From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DF20B6FA1 for ; Mon, 3 Apr 2023 14:46:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 66A04C433D2; Mon, 3 Apr 2023 14:46:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1680533176; bh=TE4xOXYqMwj5XtV3cSDXvMt3tMyHbTy3WEJzGo5XXdQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ccq59OANEYHA4dc812RG6CTYtMsM+iL9wgJUXZ0Mqs7k3gWIlZMjkFNgQfeIX3fJx Ne7JUf9sRUWC+n6bA7KVdVCKy32jWsxAfQ2ANYYro9a7N9O2PM3sACse/2pgLc1aIf uGPRpN2HfhEvqvRAsXUQ5O6TdBjIkxxeNxwV0FLs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Adham Faris , Tariq Toukan , Saeed Mahameed , Sasha Levin Subject: [PATCH 6.2 052/187] net/mlx5e: Lower maximum allowed MTU in XSK to match XDP prerequisites Date: Mon, 3 Apr 2023 16:08:17 +0200 Message-Id: <20230403140417.697209115@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230403140416.015323160@linuxfoundation.org> References: <20230403140416.015323160@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Adham Faris [ Upstream commit 78dee7befd56987283c13877b834c0aa97ad51b9 ] XSK redirecting XDP programs require linearity, hence applies restrictions on the MTU. For PAGE_SIZE=4K, MTU shouldn't exceed 3498. Features that contradict with XDP such HW-LRO and HW-GRO are enforced by the driver in advance, during XSK params validation, except for MTU, which was not enforced before this patch. This has been spotted during test scenario described below: Attaching xdpsock program (PAGE_SIZE=4K), with MTU < 3498, detaching XDP program, changing the MTU to arbitrary value in the range [3499, 3754], attaching XDP program again, which ended up with failure since MTU is > 3498. This commit lowers the XSK MTU limitation to be aligned with XDP MTU limitation, since XSK socket is meaningless without XDP program. Signed-off-by: Adham Faris Reviewed-by: Tariq Toukan Signed-off-by: Saeed Mahameed Signed-off-by: Sasha Levin --- drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c index 47d4b54d15634..1f4233b2842f7 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c @@ -4117,13 +4117,17 @@ static bool mlx5e_xsk_validate_mtu(struct net_device *netdev, struct xsk_buff_pool *xsk_pool = mlx5e_xsk_get_pool(&chs->params, chs->params.xsk, ix); struct mlx5e_xsk_param xsk; + int max_xdp_mtu; if (!xsk_pool) continue; mlx5e_build_xsk_param(xsk_pool, &xsk); + max_xdp_mtu = mlx5e_xdp_max_mtu(new_params, &xsk); - if (!mlx5e_validate_xsk_param(new_params, &xsk, mdev)) { + /* Validate XSK params and XDP MTU in advance */ + if (!mlx5e_validate_xsk_param(new_params, &xsk, mdev) || + new_params->sw_mtu > max_xdp_mtu) { u32 hr = mlx5e_get_linear_rq_headroom(new_params, &xsk); int max_mtu_frame, max_mtu_page, max_mtu; @@ -4133,9 +4137,9 @@ static bool mlx5e_xsk_validate_mtu(struct net_device *netdev, */ max_mtu_frame = MLX5E_HW2SW_MTU(new_params, xsk.chunk_size - hr); max_mtu_page = MLX5E_HW2SW_MTU(new_params, SKB_MAX_HEAD(0)); - max_mtu = min(max_mtu_frame, max_mtu_page); + max_mtu = min3(max_mtu_frame, max_mtu_page, max_xdp_mtu); - netdev_err(netdev, "MTU %d is too big for an XSK running on channel %u. Try MTU <= %d\n", + netdev_err(netdev, "MTU %d is too big for an XSK running on channel %u or its redirection XDP program. Try MTU <= %d\n", new_params->sw_mtu, ix, max_mtu); return false; } -- 2.39.2