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How to set EPT's memory type

wmirr
Novice
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Hi, my guest is Ubuntu 14.04, and I test my code in VMware 10.

When I launch vmx, the Ubuntu can run as VM correctly. But if  I enabled the EPT, the Ubuntu hangs. I have tried to set the memory type through mtrr, failed too.

Is there any more detail information? Except the Xen link?

May I make a suggestion? There are many questions in this forumn, and a lot of answer is reference the Xen or Manaual. I know these material is good, but could some one give a more detailed answer? I have read the Manaual serval times, and the Xen is complicate, it can not help sometime.

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Quoc-Thai_L_Intel
511 Views

I found some existing posts related to your topics and may have some glues for you:

EPT write back memory type and Machine Check exception

 

KVM: Enable MTRR for EPT

-Thai

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wmirr
Novice
511 Views

hi, i have tried so many times.still not work.

the strange thing is , i can see a lot of vm exit:cpuid, control register access, external interrupt. but no any response on the screen.

 

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wmirr
Novice
511 Views

hi, i solved my problem.

i did not know that, my ubuntu make PAE enabled. if the PAE is enabled, PDPTE in guest not-register state must be set, and if a write to cr3 VM-exit happend, the PDPTE must be updated.
 

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Quoc-Thai_L_Intel
511 Views

Congratulation Water!

If you could share a sample code of how you solve this issue for others to learn from, it would be very helpful.

Thanks,

-Thai

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wmirr
Novice
511 Views

i am sorry i could not share the code.it's commerical.

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Quoc-Thai_L_Intel
511 Views

No problem...I understand.

Thanks,

-Thai

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wmirr
Novice
511 Views

by the way, the operation is very simple.

1) get value of cr3, we get the base address of the pdpte.

2) then write the pdpte to guest not-register state.

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