Re: [PATCH v2] public: add RING_NR_UNCONSUMED_*() macros to ring.h

["Durrant, Paul" <xadimgnik@xxxxxxxxx>]

On 08/12/2021 23:09, Juergen Gross wrote:
> Today RING_HAS_UNCONSUMED_*() macros are returning the number of
> unconsumed requests or responses instead of a boolean as the name of
> the macros would imply.
>
> As this "feature" is already being used, rename the macros to
> RING_NR_UNCONSUMED_*() and define the RING_HAS_UNCONSUMED_*() macros
> by using the new RING_NR_UNCONSUMED_*() macros. In order to avoid
> future misuse let RING_HAS_UNCONSUMED_*() optionally really return a
> boolean (can be activated by defining RING_HAS_UNCONSUMED_IS_BOOL).
>
> Note that the known misuses need to be switched to the new
> RING_NR_UNCONSUMED_*() macros when using this version of ring.h.
>
> Cc: Roger Pau Monne <roger.pau@xxxxxxxxxx>
> Cc: Manuel Bouyer <bouyer@xxxxxxxxxxxxxxx>
> Cc: Simon Kuenzer <simon.kuenzer@xxxxxxxxx>
> Cc: Paul Durrant <paul@xxxxxxx>
> Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
> ---
> I have checked Xen, Mini-OS, qemu, grub2, OVMF and Linux kernel for
> misuses of the RING_HAS_UNCONSUMED_*() macros. There is currently only
> one instance in the Linux kernel netback driver. The BSDs, UNIKRAFT
> and Windows PV drivers should be checked for misuse, too.
> V2: make RING_HAS_UNCONSUMED_*() returning a bool optional (Jan Beulich)
> ---
Reviewed-by: Paul Durrant <paul@xxxxxxx>