P7350 support VT?

[darkbuck]

Hi, All

I recently ordered a notebook with P7350. I searched Intel website which said P7350 support Virtualization technology, http://processorfinder.intel.com/details.aspx?sSpec=SLB53. But I cannot find vmx flag in /proc/cpuinfo. Does P7350 support VT? How can I enable it?

Yours

[David_O_Intel1]

By default, systems are shipped with VT-x capabilities disabled.Look in your system BIOS for a way toenable. Details vary byvender.

You can look at MSR (0x3A) to verify. If it has 0x5 in the lower 3 bits, then VT-x is enabled.

-d

[darkbuck]

my issue is that I cannot see vmx flag in /proc/cpuinfo. after reading IA-32/32e manual, I am quite confused with the relation between IA32_FEATURE_CONTROL MSR and CPUID. Is it possible to control what value CPUID will return by controlling IA32_FEATURE_CONTROL?

The value read from IA32_FEATURE_CONTROL MSR is all 0s. I also tried to write 0x05 to it and it failed but it is ok to write value 0x01 to it.

BTW, is it possible to enable VMX in regular OS instead of BIOS?

Yours

[David_O_Intel1]

Is there a BIOS option to enable VT?

Also, what tool are you using to examine / change the MSR?

[darkbuck]

I cannot find any BIOS option to enable VT. I installed Linux on my laptop and examined MSR using the tool from http://www.etallen.com/msr.html.

The following is the output

root@laptop:~/msr-20060206# ./msr 0x3a
CPU 0:
0x0000003a = 0x0000000000000000
CPU 1:
0x0000003a = 0x0000000000000000

when I try to set 0x3a to 0x5, it always failed
root@laptop:~/msr-20060206# ./msr 0x3a=5
msr: ineffective write to MSR 0x3a
0x0000003a = 0x0000000000000000
msr: ineffective write to MSR 0x3a
0x0000003a = 0x0000000000000000

[David_O_Intel1]

MSR 0x3A should be accessible/modifiable by software if and only if the processor has a VT (VMX) fuse that is enabled.

Have you checked with yourOEM about whether they intended to offer the capability?

[darkbuck]

what you mean by "intended to offer the capability"? Do you mean that BIOS is able to disable this feature and hide this feature from CPUID? If so, does that mean I have to work with laptop vendor to solve this issue?

[David_O_Intel1]

A vender can choose to hide the feature by not offering a way to enable in the BIOS. It it also possible for a vender to use a version of an Intel product that has a feature physically disabled. They would do either of these thingsif they are not yetready to support the feature in their product line. Hence, my question -- did yourlaptop vendor intend to offer the capability?

Have you checked whether there exists a BIOS update from your vender? Perhaps one now exists that supports enabling this feature.

[darkbuck]

I don't know whether they intend or not and haven't heard any updates on BIOS yet. anyway, thanks for your information.

[jancici]

I did buy Asus laptop M51vr with P7350.

I have same problem here, when loading kvm-intel module I am geting a message "operation not supported"

I did check my BIOS and I did find there "VT-d" which was enable.

I did try to change to disable, boot and load module > same message so I did enable VT-d in BIOS boot and load module and same message.

this functionality of procesor was one of the main requiments for my new laptop.

hope that it is only software problem ...

[David_O_Intel1]

Note that many systems need to be cold booted after changing the VT-d BIOS setting for it to take effect. That is, change the setting in the BIOS, save, and then power the system down and unplug it for a minute or two. Then put theplug back in and bring it up.

[jancici]

well, I did try that, no help

looks that VT-d is something different then VT-x

I am very disapointed that this is not documented well on intel pages

[David_O_Intel1]

Please don't be discouraged yet.

Can you tell me more specifics on what OS/VMM you are working with here?

Yes, there certainly is a difference between VT-x and VT-d. Please use the Intel web site to read technical information about it. For example, VT-d is explained in some detail here:

http://software.intel.com/en-us/articles/best-practices-for-paravirtualization-enhancements-from-intel-virtualization-technology-ept-and-vt-d

Intel's virtualization technology site is here:

http://www.intel.com/technology/virtualization/index.htm

Note that not all VMMs support VT-d yet. Furthermore, you need to configure the direct assignment in VT-d before it can really be exploited.

[darkbuck]

I am really disappointed with Intel's document too. Please check the following page

http://processorfinder.intel.com/Details.aspx?sSpec=SLB53

, which state P7350 support Intel Virtualization Technology, and the following page gives an overview of this tech

http://download.intel.com/technology/virtualization/320426.pdf.

Apparently, at current stage, VT-x is appliciable to processor only and VT-d to chipset only. If Intel page stated P7350 supports VT, customer will interprete it as VT-x. But, why the processor we ordered cannot get VT-x support? It's really misleading.

Sign!

Quoting - David Ott (Intel)

Please don't be discouraged yet.

Can you tell me more specifics on what OS/VMM you are working with here?

Yes, there certainly is a difference between VT-x and VT-d. Please use the Intel web site to read technical information about it. For example, VT-d is explained in some detail here:

http://software.intel.com/en-us/articles/best-practices-for-paravirtualization-enhancements-from-intel-virtualization-technology-ept-and-vt-d

Intel's virtualization technology site is here:

http://www.intel.com/technology/virtualization/index.htm

Note that not all VMMs support VT-d yet. Furthermore, you need to configure the direct assignment in VT-d before it can really be exploited.

[David_O_Intel1]

I understand your point.

Guess the world is a little more complicated than it may first appear. Intel does not sell its products to consumers directly, it sells them to OEMs who offer products that include Intel processors and chipsets. To support some features, an OEM needs to create a BIOS that handles many technical details correctly before handing off to the OS. An OEM must decide whether or not it isready to support a particular feature from the larger set of features that come with the Intel processor they are offering. It is also possible that an OEM has ordered a feature to be physically disabled since it has no intention ofsupporting itin their offering. Thus, the list of capabilities you see on Intel's information pages may not match an OEM product offering exactly.

Can you tell me the OEM and model number of the system you are having issues with? Perhaps we can do some checking for you.

[terabytes]

Quoting - darkbuck

my issue is that I cannot see vmx flag in /proc/cpuinfo. after reading IA-32/32e manual, I am quite confused with the relation between IA32_FEATURE_CONTROL MSR and CPUID. Is it possible to control what value CPUID will return by controlling IA32_FEATURE_CONTROL?

The value read from IA32_FEATURE_CONTROL MSR is all 0s. I also tried to write 0x05 to it and it failed but it is ok to write value 0x01 to it.

BTW, is it possible to enable VMX in regular OS instead of BIOS?

Yours

darkbuck, if you cannot see the vmx flag in /proc/cpuinfo then it would indicate your CPU does not support VT even though this is contrary to intel specification for the P7350. The value in cpuid.eax=1 of ecx bit 5 (VMX feature) cannot be changed.

My question is are any of the P7350s fused for VMX or not?

[darkbuck]

my laptop is model HP660 from HASEE (http://www.hasee.com). The product detail is at http://www.hasee.com/cn/Product_Index.html?product_index=1&productid=1291&prodid=13&iszx=null (in chinese.) Their BIOS is probably from insyde (http://www.insydesw.com) and the version number is Q3B53.

BTW, if VT feature is phyiscally disabled, is there any way to enable it again? Is it possible to order a full featured P7350 somewhere?

Quoting - David Ott (Intel)

I understand your point.

Guess the world is a little more complicated than it may first appear. Intel does not sell its products to consumers directly, it sells them to OEMs who offer products that include Intel processors and chipsets. To support some features, an OEM needs to create a BIOS that handles many technical details correctly before handing off to the OS. An OEM must decide whether or not it isready to support a particular feature from the larger set of features that come with the Intel processor they are offering. It is also possible that an OEM has ordered a feature to be physically disabled since it has no intention ofsupporting itin their offering. Thus, the list of capabilities you see on Intel's information pages may not match an OEM product offering exactly.

Can you tell me the OEM and model number of the system you are having issues with? Perhaps we can do some checking for you.

[David_O_Intel1]

I am looking into your model number, thanks for your patience.

No, it is not possible to "re-enable" a feature that has been physically fused. (But remember, we are not certain this is the case yet.)

[David_O_Intel1]

An engineer sent me a nice synopsis of info yesterday. I've pasted it below.

1.1.1

Discovering Support for Intel

^{VT (VMX)}

The CPUID instruction can be used to determine whether a processor supports Intel VT. The CPUID instruction returns processor identification and feature information in the EAX, EBX, ECX, and EDX registers. If CPUID.1:ECX.VMX[bit 5] = 1, then VMX operation is supported.

Below are the assembly instructions to read check Intel VT-x capability of CPU:

MOV EAX, 01H

CPUID

Check ECX.[bit 5] -> A value of 1 indicates that the processor supports Intel VT-x

1.1.2

Checking Intel VT Enabled CPU

Bit 13 of CR4 register can be read to determine if CPU is enabled for Intel VT. A value of 1 for CR4.VMXE[bit13] means CPU is enabled for VMX operations.

Check CR4.VMXE[bit 13] = 1 -> Enables VMX operation when set.

MSR 3A can also be used to check if CPU is VT enabled.

For more information on CPUID, see Chapter 3, "Instruction Set Reference, A-M," in the Intel 64 and IA-32 Software Developer Manual, Volume 2A

Refer to Intel 64 and IA-32 Architectures Software Developers Manual, Volume 3B, section 19 and appendix G for more info on VMX capability reporting.

[terabytes]

David, your information is all good however I believe it has already been explained that the cpuid flag indicates that the P7350 of the OP does not support VT. I have come across several posts of users of the P7350 CPU who also do not have VMX indicated by the cpuid flag. IMHO I think it would be better if you would ask an Intel hardware engineer rather than a software engineer if the P7350 is supposed to support VMX or not.

[David_O_Intel1]

FYI - Still working with some staff members to look into your model number. Thanks for your patience.