Provided by: freebsd-manpages_12.2-1_all bug


     ena — FreeBSD kernel driver for Elastic Network Adapter (ENA) family


     To compile this driver into the kernel, place the following line in the kernel configuration

           device ena

     Alternatively, to load the driver as a module at boot time, place the following line in



     The ENA is a networking interface designed to make good use of modern CPU features and
     system architectures.

     The ENA device exposes a lightweight management interface with a minimal set of memory
     mapped registers and extendable command set through an Admin Queue.

     The driver supports a range of ENA devices, is link-speed independent (i.e., the same driver
     is used for 10GbE, 25GbE, 40GbE, etc.), and has a negotiated and extendable feature set.

     Some ENA devices support SR-IOV.  This driver is used for both the SR-IOV Physical Function
     (PF) and Virtual Function (VF) devices.

     The ENA devices enable high speed and low overhead network traffic processing by providing
     multiple Tx/Rx queue pairs (the maximum number is advertised by the device via the Admin
     Queue), a dedicated MSI-X interrupt vector per Tx/Rx queue pair, and CPU cacheline optimized
     data placement.

     The ena driver supports industry standard TCP/IP offload features such as checksum offload
     and TCP transmit segmentation offload (TSO).  Receive-side scaling (RSS) is supported for
     multi-core scaling.

     The ena driver and its corresponding devices implement health monitoring mechanisms such as
     watchdog, enabling the device and driver to recover in a manner transparent to the
     application, as well as debug logs.

     Some of the ENA devices support a working mode called Low-latency Queue (LLQ), which saves
     several more microseconds.  This feature will be implemented for driver in future releases.


     Supported PCI vendor ID/device IDs:

        1d0f:0ec2 - ENA PF
        1d0f:1ec2 - ENA PF with LLQ support
        1d0f:ec20 - ENA VF
        1d0f:ec21 - ENA VF with LLQ support


   Device initialization phase:
     ena%d: failed to init mmio read less

     Error occurred during initialization of the mmio register read request.

     ena%d: Can not reset device

     Device could not be reset.
     Device may not be responding or is already during reset.

     ena%d: device version is too low

     Version of the controller is too old and it is not supported by the driver.

     ena%d: Invalid dma width value %d

     The controller is able to request dma transaction width.
     Device stopped responding or it demanded invalid value.

     ena%d: Can not initialize ena admin queue with device

     Initialization of the Admin Queue failed.
     Device may not be responding or there was a problem with initialization of the resources.

     ena%d: Cannot get attribute for ena device rc: %d

     Failed to get attributes of the device from the controller.

     ena%d: Cannot configure aenq groups rc: %d

     Errors occurred when trying to configure AENQ groups.

   Driver initialisation/shutdown phase:
     ena%d: PCI resource allocation failed!
     ena%d: allocating ena_dev failed
     ena%d: failed to pmap registers bar
     ena%d: Error while setting up bufring
     ena%d: Error with initialization of IO rings
     ena%d: can not allocate ifnet structure
     ena%d: Error with network interface setup
     ena%d: Failed to enable and set the admin interrupts
     ena%d: Failed to allocate %d, vectors %d
     ena%d: Failed to enable MSIX, vectors %d rc %d
     ena%d: Error with MSI-X enablement
     ena%d: could not allocate irq vector: %d
     ena%d: Unable to allocate bus resource: registers

     Resource allocation failed when initializing the device.
     Driver will not be attached.

     ena%d: ENA device init failed (err: %d)

     Device initialization failed.
     Driver will not be attached.

     ena%d: could not activate irq vector: %d

     Error occurred when trying to activate interrupt vectors for Admin Queue.

     ena%d: failed to register interrupt handler for irq %ju: %d

     Error occurred when trying to register Admin Queue interrupt handler.

     ena%d: Cannot setup mgmnt queue intr

     Error occurred during configuration of the Admin Queue interrupts.

     ena%d: Enable MSI-X failed

     Configuration of the MSI-X for Admin Queue failed.
     There could be lack of resources or interrupts could not have been configured.
     Driver will not be attached.

     ena%d: VLAN is in use, detach first

     VLANs are being used when trying to detach the driver.
     VLANs must be detached first and then detach routine have to be called again.

     ena%d: Unmapped RX DMA tag associations
     ena%d: Unmapped TX DMA tag associations

     Error occurred when trying to destroy RX/TX DMA tag.

     ena%d: Cannot init RSS
     ena%d: Cannot fill indirect table
     ena%d: Cannot fill indirect table
     ena%d: Cannot fill hash function
     ena%d: Cannot fill hash control
     ena%d: WARNING: RSS was not properly initialized, it will affect bandwidth

     Error occurred during initialization of one of RSS resources.
     The device will work with reduced performance because all RX packets will be passed to queue
     0 and there will be no hash information.

     ena%d: failed to tear down irq: %d
     ena%d: dev has no parent while releasing res for irq: %d  Release of the interrupts failed.

   Additional diagnostic:
     ena%d: Cannot get attribute for ena device

     This message appears when trying to change MTU and driver is unable to get attributes from
     the device.

     ena%d: Invalid MTU setting. new_mtu: %d

     Requested MTU value is not supported and will not be set.

     ena%d: keep alive watchdog timeout

     Device stopped responding and will be reset.

     ena%d: Found a Tx that wasn't completed on time, qid %d, index %d.

     Packet was pushed to the NIC but not sent within given time limit.
     It may be caused by hang of the IO queue.

     ena%d: The number of lost tx completion is aboce the threshold (%d > %d). Reset the device

     If too many Tx wasn't completed on time the device is going to be reset.
     It may be caused by hanged queue or device.

     ena%d: trigger reset is on

     Device will be reset.
     Reset is triggered either by watchdog or if too many TX packets were not completed on time.

     ena%d: invalid value recvd

     Link status received from the device in the AENQ handler is invalid.

     ena%d: Allocation for Tx Queue %u failed
     ena%d: Allocation for Rx Queue %u failed
     ena%d: Unable to create Rx DMA map for buffer %d
     ena%d: Failed to create io TX queue #%d rc: %d
     ena%d: Failed to get TX queue handlers. TX queue num %d rc: %d
     ena%d: Failed to create io RX queue[%d] rc: %d
     ena%d: Failed to get RX queue handlers. RX queue num %d rc: %d
     ena%d: failed to request irq
     ena%d: could not allocate irq vector: %d
     ena%d: failed to register interrupt handler for irq %ju: %d

     IO resources initialization failed.
     Interface will not be brought up.

     ena%d: LRO[%d] Initialization failed!

     Initialization of the LRO for the RX ring failed.

     ena%d: failed to alloc buffer for rx queue
     ena%d: failed to add buffer for rx queue %d
     ena%d: refilled rx queue %d with %d pages only

     Allocation of resources used on RX path failed.
     If happened during initialization of the IO queue, the interface will not be brought up.

     ena%d: ioctl promisc/allmulti

     IOCTL request for the device to work in promiscuous/allmulti mode.
     See ifconfig(8) for more details.

     ena%d: too many fragments. Last fragment: %d!

     Packet with unsupported number of segments was queued for sending to the device.
     Packet will be dropped.


     If an issue is identified with the released source code with a supported adapter, please
     email the specific information related to the issue to ⟨⟩ and


     vlan(4), ifconfig(8)


     The ena driver was written by Semihalf.