[PATCH] 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.

Accessing 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.

So, most of the rte_eth_dev_data fields are not initialized.
For pci devices these fields are 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().
To fix it:  Allow non-pci drivers call to dev_attach_secondary() and
call it (for secondary process) from virtio_user_pmd_probe.

Signed-off-by: Ami Sabo <amis@radware.com>
---
 drivers/net/virtio/virtio_user_ethdev.c | 29 +++++++++++++++++------------
 lib/librte_ether/rte_ethdev.c           |  6 +++---
 lib/librte_ether/rte_ethdev.h           | 11 +++++++++++
 lib/librte_ether/rte_ether_version.map  |  1 +
 4 files changed, 32 insertions(+), 15 deletions(-)

diff --git a/drivers/net/virtio/virtio_user_ethdev.c b/drivers/net/virtio/virtio_user_ethdev.c
index e544acc..d388b92 100644
--- a/drivers/net/virtio/virtio_user_ethdev.c
+++ b/drivers/net/virtio/virtio_user_ethdev.c
@@ -418,18 +418,23 @@ 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;
-	}
-
-	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;
+	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,
+			queue_size, mac_addr) < 0) {
+			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 */
diff --git a/lib/librte_ether/rte_ethdev.c b/lib/librte_ether/rte_ethdev.c
index 61f44e2..ea4f76c 100644
--- a/lib/librte_ether/rte_ethdev.c
+++ b/lib/librte_ether/rte_ethdev.c
@@ -239,8 +239,8 @@ rte_eth_dev_allocate(const char *name)
  * makes sure that the same device would have the same port id both
  * in the primary and secondary process.
  */
-static struct rte_eth_dev *
-eth_dev_attach_secondary(const char *name)
+struct rte_eth_dev *
+rte_eth_dev_attach_secondary(const char *name)
 {
 	uint8_t i;
 	struct rte_eth_dev *eth_dev;
@@ -302,7 +302,7 @@ rte_eth_dev_pci_probe(struct rte_pci_driver *pci_drv,
 		if (eth_dev->data->dev_private == NULL)
 			rte_panic("Cannot allocate memzone for private port data\n");
 	} else {
-		eth_dev = eth_dev_attach_secondary(ethdev_name);
+		eth_dev = rte_eth_dev_attach_secondary(ethdev_name);
 		if (eth_dev == NULL) {
 			/*
 			 * if we failed to attach a device, it means the
diff --git a/lib/librte_ether/rte_ethdev.h b/lib/librte_ether/rte_ethdev.h
index c17bbda..3281205 100644
--- a/lib/librte_ether/rte_ethdev.h
+++ b/lib/librte_ether/rte_ethdev.h
@@ -1762,6 +1762,17 @@ struct rte_eth_dev *rte_eth_dev_allocate(const char *name);
 
 /**
  * @internal
+ * Attach to the ethdev already initialized by the primary
+ * process.
+ *
+ * @param	name	Ethernet device's name.
+  @return
+ *   - Slot in the rte_dev_devices array for attached device;
+ */
+struct rte_eth_dev *rte_eth_dev_attach_secondary(const char *name);
+
+/**
+ * @internal
  * Release the specified ethdev port.
  *
  * @param eth_dev
diff --git a/lib/librte_ether/rte_ether_version.map b/lib/librte_ether/rte_ether_version.map
index c6c9d0d..f8bf2ee 100644
--- a/lib/librte_ether/rte_ether_version.map
+++ b/lib/librte_ether/rte_ether_version.map
@@ -152,5 +152,6 @@ DPDK_17.02 {
 	rte_flow_flush;
 	rte_flow_query;
 	rte_flow_validate;
+	rte_eth_dev_attach_secondary;
 
 } DPDK_16.11;
-- 
2.7.4