Re: [PATCH 0/30] nVMX: Nested VMX, v9

[Avi Kivity <avi@redhat.com>]

On 05/12/2011 07:51 PM, Gleb Natapov wrote:
> >
> >  But if my interpretation of the code is correct, SVM isn't much closer
> >  than VMX to the goal of moving this logic to x86.c. When some logic is
> >  moved there, both SVM and VMX code will need to change - perhaps even
> >  considerably. So how will it be helpful to make VMX behave exactly like
> >  SVM does now, when the latter will also need to change considerably?
> >
> SVM design is much close to the goal of moving the logic into x86.c
> because IIRC it does not bypass parsing of IDT vectoring info into arch
> independent structure. VMX code uses vmx->idt_vectoring_info directly.
> SVM is much close to working migration with nested guests for the same
> reason.

Ah, yes.  For live migration to work, all vmcb state must be accessible 
via vendor-independent accessors once an exit is completely handled.  
For example, GPRs are accessible via kvm_register_read(), and without 
nesting, interrupt state is stowed in the interrupt queue, but if you 
keep IDT_VECTORING_INFO live between exit and entry, you can lose it if 
you migrate at this point.

-- 
error compiling committee.c: too many arguments to function