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

[Thomas Monjalon <thomas@monjalon.net>]

25/10/2019 03:48, Di, ChenxuX:
> From: Yigit, Ferruh
> > 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);


I disagree with this patch.
You are removing a call to the "close" function because it does not work
properly with your driver.
Please do not blame the tool which is showing the error.