Re: [PATCH 3/3] KVM: nVMX: check for null vmcs12 when L1 does invept

[Jan Kiszka <jan.kiszka@siemens.com>]

On 2014-03-20 04:28, Bandan Das wrote:
> Some L1 hypervisors such as Xen seem to be calling invept after
> vmclear or before vmptrld on L2. In this case, proceed with
> falling through and syncing roots as a case where
> context wide invalidation can't be supported

Can we also base this behaviour on a statement in the SDM? But on first
glance, I do not find anything like this over there.

Jan

> 
> Signed-off-by: Bandan Das <bsd@redhat.com>
> ---
>  arch/x86/kvm/vmx.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index c707389..b407b3a 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -6435,8 +6435,9 @@ static int handle_invept(struct kvm_vcpu *vcpu)
>  
>  	switch (type) {
>  	case VMX_EPT_EXTENT_CONTEXT:
> -		if ((operand.eptp & eptp_mask) !=
> -				(nested_ept_get_cr3(vcpu) & eptp_mask))
> +		if (get_vmcs12(vcpu) &&
> +		    ((operand.eptp & eptp_mask) != (nested_ept_get_cr3(vcpu) &
> +						    eptp_mask)))
>  			break;
>  	case VMX_EPT_EXTENT_GLOBAL:
>  		kvm_mmu_sync_roots(vcpu);
> 

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