[dpdk-dev] virtio PMD is not working with master version

["Mauricio Vásquez" <mauricio.vasquezbernal@studenti.polito.it>]

Hello,

I am trying to connect two virtual machines through Open vSwitch using
vhost-user ports, on the host side everything looks fine.
When using the standard virtio drivers both virtual machines are able to
exchange traffic, but when I load the virtio PMD and run a DPDK application
it shows the following error message:

...
EAL: PCI device 0000:00:04.0 on NUMA socket -1
EAL:   probe driver: 1af4:1000 rte_virtio_pmd
EAL:   PCI memory mapped at 0x7f892dc00000
PMD: virtio_read_caps(): [40] skipping non VNDR cap id: 11
PMD: virtio_read_caps(): no modern virtio pci device found.
PMD: vtpci_init(): trying with legacy virtio pci.
EAL: eal_parse_sysfs_value(): cannot open sysfs value
/sys/bus/pci/devices/0000:00:04.0/uio/uio0/portio/port0/start
EAL: pci_uio_ioport_map(): cannot parse portio start
EAL: Error - exiting with code: 1
  Cause: Requested device 0000:00:04.0 cannot be used
...

I tried it using the master version of DPDK, when I use the 2.2 version it
works without problems:

...
PMD: parse_sysfs_value(): parse_sysfs_value(): cannot open sysfs value
/sys/bus/pci/devices/0000:00:04.0/uio/uio0/portio/port0/size
PMD: virtio_resource_init_by_uio(): virtio_resource_init_by_uio(): cannot
parse size
PMD: virtio_resource_init_by_ioports(): PCI Port IO found start=0xc100 with
size=0x20
PMD: virtio_negotiate_features(): guest_features before negotiate = cf8020
PMD: virtio_negotiate_features(): host_features before negotiate = 40268020
PMD: virtio_negotiate_features(): features after negotiate = 68020
PMD: eth_virtio_dev_init(): PORT MAC: 00:00:00:00:00:11
PMD: eth_virtio_dev_init(): VIRTIO_NET_F_STATUS is not supported
PMD: eth_virtio_dev_init(): VIRTIO_NET_F_MQ is not supported
PMD: virtio_dev_cq_queue_setup():  >>
PMD: virtio_dev_queue_setup(): selecting queue: 2
PMD: virtio_dev_queue_setup(): vq_size: 64 nb_desc:0
PMD: virtio_dev_queue_setup(): vring_size: 4612, rounded_vring_size: 8192
PMD: virtio_dev_queue_setup(): vq->vq_ring_mem:      0x76d43000
PMD: virtio_dev_queue_setup(): vq->vq_ring_virt_mem: 0x7fa669743000
PMD: eth_virtio_dev_init(): config->max_virtqueue_pairs=1
PMD: eth_virtio_dev_init(): config->status=0
PMD: eth_virtio_dev_init(): PORT MAC: 00:00:00:00:00:11
PMD: eth_virtio_dev_init(): hw->max_rx_queues=1   hw->max_tx_queues=1
PMD: eth_virtio_dev_init(): port 0 vendorID=0x1af4 deviceID=0x1000
PMD: virtio_dev_vring_start():  >>
...

According to git bisect it appears to be that it does not work anymore
after the b8f04520ad71 ("virtio: use PCI ioport API") commit.

I also tried to run the "Vhost Sample Application" in the host with the
test-pmd in the guest, the problem is the same.

I am using:
QEMU v2.2.1
guest kernel: Linux ubuntu 3.19.0-25-generic
Both guest and host use 2MB huge pages

The qemu command line is
DEVICE_CMD="-chardev
socket,id=char2,path=/usr/local/var/run/openvswitch/vhost-user-2 \
-netdev type=vhost-user,id=mynet2,chardev=char2,vhostforce \
-device virtio-net-pci,mac=00:00:00:00:00:11,netdev=mynet2"

MEMORY_CMD="-object
memory-backend-file,id=mem,size=1024M,mem-path=/dev/hugepages,share=on
-numa node,memdev=mem -mem-prealloc"

qemu-system-x86_64 ... -cpu host -smp 3 -machine accel=kvm,usb=off
$MEMORY_CMD -m 1024 $DEVICE_CMD -monitor stdio

Could you check if this happens also to you?

Thank you very much.