Re: [Qemu-devel] [kvm-s390] qemu-system-s390x: cannot use stdio by multiple character devices

[Alexander Graf]

On 20.08.15 01:20, tu bo wrote:
> Hi Alex:
> 
> Ping you again just in case you did not get my mail  :-)
> 
> On 08/13/2015 03:52 PM, tu bo wrote:
>> Hi Alex:
>>
>> I added one disk device for test case 068(qemu/tests/qemu-iotests/068,
>> which is for for loading a saved VM state from a qcow2 image ),
>> and got the same problem for s390-virtio-ccw.  Below is my steps:
>> 1. qemu-img create -f qcow2 scratch/t.qcow2 64M
>> 2. address@hidden qemu-iotests]# ../../s390x-softmmu/qemu-system-s390x
>> -nodefaults -nographic -monitor stdio -serial none  -hda scratch/t.qcow2
>> QEMU 2.3.94 monitor - type 'help' for more information
>> (qemu) address@hidden qemu-iotests]#
>>
>> For s390-virtio,  test result is as expected
>> 1. qemu-img create -f qcow2 scratch/t.qcow2 64M
>> 2. address@hidden qemu-iotests]# qemu-system-s390x -nodefaults
>> -nographic -monitor stdio -serial none  -hda scratch/t.qcow2
>> QEMU 2.3.50 monitor - type 'help' for more information
>> (qemu) info roms
>> addr=0000000000009000 size=0x000ce8 mem=ram
>> name="/usr/share/qemu/s390-zipl.rom"
>> (qemu) savevm 0
>> (qemu)
>> (qemu) quit
>> address@hidden qemu-iotests]# qemu-system-s390x -nodefaults
>> -nographic -monitor stdio -serial none  -hda scratch/t.qcow2 -loadvm 0
>> QEMU 2.3.50 monitor - type 'help' for more information
>> (qemu)
>>
>> For x86-64, test result is as expected,
>> 1. address@hidden qemu-iotests]$ qemu-img create -f qcow2
>> scratch/t.qcow2 64M
>> 2. address@hidden qemu-iotests]$
>> ../../x86_64-softmmu/qemu-system-x86_64 -nodefaults -nographic
>> -monitor stdio -serial none  -hda scratch/t.qcow2
>> QEMU 2.3.94 monitor - type 'help' for more information
>> (qemu) info roms
>> fw=genroms/kvmvapic.bin size=0x002400 name="kvmvapic.bin"
>> addr=00000000fffc0000 size=0x040000 mem=rom name="bios-256k.bin"
>> /address@hidden/acpi/tables size=0x200000 name="etc/acpi/tables"
>> /address@hidden/table-loader size=0x001000 name="etc/table-loader"
>> /address@hidden/acpi/rsdp size=0x000024 name="etc/acpi/rsdp"
>> (qemu) savevm 0
>> (qemu)
>> 3. address@hidden qemu-iotests]$
>> ../../x86_64-softmmu/qemu-system-x86_64 -nodefaults -nographic
>> -monitor stdio -serial none  -hda scratch/t.qcow2 -loadvm 0
>> QEMU 2.3.94 monitor - type 'help' for more information
>> (qemu)
>>
>> Could you share me why s390-virtio-ccw has different behavior with
>> s390-virtio & x86_64 for this scenario?  thanks

Because the s390 folks at IBM thought it'd be cool to emit a panic
(read: shut down) in the ccw bootloader when there is a problem? ;)

If this breaks test cases for you, please coordinate with Christian
Borntraeger and Eugene Dvurechenski whether it makes sense to change it.


Alex