Re: [PATCH v2 02/18] KVM: nVMX: move vmcs12 EPTP consistency check to check_vmentry_prereqs()

[Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>]

On 08/28/2018 09:04 AM, Sean Christopherson wrote:
> An invalid EPTP causes a VMFail(VMXERR_ENTRY_INVALID_CONTROL_FIELD),
> not a VMExit.
>
> Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
> ---
>   arch/x86/kvm/vmx.c | 21 +++++++++------------
>   1 file changed, 9 insertions(+), 12 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index b217614de7ac..6451e63847d9 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -11277,11 +11277,9 @@ static unsigned long nested_ept_get_cr3(struct kvm_vcpu *vcpu)
>   	return get_vmcs12(vcpu)->ept_pointer;
>   }
>   
> -static int nested_ept_init_mmu_context(struct kvm_vcpu *vcpu)
> +static void nested_ept_init_mmu_context(struct kvm_vcpu *vcpu)
>   {
>   	WARN_ON(mmu_is_nested(vcpu));
> -	if (!valid_ept_address(vcpu, nested_ept_get_cr3(vcpu)))
> -		return 1;
>   
>   	kvm_init_shadow_ept_mmu(vcpu,
>   			to_vmx(vcpu)->nested.msrs.ept_caps &
> @@ -11293,7 +11291,6 @@ static int nested_ept_init_mmu_context(struct kvm_vcpu *vcpu)
>   	vcpu->arch.mmu.inject_page_fault = nested_ept_inject_page_fault;
>   
>   	vcpu->arch.walk_mmu              = &vcpu->arch.nested_mmu;
> -	return 0;
>   }
>   
>   static void nested_ept_uninit_mmu_context(struct kvm_vcpu *vcpu)
> @@ -12243,15 +12240,11 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
>   		vmcs_write16(GUEST_PML_INDEX, PML_ENTITY_NUM - 1);
>   	}
>   
> -	if (nested_cpu_has_ept(vmcs12)) {
> -		if (nested_ept_init_mmu_context(vcpu)) {
> -			*entry_failure_code = ENTRY_FAIL_DEFAULT;
> -			return 1;
> -		}
> -	} else if (nested_cpu_has2(vmcs12,
> -				   SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES)) {
> +	if (nested_cpu_has_ept(vmcs12))
> +		nested_ept_init_mmu_context(vcpu);
> +	else if (nested_cpu_has2(vmcs12,
> +				 SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES))
>   		vmx_flush_tlb(vcpu, true);
> -	}
>   
>   	/*
>   	 * This sets GUEST_CR0 to vmcs12->guest_cr0, possibly modifying those
> @@ -12458,6 +12451,10 @@ static int check_vmentry_prereqs(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
>   		}
>   	}
>   
> +	if (nested_cpu_has_ept(vmcs12) &&
> +	    !valid_ept_address(vcpu, vmcs12->ept_pointer))
> +		return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
> +
>   	return 0;
>   }
>   

Reviewed-by: Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>