Re: [dpdk-dev] [PATCH 3/5] net/virtio: add VIRTIO_SET_STATUS support to Virtio-user

[Adrian Moreno <amorenoz@redhat.com>]

On 7/16/20 10:58 AM, Xia, Chenbo wrote:
> Hi Adrian,
> 
>> -----Original Message-----
>> From: Adrian Moreno <amorenoz@redhat.com>
>> Sent: Thursday, July 16, 2020 3:43 PM
>> To: Xia, Chenbo <chenbo.xia@intel.com>; dev@dpdk.org
>> Cc: maxime.coquelin@redhat.com; Wang, Zhihong <zhihong.wang@intel.com>
>> Subject: Re: [PATCH 3/5] net/virtio: add VIRTIO_SET_STATUS support to Virtio-
>> user
>>
>>
>>
>> On 7/16/20 5:15 AM, Xia, Chenbo wrote:
>>> Hi Adrian,
>>>
>>>> -----Original Message-----
>>>> From: Adrian Moreno <amorenoz@redhat.com>
>>>> Sent: Thursday, July 16, 2020 1:18 AM
>>>> To: dev@dpdk.org
>>>> Cc: maxime.coquelin@redhat.com; Wang, Zhihong
>>>> <zhihong.wang@intel.com>; amorenoz@redhat.com; Xia, Chenbo
>>>> <chenbo.xia@intel.com>
>>>> Subject: [PATCH 3/5] net/virtio: add VIRTIO_SET_STATUS support to
>>>> Virtio-user
>>>>
>>>> From: Maxime Coquelin <maxime.coquelin@redhat.com>
>>>>
>>>> This patch adds support for VHOST_USER_SET_STATUS request. It is used
>>>> to make the backend aware of Virtio devices status update.
>>>>
>>>> It is useful for the backend to know when the Virtio driver is done
>>>> with the Virtio device configuration.
>>>>
>>>> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
>>>> Signed-off-by: Adrian Moreno <amorenoz@redhat.com>
>>>> ---
>>>>  drivers/net/virtio/virtio_user/vhost.h        |  6 +++++
>>>>  drivers/net/virtio/virtio_user/vhost_user.c   | 10 ++++++++
>>>>  .../net/virtio/virtio_user/virtio_user_dev.c  | 23 ++++++++++++++++++-
>>>>   .../net/virtio/virtio_user/virtio_user_dev.h  |  1 +
>>>>  drivers/net/virtio/virtio_user_ethdev.c       |  1 +
>>>>  5 files changed, 40 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/net/virtio/virtio_user/vhost.h
>>>> b/drivers/net/virtio/virtio_user/vhost.h
>>>> index 260e1c308..8f49ef457 100644
>>>> --- a/drivers/net/virtio/virtio_user/vhost.h
>>>> +++ b/drivers/net/virtio/virtio_user/vhost.h
>>>> @@ -57,6 +57,10 @@ struct vhost_vring_addr {  #define
>>>> VHOST_USER_PROTOCOL_F_REPLY_ACK 3  #endif
>>>>
>>>> +#ifndef VHOST_USER_PROTOCOL_F_STATUS #define
>>>> +VHOST_USER_PROTOCOL_F_STATUS 16 #endif
>>>> +
>>>>  enum vhost_user_request {
>>>>  	VHOST_USER_NONE = 0,
>>>>  	VHOST_USER_GET_FEATURES = 1,
>>>> @@ -77,6 +81,8 @@ enum vhost_user_request {
>>>>  	VHOST_USER_SET_PROTOCOL_FEATURES = 16,
>>>>  	VHOST_USER_GET_QUEUE_NUM = 17,
>>>>  	VHOST_USER_SET_VRING_ENABLE = 18,
>>>> +	VHOST_USER_SET_STATUS = 39,
>>>> +	VHOST_USER_GET_STATUS = 40,
>>>>  	VHOST_USER_MAX
>>>>  };
>>>>
>>>> diff --git a/drivers/net/virtio/virtio_user/vhost_user.c
>>>> b/drivers/net/virtio/virtio_user/vhost_user.c
>>>> index 631d0e353..2332e01d1 100644
>>>> --- a/drivers/net/virtio/virtio_user/vhost_user.c
>>>> +++ b/drivers/net/virtio/virtio_user/vhost_user.c
>>>> @@ -244,6 +244,8 @@ const char * const vhost_msg_strings[] = {
>>>>  	[VHOST_USER_SET_VRING_ENABLE] = "VHOST_SET_VRING_ENABLE",
>>>>  	[VHOST_USER_GET_PROTOCOL_FEATURES] =
>>>> "VHOST_USER_GET_PROTOCOL_FEATURES",
>>>>  	[VHOST_USER_SET_PROTOCOL_FEATURES] =
>>>> "VHOST_USER_SET_PROTOCOL_FEATURES",
>>>> +	[VHOST_USER_SET_STATUS] = "VHOST_SET_STATUS",
>>>> +	[VHOST_USER_GET_STATUS] = "VHOST_GET_STATUS",
>>>>  };
>>>>
>>>>  static int
>>>> @@ -280,6 +282,14 @@ vhost_user_sock(struct virtio_user_dev *dev,
>>>>  		need_reply = 1;
>>>>  		break;
>>>>
>>>> +	case VHOST_USER_SET_STATUS:
>>>> +		if (!(dev->protocol_features &
>>>> +				(1ULL <<
>>>> VHOST_USER_PROTOCOL_F_STATUS)))
>>>> +			return 0;
>>>> +
>>>> +		if (has_reply_ack)
>>>> +			msg.flags |= VHOST_USER_NEED_REPLY_MASK;
>>>> +		/* Fallthrough */
>>>
>>> There's a coding style issue here:
>>> WARNING:PREFER_FALLTHROUGH: Prefer 'fallthrough;' over fallthrough
>> comment.
>>> Could you fix this?
>>>
>> "fallthrough" is not defined. I think this macro is defined in the linux kernel
>> (where checkpatches.pl comes from?). We could define the same macro that
>> would depend in compiler support for __falthrough__ attribute.
>>
>> In any case, this is not the only case:
>>
>> $ find -name *.c | xargs grep -i "/\* fallthrough \*/" | wc -l
>> 62
>>
>> So maybe this warning is new?
>> Should I change all of them together in another patch?
> 
> checkpatches.pl is in linux kernel. I think it prefers 'fallthrough' rather than
> 'Fallthrough'. I think it's a linux style, right?
> 
It refers to this:
https://github.com/torvalds/linux/blob/91a9a90d040e8b9ff63d48ea71468e0f4db764ff/include/linux/compiler_attributes.h#L201

Since we don't have that pseudo-keyword, we should see if we can disable this in
checkpatches.


> Thanks!
> Chenbo
> 
>>
>>>>  	case VHOST_USER_SET_FEATURES:
>>>>  	case VHOST_USER_SET_PROTOCOL_FEATURES:
>>>>  	case VHOST_USER_SET_LOG_BASE:
>>>> diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c
>>>> b/drivers/net/virtio/virtio_user/virtio_user_dev.c
>>>> index 0a6991bcc..2c400a448 100644
>>>> --- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
>>>> +++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
>>>> @@ -424,7 +424,8 @@ virtio_user_dev_setup(struct virtio_user_dev
>>>> *dev)
>>>>
>>>>  #define VIRTIO_USER_SUPPORTED_PROTOCOL_FEATURES		\
>>>>  	(1ULL << VHOST_USER_PROTOCOL_F_MQ |		\
>>>> -	 1ULL << VHOST_USER_PROTOCOL_F_REPLY_ACK)
>>>> +	 1ULL << VHOST_USER_PROTOCOL_F_REPLY_ACK |	\
>>>> +	 1ULL << VHOST_USER_PROTOCOL_F_STATUS)
>>>>
>>>>  int
>>>>  virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int
>>>> queues, @@ -
>>>> 783,3 +784,23 @@ virtio_user_handle_cq(struct virtio_user_dev *dev,
>>>> uint16_t
>>>> queue_idx)
>>>>  		__atomic_add_fetch(&vring->used->idx, 1,
>> __ATOMIC_RELAXED);
>>>>  	}
>>>>  }
>>>> +
>>>> +int
>>>> +virtio_user_send_status_update(struct virtio_user_dev *dev, uint8_t
>>>> +status) {
>>>> +	int ret;
>>>> +	uint64_t arg = status;
>>>> +
>>>> +	/* Vhost-user only for now */
>>>> +	if (!is_vhost_user_by_type(dev->path))
>>>> +		return 0;
>>>> +
>>>> +	if (!(dev->protocol_features & (1ULL <<
>>>> VHOST_USER_PROTOCOL_F_STATUS)))
>>>> +		return 0;
>>>> +
>>>> +	ret = dev->ops->send_request(dev, VHOST_USER_SET_STATUS, &arg);
>>>> +	if (ret)
>>>> +		return -1;
>>>
>>> Do you think we should add a log here to show if SET_STAUTS failed?
>>>
>> Good idea! Will do in the next version. Thanks
>>
>>> Thanks!
>>> Chenbo
>>>
>>>> +
>>>> +	return 0;
>>>> +}
>>>> diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.h
>>>> b/drivers/net/virtio/virtio_user/virtio_user_dev.h
>>>> index 10b274d19..a76d7cfaf 100644
>>>> --- a/drivers/net/virtio/virtio_user/virtio_user_dev.h
>>>> +++ b/drivers/net/virtio/virtio_user/virtio_user_dev.h
>>>> @@ -74,4 +74,5 @@ void virtio_user_handle_cq(struct virtio_user_dev
>>>> *dev, uint16_t queue_idx);  void virtio_user_handle_cq_packed(struct
>>>> virtio_user_dev *dev,
>>>>  				  uint16_t queue_idx);
>>>>  uint8_t virtio_user_handle_mq(struct virtio_user_dev *dev, uint16_t
>>>> q_pairs);
>>>> +int virtio_user_send_status_update(struct virtio_user_dev *dev,
>>>> +uint8_t status);
>>>>  #endif
>>>> diff --git a/drivers/net/virtio/virtio_user_ethdev.c
>>>> b/drivers/net/virtio/virtio_user_ethdev.c
>>>> index 5b06d8e89..e52f11341 100644
>>>> --- a/drivers/net/virtio/virtio_user_ethdev.c
>>>> +++ b/drivers/net/virtio/virtio_user_ethdev.c
>>>> @@ -273,6 +273,7 @@ virtio_user_set_status(struct virtio_hw *hw,
>>>> uint8_t
>>>> status)
>>>>  	else if (status == VIRTIO_CONFIG_STATUS_RESET)
>>>>  		virtio_user_reset(hw);
>>>>  	dev->status = status;
>>>> +	virtio_user_send_status_update(dev, status);
>>>>  }
>>>>
>>>>  static uint8_t
>>>> --
>>>> 2.26.2
>>>
>>
>> --
>> Adrián Moreno
> 

-- 
Adrián Moreno