RE: [PATCH v2 06/11] xen/memory: Clarify the XENMEM_acquire_resource ABI description

[Paul Durrant <xadimgnik@xxxxxxxxx>]

> -----Original Message-----
> From: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
> Sent: 22 September 2020 19:25
> To: Xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxxx>
> Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>; George Dunlap 
> <George.Dunlap@xxxxxxxxxxxxx>; Ian
> Jackson <iwj@xxxxxxxxxxxxxx>; Jan Beulich <JBeulich@xxxxxxxx>; Stefano 
> Stabellini
> <sstabellini@xxxxxxxxxx>; Wei Liu <wl@xxxxxxx>; Julien Grall 
> <julien@xxxxxxx>; Paul Durrant
> <paul@xxxxxxx>; Michał Leszczyński <michal.leszczynski@xxxxxxx>; Hubert 
> Jasudowicz
> <hubert.jasudowicz@xxxxxxx>; Tamas K Lengyel <tamas@xxxxxxxxxxxxx>
> Subject: [PATCH v2 06/11] xen/memory: Clarify the XENMEM_acquire_resource ABI 
> description
> 
> This is how similar operations already operate, compatible with the sole
> implementation (in Linux), and explicitly gives us some flexibility.
> 
> Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>

Reviewed-by: Paul Durrant <paul@xxxxxxx>

> ---
> CC: George Dunlap <George.Dunlap@xxxxxxxxxxxxx>
> CC: Ian Jackson <iwj@xxxxxxxxxxxxxx>
> CC: Jan Beulich <JBeulich@xxxxxxxx>
> CC: Stefano Stabellini <sstabellini@xxxxxxxxxx>
> CC: Wei Liu <wl@xxxxxxx>
> CC: Julien Grall <julien@xxxxxxx>
> CC: Paul Durrant <paul@xxxxxxx>
> CC: Michał Leszczyński <michal.leszczynski@xxxxxxx>
> CC: Hubert Jasudowicz <hubert.jasudowicz@xxxxxxx>
> CC: Tamas K Lengyel <tamas@xxxxxxxxxxxxx>
> ---
>  xen/include/public/memory.h | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/xen/include/public/memory.h b/xen/include/public/memory.h
> index d7eb34f167..c4c47a0b38 100644
> --- a/xen/include/public/memory.h
> +++ b/xen/include/public/memory.h
> @@ -642,6 +642,7 @@ struct xen_mem_acquire_resource {
>       * IN/OUT
>       *
>       * As an IN parameter number of frames of the resource to be mapped.
> +     * This value may be updated during the course of the operation.
>       *
>       * When frame_list is NULL and nr_frames is 0, this is interpreted as a
>       * request for the size of the resource, which shall be returned in the
> @@ -656,7 +657,8 @@ struct xen_mem_acquire_resource {
>      uint32_t pad;
>      /*
>       * IN - the index of the initial frame to be mapped. This parameter
> -     *      is ignored if nr_frames is 0.
> +     *      is ignored if nr_frames is 0.  This value may be updated
> +     *      during the course of the operation.
>       */
>      uint64_t frame;
> 
> @@ -672,7 +674,8 @@ struct xen_mem_acquire_resource {
>       *          If -EIO is returned then the frame_list has only been
>       *          partially mapped and it is up to the caller to unmap all
>       *          the GFNs.
> -     *          This parameter may be NULL if nr_frames is 0.
> +     *          This parameter may be NULL if nr_frames is 0.  This
> +     *          value may be updated during the course of the operation.
>       */
>      XEN_GUEST_HANDLE(xen_pfn_t) frame_list;
>  };
> --
> 2.11.0