Intel Westmere missing feature pclmulqdq(pclmuldq) in vm guests
Issue
-
In a virtual guest running on a Westmere cpu when using the cpu feature pclmulqdq (also called pclmuldq), performance is lower compared to a physical host
-
Checking the
/proc/cpuflags for pclmulqdq(or pclmuldq) support, it is missing on the virtual machine, it will be present on the physical host if on a Westmere cpu.
Environment
- Red Hat Enterprise Virtualization (RHEV) based on RHEL6 hypervisors
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