Intel-VT Features and VMware Support of those Features?

[aaronwsmith]

Hello Everyone,

Intel published a helpful article in 2010 about the various virtualization technology (Intel VT) features offered, and which processor families supported those individual features:

Enabling Intel Virtualization Technology Features and Benefits

The guide even provided information on which Vendors such as VMware had enabled support for those individual features.

Problem I'm facing now is finding up-to-date information on the following:

• Any new Intel-VT features added?
• Which features from Intel-VT are supported by processors from the latest families.  For example, what's supported by the E5-4600 series?
• Which features from Intel-VT does VMware currently support across ESXi versions?

This information would make CPU selections much easier, but I'm struggling to find current information that goes this deep.  Anyone aware of useful sources to pull this data together?

Thanks in advance!

[nickwalt]

Hi Arrowsmith,

Have you checked Intel Ark:

Processor E5-4600 Product Family

And here:

Virtualization Technology List

If there is any significantly new tech showing up in new CPUs and chipsets, like Haswell, I would imagine information about it would be showing up here, on communities.vmware.

I hope this shed some light on your question.

Cheers,

Nick

[aaronwsmith]

Hi Nick,

Yes I did review both those resources prior to posting.  Unfortunately they only provide high level information on the processor's support of Intel VT-x, Intel EPT and Intel VT-d.  But if you look at the 2010 whitepaper I linked from Intel in 2010, the VT-x and VT-d have a specific list of features (e.g. FlexPriority, FlexMigration, etc.) that exist under each, and not all processor families support all of those features.  Further, virtualization vendors like VMware may not support all the features available either.  So depending on what you're looking for with hardware assisted virtualization, the challenge is finding up-to-date information to this level to help make a decision on a particular processor to include in your server hardware to match the planned workload that will placed on it.

Thanks for responding though!  Let me know if you come across any more content.  I will update this thread as well if/when I made headway.

[nickwalt]

Ah, yeah I figured there might be a lot more behind your question. I didn't read your post and I would have understood your question if I had, doh. I'll go back and read it, as I'm very new to the VMware space as I'm interested to understand the VM tech available in CPUs.

[aaronwsmith]

I'll inquire within VMware itself to see if I can get more information along these lines.  If I'm able to pull together more helpful/currect information, I'll update this post or write a community doc on it.

[admin]

check this guide for the link.... http://www.vmware.com/resources/compatibility/pdf/vi_systems_guide.pdf

[admin]

New VT-x features from Intel include:

• x2APIC virtualization (Sandy Bridge)
• Full APIC virtualization (Ivy Bridge)
• Shadow VMCS (Haswell)

vSphere 5.1, Workstation 9 and Fusion 5 have support for x2APIC virtualization.  The other features are not yet supported by any shipping VMware products.

[Miguel_Veguilla]

Well, Shadow VMCS ( Haswell ) IS supported by VMware in ESXi 5.1 to help nested hypervisors.

See virtuallyGhetto: Will Intel’s VMCS Shadowing Feature Benefit VMware’s Nested Vir...

[admin]

No, it isn't.  The article you reference describes how we use software techniques to achieve about 75% of the VM-exit reductions that you could get with hardware shadow VMCS support.

[Miguel_Veguilla]

To quote the article

VMCS Shadowing will provide only a small benefit when running a VMware Hypervisor as virtual machine. However, it will greatly benefit other non-VMware Hypervisors running as a virtual machine, this is particular true for Hypervisors that perform egregious number of VMREAD and VMWRITE operations and that do not cluster well, such as VirtualBox for example.

I understand the article talks about future haswell processors but current VMware ESXi. Am I wrong?

[admin]

Haswell processors are actually available now.  ESXi with shadow VMCS support is not yet available.

[Miguel_Veguilla]

Ok, I thought the article was written before haswell.

[admin]

All of the verbs are future tense.  The author did not mean to imply that ESXi already has the software support for this feature.

[Miguel_Veguilla]

Do you know if ESXi 5.5 will support it?

[admin]

Sorry.  VMware policy is to not comment on any unannounced products, features, timeframes, etc.

[Miguel_Veguilla]

I Understand,

but ESXi 5.5 has just been announced ( albeit it's not shipping ) ...

[Miguel_Veguilla]

Either way, thank you for clarifying this matter!

I sure hope this feature is present on the 5.5 release.

[admin]

ESXi 5.5 will not have support for hardware VMCS shadowing on Haswell processors.

[aaronwsmith]

Is there a KB or document that provides information on which versions of ESXi support various Intel/AMD virtualization features?

[admin]

I'll try to put something together.  Is there a particular feature you're interested in?