Re: [PATCH v2 1/3] KVM: arm: Fix NULL pointer dereference if KVM is used without in-kernel irqchip

[Marc Zyngier <marc.zyngier@arm.com>]

On 14/07/15 13:06, Pavel Fedin wrote:
> Makes qemu working again with kernel-irqchip=off option

I'd appreciate a better commit log. Which patch broke it, why is that
necessary.

> 
> Signed-off-by: Pavel Fedin <p.fedin@samsung.com>
> ---
>  arch/arm/kvm/arm.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
> index d9631ec..5668c4e 100644
> --- a/arch/arm/kvm/arm.c
> +++ b/arch/arm/kvm/arm.c
> @@ -450,7 +450,7 @@ static int kvm_vcpu_first_run_init(struct kvm_vcpu *vcpu)
>  	 * Map the VGIC hardware resources before running a vcpu the first
>  	 * time on this VM.
>  	 */
> -	if (unlikely(!vgic_ready(kvm))) {
> +	if (irqchip_in_kernel(kvm) && unlikely(!vgic_ready(kvm))) {

I think you should factor the irqchip_in_kernel() inside the unlikely
clause. Something like

bool vgic_needs_init = irqchip_in_kernel(kvm) && !vgic_ready(kvm);

if (unlikely(vfic_needs_init)) {
...
}

>  		ret = kvm_vgic_map_resources(kvm);
>  		if (ret)
>  			return ret;
> 

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...