Re: [PATCH V1 03/16] xen/ioreq: Make x86's hvm_ioreq_needs_completion() common

[Jan Beulich <jbeulich@xxxxxxxx>]

On 10.09.2020 22:21, Oleksandr Tyshchenko wrote:
> --- a/xen/include/xen/ioreq.h
> +++ b/xen/include/xen/ioreq.h
> @@ -35,6 +35,13 @@ static inline struct hvm_ioreq_server 
> *get_ioreq_server(const struct domain *d,
>      return GET_IOREQ_SERVER(d, id);
>  }
>  
> +static inline bool hvm_ioreq_needs_completion(const ioreq_t *ioreq)
> +{
> +    return ioreq->state == STATE_IOREQ_READY &&
> +           !ioreq->data_is_ptr &&
> +           (ioreq->type != IOREQ_TYPE_PIO || ioreq->dir != IOREQ_WRITE);
> +}

While the PIO aspect has been discussed to some length, what about
the data_is_ptr concept? I didn't think there were Arm insns fitting
this? Instead I thought some other Arm-specific adjustments to the
protocol might be needed. At which point the question of course would
be in how far ioreq_t as a whole really fits Arm in its current shape.

Jan