[PATCH 2/2] net/virtio-user: fix multi-process issue

[Ami Sabo <amis@radware.com>]

Secondary process doesn't properly attach to the rte_eth_device
initialized by the primary process.

ccessing device from secondary process (e.g. via rte_eth_rx_burst),
causes process to crash. because rte_eth_dev_data is not properly set.

The issue was flood by
'commit 7f95f78a8aea ("ethdev: clear data when allocating device")'
which now clears rte_eth_dev_data entry.
For pci devices the struct is initialized by rte_eth_dev_pci_probe
->eth_dev_attach_secondary().
However, for virtio-user virtio_user_pmd_probe() is called instead of
rte_eth_dev_pci_probe().

The fix is to call rte_eth_dev_attach_secondary(), for secondary
process, from virtio_user_pmd_probe.

Fixes: 7f95f78a8aea ("ethdev: clear data when allocating device")

Cc: stable@dpdk.org

Signed-off-by: Ami Sabo <amis@radware.com>
---
 drivers/net/virtio/virtio_user_ethdev.c | 26 ++++++++++++++++----------
 1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/drivers/net/virtio/virtio_user_ethdev.c b/drivers/net/virtio/virtio_user_ethdev.c
index 0b226ac..6033908 100644
--- a/drivers/net/virtio/virtio_user_ethdev.c
+++ b/drivers/net/virtio/virtio_user_ethdev.c
@@ -418,18 +418,24 @@ virtio_user_pmd_probe(const char *name, const char *params)
 		goto end;
 	}
 
-	eth_dev = virtio_user_eth_dev_alloc(name);
-	if (!eth_dev) {
-		PMD_INIT_LOG(ERR, "virtio_user fails to alloc device");
-		goto end;
-	}
+	if (rte_eal_process_type() == RTE_PROC_PRIMARY) {
+		eth_dev = virtio_user_eth_dev_alloc(name);
+		if (!eth_dev) {
+			PMD_INIT_LOG(ERR, "virtio_user fails to alloc device");
+			goto end;
+		}
 
-	hw = eth_dev->data->dev_private;
-	if (virtio_user_dev_init(hw->virtio_user_dev, path, queues, cq,
+		hw = eth_dev->data->dev_private;
+		if (virtio_user_dev_init(hw->virtio_user_dev, path, queues, cq,
 				 queue_size, mac_addr) < 0) {
-		PMD_INIT_LOG(ERR, "virtio_user_dev_init fails");
-		virtio_user_eth_dev_free(eth_dev);
-		goto end;
+			PMD_INIT_LOG(ERR, "virtio_user_dev_init fails");
+			virtio_user_eth_dev_free(eth_dev);
+			goto end;
+		}
+	} else {
+		eth_dev = rte_eth_dev_attach_secondary(name);
+		if (!eth_dev)
+			goto end;
 	}
 
 	/* previously called by rte_eal_pci_probe() for physical dev */
-- 
2.7.4