Re: [PATCH v2 2/6] accel: accel_available() function

[Claudio Fontana]

Hi Eduardo,

On 11/25/20 9:56 PM, Eduardo Habkost wrote:
> This function will be used to replace the xen_available() and
> kvm_available() functions from arch_init.c.
> 
> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
> ---
> Cc: Richard Henderson <richard.henderson@linaro.org>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: Claudio Fontana <cfontana@suse.de>
> Cc: Roman Bolshakov <r.bolshakov@yadro.com>
> ---
>  include/sysemu/accel.h | 1 +
>  accel/accel.c          | 5 +++++
>  2 files changed, 6 insertions(+)
> 
> diff --git a/include/sysemu/accel.h b/include/sysemu/accel.h
> index e08b8ab8fa..a4a00c75c8 100644
> --- a/include/sysemu/accel.h
> +++ b/include/sysemu/accel.h
> @@ -67,6 +67,7 @@ typedef struct AccelClass {
>      OBJECT_GET_CLASS(AccelClass, (obj), TYPE_ACCEL)
>  
>  AccelClass *accel_find(const char *opt_name);
> +bool accel_available(const char *name);
>  int accel_init_machine(AccelState *accel, MachineState *ms);
>  
>  /* Called just before os_setup_post (ie just before drop OS privs) */
> diff --git a/accel/accel.c b/accel/accel.c
> index cb555e3b06..4a64a2b38a 100644
> --- a/accel/accel.c
> +++ b/accel/accel.c
> @@ -46,6 +46,11 @@ AccelClass *accel_find(const char *opt_name)
>      return ac;
>  }
>  
> +bool accel_available(const char *name)
> +{
> +    return accel_find(name) != NULL;


accel_find() in its implementation allocates and then frees memory to generate 
the string,
the user of accel_available() might be unaware and overuse leading to 
fragmentation/performance issues?


> +}
> +
>  int accel_init_machine(AccelState *accel, MachineState *ms)
>  {
>      AccelClass *acc = ACCEL_GET_CLASS(accel);
>