Re: [qemu-s390x] [PATCH v1 for-2.13 2/4] pc-bios/s390-ccw/net: Stop virtio-net device before jumping into the OS

[Christian Borntraeger]

On 04/20/2018 08:31 AM, Thomas Huth wrote:
> On 19.04.2018 17:49, Christian Borntraeger wrote:
>> On 04/18/2018 02:31 PM, Thomas Huth wrote:
>>> The virtio-net receive buffers are filled asynchronously, so we should
>>> make sure to properly shut down the virtio-net device before we jump into
>>> the loaded kernel. Otherwise an incoming packet could destroy memory of
>>> the OS kernel if it did not re-initialize the virtio-net device fast
>>> enough yet.
>>
>> The normal bios does a full subsystem reset before we enter the OS.
>> (see jump_to_IPL_code the diag 308). That should reset all virtio 
>> devices on the qemu level. Shouldnt we rather do the same for
>> the net bios?
> 
> That should fix this issue, too, right. I'll give it a try and include
> it in v2 if I can make it work...

The advantage is that it also put the sclp console into a default state.
> 
>  Thomas
>