Re: [PATCH v3] vdpa/ifc: fix update_datapath error handling

[Taekyung Kim <kim.tae.kyung@navercorp.com>]

On Tue, Nov 08, 2022 at 07:56:18AM +0000, Xia, Chenbo wrote:
> > -----Original Message-----
> > From: Pei, Andy <andy.pei@intel.com>
> > Sent: Tuesday, November 8, 2022 3:39 PM
> > To: Xia, Chenbo <chenbo.xia@intel.com>; Taekyung Kim
> > <kim.tae.kyung@navercorp.com>; dev@dpdk.org
> > Cc: stable@dpdk.org; maxime.coquelin@redhat.com; Wang, Xiao W
> > <xiao.w.wang@intel.com>
> > Subject: RE: [PATCH v3] vdpa/ifc: fix update_datapath error handling
> > 
> > Hi
> > 
> > See my reply inline.
> > 
> > > -----Original Message-----
> > > From: Xia, Chenbo <chenbo.xia@intel.com>
> > > Sent: Tuesday, November 8, 2022 9:47 AM
> > > To: Taekyung Kim <kim.tae.kyung@navercorp.com>; dev@dpdk.org
> > > Cc: stable@dpdk.org; maxime.coquelin@redhat.com; Wang, Xiao W
> > > <xiao.w.wang@intel.com>
> > > Subject: RE: [PATCH v3] vdpa/ifc: fix update_datapath error handling
> > >
> > > > -----Original Message-----
> > > > From: Taekyung Kim <kim.tae.kyung@navercorp.com>
> > > > Sent: Monday, November 7, 2022 5:00 PM
> > > > To: dev@dpdk.org
> > > > Cc: stable@dpdk.org; maxime.coquelin@redhat.com; Xia, Chenbo
> > > > <chenbo.xia@intel.com>; Wang, Xiao W <xiao.w.wang@intel.com>;
> > > > kim.tae.kyung@navercorp.com
> > > > Subject: [PATCH v3] vdpa/ifc: fix update_datapath error handling
> > > >
> > > > Stop and return the error code when update_datapath fails.
> > > > update_datapath prepares resources for the vdpa device.
> > > > The driver should not perform any further actions if update_datapath
> > > > returns an error.
> > > >
> > > > Fixes: a3f8150eac6d ("net/ifcvf: add ifcvf vDPA driver")
> > > > Cc: stable@dpdk.org
> > > >
> > > > Signed-off-by: Taekyung Kim <kim.tae.kyung@navercorp.com>
> > > > ---
> > > > v3:
> > > > * Fix coding style
> > > >
> > > > v2:
> > > > * Revert the prepared resources before returning an error
> > > > * Rebase to 22.11 rc2
> > > > * Add fixes and cc for backport
> > > >
> > > > ---
> > > >  drivers/vdpa/ifc/ifcvf_vdpa.c | 26 ++++++++++++++++++++++----
> > > >  1 file changed, 22 insertions(+), 4 deletions(-)
> > > >
> > > > diff --git a/drivers/vdpa/ifc/ifcvf_vdpa.c
> > > > b/drivers/vdpa/ifc/ifcvf_vdpa.c index 8dfd49336e..0396d49122 100644
> > > > --- a/drivers/vdpa/ifc/ifcvf_vdpa.c
> > > > +++ b/drivers/vdpa/ifc/ifcvf_vdpa.c
> > > > @@ -1098,7 +1098,12 @@ ifcvf_dev_config(int vid)
> > > >  	internal = list->internal;
> > > >  	internal->vid = vid;
> > > >  	rte_atomic32_set(&internal->dev_attached, 1);
> > > > -	update_datapath(internal);
> > > > +	if (update_datapath(internal) < 0) {
> > > > +		DRV_LOG(ERR, "failed to update datapath for vDPA device %s",
> > > > +			vdev->device->name);
> > > > +		rte_atomic32_set(&internal->dev_attached, 0);
> > > > +		return -1;
> > > > +	}
> > > >
> > > >  	hw = &internal->hw;
> > > >  	for (i = 0; i < hw->nr_vring; i++) { @@ -1146,7 +1151,12 @@
> > > > ifcvf_dev_close(int vid)
> > > >  		internal->sw_fallback_running = false;
> > > >  	} else {
> > > >  		rte_atomic32_set(&internal->dev_attached, 0);
> > > > -		update_datapath(internal);
> > > > +		if (update_datapath(internal) < 0) {
> > > > +			DRV_LOG(ERR, "failed to update datapath for vDPA
> > > > device %s",
> > > > +				vdev->device->name);
> > > > +			internal->configured = 0;
> > > > +			return -1;
> > > > +		}
> > > >  	}
> > > >
> > > >  	internal->configured = 0;
> > > > @@ -1752,7 +1762,14 @@ ifcvf_pci_probe(struct rte_pci_driver *pci_drv
> > > > __rte_unused,
> > > >  	}
> > > >
> > > >  	rte_atomic32_set(&internal->started, 1);
> > > > -	update_datapath(internal);
> > > > +	if (update_datapath(internal) < 0) {
> > > > +		DRV_LOG(ERR, "failed to update datapath %s", pci_dev->name);
> > > > +		rte_atomic32_set(&internal->started, 0);
> > > > +		pthread_mutex_lock(&internal_list_lock);
> > > > +		TAILQ_REMOVE(&internal_list, list, next);
> > > > +		pthread_mutex_unlock(&internal_list_lock);
> > > > +		goto error;
> > > > +	}
> > > >
> > 
> > Is it necessary to unregister vdpa device?
> 
> Good catch, yes it's needed.
> 
> Kim, please add the unregistration.
> 
> Thanks,
> Chenbo

Hi Andy and Chenbo,

Thanks for your comments.
I forgot to add `rte_vdpa_unregister_device(internal->vdev)`.
I will send a new patch soon.

By the way, it seems that deallocation for `ifcvf_vfio_setup(internal)`
is also ommitted in `ifcvf_pci_probe(...)`.
I will submit another commit to split `error:` into `error2:` and `error1:`,
which calls `rte_pci_unmap_device(...)` and `rte_vfio_container_destroy(...)`.

Thanks,
Taekyung

> 
> > 
> > > >  	rte_kvargs_free(kvlist);
> > > >  	return 0;
> > > > @@ -1781,7 +1798,8 @@ ifcvf_pci_remove(struct rte_pci_device *pci_dev)
> > > >
> > > >  	internal = list->internal;
> > > >  	rte_atomic32_set(&internal->started, 0);
> > > > -	update_datapath(internal);
> > > > +	if (update_datapath(internal) < 0)
> > > > +		DRV_LOG(ERR, "failed to update datapath %s", pci_dev->name);
> > > >
> > > >  	rte_pci_unmap_device(internal->pdev);
> > > >  	rte_vfio_container_destroy(internal->vfio_container_fd);
> > > > --
> > > > 2.34.1
> > >
> > > Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>