduce:
1.Install a guest with a scsi disk set lun=1
eg:
/usr/libexec/qemu-kvm \
-name rhel7_4-11853 \
-m 2G \
-nodefaults \
-boot menu=on,order=cd \
-device VGA,id=vga0 \
-device nec-usb-xhci,id=xhci \
-device usb-tablet,id=usb-tablet0 \
-device usb-kbd,id=usb-kbd0 \
-device virtio-scsi-pci,id=scsi-pci-0 \
-device virtio-scsi-pci,id=scsi-pci-1 \
-drive file=/home/hyx/iso/RHEL-7.4-20170330.1-Server-x86_64-dvd1.iso,if=none,media=cdrom,id=cd-0 \
-device scsi-cd,bus=scsi-pci-0.0,id=scsi-cd-0,drive=cd-0,channel=0,scsi-id=0,lun=0,bootindex=0 \
-drive file=/home/hyx/image/rhel-7_4-11853-20G.qcow2,format=qcow2,if=none,cache=none,media=disk,werror=stop,rerror=stop,id=drive-0 \
-device scsi-hd,bus=scsi-pci-1.0,id=scsi-hd-0,drive=drive-0,channel=0,scsi-id=0,lun=1 \
-netdev tap,id=hostnet0,script=/etc/qemu-ifup \
-device virtio-net-pci,netdev=hostnet0,id=virtio-net-pci0,mac=40:f2:e9:5d:9c:03 \
-serial unix:./sock0,server,nowait \
-qmp tcp:0:3000,server,nowait \
-monitor stdio \
-vnc :10

2.Boot the guset
eg:
/usr/libexec/qemu-kvm \
-name rhel7_4-11853 \
-m 2G \
-nodefaults \
-boot menu=on,order=cd \
-device VGA,id=vga0 \
-device nec-usb-xhci,id=xhci \
-device usb-tablet,id=usb-tablet0 \
-device usb-kbd,id=usb-kbd0 \
-device virtio-scsi-pci,id=scsi-pci-0 \
-device virtio-scsi-pci,id=scsi-pci-1 \
-drive file=/home/hyx/image/rhel-7_4-11853-20G.qcow2,format=qcow2,if=none,cache=none,media=disk,werror=stop,rerror=stop,id=drive-0 \
-device scsi-hd,bus=scsi-pci-1.0,id=scsi-hd-0,drive=drive-0,channel=0,scsi-id=0,lun=1,bootindex=0 \
-netdev tap,id=hostnet0,script=/etc/qemu-ifup \
-device virtio-net-pci,netdev=hostnet0,id=virtio-net-pci0,mac=40:f2:e9:5d:9c:03 \
-serial unix:./sock0,server,nowait \
-qmp tcp:0:3000,server,nowait \
-monitor stdio \
-vnc :10

Actual results:
The guest can not boot up because can not read the boot disk

Expected results:
The guest can boot up successfully.

Additional info:
It did not be reproduced in ppc.