Re: [dpdk-dev] virtio still blindly take over virtio device managed by kernel

["Xie, Huawei" <huawei.xie@intel.com>]

On 5/5/2016 12:21 AM, Vincent Li wrote:
> Hi,
>
> I am running the dpdk git repo which already had commit ac5e1d838dc
> (virtio: skip error when probing kernel managed device), but in my
> test, it seems still taking control of the kernel managed virtio
> device and segmentation fault, here is the example:
>
> # ./tools/dpdk_nic_bind.py --status
>
> Network devices using DPDK-compatible driver
> ============================================
> 0000:00:07.0 'Virtio network device' drv=igb_uio unused=
> 0000:00:08.0 'Virtio network device' drv=igb_uio unused=
>
> Network devices using kernel driver
> ===================================
> 0000:00:03.0 'Virtio network device' if= drv=virtio-pci unused=igb_uio
>
>  #./x86_64-native-linuxapp-gcc/app/testpmd -c 0xf -n 4  -- -i
> EAL: Detected 4 lcore(s)
> EAL: Probing VFIO support...
> EAL: WARNING: cpu flags constant_tsc=yes nonstop_tsc=no -> using
> unreliable clock cycles !
> EAL: PCI device 0000:00:03.0 on NUMA socket -1
> EAL:   probe driver: 1af4:1000 rte_virtio_pmd
> PMD: vtpci_init(): trying with legacy virtio pci.
> Segmentation fault (core dumped)

Hi Vincent:
Could you try this?
Weird. I had tested by binding the virtio nic with different kernel
drivers including unbinding any drivers when submitting patches. But i
find that it doesn't work even with that commit.
So dev->devargs could be NULL.

If it works for you, i will submit the fix.

diff --git a/drivers/net/virtio/virtio_pci.c
b/drivers/net/virtio/virtio_pci.c
index 45edecc..8aeb44a 100644
--- a/drivers/net/virtio/virtio_pci.c
+++ b/drivers/net/virtio/virtio_pci.c
@@ -650,7 +650,8 @@ vtpci_init(struct rte_pci_device *dev, struct
virtio_hw *hw)
        PMD_INIT_LOG(INFO, "trying with legacy virtio pci.");
        if (legacy_virtio_resource_init(dev, hw) < 0) {
                if (dev->kdrv == RTE_KDRV_UNKNOWN &&
-                   dev->devargs->type != RTE_DEVTYPE_WHITELISTED_PCI) {
+                   (!dev->devargs ||
+                    dev->devargs->type != RTE_DEVTYPE_WHITELISTED_PCI)){
                        PMD_INIT_LOG(INFO,
                                "skip kernel managed virtio device.");
                        return 1;


>
> if I blacklist 0000:00:03.0 from testpmd, testpmd works:
>
> # ./x86_64-native-linuxapp-gcc/app/testpmd -c 0xf -n 4  -b 0000:00:03.0 -- -i
> EAL: Detected 4 lcore(s)
> EAL: Probing VFIO support...
> EAL: WARNING: cpu flags constant_tsc=yes nonstop_tsc=no -> using
> unreliable clock cycles !
> EAL: PCI device 0000:00:03.0 on NUMA socket -1
> EAL: PCI device 0000:00:07.0 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.
> EAL: PCI device 0000:00:08.0 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
> Configuring Port 0 (socket 0)
> rte_eth_dev_config_restore: port 0: MAC address array not supported
> Port 0: 52:54:00:EA:6E:3E
> Configuring Port 1 (socket 0)
> rte_eth_dev_config_restore: port 1: MAC address array not supported
> Port 1: 52:54:00:24:06:DB
> Checking link statuses...
> Port 0 Link Up - speed 10000 Mbps - full-duplex
> Port 1 Link Up - speed 10000 Mbps - full-duplex
> Done
> testpmd>
>