[Intel-wired-lan] [PATCH iwl-net] idpf: avoid compiler introduced padding in virtchnl2_rss_key struct

[Register, Scott]

> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces at osuosl.org> On Behalf Of
> Pavan Kumar Linga
> Sent: Friday, December 15, 2023 3:48 PM
> To: intel-wired-lan at lists.osuosl.org
> Cc: netdev at vger.kernel.org; Lobakin, Aleksander
> <aleksander.lobakin at intel.com>; Linga, Pavan Kumar
> <pavan.kumar.linga at intel.com>; Kitszel, Przemyslaw
> <przemyslaw.kitszel at intel.com>; Zaremba, Larysa
> <larysa.zaremba at intel.com>
> Subject: [Intel-wired-lan] [PATCH iwl-net] idpf: avoid compiler introduced
> padding in virtchnl2_rss_key struct
> 
> Size of the virtchnl2_rss_key struct should be 7 bytes but the
> compiler introduces a padding byte for the structure alignment.
> This results in idpf sending an additional byte of memory to the device
> control plane than the expected buffer size. As the control plane
> enforces virtchnl message size checks to validate the message,
> set RSS key message fails resulting in the driver load failure.
> 
> Remove implicit compiler padding by using "__packed" structure
> attribute for the virtchnl2_rss_key struct.
> 
> Also there is no need to use __DECLARE_FLEX_ARRAY macro for the
> 'key_flex' struct field. So drop it.
> 
> Fixes: 0d7502a9b4a7 ("virtchnl: add virtchnl version 2 ops")
> Reviewed-by: Larysa Zaremba <larysa.zaremba at intel.com>
> Signed-off-by: Pavan Kumar Linga <pavan.kumar.linga at intel.com>
> ---
>  drivers/net/ethernet/intel/idpf/virtchnl2.h | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)

Tested-by: Scott Register <scott.register at intel.com>