[Qemu-devel] Re: [PATCH] temporary fix for on_vcpu

[Jan Kiszka <jan.kiszka@siemens.com>]

Glauber Costa wrote:
> Recent changes made on_vcpu hit the abort() path, even with the IO thread
> disabled. This is because cpu_single_env is no longer set when we call this
> function. Although the correct fix is a little bit more complicated that that,
> the recent thread in which I proposed qemu_queue_work (which fixes that, btw),
> is likely to go on a quite different direction.
> 
> So for the benefit of those using guest debugging, I'm proposing this simple
> fix in the interim.
> 
> Signed-off-by: Glauber Costa <glommer@redhat.com>
> ---
>  kvm-all.c |    4 ++++
>  1 files changed, 4 insertions(+), 0 deletions(-)
> 
> diff --git a/kvm-all.c b/kvm-all.c
> index df4e849..2c24440 100644
> --- a/kvm-all.c
> +++ b/kvm-all.c
> @@ -902,11 +902,15 @@ void kvm_setup_guest_memory(void *start, size_t size)
>  #ifdef KVM_CAP_SET_GUEST_DEBUG
>  static void on_vcpu(CPUState *env, void (*func)(void *data), void *data)
>  {
> +#ifdef CONFIG_IOTHREAD
>      if (env == cpu_single_env) {
>          func(data);
>          return;
>      }
>      abort();
> +#else
> +   func(data);

spaces++ :) But the workaround works.

> +#endif
>  }
>  
>  struct kvm_sw_breakpoint *kvm_find_sw_breakpoint(CPUState *env,

Unless there is hope to fix kvm in iothread mode soon, we should issue a
warning or even disable kvm support in that setup. That is particularly
important for 0.11-stable.

Jan

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