[dpdk-dev] [dpdk-stable] [PATCH v3 1/7] ethdev: fix port data reset timing

[Matan Azrad]

HI

From: Ferruh Yigit, Sent: Monday, March 5, 2018 1:24 PM
> On 1/18/2018 4:35 PM, Matan Azrad wrote:
> > rte_eth_dev_data structure is allocated per ethdev port and can be
> > used to get a data of the port internally.
> >
> > rte_eth_dev_attach_secondary tries to find the port identifier using
> > rte_eth_dev_data name field comparison and may get an identifier of
> > invalid port in case of this port was released by the primary process
> > because the port release API doesn't reset the port data.
> >
> > So, it will be better to reset the port data in release time instead
> > of allocation time.
> >
> > Move the port data reset to the port release API.
> >
> > Fixes: d948f596fee2 ("ethdev: fix port data mismatched in multiple
> > process model")
> > Cc: stable at dpdk.org
> >
> > Signed-off-by: Matan Azrad <matan at mellanox.com>
> > ---
> >  lib/librte_ether/rte_ethdev.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/lib/librte_ether/rte_ethdev.c
> > b/lib/librte_ether/rte_ethdev.c index 7044159..156231c 100644
> > --- a/lib/librte_ether/rte_ethdev.c
> > +++ b/lib/librte_ether/rte_ethdev.c
> > @@ -204,7 +204,6 @@ struct rte_eth_dev *
> >  		return NULL;
> >  	}
> >
> > -	memset(&rte_eth_dev_data[port_id], 0, sizeof(struct
> rte_eth_dev_data));
> >  	eth_dev = eth_dev_get(port_id);
> >  	snprintf(eth_dev->data->name, sizeof(eth_dev->data->name),
> "%s", name);
> >  	eth_dev->data->port_id = port_id;
> > @@ -252,6 +251,7 @@ struct rte_eth_dev *
> >  	if (eth_dev == NULL)
> >  		return -EINVAL;
> >
> > +	memset(eth_dev->data, 0, sizeof(struct rte_eth_dev_data));
> 
> Hi Matan,
> 
> What most of the vdev release path does is:
> 
> eth_dev = rte_eth_dev_allocated(...)
> rte_free(eth_dev->data->dev_private);
> rte_free(eth_dev->data);
> rte_eth_dev_release_port(eth_dev);
> 
> Since eth_dev->data freed, memset() it in rte_eth_dev_release_port() will
> be problem.
> 
> We don't run remove path that is why we didn't hit the issue but this seems
> problem for all virtual PMDs.

Yes, it is a problem and should be fixed:
For vdevs which use private rte_eth_dev_data the remove order can be:
	private_data = eth_dev->data;
	rte_free(eth_dev->data->dev_private);
	rte_eth_dev_release_port(eth_dev); /* The last operation working on ethdev structure. */
	rte_free(private_data);


> Also rte_eth_dev_pci_release() looks problematic now.

Yes, again, the last operation working on ethdev structure should be rte_eth_dev_release_port().

So need to fix all vdevs and the rte_eth_dev_pci_release() function.

Any comments?