On 10.07.2017 11:17, Paolo Bonzini wrote:
>
>
> On 10/07/2017 10:54, David Hildenbrand wrote:
>>
>>> /*
>>> * The exit handlers return 1 if the exit was handled fully and guest execution
>>> * may resume. Otherwise they set the kvm_run parameter to indicate what needs
>>> @@ -7790,6 +7806,7 @@ static int (*const kvm_vmx_exit_handlers[])(struct kvm_vcpu *vcpu) = {
>>> [EXIT_REASON_XSAVES] = handle_xsaves,
>>> [EXIT_REASON_XRSTORS] = handle_xrstors,
>>> [EXIT_REASON_PML_FULL] = handle_pml_full,
>>> + [EXIT_REASON_VMFUNC] = handle_vmfunc,
>>> [EXIT_REASON_PREEMPTION_TIMER] = handle_preemption_timer,
>>> };
>>>
>>> @@ -8111,6 +8128,9 @@ static bool nested_vmx_exit_handled(struct kvm_vcpu *vcpu)
>>> case EXIT_REASON_PML_FULL:
>>> /* We emulate PML support to L1. */
>>> return false;
>>> + case EXIT_REASON_VMFUNC:
>>> + /* VM functions are emulated through L2->L0 vmexits. */
>>> + return false;
>>
>> This would fit better into the second patch.
>
> It depends on how you reason about it. I put it here because:
>
> - until this patch, EXIT_REASON_VMFUNC should never be generated. We
> don't even know that it exists.
>
> - after this patch, it should still never be generated in nested
> scenarios. However, if it did because of a bug, we're in a better place
> to handle it than L1 (because as far as L1 knows, it should never be
> generated).
>
> Perhaps this is an argument in favor of changing the default case of
> nested_vmx_exit_handled from true to false.
I remember having the same discussion before :) I still think the
default should be changed (then we don't need nVMX hunks in VMX patches
;) ).
Anyhow
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
>
> Paolo
--
Thanks,
David
