Is there any processor that supports EPT-based Sub-page Write Protection

[IceCY]

Hello Community,

Is there any processor that supports EPT-based Sub-page Write Protection?

I am interested in the EPT-based Sub-page Write Protection capability in Intel processors. According to the patch (https://lwn.net/Articles/8100) in Linux Kernel Mail List, it says

This patch serial passed SPP function test and selftest on Ice-Lake platform.

It seems like the Ice-Lake platform supports EPT-based Sub-page Write Protection. But after testing, I found that my laptop (i7-1065G7, Ice-Lake) does not support it. So I wonder whether there is any processor that supports this capability. 

Any information would be highly appreciated.

Thanks again

Yuan

[Alberto_Sykes]

IceCY, Thank you for posting in the Intel® Communities Support.

In order for us to provide the most accurate information in reference to your inquiry, we will do further research on this matter, as soon as I get any updates I will post all the details on this thread.

Regards,

Albert R.

Intel Customer Support Technician

A Contingent Worker at Intel

[Alberto_Sykes]

IceCY, I just received an update on this matter.

Just to confirm:

Is there any reason why you are requesting access to the SPP?

Are you running any virtualization Software that it's demanding access to the SSP?

Can you give us more details about why you need a list of processors supporting SPP?

Can you share a picture of the issue or error that you are having?

Regards,

Albert R.

Intel Customer Support Technician

A Contingent Worker at Intel

[IceCY]

Hello Albert R. Thanks again for your response.

> Is there any reason why you are requesting access to the SPP?

I found the SPP in the Intel SDM. It is an interesting feature and I want to play around with it.

> Are you running any virtualization Software that it's demanding access to the SSP?

No. Currently, I just wrote a simple program to test whether my laptop supports the SPP.

> Can you give us more details about why you need a list of processors supporting SPP?

If there is any processor that supports SPP, maybe I could try to find a platform equipped with the processor and buy one (if it is affordable for me).

> Can you share a picture of the issue or error that you are having?

I wrote a simple Linux Module to get the value of IA32_VMX_PROCBASED_CTLS2 MSR (index 48BH) with `rdmsr` instruction and tested whether bit (32 + 23) (start from 0) was 1.
the output is 0x335fbfff00000000. We can see the bit 55 is 0. According to the Intel SDM, the processor does not support "Sub-page write permissions for EPT".
I'm not sure if there is any mistake or this Ice-Lake CPU does not support SPP.

Regards

Yuan

[IceCY]

Hello Albert R. Thanks again for your response.

> Is there any reason why you are requesting access to the SPP?

I found the SPP in Intel SDM. It is an interesting feature and I want to play around with it.

> Are you running any virtualization Software that it's demanding access to the SSP?

No. Currently, I wrote a simple program to test whether my laptop supports the SPP.

> Can you give us more details about why you need a list of processors supporting SPP?

If there is any processor that supports SPP, maybe I could try to find a platform equipped with the processor and buy it (if it is affordable for me).

> Can you share a picture of the issue or error that you are having?

I wrote a simple Linux Module to get the value of IA32_VMX_PROCBASED_CTLS2 MSR (index 48BH) with `rdmsr` instruction and tested whether bit (32 + 23) (start from 0) was 1.
the output is 0x335fbfff00000000. We can see the bit 55 is 0. According to Intel SDM, the processor does not support "Sub-page write permission for EPT".
I'm not sure if there is any mistake or this Ice-Lake CPU does not support SPP.

Regards

Yuan

[Alberto_Sykes]

IceCY, Thak you very much for providing that information.

We will continue with our research on this matter, as soon as I get any more details I will post all the information on this thread.

Regards,

Albert R.

Intel Customer Support Technician

A Contingent Worker at Intel

[Alberto_Sykes]

Hello IceCY, I just received an update on this matter.

Based on Intel® Ark web site, the Intel® Core™ i7-1065G7 Processor supports the latest Intel® VT-x with Extended Page Tables (EPT), but all virtualization capabilities require the system BIOS to enable them. So, the next thing to do will be to get in contact directly with the manufacturer of the board or system to confirm on what is supported.

In reference to your code to test the EPT-based Sub-page Write Protection, please post your inquiry about that matter in the Intel® Software site for further assistance on this topic:

https://community.intel.com/t5/Software-Development-Topics/ct-p/software-dev-topics

Regards,

Albert R.

Intel Customer Support Technician

A Contingent Worker at Intel

[Zhuzhuzaizai]

Hi,

I also want to know what processor supports the SPP, and I also want to buy one. do you get this answer now? Can you tell me something about it?

Thanks a lot.

[vickieGPT]

I found that my 9750H does not support SPP but my 6700 and 12900k both support, so I guess all the desktop end CPU and above will support this feature.