On 9/10/2026 2:13 PM, Burakov, Anatoly wrote:
On 9/4/2026 2:28 PM, David Marchand wrote:
E810 hardware provides 32k switch lookups.
Thanks to this, it is possible to allow a lot more secondary mac
addresses than what is possible today.
In practice, the maximum number of macs available per port may be lower
and depends on usage by other (trusted?) VFs on the same PF.
There is no way to figure out this limit but to try adding a mac address
and get an error from the PF driver.
Mailbox exchanges are limited to IAVF_AQ_BUF_SZ, segment messages
accordingly.
Signed-off-by: David Marchand <[email protected]>
---
On another note, I don't think this is even compatible with ethdev API.
In `ethdev_driver.h`:
struct __rte_cache_aligned rte_eth_dev_data {
...
/**
* Device Ethernet link addresses.
* All entries are unique.
* The first entry (index zero) is the default address.
*/
struct rte_ether_addr *mac_addrs;
/** Bitmap associating MAC addresses to pools */
uint64_t mac_pool_sel[RTE_ETH_NUM_RECEIVE_MAC_ADDR];
...
}
example of this bitmap in rte_eth_dev_mac_addr_remove:
/* Update NIC */
dev->dev_ops->mac_addr_remove(dev, index);
/* Update address in NIC data structure */
rte_ether_addr_copy(&null_mac_addr, &dev->data->mac_addrs[index]);
/* reset pool bitmap */
dev->data->mac_pool_sel[index] = 0;
rte_ethdev_trace_mac_addr_remove(port_id, addr);
meaning, the mac_addrs array and the mac_pool_sel have the same
limitation because they are indexed by the same index.
RTE_ETH_NUM_RECEIVE_MAC_ADDR is defined as 128, so correct me if I'm
wrong here, but according to ethdev API one cannot have more than 128
MAC addresses?
I would even go as far as to suggest that ethdev API should probably
check max MAC addrs number to make sure it doesn't exceed the size of
RTE_ETH_NUM_RECEIVE_MAC_ADDR, because otherwise that's a latent
potential buffer overrun?
--
Thanks,
Anatoly
