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[thekostya]

I am trying to create a basic VM using AMD-V. From looking at AMD64 Architecture Programmer’s Manual Volume 2, I can set up EFER.SVME but I am not sure how much of my address space I should reserve for the host state-save area (memory pointed to by VM_HSAVE_PA MSR) or what a valid initial set of values for the VMCB are. I imagine that these are very basic questions, but from looking at the Architecture Programmer’s Manual Volume 2 and Architecture Programmer’s Manual Volume 3 the answers do not seem to be anywhere to be found and there is no other material (that I can find by Googling) about it.

[avk]

I hope that you already have a look at this AMD document #34434. The other way to learn AMD-v is to look how it does work in some open source projects. Here is a quote from Neil Kelly at AMD:

"Two open source virtualization projects are using AMD-V: Xen and KVM. Consider looking at source at http://www.xen.org and http://kvm.qumranet.com/kvmwiki.


Regards, Neil Kelly"

[thekostya]

Does anyone have a source that can tell me the layout of the VMCB that does not require me to look through many thousands of lines of code?

[anton_chernoff]

The layout of the VMCB is in Appendix B of the APM Volume 2 that you already have.  It's pretty easy to read.

The host save area is a 4Kb page in memory.  Surprisingly, we don't mention that in the documentation.  We've let the documentation folks know about the problem, and we'll get it into the APM in a future revision.

Thank you, thekostya - good catch.

[thekostya]

Ok, thank you