RE: [PATCH v4] tools/foreignmem: Support querying the size of a resource

[Paul Durrant <xadimgnik@xxxxxxxxx>]

> -----Original Message-----
> From: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
> Sent: 28 January 2021 12:02
> To: Xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxxx>
> Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>; Wei Liu <wl@xxxxxxx>; Paul 
> Durrant <paul@xxxxxxx>;
> Roger Pau Monné <roger.pau@xxxxxxxxxx>; Juergen Gross <jgross@xxxxxxxx>; Ian 
> Jackson
> <iwj@xxxxxxxxxxxxxx>; Michał Leszczyński <michal.leszczynski@xxxxxxx>; Hubert 
> Jasudowicz
> <hubert.jasudowicz@xxxxxxx>; Tamas K Lengyel <tamas@xxxxxxxxxxxxx>; Manuel 
> Bouyer <bouyer@xxxxxxxxxx>
> Subject: [PATCH v4] tools/foreignmem: Support querying the size of a resource
> 
> With the Xen side of this interface (soon to be) fixed to return real sizes,
> userspace needs to be able to make the query.
> 
> Introduce xenforeignmemory_resource_size() for the purpose, bumping the
> library minor version.
> 
> Update both all osdep_xenforeignmemory_map_resource() implementations to
> understand size requests, skip the mmap() operation, and copy back the
> nr_frames field.
> 
> For NetBSD, also fix up the ioctl() error path to issue an unmap(), which was
> overlooked by c/s 4a64e2bb39 "libs/foreignmemory: Implement on NetBSD".
> 
> Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
> Reviewed-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>

Reviewed-by: Paul Durrant <paul@xxxxxxx>