From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9F240C64E8A for ; Mon, 30 Nov 2020 10:43:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3B7D3204EF for ; Mon, 30 Nov 2020 10:43:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="HTqeYw1k" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728814AbgK3Kny (ORCPT ); Mon, 30 Nov 2020 05:43:54 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:48108 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727818AbgK3Knx (ORCPT ); Mon, 30 Nov 2020 05:43:53 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1606732946; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=TAOzrB1JNY9m5cJZp5Sd6U0cG3CpY/RY5rrZyGT/PLI=; b=HTqeYw1kMQIyysnoZdVbaTXffl6dl/5cmFIOHRv08zxLSXM0hU1ZrDY+pl2Os2bzVj2BIg S5NdZGnnRRYBjT8nGmP9SOxLu4kZ8f7TsOIzA11P9n9F3h/bcrklRTykOuqXFOq/MFwi7w LFjLffZsBQH2pstDDeGQwKkB5iyhXj8= Received: from mail-pl1-f197.google.com (mail-pl1-f197.google.com [209.85.214.197]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-191-skr0V_yfPSC3NbJyZqRRUQ-1; Mon, 30 Nov 2020 05:42:23 -0500 X-MC-Unique: skr0V_yfPSC3NbJyZqRRUQ-1 Received: by mail-pl1-f197.google.com with SMTP id ba3so7457987plb.9 for ; Mon, 30 Nov 2020 02:42:23 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=TAOzrB1JNY9m5cJZp5Sd6U0cG3CpY/RY5rrZyGT/PLI=; b=byi7XxsVpJ6ucoIH4NIjNXz7xvtopDb08oxgx/OihsfyQ4G/eqzHwpv+kjpz/+xGJL 0vV7p2dVRzI5tpq73m7NxbhWbmgLzebNI82cM7F3woSC9ueqbE9nr81juagEn5OK1MNn 3oVHpgUuDHASf5SXZOKPMr5QcBckM7r6Rlsg628zRI/dbSuJErnuQs+ntFhDadQzvQGo 7LqcFo9PJUoHO64/Je2AkD4nrzmKZ43a6oR29QASJws6ejABy57iWxoo4VS9N5fk6Kj2 qdOrA1PHruZeFN1T80tcCurHaev6ngex9kwXbalN99nV6K6E+uXDqR3MbwSY/kbLG6iU N0gg== X-Gm-Message-State: AOAM532NabskepsCRzIbD+SfQsnUlUT9h5ATLOHbCcMz9V3yPDhqkkoF H6odCa6z6jgOMQ/OuZ6O0p/d6xJkRiyQLGUcc+cJGqI2fht1drW7AzJ7URm2hXGg2fpsBeRZzJ0 G6NaxuUwUnALasp6O2MdcccwP7pjAqOJjXPTRmM7H X-Received: by 2002:a63:1514:: with SMTP id v20mr17173190pgl.203.1606732942060; Mon, 30 Nov 2020 02:42:22 -0800 (PST) X-Google-Smtp-Source: ABdhPJzLMmCKo2lY01uZqANDDMDZYSfT0+RFaNOGs+jH0YjAE6/iiHA/MZM6xvifVLYPA1JvIPRWELGWgLy55MsWwPs= X-Received: by 2002:a63:1514:: with SMTP id v20mr17173173pgl.203.1606732941762; Mon, 30 Nov 2020 02:42:21 -0800 (PST) MIME-Version: 1.0 References: <20201129064351.63618-1-elic@nvidia.com> <20201129150505-mutt-send-email-mst@kernel.org> <20201130062746.GA99449@mtl-vdi-166.wap.labs.mlnx> <20201130035147-mutt-send-email-mst@kernel.org> <20201130092759.GB99449@mtl-vdi-166.wap.labs.mlnx> <20201130043050-mutt-send-email-mst@kernel.org> In-Reply-To: <20201130043050-mutt-send-email-mst@kernel.org> From: Cindy Lu Date: Mon, 30 Nov 2020 18:41:45 +0800 Message-ID: Subject: Re: [PATCH] vdpa/mlx5: Use random MAC for the vdpa net instance To: "Michael S. Tsirkin" Cc: Eli Cohen , Jason Wang , virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 30, 2020 at 5:33 PM Michael S. Tsirkin wrote: > > On Mon, Nov 30, 2020 at 11:27:59AM +0200, Eli Cohen wrote: > > On Mon, Nov 30, 2020 at 04:00:51AM -0500, Michael S. Tsirkin wrote: > > > On Mon, Nov 30, 2020 at 08:27:46AM +0200, Eli Cohen wrote: > > > > On Sun, Nov 29, 2020 at 03:08:22PM -0500, Michael S. Tsirkin wrote: > > > > > On Sun, Nov 29, 2020 at 08:43:51AM +0200, Eli Cohen wrote: > > > > > > We should not try to use the VF MAC address as that is used by the > > > > > > regular (e.g. mlx5_core) NIC implementation. Instead, use a random > > > > > > generated MAC address. > > > > > > > > > > > > Suggested by: Cindy Lu > > > > > > Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for supported mlx5 devices") > > > > > > Signed-off-by: Eli Cohen > > > > > > > > > > I didn't realise it's possible to use VF in two ways > > > > > with and without vdpa. > > > > > > > > Using a VF you can create quite a few resources, e.g. send queues > > > > recieve queues, virtio_net queues etc. So you can possibly create > > > > several instances of vdpa net devices and nic net devices. > > > > > > > > > Could you include a bit more description on the failure > > > > > mode? > > > > > > > > Well, using the MAC address of the nic vport is wrong since that is the > > > > MAC of the regular NIC implementation of mlx5_core. > > > > > > Right but ATM it doesn't coexist with vdpa so what's the problem? > > > > > > > This call is wrong: mlx5_query_nic_vport_mac_address() > > > > > > > Is switching to a random mac for such an unusual > > > > > configuration really justified? > > > > > > > > Since I can't use the NIC's MAC address, I have two options: > > > > 1. To get the MAC address as was chosen by the user administering the > > > > NIC. This should invoke the set_config callback. Unfortunately this > > > > is not implemented yet. > > > > > > > > 2. Use a random MAC address. This is OK since if (1) is implemented it > > > > can always override this random configuration. > > > > > > > > > It looks like changing a MAC could break some guests, > > > > > can it not? > > > > > > > > > > > > > No, it will not. The current version of mlx5 VDPA does not allow regular > > > > NIC driver and VDPA to co-exist. I have patches ready that enable that > > > > from steering point of view. I will post them here once other patches on > > > > which they depend will be merged. > > > > > > > > https://patchwork.ozlabs.org/project/netdev/patch/20201120230339.651609-12-saeedm@nvidia.com/ > > > > > > Could you be more explicit on the following points: > > > - which configuration is broken ATM (as in, two device have identical > > > macs? any other issues)? > > > > The only wrong thing is the call to mlx5_query_nic_vport_mac_address(). > > It's not breaking anything yet is wrong. The random MAC address setting > > is required for the steering patches. > > Okay so I'm not sure the Fixes tag at least is appropriate if it's a > dependency of a new feature. > > > > - why won't device MAC change from guest point of view? > > > > > > > It's lack of implementation in qemu as far as I know. > > Sorry not sure I understand. What's not implemented in QEMU? > HI Michael, there are some bug in qemu to set_config, this will fix in future, But this patch is still needed, because without this patch the mlx driver will give an 0 mac address to qemu and qemu will overwrite the default mac address. This will cause traffic down. > > > > > > > > > --- > > > > > > drivers/vdpa/mlx5/net/mlx5_vnet.c | 5 +---- > > > > > > 1 file changed, 1 insertion(+), 4 deletions(-) > > > > > > > > > > > > diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c > > > > > > index 1fa6fcac8299..80d06d958b8b 100644 > > > > > > --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c > > > > > > +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c > > > > > > @@ -1955,10 +1955,7 @@ void *mlx5_vdpa_add_dev(struct mlx5_core_dev *mdev) > > > > > > if (err) > > > > > > goto err_mtu; > > > > > > > > > > > > - err = mlx5_query_nic_vport_mac_address(mdev, 0, 0, config->mac); > > > > > > - if (err) > > > > > > - goto err_mtu; > > > > > > - > > > > > > + eth_random_addr(config->mac); > > > > > > mvdev->vdev.dma_dev = mdev->device; > > > > > > err = mlx5_vdpa_alloc_resources(&ndev->mvdev); > > > > > > if (err) > > > > > > -- > > > > > > 2.26.2 > > > > > > > > >