Re: [dpdk-dev] [PATCH] app/testpmd: fix device hotplug remove

["Di, ChenxuX" <chenxux.di@intel.com>]

Hi, Ferruh

> -----Original Message-----
> From: Yigit, Ferruh
> Sent: Friday, October 25, 2019 1:24 AM
> To: Di, ChenxuX <chenxux.di@intel.com>; dev@dpdk.org
> Cc: Lu, Wenzhuo <wenzhuo.lu@intel.com>; Yang, Qiming
> <qiming.yang@intel.com>
> Subject: Re: [dpdk-dev] [PATCH] app/testpmd: fix device hotplug remove
> 
> On 10/24/2019 2:03 AM, Di ChenxuX wrote:
> > Hotplug remove cause infinite loops. Fix by canceling port_close
> > before port_detach function when rmv_port_callback.
> 
> Can you please give more details/backtrace of how loop happens?
> How can trigger it?

Here is the test case

Environment
Os: Ubuntu 18.04
Device: X710 nic
Software: qemu

1. Bind pf0 to vfio-pci

	[root@xxxxxxxxx dpdk]# modprobe vfio-pci
	[root@ xxxxxxxxx dpdk]# usertools/dpdk-devbind.py --force --bind=vfio-pci 0000:81:00.0
2. Passthrough PF and start qemu

	[root@ xxxxxxxxx dpdk]# taskset -c 0-7 qemu-system-x86_64 -enable-kvm -pidfile /tmp/.vm0.pid -m 10240 -cpu host -smp 8 -name vm0 -monitor unix:/tmp/vm0_monitor.sock,server,nowait -chardev socket,path=/tmp/vm0_qga0.sock,server,nowait,id=vm0_qga0 -device virtio-serial -device virtserialport,chardev=vm0_qga0,name=org.qemu.guest_agent.0 -device e1000,netdev=nttsip1 -netdev user,id=nttsip1,hostfwd=tcp: xxxxxxxxx:6000-:22 -monitor stdio -drive file=/home/image/test_vfio.img -vnc :5 -device vfio-pci,host=0000:81:00.0,id=dev1
3. Log in VM, bind passthrough port 0 to vfio-pci

	virtdut. xxxxxxxxx:6000: modprobe -r vfio_iommu_type1
	virtdut. xxxxxxxxx:6000: modprobe -r vfio
	virtdut. xxxxxxxxx:6000: modprobe vfio enable_unsafe_noiommu_mode=1
	virtdut. xxxxxxxxx:6000: modprobe vfio-pci

	virtdut. xxxxxxxxx:6000: ./usertools/dpdk-devbind.py -b vfio-pci 0000:00:05.0
4. Start testpmd with "--hot-plug" enable

	virtdut. xxxxxxxxx:6000: ./x86_64-native-linuxapp-gcc/app/testpmd -l 0,1,2,3,4,5,6,7 -n 1 -w 0000:00:05.0  --file-prefix=dpdk_24610_20191014100036   -- -i --hot-plug
5. Remove device from qemu interface

	(qemu) device_del dev1

6.before change
	Removing a device...	
	EAL: Driver cannot detach the device (0000:00:05.0)
	EAL: Failed to detach device on primary process
	testpmd: Failed to detach device 0000:00:05.0
	EAL: can not get port by device 0000:00:05.0!
	EAL: can not get port by device 0000:00:05.0!
	...
	EAL: can not get port by device 0000:00:05.0!
	...
	...
 after change:
	Removing a device...
	EAL: Error disabling MSI-X interrupts for fd 47
	EAL: Releasing pci mapped resource for 0000:00:05.0
	EAL: Calling pci_unmap_resource for 0000:00:05.0 at 0x1100800000
	EAL: Calling pci_unmap_resource for 0000:00:05.0 at 0x1101000000
	Device of port 0 is detached
	Now total ports is 0
	Done
	Invalid port_id=0
	EAL: Cannot find device (0000:00:05.0) on bus (pci)


> 
> >
> > Fixes: ac89d46096d5 ("net/i40e: release port upon close")
> >
> > Signed-off-by: Di ChenxuX <chenxux.di@intel.com>
> > ---
> >  app/test-pmd/testpmd.c | 1 -
> >  1 file changed, 1 deletion(-)
> >
> > diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c index
> > 5701f3141..a264644a1 100644
> > --- a/app/test-pmd/testpmd.c
> > +++ b/app/test-pmd/testpmd.c
> > @@ -2708,7 +2708,6 @@ rmv_port_callback(void *arg)
> >  	no_link_check = 1;
> >  	stop_port(port_id);
> >  	no_link_check = org_no_link_check;
> > -	close_port(port_id);
> >  	detach_port_device(port_id);
> >  	if (need_to_start)
> >  		start_packet_forwarding(0);
> >