Re: [Qemu-devel] BUG: commit 50a2c6e breaks KVM/ARM (reset/init vcpu order)

[Paolo Bonzini <pbonzini@redhat.com>]

Il 26/05/2014 11:18, Christoffer Dall ha scritto:
> Hi,
>
> I noticed that commit 50a2c6e55fa2ce5a2916a2c206bad2c6b0e06df1 broke
> KVM/ARM, because the realize function (arm_cpu_realizefn()) now calls
> cpu_reset() before qemu_init_vcpu(), which causes kvm_arm_reset_cpu() to
> segfault because it dereferences cpu->cpreg_reset_values, which is not
> allocated before kvm_arch_init_vcpu().
>
> Simply changing the order of the reset/init calls (see the tiny patch
> below) seems to fix it, but I'm not completely sure this is a clean and
> correct fix:
>
>
> diff --git a/target-arm/cpu.c b/target-arm/cpu.c
> index 6c6f2b3..794dcb9 100644
> --- a/target-arm/cpu.c
> +++ b/target-arm/cpu.c
> @@ -370,8 +370,8 @@ static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
>
>      init_cpreg_list(cpu);
>
> -    cpu_reset(cs);
>      qemu_init_vcpu(cs);
> +    cpu_reset(cs);
>
>      acc->parent_realize(dev, errp);
>  }
>
>
>
> Please adivce :)

I looked at the kvm_arch_init_vcpu implementation and it looks good to me.

Acked-by: Paolo Bonzini <pbonzini@redhat.com>

Paolo