PSA: VMDirectpath / PCI Passthrough on HP DL380 g8 (and others)

It looks as if HP has broken PCI Passthrough or VMDirectpath in ESXi 5.5 and certain recent patch versions of ESXi 5.1 due to an architecture issue in the HP PCI Bus.

While i’m not 100% sure why, I believe the issue lies around the PCI bridging chipset used in G7, G6, and G8 servers that may cause corruption of data as it flows through the PCI bus.

This is one of those posts that I wish were incorrect but all signs point this being the case so I thought I would pass this along.

Because of this, they have disabled VMDirectpath and are not planning on bringing it back anytime soon as far as I can tell.


The symptoms are that when a VM Guest is given a Passthrough device, that guest will fail to boot with:

“Failed to register the device pciPassthru0 for XX:YY.0 due to unavailable hardware or software support”


With an HP customized install, the error may also be:

“Device (XX/YY/ZZ) Is Not a Passthrough Device”


Honestly I suppose I cant really fault anyone since NO HP servers are listed in VMWare’s compatibility matrix to have PCI passthrough support!


I suppose it pays to always double check that you have official vendor backing on a feature before trying to implement it.

The only self-help workaround as far as I can tell is to either stay on ESXi 5.1 and earlier or downgrade and hope you don’t hit whatever PCI pass-through edge case that HP has identified.

For my situation, I was looking on passing through an HBA to support a tape library. Now it looks like the best choice for me is to install Windows Server 2012R2 on bare-metal without virtualization (or even *gasp* add the HyperV roles!)


Read more about the HP issue identified here:



1 Comment

  1. David Jones

    Dell still fully support DirectPath in ESXi. HP are continuing to give us, long term HP users, more reasons to start using Dell!


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