Re: [PATCH v5 2/2] s390: virtio: PV needs VIRTIO I/O device protection

[Pierre Morel <pmorel@linux.ibm.com>]

On 2020-07-09 16:47, Halil Pasic wrote:
> On Thu, 9 Jul 2020 12:51:58 +0200
> Pierre Morel <pmorel@linux.ibm.com> wrote:
> 
>>>> +int arch_validate_virtio_features(struct virtio_device *dev)
>>>> +{
>>>> +	if (!is_prot_virt_guest())
>>>> +		return 0;
>>>> +
>>>> +	if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1)) {
>>>> +		dev_warn(&dev->dev, "device must provide VIRTIO_F_VERSION_1\n");
>>>
>>> I'd probably use "legacy virtio not supported with protected
>>> virtualization".
>>>    
>>>> +		return -ENODEV;
>>>> +	}
>>>> +
>>>> +	if (!virtio_has_feature(dev, VIRTIO_F_IOMMU_PLATFORM)) {
>>>> +		dev_warn(&dev->dev,
>>>> +			 "device must provide VIRTIO_F_IOMMU_PLATFORM\n");
>>>
>>> "support for limited memory access required for protected
>>> virtualization"
>>>
>>> ?
>>>
>>> Mentioning the feature flag is shorter in both cases, though.
>>
>> And I think easier to look for in case of debugging purpose.
>> I change it if there is more demands.
> 
> Not all our end users are kernel and/or qemu developers. I find the
> messages from v4 less technical, more informative, and way better.
> 
> Regards,
> Halil
> 

Can you please tell me the messages you are speaking of, because for me 
the warning's messages are exactly the same in v4 and v5!?

I checked many times, but may be I still missed something.

Regards,
Pierre


-- 
Pierre Morel
IBM Lab Boeblingen