Hardware and firmware requirements for 64bit guest operating systems
Purpose
This article explains what the host machine hardware and firmware requirements are for installing virtual machines with 64bit guest operating systems.
Resolution
VMware's virtual machine monitor has traditionally used segmentation to provide isolation between the guest operating system and the virtual machine monitor. This is necessary because the guest operating system and virtual machine monitor share the linear address space.
AMD
Segmentation support is missing from the initial AMD64 processors (that is, revision C and earlier) while running in long mode. As a result, AMD64 processors prior to revision D do not have an efficient mechanism for isolating the virtual machine monitor from 64bit guest operating systems.
A limited form of segmentation was reintroduced in long mode, in revision D AMD64 processors. As a result, AMD64 processors must be revision D or later to run 64bit guest operating systems.
Note: Because AMD Opteron and Turion processors do not ship in revision D, AMD Opteron and Turion 64 processors must be revision E or later to run 64bit guest operating systems.
When reading AMD's documentation revisions may be given in decimal format. For example, Revision F may also be referred to as Revision 15.
Note: 64bit guests are not supported for ESX versions 2.5.x and earlier.
For AMD Opteron‐based systems, the processors must be Opteron Rev E and later.
Note: The preceding link was correct as of October 13, 2009. If you find the link is broken, provide feedback and a VMware employee will update the link.
Intel
Intel CPUs require EM64T and VT support in the chip and in the BIOS.
Note: If VT is enabled in ESX host then vmx flag is found in /proc/cpuinfo.
Intel EM64T CPUs do not have segmentation support in long mode. If the Intel EM64T CPU is VT-capable, it comes with hardware virtualization support (Intel's Virtualization Technology). This hardware virtualization support allows VMware to work around the lack of segmentation, making it possible to run 64bit guest operating systems on Intel EM64T VT-capable CPUs.
Notes:
Firmware/BIOS support is required to enable Intel Virtualization Technology. Some systems (particularly laptops) do not have the necessary firmware/BIOS support to enable Intel Virtualization Technology, and cannot run 64bit guest operating systems.
In multi-processor systems, all processors must support compatible VT implementations. At a minimum, all processors must implement the same VMCS revision ID. In multi-processor systems with mixed processor steppings, 64bit guest operating systems may not be supported.
64bit guests are not supported for ESX versions 2.5.x and earlier.
Many servers that include CPUs with VT support might ship with VT disabled by default, and VT must be enabled manually. If your CPUs support VT but you do not see this option in the BIOS, contact your system vendor to request a BIOS version that lets you enable VT support.
32bit CPUs
Please note that Workstation and VMware Server require a 64bit CPU to run a 64bit guest operating system.
VMware distributes a free utility that can be used to determine whether or not your CPU is suitable for running 64bit guest operating systems. You can download this utility from the VMware Web site athttp://www.vmware.com/download/ws/drivers_tools.html(scroll down to Processor Check for 64Bit Compatibility). VMware Server includes this utility in its product distribution, so you do not need to download an additional tool.
Workstation 5.5 - 6.x and VMware Server 1.x support virtual machines with 64bit guest operating systems only on host machines that have one of the supported 64bit processors:
AMD Athlon 64, revision D or later
AMD Opteron, revision E or later
AMD Turion 64, revision E or later
AMD Sempron, 64bit-capable revision D or later (experimental support)
Note: In shopping for a processor that is compatible with Workstation or VMware Server 64bit guests, you may be unable to determine the revision numbers of a given vendor's offering of AMD Athlon 64, Opteron, Turion 64, or Sempron processors. At this time, the only reliable way to determine whether or not any of these processors is a revision supported by VMware software is by noting the manufacturing technology (CMOS). Any of the AMD Athlon 64, Opteron, Turion 64, or Sempron processors whose manufacturing technology is 90nm SOI (.09 micron SOI) is compatible with Workstation or VMware Server 64-bit guests. Using this information, you should be able to determine — with the help of your vendor, or from the AMD Web site— whether a particular Athlon 64 or Opteron processor model is compatible with Workstation or VMware Server 64-bit guests.
