How to test Accelerated Networking VF removal?

Question

How to test Accelerated Networking VF removal?

Josh Knight 40

We are developing a DPDK-based application on a VM with Accelerated Networking enabled. According to the Azure documentation, for host servicing reasons there can be times when the VF disappears/reappears and the synthetic network device is used during that period. My question is, is there a way to invoke this VF removal manually to test that our application will work correctly in the case where the VF is removed during host servicing?

https://learn.microsoft.com/en-us/azure/virtual-network/accelerated-networking-how-it-works#azure-host-servicing

Would disabling and then re-enabling Accelerated Networking on the interface in the Azure Portal be a valid way to test this scenario?

kobulloc-MSFT 26,811 Reputation points Microsoft Employee Moderator

2024-01-09T01:17:49.2733333+00:00

We are investigating this and will get back to you as soon as possible.
ChaitanyaNaykodi-MSFT 27,481 Reputation points Microsoft Employee Moderator

2024-01-09T03:45:22.18+00:00

@Josh Knight

Thank you for reaching out.

I understand you are running a DPDK application on your VM with accelerated Networking enabled and you wish to test your application when the VF interface is removed during Azure host servicing.

Usually disabling and then re-enabling Accelerated Networking will be a valid way to test such scenario but as Accelerated Networking is listed as a perquisite for running DPDK on Linux VM here. Not sure if this way will be correct way to test Azure host servicing scenario.

I have reached out to the team internally regarding this issue and will make an update here as soon as I get a response. Thank you!

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kobulloc-MSFT 26,811 Reputation points Microsoft Employee Moderator

2024-01-09T01:17:49.2733333+00:00

We are investigating this and will get back to you as soon as possible.
ChaitanyaNaykodi-MSFT 27,481 Reputation points Microsoft Employee Moderator

2024-01-09T03:45:22.18+00:00

@Josh Knight

Thank you for reaching out.

I understand you are running a DPDK application on your VM with accelerated Networking enabled and you wish to test your application when the VF interface is removed during Azure host servicing.

Usually disabling and then re-enabling Accelerated Networking will be a valid way to test such scenario but as Accelerated Networking is listed as a perquisite for running DPDK on Linux VM here. Not sure if this way will be correct way to test Azure host servicing scenario.

I have reached out to the team internally regarding this issue and will make an update here as soon as I get a response. Thank you!

Answer 1

ChaitanyaNaykodi-MSFT 27,481 Microsoft Employee Moderator

@Josh Knight
Thank you for your patience here I got a response back from the team.

Can you please let us know which image you are testing MarketPlace or custom image?

For marketplace currently it is not possible to implement such testing functionality and the team is currently tracking this capability internally. For custom image, you can add/remove the VF that will simulate the behavior. As shown here.

Hope this helps! Please let me know if you have any additional questions. Thank you!

Please "Accept the answer" if the information helped you. This will help us and others in the community as well.

AliAlinejad-8326 0 Reputation points

2024-01-19T03:14:48.9233333+00:00

Hi Is there a way to remove VF's functionally from inside the VM using PowerShell?
AliAlinejad-8326 0 Reputation points

2024-01-19T03:17:38.01+00:00

Is there a way to remove VF's functionality from inside the VM using PowerShell? Thanks,

Josh Knight 40

We are using a custom kernel based on 6.1.27, and using dpdk 22.11. Are we missing commits in either of these that are needed to make the Netvsc PMD approach work?

We tested VF path removal, but the dpdk application doesn't seem to switch over to the vmbus interface properly, here is what we see on removal:


mlx5_net: Failed to update link status: No such device or address mlx5_net: port 1 ioctl(SIOCGIFFLAGS) failed: No such device or address mlx5_net: Failed to update link status: No such device or address kernel: pci_bus c75b:00: busn_res: [bus 00] is released
What we expected to see was what we see when doing this on ubuntu:
Port 0: device removal event hn_eth_rmv_event_callback(): Removing VF portid 0 hn_remove_delayed(): Start to remove port 0 Port 0 is closed hn_vf_remove(): VF path not active

Then when we re-enable the VF path, here are the logs we see:

hv_pci 98710889-c75b-4655-a445-882c5e0185dc: PCI VMBus probing: Using version 0x10004
hv_pci 98710889-c75b-4655-a445-882c5e0185dc: PCI host bridge to bus c75b:00
pci_bus c75b:00: root bus resource [mem 0xfe0000000-0xfe00fffff window]
pci_bus c75b:00: No busn resource found for root bus, will use [bus 00-ff]
pci c75b:00:02.0: [15b3:1016] type 00 class 0x020000
pci c75b:00:02.0: reg 0x10: [mem 0xfe0000000-0xfe00fffff 64bit pref]
pci c75b:00:02.0: enabling Extended Tags
pci c75b:00:02.0: 0.000 Gb/s available PCIe bandwidth, limited by Unknown x0 link at c75b:00:02.0 (capable of 63.008 Gb/s with 8.0 GT/s PCIe x8 link)
pci_bus c75b:00: busn_res: [bus 00-ff] end is updated to 00
pci c75b:00:02.0: BAR 0: assigned [mem 0xfe0000000-0xfe00fffff 64bit pref]
mlx5_core c75b:00:02.0: enabling device (0000 -> 0002)
mlx5_core c75b:00:02.0: firmware version: 14.30.1238
mlx5_core c75b:00:02.0: MLX5E: StrdRq(0) RqSz(1024) StrdSz(256) RxCqeCmprss(0)
mlx5_core c75b:00:02.0 eth0: no netdev found for vf serial:3

ChaitanyaNaykodi-MSFT 27,481 Reputation points Microsoft Employee Moderator

2024-01-30T03:21:04.85+00:00

@Josh Knight

Thank you for getting back and apologies for the delay here.

To troubleshoot the exact issue I think we will need specialized 1:1 session, where a support engineer can have a screen share session to pin point the issue. If you have a support plan you may file a support ticket, else could you please send an email to azcommunity@microsoft.com with the below details and I will enable a one-time free support request for you in this case.

Subject : Attn Chaitanya

Thread URL: Link to this thread.

Subscription ID

Please let me know once you have done the same.

Answer 2

Josh Knight 40

We are using a custom image, so that linked article looks like what I was looking for. Thank you!

ChaitanyaNaykodi-MSFT 27,481 Reputation points Microsoft Employee Moderator

2024-01-10T20:21:56.2433333+00:00

@Josh Knight
Thank you for the prompt reply. Glad I could help!

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How to test Accelerated Networking VF removal?

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