Re: [PATCH] Nested VMX: CR emulation fix up

[Boris Ostrovsky <boris.ostrovsky@oracle.com>]

On 10/09/2013 03:28 AM, Zhang, Yang Z wrote:
> Boris Ostrovsky wrote on 2013-10-08:
>> On 10/08/2013 04:31 AM, Jan Beulich wrote:
>>
>>> Considering that this touches code common with nested SVM, I'd
>>> expect the SVM maintainers to have to approve of the change in any case.
>>>
>>> In particular I wonder whether this addition isn't obsoleting SVM's
>>> ns_cr0.
>>>
>> I am not sure whether ns_cr0 (replaced with nv_guest_cr[0]) would then
>> be updated in paths where it currently is not.
>>
>> For example in nsvm_vmcb_prepare4vmrun():
>>
>>       /* CR0 */ svm->ns_cr0 = v->arch.hvm_vcpu.guest_cr[0]; cr0 =
>>       nestedsvm_fpu_vmentry(svm->ns_cr0, ns_vmcb, n1vmcb, n2vmcb);
>>       v->arch.hvm_vcpu.guest_cr[0] = ns_vmcb->_cr0; rc =
>>       hvm_set_cr0(cr0);  <------ nv_guest_cr[0] will get set here.
> I am not familiar with SVM code. If you think this change may impact the nested SVM. Then I will move the change to VMX specific code.

No, it doesn't affect SVM code. I was responding to Jan's suggestion to 
replace
SVM's ns_cr0 with the new guest_cr[0].

-boris