Re: [Qemu-devel] [PATCH] ipmi: do not take/drop iothread lock

[Michael S. Tsirkin]

On Tue, Jan 26, 2016 at 05:15:53PM +0100, Paolo Bonzini wrote:
> This is not necessary and actually causes a hang; it was probably copied
> and pasted from KVM code, that is one of the very few places that run
> outside iothread lock.
> 
> Signed-off-by: Paolo Bonzini <address@hidden>

Makes sense. I wonder how hard would it be to have a test to catch this.

> ---
>  hw/ipmi/ipmi.c | 2 --
>  1 file changed, 2 deletions(-)
> 
> diff --git a/hw/ipmi/ipmi.c b/hw/ipmi/ipmi.c
> index 52aba1e..fcba0ca 100644
> --- a/hw/ipmi/ipmi.c
> +++ b/hw/ipmi/ipmi.c
> @@ -50,9 +50,7 @@ static int ipmi_do_hw_op(IPMIInterface *s, enum ipmi_op op, 
> int checkonly)
>          if (checkonly) {
>              return 0;
>          }
> -        qemu_mutex_lock_iothread();
>          qmp_inject_nmi(NULL);
> -        qemu_mutex_unlock_iothread();
>          return 0;
>  
>      case IPMI_POWERCYCLE_CHASSIS:
> -- 
> 2.5.0