Re: [PATCH] KVM: VMX: Fix locking order in handle_invalid_guest_state

[Marcelo Tosatti <mtosatti@redhat.com>]

On Wed, Jul 22, 2009 at 11:53:26PM +0200, Jan Kiszka wrote:
> Release and re-acquire preemption and IRQ lock in the same order as
> vcpu_enter_guest does.

This should happen in vcpu_enter_guest, before it decides to disable
preemption/irqs (so you consolidate the control there).

Maybe add a new member to x86_ops?

> 
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> ---
> 
>  arch/x86/kvm/vmx.c |    4 ++--
>  1 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index d75c271..4f914c3 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -3324,8 +3324,8 @@ static void handle_invalid_guest_state(struct kvm_vcpu *vcpu,
>  	struct vcpu_vmx *vmx = to_vmx(vcpu);
>  	enum emulation_result err = EMULATE_DONE;
>  
> -	preempt_enable();
>  	local_irq_enable();
> +	preempt_enable();
>  
>  	while (!guest_state_valid(vcpu)) {
>  		err = emulate_instruction(vcpu, kvm_run, 0, 0, 0);
> @@ -3344,8 +3344,8 @@ static void handle_invalid_guest_state(struct kvm_vcpu *vcpu,
>  			schedule();
>  	}
>  
> -	local_irq_disable();
>  	preempt_disable();
> +	local_irq_disable();
>  
>  	vmx->invalid_state_emulation_result = err;
>  }
>