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 6FD6FC64E8A for ; Wed, 2 Dec 2020 02:29:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 089D2221E2 for ; Wed, 2 Dec 2020 02:29:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727787AbgLBC3M (ORCPT ); Tue, 1 Dec 2020 21:29:12 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:27579 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726245AbgLBC3L (ORCPT ); Tue, 1 Dec 2020 21:29:11 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1606876064; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=w11V4bmvhWru2IiQcOjCMFc2jaajSUpY7gF7ScGtZGE=; b=RZ9HVxkIRp7KLhaEXMgPmEX7y9o1a7nNyqeUE1Rcq3BzNK3PI4XHKJPhsplGZ/7FP7PmQq S+3A23cddCrvuRpZ959peZAhchYYmkVRtbn854Vr3tSpcM6rK0o9JEGRWwywSAHUcSYQkt RWlPtKCO9Vi/5ozl5MwoJSojtPBvLZI= Received: from mail-pg1-f199.google.com (mail-pg1-f199.google.com [209.85.215.199]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-546-wgZzBt9EPE24PoqPrCCuew-1; Tue, 01 Dec 2020 21:27:40 -0500 X-MC-Unique: wgZzBt9EPE24PoqPrCCuew-1 Received: by mail-pg1-f199.google.com with SMTP id o17so34285pgm.18 for ; Tue, 01 Dec 2020 18:27:40 -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:content-transfer-encoding; bh=w11V4bmvhWru2IiQcOjCMFc2jaajSUpY7gF7ScGtZGE=; b=LExiG8K7feMYf4TrRd5KWepAuYXe7AAPvJiJqEv2efH8qC4fl5LndJSU2C83KiT3it wB9dESvQ0468nQv93JcOnre1QQuKFJ0GXHjD0315zIVi+jvItaWBmFWvVpVIcmzdm7Lm E3kxWPT3yp3KF+10wREfePMWFoIUhlstobs1cejYN1ypVwCeWFGAEaA4FTs25LiZsDog 8SGMa4WXMaw91UWIFeAGKACwRU5zNFsXZY+Ch9vAkPdEGxwPw6Wkfgf002BDY097QILL 3FrAah6rjysNmq5rsMLP45jt6TZKLB60P/761DdOYEOViuhLM/FbEM8qaAVTJMhqRxPm JuJg== X-Gm-Message-State: AOAM531ubIgTH+FL+kv9GCB1hL8PheSK61lNMe+u6BUGyKjPtueH9Tbs vXlp3vTWdkJWm6gAhch2qLIlqkjArqf1qLkp1U2F8SRN/BcO1Gj0KLbHGTm80Rc1xvrvZ+YIZ/0 MmbObRlJdodnqFGv/GJ0/JhgRNNpr5P7gkXhYkWNb X-Received: by 2002:a63:1514:: with SMTP id v20mr576245pgl.203.1606876059374; Tue, 01 Dec 2020 18:27:39 -0800 (PST) X-Google-Smtp-Source: ABdhPJzSJ8R0B92O5F3oBauIq411KXta9R2sA3A1MD3U3rRfyZtoJjnNKARUpPkOxjr1Guuriz8gsSvh4ObPZcysvGU= X-Received: by 2002:a63:1514:: with SMTP id v20mr576227pgl.203.1606876059014; Tue, 01 Dec 2020 18:27:39 -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> <20201130103142-mutt-send-email-mst@kernel.org> <20201201063124-mutt-send-email-mst@kernel.org> In-Reply-To: <20201201063124-mutt-send-email-mst@kernel.org> From: Cindy Lu Date: Wed, 2 Dec 2020 10:27:02 +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" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 1, 2020 at 7:32 PM Michael S. Tsirkin wrote: > > On Tue, Dec 01, 2020 at 05:23:18PM +0800, Cindy Lu wrote: > > On Mon, Nov 30, 2020 at 11:33 PM Michael S. Tsirkin wr= ote: > > > > > > On Mon, Nov 30, 2020 at 06:41:45PM +0800, Cindy Lu wrote: > > > > 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 wr= ote: > > > > > > > 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. Tsirki= n 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, u= se a random > > > > > > > > > > generated MAC address. > > > > > > > > > > > > > > > > > > > > Suggested by: Cindy Lu > > > > > > > > > > Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for su= pported 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 prob= lem? > > > > > > > > > > > > > > > > > > > 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 adminis= tering the > > > > > > > > NIC. This should invoke the set_config callback. Unfortu= nately this > > > > > > > > is not implemented yet. > > > > > > > > > > > > > > > > 2. Use a random MAC address. This is OK since if (1) is imp= lemented 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 oth= er patches on > > > > > > > > which they depend will be merged. > > > > > > > > > > > > > > > > https://patchwork.ozlabs.org/project/netdev/patch/202011202= 30339.651609-12-saeedm@nvidia.com/ > > > > > > > > > > > > > > Could you be more explicit on the following points: > > > > > > > - which configuration is broken ATM (as in, two device have i= dentical > > > > > > > macs? any other issues)? > > > > > > > > > > > > The only wrong thing is the call to mlx5_query_nic_vport_mac_a= ddress(). > > > > > > 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 t= raffic down. > > > > > > Hmm the patch description says VF mac address, not 0 address. Confuse= d. > > > If there's no mac we can clear VIRTIO_NET_F_MAC and have guest > > > use a random value ... > > > > > hi Michael=EF=BC=8C > > I have tried as your suggestion, seems even remove the > > VIRTIO_NET_F_MAC the qemu will still call get_cinfig and overwrite the > > default address in VM, > > this process is like > > vdpa _init -->qemu call get_config ->mlx driver will give an mac > > address with all 0--> > > qemu will not check this mac address and use it --> overwrite the mac > > address in qemu > > Right but guest will ignore it then, right? > I have tired, but guest will use it, here is some information from guest [root@localhost ~]# cat /sys/bus/pci/devices/0000\:00\:04.0/virtio0/feature= s 1110010000011000111100010000000010000000000000000000000000000000 [root@localhost ~]# ifconfig -a eth0: flags=3D4098 mtu 1500 ether 00:00:00:00:00:00 txqueuelen 1000 (Ethernet) RX packets 0 bytes 0 (0.0 B) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 0 bytes 0 (0.0 B) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 For my understanding, this NIC should have MAC address by default , and this should not depend on any other function/use case,for driver itself it's incorrect to give an mac address with all 0 to qemu without error/fail Thanks Cindy > > So for my understanding there are several method to fix this problem > > > > 1, qemu check the mac address, if the mac address is all 0, qemu will > > ignore it and set the random mac address to mlx driver. > > 2. mlx driver checks the mac address and if this mac is 0, return fail > > to qemu, but this need to change the UAPI. > > 3. mlx driver it shelf should get an correct mac address while it init. > > 4. add check in qemu get_config function , if there is not F_MAC Then > > ignore the mac address from mlx driver > > > > not sure which method is more suitable ? > > > > Thanks > > Cindy > > > > > > > > > > > > > > > > > > > > > > > --- > > > > > > > > > > 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/driver= s/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 m= lx5_core_dev *mdev) > > > > > > > > > > if (err) > > > > > > > > > > goto err_mtu; > > > > > > > > > > > > > > > > > > > > - err =3D 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 =3D mdev->device; > > > > > > > > > > err =3D mlx5_vdpa_alloc_resources(&ndev->mvdev); > > > > > > > > > > if (err) > > > > > > > > > > -- > > > > > > > > > > 2.26.2 > > > > > > > > > > > > > > > > > > > > > > > > >