Increased dom0 memory requirement when using Mellanox HCAs on Oracle VM Server

Oracle VM Servers running UEKR4u2 and upward in dom0 require at least 400MB more memory to use the Mellanox® drivers. This memory requirement is a result of the default size of the SRQ count being increased from 64K to 256K in later versions of the kernel and the scale_profile option is now enabled by default in the mlx_core module.

In the case where out-of-memory errors are observed in dom0, the maximum dom0 memory size should be increased. Alternative workarounds might involve manually setting the module parameters for the mlx4_core driver. To set these parameters, edit /etc/modprobe.d/mlx4_core.conf and set scale_profile to 0. Alternately, set log_num_srq to 16. The preferred resolution to this issue is to increase the memory allocated to dom0 on an Oracle VM Server. (Bug ID 23581534)