Re: [PATCH] KVM: nVMX: Fix nested bus lock VM exit

[Xiaoyao Li]

On 8/27/2021 4:51 PM, Chenyi Qiang wrote:
> Nested bus lock VM exits are not supported yet. If L2 triggers bus lock
> VM exit, it will be directed to L1 VMM, which would cause unexpected
> behavior. Therefore, handle L2's bus lock VM exits in L0 directly.
>
> Fixes: fe6b6bc802b4 ("KVM: VMX: Enable bus lock VM exit")
> Signed-off-by: Chenyi Qiang <chenyi.qiang@xxxxxxxxx>
> ---
>   arch/x86/kvm/vmx/nested.c | 2 ++
>   1 file changed, 2 insertions(+)
>
> diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
> index bc6327950657..754f53cf0f7a 100644
> --- a/arch/x86/kvm/vmx/nested.c
> +++ b/arch/x86/kvm/vmx/nested.c
> @@ -5873,6 +5873,8 @@ static bool nested_vmx_l0_wants_exit(struct kvm_vcpu *vcpu,
>   	case EXIT_REASON_VMFUNC:
>   		/* VM functions are emulated through L2->L0 vmexits. */
>   		return true;
> +	case EXIT_REASON_BUS_LOCK:
> +		return true;
>   	default:
>   		break;
>   	}
Reviewed-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>