[dpdk-dev] crash in virtio pmd

[Olivier Matz <olivier.matz@6wind.com>]

Hi,

On 16.07-rc3, when I start testpmd with a virtio driver in a VM,
requesting options that are not implemented (rx checksum), it crashes:

./build/app/testpmd -l 0,1 --log-level 8 -- --total-num-mbufs=16384 -i
--port-topology=chained --disable-hw-vlan-filter --disable-hw-vlan-strip
--enable-rx-cksum --crc-strip --txqflags=0
EAL: Detected 3 lcore(s)
EAL: Probing VFIO support...
EAL: WARNING: cpu flags constant_tsc=yes nonstop_tsc=no -> using
unreliable clock cycles !
PMD: bnxt_rte_pmd_init() called for (null)
EAL: PCI device 0000:00:02.0 on NUMA socket -1
EAL:   probe driver: 8086:10fb rte_ixgbe_pmd
EAL: PCI device 0000:00:04.0 on NUMA socket -1
EAL:   probe driver: 8086:10fb rte_ixgbe_pmd
EAL: PCI device 0000:00:05.0 on NUMA socket -1
EAL:   probe driver: 1af4:1000 rte_virtio_pmd
PMD: virtio_read_caps(): no modern virtio pci device found.
PMD: vtpci_init(): trying with legacy virtio pci.
Interactive-mode selected
USER1: create a new mbuf pool <mbuf_pool_socket_0>: n=16384, size=2176,
socket=0
Configuring Port 0 (socket 0)
Port 0: 00:1B:21:AB:8F:10
Configuring Port 1 (socket 0)
Segmentation fault


The crash occurs here (rxvq is NULL):

  void
  virtio_dev_rx_queue_release(void *rxq)
  {
          struct virtnet_rx *rxvq = rxq;
  =>      struct virtqueue *vq = rxvq->vq;
          /* rxvq is freed when vq is freed, and as mz should be freed
after the
           * del_queue, so we reserve the mz pointer first.

           */
          const struct rte_memzone *mz = rxvq->mz;


Here is the backtrace:

#0  0x0000000000b01744 in virtio_dev_rx_queue_release (rxq=0x0) at
/root/dpdk.org/drivers/net/virtio/virtio_rxtx.\
c:470
#1  0x0000000000583783 in rte_eth_dev_rx_queue_config (dev=0x10ac700
<rte_eth_devices+16512>, nb_queues=0) at /ro\
ot/dpdk.org/lib/librte_ether/rte_ethdev.c:713
#2  0x00000000005840e1 in rte_eth_dev_configure (port_id=1 '\001',
nb_rx_q=1, nb_tx_q=1, dev_conf=0x7fffd41a3838)\
 at /root/dpdk.org/lib/librte_ether/rte_ethdev.c:1027
#3  0x0000000000440037 in start_port (pid=255 '\377') at
/root/dpdk.org/app/test-pmd/testpmd.c:1338
#4  0x00000000004419d9 in main (argc=9, argv=0x7fffffffe630) at
/root/dpdk.org/app/test-pmd/testpmd.c:2114


Actually, virtio_dev_configure() returns an error here:

        if (rxmode->hw_ip_checksum) {
                PMD_DRV_LOG(ERR, "HW IP checksum not supported");
=>              return -EINVAL;
        }


Then, rte_eth_dev_configure() tries to do some cleanup and crashes here:

          diag = (*dev->dev_ops->dev_configure)(dev);
          if (diag != 0) {
                  RTE_PMD_DEBUG_TRACE("port%d dev_configure = %d\n",
                                  port_id, diag);
  =>              rte_eth_dev_rx_queue_config(dev, 0);
                  rte_eth_dev_tx_queue_config(dev, 0);
                  return diag;
          }


I suppose it is related to this commit:
http://dpdk.org/browse/dpdk/commit/?id=01ad44fd374fb8ecb9ecc80b9bfd1f45dbaa4a1f


Sorry, I have not a lot of time to investigate further, hope you can
find the appropriate fix with the info above.


Regards,
Olivier