[dpdk-dev] [PATCH v3 0/2] support MAC changes when no live changes allowed

[dpdk-dev] [PATCH v3 0/2] support MAC changes when no live changes allowed

[Alejandro Lucero]

This is a patched to fix a functionality coming with the first public
release: changing/setting MAC address.

The original patch assumes all NICs can safely change or set the MAC
in any case. However, this is not always true. NFP depends on the firmware
capabilities and this is not always supported. There are other NICs with
this same limitation, although, as far as I know, not in DPDK. Linux kernel
has a IFF_LIVE_ADDR_CHANGE flag and two NICs are checking this flag for
allowing or not live MAC changes.

The flag proposed in this patch is just the opposite: advertise if live
change not supported and assuming it is supported other way.

Although most NICs support rte_eth_dev_default_mac_addr_set and this
function returns and error when live change is not supported, note that
this function is invoked during port start but the value returned is not
checked. It is likely this is good enough for most of the cases, but
bonding is relying on this start then mac set/change, and a PMD ports is
not properly configured for being used as an slave port in some bonding
modes.

v2:
 - add RTE_ETH_DEV_NOLIVE_MAC_ADDR comment in rte_eth_dev_default_mac_addr_set doc
 - add rte_eth_dev_start change in release API changes

v3:
 - merge doc API changes with first patch
 - comment behaviour change in rte_eth_dev_start
 - remove comment on rte_eth_dev_default_mac_addr_set

[dpdk-dev] [PATCH v3 1/2] ethdev: fix MAC changes when live change not supported

[Alejandro Lucero]

Current code assumes a MAC change can occur when the port has been
started. In fact, there are some NICs which require this port state
for being successful, but other NICs not always support MAC change
in that case.

This patch supports a new device flag for a device advertising this
limitation, and if the flag is set, the MAC is changed before the
port starts.

Fixes: af75078fece3 ("first public release")
Cc: stable@dpdk.org

Signed-off-by: Alejandro Lucero <alejandro.lucero@netronome.com>
---
 doc/guides/rel_notes/release_18_11.rst |  6 +++++-
 lib/librte_ethdev/rte_ethdev.c         | 28 +++++++++++++++++++---------
 lib/librte_ethdev/rte_ethdev.h         |  6 ++++++
 3 files changed, 30 insertions(+), 10 deletions(-)

diff --git a/doc/guides/rel_notes/release_18_11.rst b/doc/guides/rel_notes/release_18_11.rst
index 3ae6b3f..b0c73bd 100644
--- a/doc/guides/rel_notes/release_18_11.rst
+++ b/doc/guides/rel_notes/release_18_11.rst
@@ -67,7 +67,11 @@ API Changes
    This section is a comment. Do not overwrite or remove it.
    Also, make sure to start the actual text at the margin.
    =========================================================
-
+   * A new device flag, RTE_ETH_DEV_NOLIVE_MAC_ADDR, changes the order of
+     actions inside rte_eth_dev_start regarding MAC set. Some NICs do not
+     support MAC changes once the port has started and with this new device
+     flag the MAC can be properly configured in any case. This is particularly
+     important for bonding.
 
 ABI Changes
 -----------
diff --git a/lib/librte_ethdev/rte_ethdev.c b/lib/librte_ethdev/rte_ethdev.c
index f32722f..16825bf 100644
--- a/lib/librte_ethdev/rte_ethdev.c
+++ b/lib/librte_ethdev/rte_ethdev.c
@@ -1219,19 +1219,14 @@ struct rte_eth_dev *
 }
 
 static void
-rte_eth_dev_config_restore(uint16_t port_id)
+rte_eth_dev_mac_restore(struct rte_eth_dev *dev,
+			struct rte_eth_dev_info *dev_info)
 {
-	struct rte_eth_dev *dev;
-	struct rte_eth_dev_info dev_info;
 	struct ether_addr *addr;
 	uint16_t i;
 	uint32_t pool = 0;
 	uint64_t pool_mask;
 
-	dev = &rte_eth_devices[port_id];
-
-	rte_eth_dev_info_get(port_id, &dev_info);
-
 	/* replay MAC address configuration including default MAC */
 	addr = &dev->data->mac_addrs[0];
 	if (*dev->dev_ops->mac_addr_set != NULL)
@@ -1240,7 +1235,7 @@ struct rte_eth_dev *
 		(*dev->dev_ops->mac_addr_add)(dev, addr, 0, pool);
 
 	if (*dev->dev_ops->mac_addr_add != NULL) {
-		for (i = 1; i < dev_info.max_mac_addrs; i++) {
+		for (i = 1; i < dev_info->max_mac_addrs; i++) {
 			addr = &dev->data->mac_addrs[i];
 
 			/* skip zero address */
@@ -1259,6 +1254,14 @@ struct rte_eth_dev *
 			} while (pool_mask);
 		}
 	}
+}
+
+static void
+rte_eth_dev_config_restore(struct rte_eth_dev *dev,
+			   struct rte_eth_dev_info *dev_info, uint16_t port_id)
+{
+	if (!(*dev_info->dev_flags & RTE_ETH_DEV_NOLIVE_MAC_ADDR))
+		rte_eth_dev_mac_restore(dev, dev_info);
 
 	/* replay promiscuous configuration */
 	if (rte_eth_promiscuous_get(port_id) == 1)
@@ -1277,6 +1280,7 @@ struct rte_eth_dev *
 rte_eth_dev_start(uint16_t port_id)
 {
 	struct rte_eth_dev *dev;
+	struct rte_eth_dev_info dev_info;
 	int diag;
 
 	RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -EINVAL);
@@ -1292,13 +1296,19 @@ struct rte_eth_dev *
 		return 0;
 	}
 
+	rte_eth_dev_info_get(port_id, &dev_info);
+
+	/* Lets restore MAC now if device does not support live change */
+	if (*dev_info.dev_flags & RTE_ETH_DEV_NOLIVE_MAC_ADDR)
+		rte_eth_dev_mac_restore(dev, &dev_info);
+
 	diag = (*dev->dev_ops->dev_start)(dev);
 	if (diag == 0)
 		dev->data->dev_started = 1;
 	else
 		return eth_err(port_id, diag);
 
-	rte_eth_dev_config_restore(port_id);
+	rte_eth_dev_config_restore(dev, &dev_info, port_id);
 
 	if (dev->data->dev_conf.intr_conf.lsc == 0) {
 		RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->link_update, -ENOTSUP);
diff --git a/lib/librte_ethdev/rte_ethdev.h b/lib/librte_ethdev/rte_ethdev.h
index 7070e9a..fa2812b 100644
--- a/lib/librte_ethdev/rte_ethdev.h
+++ b/lib/librte_ethdev/rte_ethdev.h
@@ -1268,6 +1268,8 @@ struct rte_eth_dev_owner {
 #define RTE_ETH_DEV_INTR_RMV     0x0008
 /** Device is port representor */
 #define RTE_ETH_DEV_REPRESENTOR  0x0010
+/** Device does not support MAC change after started */
+#define RTE_ETH_DEV_NOLIVE_MAC_ADDR  0x0020
 
 /**
  * Iterates over valid ethdev ports owned by a specific owner.
@@ -1750,6 +1752,10 @@ int rte_eth_tx_queue_setup(uint16_t port_id, uint16_t tx_queue_id,
  * The device start step is the last one and consists of setting the configured
  * offload features and in starting the transmit and the receive units of the
  * device.
+ *
+ * Device RTE_ETH_DEV_NOLIVE_MAC_ADDR flag causes MAC address to be set before
+ * PMD port start callback function is invoked.
+ *
  * On success, all basic functions exported by the Ethernet API (link status,
  * receive/transmit, and so on) can be invoked.
  *
-- 
1.9.1

[dpdk-dev] [PATCH v3 2/2] net/nfp: fix live MAC changes not supported

[Alejandro Lucero]

Some NFP firmwares support live changes to the MAC address, but
this is not always true and the firmware advertises it accordingly.

This patch checks if firmware does not support live changes and
sets RTE_ETH_DEV_NOLIVE_MAC_ADDR in that case.

Cc: stable@dpdk.org

Signed-off-by: Alejandro Lucero <alejandro.lucero@netronome.com>
---
 drivers/net/nfp/nfp_net.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/nfp/nfp_net.c b/drivers/net/nfp/nfp_net.c
index 6e5e305..ee743e9 100644
--- a/drivers/net/nfp/nfp_net.c
+++ b/drivers/net/nfp/nfp_net.c
@@ -2886,6 +2886,9 @@ uint32_t nfp_net_txq_full(struct nfp_net_txq *txq)
 	ether_addr_copy((struct ether_addr *)hw->mac_addr,
 			&eth_dev->data->mac_addrs[0]);
 
+	if (!(hw->cap & NFP_NET_CFG_CTRL_LIVE_ADDR))
+		eth_dev->data->dev_flags |= RTE_ETH_DEV_NOLIVE_MAC_ADDR;
+
 	PMD_INIT_LOG(INFO, "port %d VendorID=0x%x DeviceID=0x%x "
 		     "mac=%02x:%02x:%02x:%02x:%02x:%02x",
 		     eth_dev->data->port_id, pci_dev->id.vendor_id,
-- 
1.9.1

Re: [dpdk-dev] [PATCH v3 0/2] support MAC changes when no live changes allowed

[Stephen Hemminger]

On Fri, 24 Aug 2018 15:25:34 +0100
Alejandro Lucero <alejandro.lucero@netronome.com> wrote:

> The original patch assumes all NICs can safely change or set the MAC
> in any case. However, this is not always true. NFP depends on the firmware
> capabilities and this is not always supported. There are other NICs with
> this same limitation, although, as far as I know, not in DPDK. Linux kernel
> has a IFF_LIVE_ADDR_CHANGE flag and two NICs are checking this flag for
> allowing or not live MAC changes

The semantic in Linux is different than what I think you are trying to do.
Some devices can not change MAC address at all because of hardware or hypervisor
restrictions. Other devices can not change address while device is up (started
in DPDK API).

With Linux the policy was to assume by default device could change address while up.
And then let a few virtual devices allow it.

Re: [dpdk-dev] [PATCH v3 1/2] ethdev: fix MAC changes when live change not supported

[Ferruh Yigit]

On 8/24/2018 3:25 PM, Alejandro Lucero wrote:
> Current code assumes a MAC change can occur when the port has been
> started. In fact, there are some NICs which require this port state
> for being successful, but other NICs not always support MAC change
> in that case.
> 
> This patch supports a new device flag for a device advertising this
> limitation, and if the flag is set, the MAC is changed before the
> port starts.
> 
> Fixes: af75078fece3 ("first public release")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Alejandro Lucero <alejandro.lucero@netronome.com>

Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>

Re: [dpdk-dev] [PATCH v3 0/2] support MAC changes when no live changes allowed

[Ferruh Yigit]

On 8/24/2018 3:25 PM, Alejandro Lucero wrote:
> This is a patched to fix a functionality coming with the first public
> release: changing/setting MAC address.
> 
> The original patch assumes all NICs can safely change or set the MAC
> in any case. However, this is not always true. NFP depends on the firmware
> capabilities and this is not always supported. There are other NICs with
> this same limitation, although, as far as I know, not in DPDK. Linux kernel
> has a IFF_LIVE_ADDR_CHANGE flag and two NICs are checking this flag for
> allowing or not live MAC changes.
> 
> The flag proposed in this patch is just the opposite: advertise if live
> change not supported and assuming it is supported other way.
> 
> Although most NICs support rte_eth_dev_default_mac_addr_set and this
> function returns and error when live change is not supported, note that
> this function is invoked during port start but the value returned is not
> checked. It is likely this is good enough for most of the cases, but
> bonding is relying on this start then mac set/change, and a PMD ports is
> not properly configured for being used as an slave port in some bonding
> modes.
> 
> v2:
>  - add RTE_ETH_DEV_NOLIVE_MAC_ADDR comment in rte_eth_dev_default_mac_addr_set doc
>  - add rte_eth_dev_start change in release API changes
> 
> v3:
>  - merge doc API changes with first patch
>  - comment behaviour change in rte_eth_dev_start
>  - remove comment on rte_eth_dev_default_mac_addr_set

Series applied to dpdk-next-net/master, thanks.