Re: [PATCH] s390x/s390-virtio-ccw: Reset PCI devices during subsystem reset

[Niklas Schnelle]

On 10/15/20 3:34 PM, Christian Borntraeger wrote:
> 
> 
> On 15.10.20 15:32, Christian Borntraeger wrote:
>>
>>
>> On 15.10.20 15:16, Matthew Rosato wrote:
>>> Currently, a subsystem reset event leaves PCI devices enabled, causing
>>> issues post-reset in the guest (an example would be after a kexec).  These
>>> devices need to be reset during a subsystem reset, allowing them to be
>>> properly re-enabled afterwards.  Add the S390 PCI host bridge to the list
>>> of qdevs to be reset during subsystem reset.
>>>
>>> Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
>>> Reviewed-by: Eric Farman <farman@linux.ibm.com>
>>
>> Makese sense. 
>> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
> 
> A question. Is this a stable candidate?

As this can prevent a SUSE guest (which does kexec during boot because of grub)
from seeing any PCI devices I'd say yes.

> 
>>
>>
>>> ---
>>>  hw/s390x/s390-virtio-ccw.c | 1 +
>>>  1 file changed, 1 insertion(+)
>>>
>>> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
>>> index e52182f..2e90033 100644
>>> --- a/hw/s390x/s390-virtio-ccw.c
>>> +++ b/hw/s390x/s390-virtio-ccw.c
>>> @@ -101,6 +101,7 @@ static const char *const reset_dev_types[] = {
>>>      "s390-sclp-event-facility",
>>>      "s390-flic",
>>>      "diag288",
>>> +    TYPE_S390_PCI_HOST_BRIDGE,
>>>  };
>>>  
>>>  static void subsystem_reset(void)
>>>