Re: [dpdk-dev] [PATCH 2/4] net/mlx5: add reference counter for DV/DR structures

[Slava Ovsiienko <viacheslavo@mellanox.com>]

> -----Original Message-----
> From: Shahaf Shuler
> Sent: Tuesday, April 2, 2019 22:10
> To: Slava Ovsiienko <viacheslavo@mellanox.com>; dev@dpdk.org
> Subject: RE: [PATCH 2/4] net/mlx5: add reference counter for DV/DR
> structures
> 
> Tuesday, April 2, 2019 9:23 AM, Viacheslav Ovsiienko:
> > Subject: [PATCH 2/4] net/mlx5: add reference counter for DV/DR
> > structures
> 
> Same comment about the title.
> 
> >
> > This patch introduces the reference counter for DV/DR flow engine
> > structure, which we are going to share between master and representors
> > in E-Switch configurations over multiport Infiniband device.
> >
> > Signed-off-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
> > ---
> >  drivers/net/mlx5/mlx5.c | 26 ++++++++++++++++++++++++--
> > drivers/net/mlx5/mlx5.h |  4 ++++
> >  2 files changed, 28 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/net/mlx5/mlx5.c b/drivers/net/mlx5/mlx5.c index
> > 9de122d..79e0c17 100644
> > --- a/drivers/net/mlx5/mlx5.c
> > +++ b/drivers/net/mlx5/mlx5.c
> > @@ -299,7 +299,8 @@ struct mlx5_dev_spawn_data {  #ifdef
> > HAVE_MLX5DV_DR
> >  /**
> >   * Initialize DV/DR related data within private structure.
> > - * This is preparation step for the data sharing.
> > + * Routine checks the reference counter and does actual
> > + * resources creation/iniialization only if counter is zero.
> >   *
> >   * @param[in] priv
> >   *   Pointer to the private device data structure.
> > @@ -314,6 +315,14 @@ struct mlx5_dev_spawn_data {
> >  	int err = 0;
> >  	void *ns;
> >
> > +	assert(sh);
> > +	if (sh->dv_refcnt) {
> > +		/* Shared DV/DR structures is already initialized. */
> > +		sh->dv_refcnt++;
> > +		priv->dv_shared = 1;
> > +		return 0;
> > +	}
> > +	/* Reference counter is zero, we should initialize structures. */
> >  	ns = mlx5dv_dr_create_ns(sh->ctx,
> > MLX5DV_DR_NS_DOMAIN_INGRESS_BYPASS);
> >  	if (!ns) {
> >  		DRV_LOG(ERR, "ingress mlx5dv_dr_create_ns failed"); @@ -
> > 328,6 +337,8 @@ struct mlx5_dev_spawn_data {
> >  		goto error;
> >  	}
> >  	priv->tx_ns = ns;
> > +	sh->dv_refcnt++;
> > +	priv->dv_shared = 1;
> >  	return 0;
> >
> >  error:
> > @@ -352,6 +363,16 @@ struct mlx5_dev_spawn_data {  static void
> > mlx5_free_shared_dv(struct mlx5_priv *priv)  {
> > +	struct mlx5_ibv_shared *sh;
> > +
> > +	if (!priv->dv_shared)
> > +		return;
> > +	priv->dv_shared = 0;
> > +	sh = priv->sh;
> > +	assert(sh);
> > +	assert(sh->dv_refcnt);
> > +	if (sh->dv_refcnt && --sh->dv_refcnt)
> > +		return;
> >  	if (priv->rx_ns) {
> >  		mlx5dv_dr_destroy_ns(priv->rx_ns);
> >  		priv->rx_ns = NULL;
> > @@ -1491,7 +1512,8 @@ struct mlx5_dev_spawn_data {
> >  error:
> >  	if (priv) {
> >  #ifdef HAVE_MLX5DV_DR
> > -		mlx5_free_shared_dv(priv);
> > +		if (priv->sh)
> > +			mlx5_free_shared_dv(priv);
> >  #endif
> >  		if (priv->nl_socket_route >= 0)
> >  			close(priv->nl_socket_route);
> > diff --git a/drivers/net/mlx5/mlx5.h b/drivers/net/mlx5/mlx5.h index
> > a3d5f8e..56a2c61 100644
> > --- a/drivers/net/mlx5/mlx5.h
> > +++ b/drivers/net/mlx5/mlx5.h
> > @@ -213,6 +213,9 @@ struct mlx5_ibv_shared {
> >  	char ibdev_name[IBV_SYSFS_NAME_MAX]; /* IB device name. */
> >  	char ibdev_path[IBV_SYSFS_PATH_MAX]; /* IB device path for
> secondary
> > */
> >  	struct ibv_device_attr_ex device_attr; /* Device properties. */
> > +	/* Shared DV/DR flow data section. */
> > +	uint32_t dv_refcnt; /* DV/DR data reference counter. */
> > +	/* Shared interrupt handler section. */
> >  	pthread_mutex_t intr_mutex; /* Interrupt config mutex. */
> >  	uint32_t intr_cnt; /* Interrupt handler reference counter. */
> >  	struct rte_intr_handle intr_handle; /* Interrupt handler for device.
> > */ @@ -244,6 +247,7 @@ struct mlx5_priv {
> >  	unsigned int isolated:1; /* Whether isolated mode is enabled. */
> >  	unsigned int representor:1; /* Device is a port representor. */
> >  	unsigned int master:1; /* Device is a E-Switch master. */
> > +	unsigned int dv_shared:1; /* DV/DR data is shared. */
> 
> Why this flags is needed? Aren't we always going to share?

I think we can get rid of this flag, because it is used for correct cleanup
in device spawning routines If something goes wrong (on error exit)

> 
> 
> >  	uint16_t domain_id; /* Switch domain identifier. */
> >  	uint16_t vport_id; /* Associated VF vport index (if any). */
> >  	int32_t representor_id; /* Port representor identifier. */
> > --
> > 1.8.3.1