Re: [RFC QEMU PATCH v8 2/2] virtio-pci: implement No_Soft_Reset bit

[Chen, Jiqian]

On 2024/4/8 12:56, Jason Wang wrote:
>>>> I will set the default value of No_Soft_Reset bit to true in next version 
>>>> according to your opinion.
>>>> About the compatibility of old machine types, which types should I 
>>>> consider? Does the same as x-pcie-pm-init(hw_compat_2_8)?
>>>> Forgive me for not knowing much about compatibility.
>>>
>>> "x" means no compatibility at all, please drop the "x" prefix. And it
>>> looks more safe to start as "false" by default.
>>>
>>> Thanks
>>
>>
>> Not sure I agree. External flags are for when users want to tweak them.
>> When would users want it to be off?
> 
> If I understand the suspending status proposal correctly, there are at
> least 1 device that is not safe. And this series does not mention
> which device it has tested.
I only tested virtio-gpu with my patch, I will mention this in "commit message" 
in next version.

> 
> It means if we enable it unconditionally, guests may break.
Make sense, will keep " No_Soft_Reset bit " false by default. And add some 
comments in the codes to describe what you considered.

> 
> Thanks
> 
>> What is done here is I feel sane, just add machine compat machinery
>> to change to off for old machine types.

-- 
Best regards,
Jiqian Chen.