Re: [dpdk-dev] [PATCH 2/2] net/vhost: prevent multiple setup on reconfig

[Itsuro ODA <oda@valinux.co.jp>]

Hi Maxime, Tiewi,

On Wed, 19 Feb 2020 09:17:41 +0100
Maxime Coquelin <maxime.coquelin@redhat.com> wrote:

> Hi Tiwei,
> 
> On 2/19/20 4:44 AM, Tiwei Bie wrote:
> > On Tue, Feb 18, 2020 at 06:22:40PM +0100, Maxime Coquelin wrote:
> >> Ethdev's .dev_configure callback can be called multiple
> >> time during a device life-time, but Vhost makes the
> >> wrong assumption that it is not the case and try to
> >> setup again the device on reconfiguration.
> >>
> >> This patch ensures the device hasn't been already setup
> >> before proceeding.
> >>
> >> Fixes: 3d01b759d267 ("net/vhost: delay driver setup")
> >>
> >> Reported-by: Yinan Wang <yinan.wang@intel.com>
> >> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> >> Tested-by: Yinan Wang <yinan.wang@intel.com>
> >> Reviewed-by: David Marchand <david.marchand@redhat.com>
> >> ---
> >>  drivers/net/vhost/rte_eth_vhost.c | 5 +++++
> >>  1 file changed, 5 insertions(+)
> >>
> >> diff --git a/drivers/net/vhost/rte_eth_vhost.c b/drivers/net/vhost/rte_eth_vhost.c
> >> index 4a7b1b608c..458ed58f5f 100644
> >> --- a/drivers/net/vhost/rte_eth_vhost.c
> >> +++ b/drivers/net/vhost/rte_eth_vhost.c
> >> @@ -876,6 +876,11 @@ vhost_driver_setup(struct rte_eth_dev *eth_dev)
> >>  	unsigned int numa_node = eth_dev->device->numa_node;
> >>  	const char *name = eth_dev->device->name;
> >>  
> >> +	/* Don't try to setup again if it has already been done. */
> >> +	list = find_internal_resource(internal->iface_name);
> >> +	if (list)
> >> +		return 0;
> >> +
> >>  	list = rte_zmalloc_socket(name, sizeof(*list), 0, numa_node);
> >>  	if (list == NULL)
> >>  		return -1;
> >> -- 
> >> 2.24.1
> > 
> > Thanks Maxime for the fix!
> > 
> > Reviewed-by: Tiwei Bie <tiwei.bie@intel.com>
> > 
> > Not related to this fix, it seems there is a potential leak after
> > delaying the driver setup to _configure, as the list won't be
> > registered until users configure the device. So internal->iface_name
> > allocated in _create will leak if the device is released without
> > doing _configure first.
> > 
> > https://github.com/DPDK/dpdk/blob/e6c78e736d77/drivers/net/vhost/rte_eth_vhost.c#L1058
> > https://github.com/DPDK/dpdk/blob/e6c78e736d77/drivers/net/vhost/rte_eth_vhost.c#L1075
> > 
> > It's not a common case and it's quite late in this release,
> > probably it's fine to fix it later.
> 
> That's a valid point, and I also agree there is no urgency for v20.02.
> Itsuro, would you take care of fixing it for v20.05?

Sure, I will do it.

Thanks.
Itsuro Oda

> Thanks,
> Maxime
> > Thanks,
> > Tiwei
> > 

-- 
Itsuro ODA <oda@valinux.co.jp>