Re: [Qemu-devel] [PATCH 00/30] complete conversion to hotplug-handler API

[Cornelia Huck]

On Wed, 24 Sep 2014 16:20:56 +0200
Igor Mammedov <address@hidden> wrote:

> Cornelia,
> Thanks for testing, could you share your QEMU CLI and commands you use
> for testing. Since it's surprise removal, I'll probably would be able
> to debug it without working guest.
> 
> BTW:
> Is there a way to test it without s390 host+kvm, I've googled for
> howto, but haven't found a working CLI+guest combination yet on
> x86 fedora host?
> 

I'm afraid you'll need an s390 host to test this :( However, here's
what I did:

/data/git/yyy/qemu/build/s390x-softmmu/qemu-system-s390x -machine 
s390-ccw-virtio,accel=kvm,usb=off,kernel_irqchip=on -m 1024 -smp 4 -nographic 
-drive 
file=/dev/sda,if=none,id=drive-virtio-disk0,format=raw,serial=ccwzfcp1,cache=none
 -device 
virtio-blk-ccw,devno=fe.0.0001,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1
 -kernel /data/git/xxx/linux/arch/s390/boot/image -append "root=/dev/vda1"

<guest>
address@hidden ~]# lscss
Device   Subchan.  DevType CU Type Use  PIM PAM POM  CHPIDs
----------------------------------------------------------------------
0.0.0000 0.0.0000  0000/00 3832/01 yes  80  80  ff   00000000 00000000 
0.0.0001 0.0.0001  0000/00 3832/02 yes  80  80  ff   00000000 00000000 
</guest>

In the monitor:
device_add virtio-balloon-ccw,id=xxx,devno=fe.2.1111

<guest>
address@hidden ~]# lscss
Device   Subchan.  DevType CU Type Use  PIM PAM POM  CHPIDs
----------------------------------------------------------------------
0.0.0000 0.0.0000  0000/00 3832/01 yes  80  80  ff   00000000 00000000 
0.0.0001 0.0.0001  0000/00 3832/02 yes  80  80  ff   00000000 00000000 
0.2.1111 0.2.0000  0000/00 3832/05 yes  80  80  ff   00000000 00000000 
address@hidden ~]# dmesg | grep CRW
[   26.098964] crw_info : CRW reports slct=0, oflw=0, chn=1, rsc=3, anc=0, 
erc=4, rsid=0
[   26.098981] crw_info : CRW reports slct=0, oflw=0, chn=0, rsc=3, anc=0, 
erc=4, rsid=20
</guest>

In the monitor:
device_del xxx

lscss in the guest now still shows the same output (the 0.2.1111 line
should be gone), and no new crws show up in dmesg (there should be two
further crws).

I hope this is helpful. Let me know if there's something I can do (like
stepping through qemu in gdb).