linux-kernel - Re: [PATCH net-next v2] gve: Add RSS cache for non RSS device option scenario

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250205162839.GH554665@kernel.org>
Date: Wed, 5 Feb 2025 16:28:39 +0000
From: Simon Horman <horms@...nel.org>
To: Jeroen de Borst <jeroendb@...gle.com>
Cc: netdev@...r.kernel.org, davem@...emloft.net, edumazet@...gle.com,
	kuba@...nel.org, pabeni@...hat.com, pkaligineedi@...gle.com,
	shailend@...gle.com, andrew+netdev@...n.ch, willemb@...gle.com,
	hramamurthy@...gle.com, ziweixiao@...gle.com,
	linux-kernel@...r.kernel.org, Jeroen de Borst <jeroend@...gle.com>
Subject: Re: [PATCH net-next v2] gve: Add RSS cache for non RSS device option
 scenario

On Tue, Feb 04, 2025 at 01:31:21PM -0800, Jeroen de Borst wrote:
> From: Ziwei Xiao <ziweixiao@...gle.com>
> 
> Not all the devices have the capability for the driver to query for the
> registered RSS configuration. The driver can discover this by checking
> the relevant device option during setup. If it cannot, the driver needs
> to store the RSS config cache and directly return such cache when
> queried by the ethtool. RSS config is inited when driver probes. Also the
> default RSS config will be adjusted when there is RX queue count change.
> 
> At this point, only keys of GVE_RSS_KEY_SIZE and indirection tables of
> GVE_RSS_INDIR_SIZE are supported.
> 
> Signed-off-by: Ziwei Xiao <ziweixiao@...gle.com>
> Reviewed-by: Harshitha Ramamurthy <hramamurthy@...gle.com>
> Reviewed-by: Willem de Bruijn <willemb@...gle.com>
> Signed-off-by: Praveen Kaligineedi <pkaligineedi@...gle.com>
> Signed-off-by: Jeroen de Borst <jeroend@...gle.com>
> ---
> Changes in v2:
>  - Change to initialize RSS config when the driver is up instead of
>    doing that when the user setting the RSS.(Jakub Kicinski)
>  - Use NL_SET_ERR_MSG_MOD to log errors when there is extack
>    available.(Jakub Kicinski)
>  - Use ethtool_rxfh_indir_default to set default RSS indir
>    table.(Jakub Kicinski)
>  - Adjust the default RSS config when there is RX queue count change to
>    ensure the default RSS config is correct.
> 
>  drivers/net/ethernet/google/gve/gve.h         | 16 +++-
>  drivers/net/ethernet/google/gve/gve_adminq.c  | 64 ++++++++++---
>  drivers/net/ethernet/google/gve/gve_ethtool.c | 60 ++++++++++--
>  drivers/net/ethernet/google/gve/gve_main.c    | 92 ++++++++++++++++++-
>  4 files changed, 209 insertions(+), 23 deletions(-)

...

> diff --git a/drivers/net/ethernet/google/gve/gve_ethtool.c b/drivers/net/ethernet/google/gve/gve_ethtool.c
> index bdfc6e77b2af..efcafc607b2a 100644
> --- a/drivers/net/ethernet/google/gve/gve_ethtool.c
> +++ b/drivers/net/ethernet/google/gve/gve_ethtool.c
> @@ -482,6 +482,7 @@ static int gve_set_channels(struct net_device *netdev,
>  	struct ethtool_channels old_settings;
>  	int new_tx = cmd->tx_count;
>  	int new_rx = cmd->rx_count;
> +	bool reset_rss;
>  
>  	gve_get_channels(netdev, &old_settings);
>  
> @@ -498,16 +499,14 @@ static int gve_set_channels(struct net_device *netdev,
>  		return -EINVAL;
>  	}
>  
> -	if (!netif_running(netdev)) {
> -		priv->tx_cfg.num_queues = new_tx;
> -		priv->rx_cfg.num_queues = new_rx;
> -		return 0;
> -	}
> +	if (new_rx != priv->rx_cfg.num_queues &&
> +	    priv->cache_rss_config && !netif_is_rxfh_configured(netdev))
> +		reset_rss = true;

Hi Jerome,

This is not a full review (which I was working on but ran out of time for now).
But, if the condition above is not met then reset_rss will be used
uninitialised below.

Flagged by W=1 build with clang-19.

>  
>  	new_tx_cfg.num_queues = new_tx;
>  	new_rx_cfg.num_queues = new_rx;
>  
> -	return gve_adjust_queues(priv, new_rx_cfg, new_tx_cfg);
> +	return gve_adjust_queues(priv, new_rx_cfg, new_tx_cfg, reset_rss);
>  }
>  
>  static void gve_get_ringparam(struct net_device *netdev,

...

-- 
pw-bot: cr