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

["Xia, Chenbo" <chenbo.xia@intel.com>]

Hi Adrian,

> -----Original Message-----
> From: Adrian Moreno <amorenoz@redhat.com>
> Sent: Thursday, July 16, 2020 5:51 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 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/91a9a90d040e8b9ff63d48ea71468e0f4
> db764ff/include/linux/compiler_attributes.h#L201
> 
> Since we don't have that pseudo-keyword, we should see if we can disable this
> in checkpatches.

Yeah, I confirmed this could be ignored. So you could change it or keep it.
Both fine.

Cheers,
Chenbo

> 
> 
> > 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