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

[Bandan Das <bsd@redhat.com>]

Paolo Bonzini <pbonzini@redhat.com> writes:

> Il 20/03/2014 04:28, Bandan Das ha scritto:
>> 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
>>
>> 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);
>>
>
> Please add a /* fall through */ comment as well.

Thanks for reviewing Paolo, will fix in v2.

> Paolo