Re: [Qemu-stable] Possible bug in qemu-1.4.2: boot=off not honoured for -drive instances of virtio-scsi devices?

[Michael Roth]

Quoting George Diamantopoulos (2013-06-26 12:48:20)
> Hello,
> 
>    I've been testing out qemu-kvm 1.4.2 with virtio-scsi drives and I think I
>    might have encountered a bug. The VM is configured with: 1) a virtio-blk
>    drive, which is the one I want to boot, 2) another virtio-blk cdrom drive
>    and two virtio-scsi drives.
> 
>    Although I have set the boot=off flag for the virtio-scsi drives, I
>    believe the VM tries two boot off one of these drives, because 1) if I
>    start the VM without initializing these two virtio-scsi devices, it boots
>    off the virtio-blk disk and 2) if I initialize the virtio-scsi drives, the
>    VM stalls during booting.
> 
>    However, if I use "-boot order=c,menu=on" when starting qemu-kvm, and then
>    enter the boot menu, all devices appear in the list there, and the
>    virtio-scsi drives make it to the top, despite my having set the boot=off
>    flag for the virtio-scsi drives. If I manually choose the virtio-blk drive
>    from the boot menu, the instance boots successfully, even if the
>    virtio-scsi disks are present.
> 
>    I could get around the issue perhaps by setting proper bootindex
>    priorities, but unfortunately ganeti won't let me choose bootindex value
>    for the disk instances it manages itself (namely the virtio-blk drives).
> 
>    Here's how ganeti starts the instance:
> 
>    /usr/bin/qemu-system-x86_64 -machine accel=kvm -name nas.mydomain.tld -m
>    2560 -smp 1 -pidfile /var/run/ganeti/kvm-hypervisor/pid/nas.mydomain.tld
>    -balloon virtio -daemonize -machine pc-i440fx-1.4 -boot c -drive
>    file=/var/run/ganeti/instance-disks/nas.mydomain.tld:0,format=raw,if=virtio
>    -drive
>    
> file=/srv/ganeti/isos/FreeNAS-9.1.0-BETA-a9c3cf1-x64.iso,format=raw,media=cdrom,if=virtio
>    -monitor
>    
> unix:/var/run/ganeti/kvm-hypervisor/ctrl/nas.mydomain.tld.monitor,server,nowait
>    -serial
>    
> unix:/var/run/ganeti/kvm-hypervisor/ctrl/nas.mydomain.tld.serial,server,nowait
>    -usb -usbdevice tablet -vnc 10.2.24.30:5101 -cpu host -device
>    virtio-scsi-pci,id=scsihw0 -drive
>    file=/dev/sdb,if=none,id=sdb,cache=writeback,boot=off,aio=native -device
>    
> scsi-hd,drive=sdb,id=scsi1,bus=scsihw0.0,channel=0,scsi-id=0,lun=0,bootindex=100
>    -drive file=/dev/sdc,if=none,id=sdc,cache=writeback,boot=off,aio=native
>    -device
>    
> scsi-hd,drive=sdc,id=scsi2,bus=scsihw0.0,channel=0,scsi-id=1,lun=0,bootindex=101
>    -boot order=c,menu=on -netdev type=tap,id=netdev0,fd=9 -device
>    virtio-net-pci,mac=aa:00:00:3c:89:c2,netdev=netdev0 -qmp
>    unix:/var/run/ganeti/kvm-hypervisor/ctrl/nas.mydomain.tld.qmp,server,nowait
>    -S
> 
>    Shouldn't this result in only the virtio-blk device being selected for
>    boot, given these arguments

That would be my expectation. This might be a known issue with SeaBIOS:

  https://lists.gnu.org/archive/html/qemu-devel/2012-09/msg00417.html

Are you seeing this upstream as well? CC'ing qemu-devel just in case.

>    boot, given these arguments, or is this behaviour intended? Thanks.


>    Best regards,
>    George Diamantopoulos