Re: [Qemu-devel] [PATCH v3 6/6] vfio-ccw: add handling for async channel instructions

[Halil Pasic <pasic@linux.ibm.com>]

On Wed, 30 Jan 2019 14:22:12 +0100
Cornelia Huck <cohuck@redhat.com> wrote:

> +static void fsm_async_retry(struct vfio_ccw_private *private,
> +			    enum vfio_ccw_event event)
> +{
> +	private->cmd_region->ret_code = -EAGAIN;
> +}
> +

This is essentially dead code at the moment, isn't it? I mean we hold the
io_mutex whenever we are in state VFIO_CCW_STATE_CP_PROCESSING, and we
call vfio_ccw_fsm_event() with the very same mutex held.

> @@ -213,26 +323,31 @@ fsm_func_t *vfio_ccw_jumptable[NR_VFIO_CCW_STATES][NR_VFIO_CCW_EVENTS] = {
>  	[VFIO_CCW_STATE_NOT_OPER] = {
>  		[VFIO_CCW_EVENT_NOT_OPER]	= fsm_nop,
>  		[VFIO_CCW_EVENT_IO_REQ]		= fsm_io_error,
> +		[VFIO_CCW_EVENT_ASYNC_REQ]	= fsm_async_error,
>  		[VFIO_CCW_EVENT_INTERRUPT]	= fsm_disabled_irq,
>  	},
>  	[VFIO_CCW_STATE_STANDBY] = {
>  		[VFIO_CCW_EVENT_NOT_OPER]	= fsm_notoper,
>  		[VFIO_CCW_EVENT_IO_REQ]		= fsm_io_error,
> +		[VFIO_CCW_EVENT_ASYNC_REQ]	= fsm_async_error,
>  		[VFIO_CCW_EVENT_INTERRUPT]	= fsm_irq,
>  	},
>  	[VFIO_CCW_STATE_IDLE] = {
>  		[VFIO_CCW_EVENT_NOT_OPER]	= fsm_notoper,
>  		[VFIO_CCW_EVENT_IO_REQ]		= fsm_io_request,
> +		[VFIO_CCW_EVENT_ASYNC_REQ]	= fsm_async_request,
>  		[VFIO_CCW_EVENT_INTERRUPT]	= fsm_irq,
>  	},
>  	[VFIO_CCW_STATE_CP_PROCESSING] = {
>  		[VFIO_CCW_EVENT_NOT_OPER]	= fsm_notoper,
>  		[VFIO_CCW_EVENT_IO_REQ]		= fsm_io_retry,
> +		[VFIO_CCW_EVENT_ASYNC_REQ]	= fsm_async_retry,

Used here.

Regards,
Halil

>  		[VFIO_CCW_EVENT_INTERRUPT]	= fsm_irq,
>  	},