Re: [Qemu-devel] [PATCH] introduce on_vcpu

[Anthony Liguori]

Glauber Costa wrote:
> on_vcpu is a qemu-kvm function that will make sure that a specific
> piece of code will run on a requested cpu. We don't need that because
> we're restricted to -smp 1 right now, but those days are likely to end soon.
>
> So for the benefit of having qemu-kvm share more code with us, I'm
> introducing our own version of on_vcpu(). Right now, we either run
> a function on the current cpu, or abort the execution, because it would
> mean something is seriously wrong.
>
> As an example code, I "ported" kvm_update_guest_debug to use it,
> with some slight differences from qemu-kvm.
>
> This is probably 0.12 material
>
> Signed-off-by: Glauber Costa <address@hidden>
> CC: Jan Kiszka <address@hidden>
> ---
>  kvm-all.c |   37 +++++++++++++++++++++++++++++++------
>  1 files changed, 31 insertions(+), 6 deletions(-)
>
> diff --git a/kvm-all.c b/kvm-all.c
> index 4e913e5..1d91f2e 100644
> --- a/kvm-all.c
> +++ b/kvm-all.c
> @@ -39,6 +39,8 @@
>      do { } while (0)
>  #endif
>  
> +CPUState *current_env;
> +
>  typedef struct KVMSlot
>  {
>      target_phys_addr_t start_addr;
> @@ -145,6 +147,14 @@ static int kvm_set_user_memory_region(KVMState *s, KVMSlot 
> *slot)
>      return kvm_vm_ioctl(s, KVM_SET_USER_MEMORY_REGION, &mem);
>  }
>  
> +static void on_vcpu(CPUState *env, void (*func)(void *data), void *data)
> +{
> +    if (env == current_env) {
>   

Can't you just use cpu_single_env?

> +        func(data);
> +        return;
> +    }
> +    assert(1);
>   

Wouldn't assert(env == current_env) or abort() make more sense?

Regards,

Anthony Liguori