[dpdk-dev] [PATCH v2 1/2] librte_ether: ensure not overwrite device data in mp app

[Marcin Kerlin <marcinx.kerlin@intel.com>]

Added prevention not overwrite device data in array rte_eth_dev_data[].
Secondary process appends in the first free place rather than at the
beginning. This behavior prevents overwriting devices of primary process
by secondary process.

Signed-off-by: Marcin Kerlin <marcinx.kerlin@intel.com>
---
 lib/librte_ether/rte_ethdev.c          | 90 +++++++++++++++++++++++++++++++---
 lib/librte_ether/rte_ethdev.h          | 24 +++++++++
 lib/librte_ether/rte_ether_version.map |  7 +++
 3 files changed, 113 insertions(+), 8 deletions(-)

diff --git a/lib/librte_ether/rte_ethdev.c b/lib/librte_ether/rte_ethdev.c
index 382c959..dadd77a 100644
--- a/lib/librte_ether/rte_ethdev.c
+++ b/lib/librte_ether/rte_ethdev.c
@@ -176,6 +176,19 @@ rte_eth_dev_allocated(const char *name)
 	return NULL;
 }
 
+struct rte_eth_dev_data *
+rte_eth_dev_data_allocated(const char *name)
+{
+	unsigned int i;
+
+	for (i = 0; i < RTE_MAX_ETHPORTS; i++) {
+		if (strcmp(rte_eth_dev_data[i].name, name) == 0)
+			return &rte_eth_dev_data[i];
+	}
+
+	return NULL;
+}
+
 static uint8_t
 rte_eth_dev_find_free_port(void)
 {
@@ -188,10 +201,43 @@ rte_eth_dev_find_free_port(void)
 	return RTE_MAX_ETHPORTS;
 }
 
+static uint8_t
+rte_eth_dev_find_free_dev_data_id(void)
+{
+	unsigned int i;
+
+	for (i = 0; i < RTE_MAX_ETHPORTS; i++) {
+		if (!strlen(rte_eth_dev_data[i].name))
+			return i;
+	}
+	return RTE_MAX_ETHPORTS;
+}
+
+int
+rte_eth_dev_release_dev_data(uint8_t port_id)
+{
+	char device[RTE_ETH_NAME_MAX_LEN];
+	struct rte_eth_dev_data *eth_dev_data = NULL;
+
+	/* get device name by port id */
+	if (rte_eth_dev_get_name_by_port(port_id, device))
+		return -EINVAL;
+
+	/* look for an entry in the device data */
+	eth_dev_data = rte_eth_dev_data_allocated(device);
+	if (eth_dev_data == NULL)
+		return -EINVAL;
+
+	/* clear an entry in the device data */
+	memset(eth_dev_data, 0, sizeof(struct rte_eth_dev_data));
+
+	return 0;
+}
+
 struct rte_eth_dev *
 rte_eth_dev_allocate(const char *name, enum rte_eth_dev_type type)
 {
-	uint8_t port_id;
+	uint8_t port_id, dev_data_id;
 	struct rte_eth_dev *eth_dev;
 
 	port_id = rte_eth_dev_find_free_port();
@@ -203,17 +249,35 @@ rte_eth_dev_allocate(const char *name, enum rte_eth_dev_type type)
 	if (rte_eth_dev_data == NULL)
 		rte_eth_dev_data_alloc();
 
+	do {
+		dev_data_id = rte_eth_dev_find_free_dev_data_id();
+	} while (!rte_spinlock_trylock(&rte_eth_dev_data[dev_data_id].lock)
+			&& dev_data_id < RTE_MAX_ETHPORTS);
+
+	if (dev_data_id == RTE_MAX_ETHPORTS) {
+		RTE_PMD_DEBUG_TRACE("Reached maximum number of Ethernet ports by all "
+				"the processes\n");
+		return NULL;
+	}
+
 	if (rte_eth_dev_allocated(name) != NULL) {
 		RTE_PMD_DEBUG_TRACE("Ethernet Device with name %s already allocated!\n",
 				name);
 		return NULL;
 	}
 
+	if (rte_eth_dev_data_allocated(name) != NULL) {
+		RTE_PMD_DEBUG_TRACE("Ethernet Device with name %s already allocated by "
+				"another process!\n", name);
+		return NULL;
+	}
+
 	eth_dev = &rte_eth_devices[port_id];
-	eth_dev->data = &rte_eth_dev_data[port_id];
+	eth_dev->data = &rte_eth_dev_data[dev_data_id];
 	snprintf(eth_dev->data->name, sizeof(eth_dev->data->name), "%s", name);
 	eth_dev->data->port_id = port_id;
 	eth_dev->attached = DEV_ATTACHED;
+	rte_spinlock_unlock(&eth_dev->data->lock);
 	eth_dev->dev_type = type;
 	nb_ports++;
 	return eth_dev;
@@ -417,9 +481,7 @@ rte_eth_dev_get_name_by_port(uint8_t port_id, char *name)
 		return -EINVAL;
 	}
 
-	/* shouldn't check 'rte_eth_devices[i].data',
-	 * because it might be overwritten by VDEV PMD */
-	tmp = rte_eth_dev_data[port_id].name;
+	tmp = rte_eth_devices[port_id].data->name;
 	strcpy(name, tmp);
 	return 0;
 }
@@ -438,9 +500,7 @@ rte_eth_dev_get_port_by_name(const char *name, uint8_t *port_id)
 
 	for (i = 0; i < RTE_MAX_ETHPORTS; i++) {
 
-		if (!strncmp(name,
-			rte_eth_dev_data[i].name, strlen(name))) {
-
+		if (!strncmp(name, rte_eth_devices[i].data->name, strlen(name))) {
 			*port_id = i;
 
 			return 0;
@@ -631,6 +691,8 @@ int
 rte_eth_dev_detach(uint8_t port_id, char *name)
 {
 	struct rte_pci_addr addr;
+	struct rte_eth_dev_data *eth_dev_data = NULL;
+	char device[RTE_ETH_NAME_MAX_LEN];
 	int ret = -1;
 
 	if (name == NULL) {
@@ -642,6 +704,15 @@ rte_eth_dev_detach(uint8_t port_id, char *name)
 	if (rte_eth_dev_is_detachable(port_id))
 		goto err;
 
+	/* get device name by port id */
+	if (rte_eth_dev_get_name_by_port(port_id, device))
+		goto err;
+
+	/* look for an entry in the shared device data */
+	eth_dev_data = rte_eth_dev_data_allocated(device);
+	if (eth_dev_data == NULL)
+		goto err;
+
 	if (rte_eth_dev_get_device_type(port_id) == RTE_ETH_DEV_PCI) {
 		ret = rte_eth_dev_get_addr_by_port(port_id, &addr);
 		if (ret < 0)
@@ -661,6 +732,9 @@ rte_eth_dev_detach(uint8_t port_id, char *name)
 			goto err;
 	}
 
+	/* clear an entry in the shared device data */
+	memset(eth_dev_data, 0, sizeof(struct rte_eth_dev_data));
+
 	return 0;
 
 err:
diff --git a/lib/librte_ether/rte_ethdev.h b/lib/librte_ether/rte_ethdev.h
index 96575e8..541e44e 100644
--- a/lib/librte_ether/rte_ethdev.h
+++ b/lib/librte_ether/rte_ethdev.h
@@ -1708,6 +1708,7 @@ struct rte_eth_dev_data {
 	enum rte_kernel_driver kdrv;    /**< Kernel driver passthrough */
 	int numa_node;  /**< NUMA node connection */
 	const char *drv_name;   /**< Driver name */
+	rte_spinlock_t lock; /** Lock on allocate eth device */
 };
 
 /** Device supports hotplug detach */
@@ -1752,6 +1753,29 @@ struct rte_eth_dev *rte_eth_dev_allocated(const char *name);
 
 /**
  * @internal
+ * Returns a shared device data slot specified by the unique identifier name.
+ *
+ * @param	name
+ *  The pointer to the Unique identifier name for each shared Ethernet device
+ *  between multiple processes.
+ * @return
+ *   - The pointer to the device data slot, on success. NULL on error
+ */
+struct rte_eth_dev_data *rte_eth_dev_data_allocated(const char *name);
+
+/**
+ * @internal
+ * Release device data kept in shared memory for all processes.
+ *
+ * @param	port_id
+ *   The port identifier of the device to release device data.
+ * @return
+ *   - 0 on success, negative on error
+ */
+int rte_eth_dev_release_dev_data(uint8_t port_id);
+
+/**
+ * @internal
  * Allocates a new ethdev slot for an ethernet device and returns the pointer
  * to that slot for the driver to use.
  *
diff --git a/lib/librte_ether/rte_ether_version.map b/lib/librte_ether/rte_ether_version.map
index 45ddf44..f37a15c 100644
--- a/lib/librte_ether/rte_ether_version.map
+++ b/lib/librte_ether/rte_ether_version.map
@@ -139,3 +139,10 @@ DPDK_16.07 {
 	rte_eth_dev_get_port_by_name;
 	rte_eth_xstats_get_names;
 } DPDK_16.04;
+
+DPDK_16.11 {
+	global:
+
+	rte_eth_dev_data_allocated;
+	rte_eth_dev_release_dev_data;
+} DPDK_16.07;
-- 
1.9.1