Re: [PATCH] gdbstub: move update guest debug to accel ops

["Alex Bennée" <alex.bennee@linaro.org>]

Mads Ynddal <mads@ynddal.dk> writes:

>> Isn't this '0' flag here accelerator-specific? ...
>
>> ... if so the prototype should be:
>> 
>>       int (*update_guest_debug)(CPUState *cpu);
>> 
>> and the '0' value set within kvm-accel-ops.c handler implementation.
>> 
>
> You're right, we can avoid the additional variable. We'll then have to wrap
> `kvm_update_guest_debug`. Would the following be ok?
>
> diff --git a/accel/kvm/kvm-accel-ops.c b/accel/kvm/kvm-accel-ops.c
> index 6ebf9a644f..5e0fb42408 100644
> --- a/accel/kvm/kvm-accel-ops.c
> +++ b/accel/kvm/kvm-accel-ops.c
> @@ -86,6 +86,10 @@ static bool kvm_cpus_are_resettable(void)
>      return !kvm_enabled() || kvm_cpu_check_are_resettable();
>  }
>  
> +static int kvm_update_guest_debug_ops(CPUState *cpu) {
> +    return kvm_update_guest_debug(cpu, 0);
> +}
> +
>  static void kvm_accel_ops_class_init(ObjectClass *oc, void *data)
>  {
>      AccelOpsClass *ops = ACCEL_OPS_CLASS(oc);
> @@ -99,7 +103,7 @@ static void kvm_accel_ops_class_init(ObjectClass *oc, void *data)
>      ops->synchronize_pre_loadvm = kvm_cpu_synchronize_pre_loadvm;
>  
>  #ifdef KVM_CAP_SET_GUEST_DEBUG
> -    ops->update_guest_debug = kvm_update_guest_debug;
> +    ops->update_guest_debug = kvm_update_guest_debug_ops;
>      ops->supports_guest_debug = kvm_supports_guest_debug;
>      ops->insert_breakpoint = kvm_insert_breakpoint;
>      ops->remove_breakpoint = kvm_remove_breakpoint;
> diff --git a/cpu.c b/cpu.c
> index ef433a79e3..b2ade96caa 100644
> --- a/cpu.c
> +++ b/cpu.c
> @@ -383,7 +383,7 @@ void cpu_single_step(CPUState *cpu, int enabled)
>          cpu->singlestep_enabled = enabled;
>  
>          if (ops->update_guest_debug) {
> -            ops->update_guest_debug(cpu, 0);
> +            ops->update_guest_debug(cpu);
>          }
>  
>          trace_breakpoint_singlestep(cpu->cpu_index, enabled);
> diff --git a/include/sysemu/accel-ops.h b/include/sysemu/accel-ops.h
> index 0a47a2f00c..cd6a4ef7a5 100644
> --- a/include/sysemu/accel-ops.h
> +++ b/include/sysemu/accel-ops.h
> @@ -48,7 +48,7 @@ struct AccelOpsClass {
>  
>      /* gdbstub hooks */
>      bool (*supports_guest_debug)(void);
> -    int (*update_guest_debug)(CPUState *cpu, unsigned long flags);
> +    int (*update_guest_debug)(CPUState *cpu);
>      int (*insert_breakpoint)(CPUState *cpu, int type, hwaddr addr, hwaddr len);
>      int (*remove_breakpoint)(CPUState *cpu, int type, hwaddr addr, hwaddr len);
>      void (*remove_all_breakpoints)(CPUState *cpu);
>
>
> If you have a better name for `kvm_update_guest_debug_ops`, I'm open for
> suggestions.

It will do. You could just call it update_guest_debug as it is an
internal static function although I guess that makes grepping a bit of a
pain.

> On a side note. When compiling for an arch that isn't the same as the system
> (i.e. aarch64 on x86_64), I'm getting a linker-error for cpu.c that
> `cpus_get_accel` isn't defined. Do I need to move `cpus_get_accel` or somehow
> #ifdef its use?

Is something being accidentally linked with linux-user and softmmu?

-- 
Alex Bennée
Virtualisation Tech Lead @ Linaro