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

[Maxime Coquelin <maxime.coquelin@redhat.com>]

On 6/17/20 2:07 PM, Xia, Chenbo wrote:
> Hi Maxime,
> 
>> -----Original Message-----
>> From: dev <dev-bounces@dpdk.org> On Behalf Of Maxime Coquelin
>> Sent: Thursday, May 28, 2020 3:46 PM
>> To: dev@dpdk.org; amorenoz@redhat.com; Ye, Xiaolong
>> <xiaolong.ye@intel.com>; shahafs@mellanox.com; matan@mellanox.com
>> Cc: Maxime Coquelin <maxime.coquelin@redhat.com>
>> Subject: [dpdk-dev] [PATCH 3/3] net/virtio: add Virtio status support to Virtio-
>> user
>>
>> 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>
>> ---
>>  drivers/net/virtio/virtio_user/vhost.h        |  5 +++++
>>  drivers/net/virtio/virtio_user/vhost_user.c   |  8 ++++++++
>>  .../net/virtio/virtio_user/virtio_user_dev.c  | 20 ++++++++++++++++++-
>>   .../net/virtio/virtio_user/virtio_user_dev.h  |  1 +
>>  drivers/net/virtio/virtio_user_ethdev.c       |  1 +
>>  5 files changed, 34 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/net/virtio/virtio_user/vhost.h
>> b/drivers/net/virtio/virtio_user/vhost.h
>> index 260e1c3081..fc360564eb 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 15 #endif
>> +
>>  enum vhost_user_request {
>>  	VHOST_USER_NONE = 0,
>>  	VHOST_USER_GET_FEATURES = 1,
>> @@ -77,6 +81,7 @@ 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 = 36,
> 
> I see in qemu's vhost-user spec (https://www.qemu.org/docs/master/interop/vhost-user.html#protocol-features)
> that '36' is used by VHOST_USER_GET_MAX_MEM_SLOTS. And I don't see VHOST_USER_PROTOCOL_F_STATUS.
> Do I miss something here?

Partly, yes :)

In the cover letter, I mention that this patch should be applied only
once the spec update part of the Qemu series it depends on is merged:
"
So the first two patches can be applied as-is, while
for the last one, we have at least to wait the Qemu bits,
which includes the specification update, is merged
upstream.
"

This is a link to the Qemu patch:
https://patchwork.ozlabs.org/project/qemu-devel/patch/20200514073332.1434576-1-maxime.coquelin@redhat.com/

> Also, I see in drivers/net/virtio/virtio_pci.h, the status definition is too old and does not align with the spec now.
> Should we update that one?

Yes, that could be done, feel free to send a patch for this.

Thanks,
Maxime

> Thanks!
> Chenbo
> 
>>  	VHOST_USER_MAX
>>  };
>>
>> diff --git a/drivers/net/virtio/virtio_user/vhost_user.c
>> b/drivers/net/virtio/virtio_user/vhost_user.c
>> index f8d751c98e..68232d75d7 100644
>> --- a/drivers/net/virtio/virtio_user/vhost_user.c
>> +++ b/drivers/net/virtio/virtio_user/vhost_user.c
>> @@ -278,6 +278,14 @@ 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 */
>>  	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 ea22af5dc4..cf29ea0b88 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, @@ -
>> 782,3 +783,20 @@ 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_update_status(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;
>> +
>> +	ret = dev->ops->send_request(dev, VHOST_USER_SET_STATUS, &arg);
>> +	if (ret)
>> +		return -1;
>> +
>> +	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 56e638f8a6..c49a896a88 100644
>> --- a/drivers/net/virtio/virtio_user/virtio_user_dev.h
>> +++ b/drivers/net/virtio/virtio_user/virtio_user_dev.h
>> @@ -71,4 +71,5 @@ 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_update_status(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 ccb5a18e25..bed161ba07 100644
>> --- a/drivers/net/virtio/virtio_user_ethdev.c
>> +++ b/drivers/net/virtio/virtio_user_ethdev.c
>> @@ -271,6 +271,7 @@ 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_update_status(dev, status);
>>  }
>>
>>  static uint8_t
>> --
>> 2.26.2
>