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RE: [Xen-devel] [PATCH][SVM] fix pae for guests on 32bit HV

To: "Nakajima, Jun" <jun.nakajima@xxxxxxxxx>, xen-devel@xxxxxxxxxxxxxxxxxxx
Subject: RE: [Xen-devel] [PATCH][SVM] fix pae for guests on 32bit HV
From: "Woller, Thomas" <thomas.woller@xxxxxxx>
Date: Thu, 20 Apr 2006 17:22:58 -0500
Delivery-date: Thu, 20 Apr 2006 15:23:32 -0700
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Thread-index: AcZkkzsYgEcC4MlST6+Afk5oQfG/3AAKiugwAAI48xA=
Thread-topic: [Xen-devel] [PATCH][SVM] fix pae for guests on 32bit HV
> The current shadow code does not support PAE guests on the 
> PAE Xen. It's much harder given (compared with x64-64) the 
> limited bits in page_info.
> Should work on the 64-bit Xen. Anyway, we need to cleanly 
> kill such guests on the PAE Xen.
Now this does mean no NX support on PAE xen.

Attached patch simply turns off PAE if paging level < 4 in vt and svm. 

Tested win2003 EE on svm and vt, allows 32bit windows guests to boot
without shadow.c bug() crash.  

Only issue seen is if setting guest config memory >~4096 then the guest
does not boot, but does not crash the hv - stays in blocked state.  So,
I think that this solution is fine for now.  Svm shadows PAE and NX so
the code is slightly different.  
I'll post with signed-off if ok for vmx also.

Attachment: svm_vmx_pae32_off.patch
Description: svm_vmx_pae32_off.patch

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