Re: [PATCH net-next,v2] net: mana: Add support for Multi Vports on Bare metal

[Simon Horman <horms@kernel.org>]

On Mon, May 19, 2025 at 09:20:36AM -0700, Haiyang Zhang wrote:
> To support Multi Vports on Bare metal, increase the device config response
> version. And, skip the register HW vport, and register filter steps, when
> the Bare metal hostmode is set.
> 
> Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
> ---
> v2:
>   Updated comments as suggested by ALOK TIWARI.
>   Fixed the version check.
> 
> ---
>  drivers/net/ethernet/microsoft/mana/mana_en.c | 24 ++++++++++++-------
>  include/net/mana/mana.h                       |  4 +++-
>  2 files changed, 19 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
> index 2bac6be8f6a0..9c58d9e0bbb5 100644
> --- a/drivers/net/ethernet/microsoft/mana/mana_en.c
> +++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
> @@ -921,7 +921,7 @@ static void mana_pf_deregister_filter(struct mana_port_context *apc)
>  
>  static int mana_query_device_cfg(struct mana_context *ac, u32 proto_major_ver,
>  				 u32 proto_minor_ver, u32 proto_micro_ver,
> -				 u16 *max_num_vports)
> +				 u16 *max_num_vports, u8 *bm_hostmode)
>  {
>  	struct gdma_context *gc = ac->gdma_dev->gdma_context;
>  	struct mana_query_device_cfg_resp resp = {};
> @@ -932,7 +932,7 @@ static int mana_query_device_cfg(struct mana_context *ac, u32 proto_major_ver,
>  	mana_gd_init_req_hdr(&req.hdr, MANA_QUERY_DEV_CONFIG,
>  			     sizeof(req), sizeof(resp));
>  
> -	req.hdr.resp.msg_version = GDMA_MESSAGE_V2;
> +	req.hdr.resp.msg_version = GDMA_MESSAGE_V3;
>  
>  	req.proto_major_ver = proto_major_ver;
>  	req.proto_minor_ver = proto_minor_ver;

> @@ -956,11 +956,16 @@ static int mana_query_device_cfg(struct mana_context *ac, u32 proto_major_ver,
>  
>  	*max_num_vports = resp.max_num_vports;
>  
> -	if (resp.hdr.response.msg_version == GDMA_MESSAGE_V2)
> +	if (resp.hdr.response.msg_version >= GDMA_MESSAGE_V2)
>  		gc->adapter_mtu = resp.adapter_mtu;
>  	else
>  		gc->adapter_mtu = ETH_FRAME_LEN;
>  
> +	if (resp.hdr.response.msg_version >= GDMA_MESSAGE_V3)
> +		*bm_hostmode = resp.bm_hostmode;
> +	else
> +		*bm_hostmode = 0;

Hi,

Perhaps not strictly related to this patch, but I see
that mana_verify_resp_hdr() is called a few lines above.
And that verifies a minimum msg_version. But I do not see
any verification of the maximum msg_version supported by the code.

I am concerned about a hypothetical scenario where, say the as yet unknown
version 5 is sent as the version, and the above behaviour is used, while
not being correct.

Could you shed some light on this?

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