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 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?

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