Re: [Qemu-devel] [PATCH 0/3] correct some register return values for vxmnet3

[Jason Wang <jasowang@redhat.com>]

On 12/22/2015 03:05 PM, Dmitry Fleytman wrote:
>
>> On 22 Dec 2015, at 04:44 AM, Miao Yan <yanmiaobest@gmail.com
>> <mailto:yanmiaobest@gmail.com>> wrote:
>>
>> Hi Dmitry,
>>
>> 2015-12-22 1:19 GMT+08:00 Dmitry Fleytman <dmitry@daynix.com
>> <mailto:dmitry@daynix.com>>:
>>> Hello Miao,
>>>
>>> While patches look good technically, I cannot find any code snippets
>>> that prove correctness of these changes.
>>
>> Linux driver does not read those registers currently,
>> not sure about Windows version.
>>
>>
>>> How do you know this is the correct behaviour? Could you please
>>> extend commit messages with corresponding references?
>>
>>
>> This behavior can be observed by modifying linux driver to read those
>> registers
>> at probe time (in vmxnet3_device_probe) and kernel log will have the
>> following
>> message (running on esxi server, of source):
>>
>> [  198.427389] VMware vmxnet3 virtual NIC driver - version 1.2.0.0-k-NAPI
>> [  198.428863] vmxnet3 0000:03:00.0: # of Tx queues : 1, # of Rx
>> queues : 1
>> [  198.559625] vmxnet3 DID lo: 0x7b0, high: 0x1, dev_info: 0x0
>> [  198.561151] vmxnet3 0000:03:00.0: irq 72 for MSI/MSI-X
>>
>> Here DID_LO is the pci device id, DID_HIGH is 0x1 and
>> GET_DEV_EXTRA_INFO returns 0.
>>
>> putting above into commit message should be enough ?
>
> Yes, this should be good enough. Please also provide ESX version
> you’re running on.
>
> Reviewed-by: Dmitry Fleytman <dmitry@daynix.com
> <mailto:dmitry@daynix.com>>
>
> Jason, these changes are guest visible but init time only. Do you
> think compatibility code is needed in this case?

I think it was probably no need to do compatibility things here,
consider no device state but only register read changes and I believe no
driver should depend on those values.

>
>>
>>
>>>
>>> Thanks,
>>> Dmitry
>>>
>>>> On 21 Dec 2015, at 13:06 PM, Miao Yan <yanmiaobest@gmail.com
>>>> <mailto:yanmiaobest@gmail.com>> wrote:
>>>>
>>>> Qemu vmxnet3 emulation doesn't recognize VMXNET3_CMD_GET_DID_LO,
>>>> VMXNET3_CMD_GET_DID_HI and VMXNET3_CMD_GET_DEV_EXTRA_INFO command and
>>>> returns -1 on all of them.
>>>>
>>>> This patchset makes them return correct values.
>>>>
>>>> Miao Yan (3):
>>>> net/vmxnet3: return 1 on device activation failure
>>>> net/vmxnet3: return correct value for VMXNET3_CMD_GET_DID command
>>>> net/vmxnet3: return correct value for VMXNET3_CMD_GET_DEV_EXTRA_INFO
>>>>
>>>> hw/net/vmxnet3.c | 11 ++++++++++-
>>>> 1 file changed, 10 insertions(+), 1 deletion(-)
>>>>
>>>> --
>>>> 1.9.1
>>>>
>>>
>