about vt-d

[wmirr]

hi, the vt-d is very complicate.

is there any sample code could help me to implment the dma-remapping in my system?

my processor is i7 2600.

thanks.

[Kevin_M_Intel]

Hi watermirror,

Can you confirm if you are referring to a code to modify the DMA on the processor? I mean changing the configuration on it?

Here is some information you can find very helpful:

https://www-ssl.intel.com/content/www/us/en/intelligent-systems/intel-technology/vt-directed-io-spec.html https://www-ssl.intel.com/content/www/us/en/intelligent-systems/intel-technology/vt-directed-io-spec.html

[wmirr]

Hi kevin,

My goal is to prevent some part of memory from being destroied by DMA access.

I have already read the

https://www-ssl.intel.com/content/www/us/en/intelligent-systems/intel-technology/vt-directed-io-spec.html Intel® Virtualization Technology for Directed I/O: Spec

But I still do not know how to start code.I can understand the table which remaped dma.

But how could I assign device to certain guest(or VM), how could I know if there any access volating the dma remaping table?

Is there any more document I should read?

[Kevin_M_Intel]

I will verify this with the development team. Let me check and I will be back with more information.

[Kevin_M_Intel]

Hello watermirror,

I am sorry for the delay and I appreciate your patience.

Based on the research, there is a link that contains very detail information that can help you with your task. Here is it:

https://software.intel.com/en-us/blogs/2009/02/24/step-by-step-guide-on-how-to-enable-vt-d-and-perform-direct-device-assignment/ https://software.intel.com/en-us/blogs/2009/02/24/step-by-step-guide-on-how-to-enable-vt-d-and-perform-direct-device-assignment/

With this, you should not need to do any programming. Let me know if it works.