6.0.1

The virtual machine log file vmware.log contains the following message about the VF:
PCIPassthruChangeIntrSettings: vf_name failed to register interrupt (error code 195887110)
The VMkernel log file vmkernel.log contains the following messages about the VF assigned to the virtual
machine:
VMKPCIPassthru: 2565: BDF = vf_name intrType = 4 numVectors: 3
WARNING: IntrVector: 233: Out of interrupt vectors
Cause
The number of allocatable interrupt vectors scales up with the number of physical CPUs on an ESXi host.
An ESXi host that has 32 CPUs can provide a total of 4096 interrupt vectors. When the host boots, devices on
the host such as storage controllers, physical network adapters, and USB controllers consume a subset of the
4096 vectors. If these devices require more than 1024 vectors, the maximum number of potentially
supported VFs is reduced.
When a virtual machine powers on and the guest operating system VF driver starts, interrupt vectors are
consumed. If the required number of interrupt vectors is not available, the guest operating system shuts
down unexpectedly without any error messages.
No rule presently exists to determine the number of interrupt vectors consumed or available on a host. This
number depends on the hardware configuration of the host.
Solution
u
To be able to power on the virtual machines, reduce the total number of VFs assigned to virtual
machines on the host.
For example, change the SR-IOV network adapter of a virtual machine to an adapter that is connected
to a vSphere Standard Switch or vSphere Distributed Switch.
SR-IOV Enabled Workload Cannot Communicate After You Change Its MAC
Address
After you change the MAC address in the guest operating system of an SR-IOV enabled virtual machine, the
virtual machine loses connectivity.
Problem
When you connect the network adapter of a virtual machine to an SR-IOV virtual function (VF), you create a
passthrough network adapter for the virtual machine. After the (VF) driver in the guest operating system
modifies the MAC address for the passthrough network adapter, the guest operating system shows that the
change is successful but the VM network adapter loses connectivity. Although the guest operating system
shows that the new MAC address is enabled, a log message in the /var/log/vmkernel.log file indicates that
the operation has failed.
Requested mac address change to new MAC address on port VM NIC port number, disallowed by
vswitch policy.
where
n
new MAC address is the MAC address in the guest operation system.
n
VM NIC port number is the port number of the VM network adapter in hexadecimal format.
Cause
The default security policy on the port group to which the passthrough network adapter is connected does
not allow changes in the MAC address in the guest operating system. As a result, the networking interface
in the guest operating system cannot acquire an IP address and loses connectivity.
vSphere Troubleshooting
88 VMware, Inc.