Re: [PATCH RFC 0/1] To add HMP interface to dump PCI MSI-X table/PBA

[Dongli Zhang]

On 4/22/21 11:01 PM, Jason Wang wrote:
> 
> 在 2021/4/23 下午12:47, Dongli Zhang 写道:
>> This is inspired by the discussion with Jason on below patchset.
>>
>> https://urldefense.com/v3/__https://lists.gnu.org/archive/html/qemu-devel/2021-03/msg09020.html__;!!GqivPVa7Brio!KbGQZW5lq3JZ60k12NuWZ6Th1lT6AwmBTF0pBgoWUKKQ4-2UhdW57PtvXUN5XQnZ2NU$
>>
>> The new HMP command is introduced to dump the MSI-X table and PBA.
>>
>> Initially, I was going to add new option to "info pci". However, as the
>> number of entries is not determined and the output of MSI-X table is much
>> more similar to the output of hmp_info_tlb()/hmp_info_mem(), this patch
>> adds interface for only HMP.
>>
>> The patch is tagged with RFC because I am looking for suggestions on:
>>
>> 1. Is it fine to add new "info msix <dev>" command?
> 
> 
> I wonder the reason for not simply reusing "info pci"?

The "info pci" will show PCI data for all devices and it does not accept any
argument to print for a specific device.

In addition, the "info pci" relies on qmp_query_pci(), where this patch will not
implement the interface for QMP considering the number of MSI-X entries is not
determined.

Suppose we have 10 NVMe (emulated by QEMU with default number of queues), we
will have about 600+ lines of output.

Dongli Zhang

> 
> 
>>
>> 2. Is there any issue with output format?
> 
> 
> If it's not for QMP, I guess it's not a part of ABI so it should be fine.
> 
> 
>>
>> 3. Is it fine to add only for HMP, but not QMP?
> 
> 
> I think so.
> 
> Thanks
> 
> 
>>
>> Thank you very much!
>>
>> Dongli Zhang
>>
>>
>>
>