A few more details on this, on 14.04 the legacy adapter seems to be handled through the tulip driver. However, on Vivid the PCI device is still recognized, but not shown as handled through any kernel module:
#lspci 00:00.0 Host bridge: Intel Corporation 440BX/ZX/DX - 82443BX/ZX/DX Host bridge (AGP disabled) (rev 03) 00:07.0 ISA bridge: Intel Corporation 82371AB/EB/MB PIIX4 ISA (rev 01) 00:07.1 IDE interface: Intel Corporation 82371AB/EB/MB PIIX4 IDE (rev 01) 00:07.3 Bridge: Intel Corporation 82371AB/EB/MB PIIX4 ACPI (rev 02) 00:08.0 VGA compatible controller: Microsoft Corporation Hyper-V virtual VGA 00:0a.0 Ethernet controller: Digital Equipment Corporation DECchip 21140 [FasterNet] (rev 20) Ethernet controller info: 00:0a.0 Ethernet controller: Digital Equipment Corporation DECchip 21140 [FasterNet] (rev 20) Subsystem: Device 0a00:2114 Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV+ VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx- Status: Cap- 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 64 (5000ns min, 10000ns max), Cache Line Size: 32 bytes Interrupt: pin A routed to IRQ 11 Region 0: I/O ports at ec00 [size=128] Region 1: Memory at febff000 (32-bit, non-prefetchable) [size=4K] Expansion ROM at febe0000 [disabled] [size=64K] On 14.04 the last command reads also this line: Kernel driver in use: tulip ** Changed in: linux (Ubuntu) Status: Incomplete => New -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1440072 Title: [Hyper-V] Legacy network adapter is not detected Status in linux package in Ubuntu: New Bug description: Issue description: Attaching a Legacy network adapter to a VM will not be detected on the VM side. This is not the case with synthetic adapters, which are properly identified. Steps to Reproduce: 1. Add a Legacy Network adapter to the VM 2. Boot the vm 3. Verify the identified network adapter, the legacy NIC is missing Versions details: Windows Server Host Edition: Microsoft Windows Server 2012 R2 Datacenter build 9600 and Microsoft Windows Server 2008 R2 Standard SP 1 build 7601 Distribution name and release: Ubuntu Vivid Vervet Kernel version: Linux ubuntu31 3.19.0-11-generic #11lp14233432v201504021617 SMP Hyper-V side: PS> Get-VMNetworkAdapter -VMName vivid1 Name IsManagementOs VMName SwitchName MacAddress Status IPAddresses ---- -------------- ------ ---------- ---------- ------ ----------- Network Adapter False vivid1 external 00155D06332D {Ok} {IP, fe80::215:5dff:fe06:332d} Legacy Network Adapter False vivid1 external 00155D063336 {Ok} {} On the VM Side: root@ubuntu31:~# ls /sys/class/net/ eth0 lo eth0 has the MAC of the Network Adapter, which is the synthetic interface. This has been verified with also 1 vCPU or with irqbalancer daemon disabled, as that is a common requirements when using legacy adapters. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1440072/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp