Intel E810 PF Passthrough: Intermittent Link Bring‑Up Failure After Reboot (NVM 4.20)

Susmitha · ‎04-29-2026

Hello Intel Community,

We are seeing an intermittent physical link bring‑up failure on an Intel E810 NIC when using PF passthrough (PFPT) to a VM. After reboot (host or VM), the passed‑through PF sometimes fails to establish link.

Environment
==========

Server: Dell PowerEdge R640
NIC: Intel Ethernet Controller E810-C for QSPF [8086:1592] (Dell OEM, dual‑port)
NVM/Firmware: 4.20
Host ICE driver: 1.11.14
Guest ICE driver: 1.6.4
DDP: 1.3.26 and 1.3.53
DPDK: 24.11.1
Mode: PF passthrough
Compute Host OS:
Host OS: SUSE Linux and kernel version: 5.3.18
Guest OS: Linux - 4.19

Observed Behaviour
================

After reboot, the PF in the VM fails to establish physical link.
The peer switch port also goes down, confirming this is not just a software reporting issue.
After a VM reboot, port availability is inconsistent; occasionally both ports come up, but often only one or neither initializes.
No kernel dmesg errors are seen.

Could you please advise on:

Known limitations of Intel E810 in PF passthrough mode.
Known issues in NVM 4.20 related to EMP behaviour, global reset, or dual‑port interactions.
Recommended firmware and driver combinations for PFPT (DPDK‑based deployments).
Any potential software-level workarounds to mitigate compatibility issues or performance bottlenecks without changing the underlying firmware/driver?

Thanks in advance for your guidance.

Regards,
Susmitha

Steve_Jerome22 · ‎04-29-2026

Hi Susmitha,

Greetings for the day!

Thanks for contacting Intel Customer Support with your query:

Kindly share the complete model of the NIC card and the also the clear picture of the card with serial number and part number visible.

Looking forward to your response.

Regards

Jerome

Intel Customer Support Technician

Susmitha · ‎04-30-2026

Hi Jerome,

Thank you for your response.

I will share the clear pictures of the NIC card via email, rather than posting them on the public forum.

Kindly let me know if there is a specific email address I should send them to.

Looking forward to your confirmation.

Regards,
Susmitha

IntelSupport · ‎04-30-2026

Hi Susmitha,

Thank you for your response. We will contact through your Email for further details.

Regards,

Pavithra_Intel