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 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 571DFCD4F5F for ; Thu, 13 Nov 2025 08:54:43 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vJT5a-0001Jl-0X; Thu, 13 Nov 2025 03:53:58 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1vJT5T-0001D9-AG for qemu-devel@nongnu.org; Thu, 13 Nov 2025 03:53:52 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1vJT5O-0001qH-Se for qemu-devel@nongnu.org; Thu, 13 Nov 2025 03:53:50 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1763024025; h=from:from:reply-to: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=5xpAhBR+RDcMUel8zK04PX2o2nGk1xXVph5O4YzxwBI=; b=eCtq3H0yU+WSHsWSunSEhjJhok2tV3W5RZw0KbQ+uAju0jG7l1PWoNCzSf4P+InI5hrkij IC9vNEqv+dtBWyShP95G2ZY6lg5IHql6+pJscU1mZk+ScaEW3o4ch/tKkgynqeWwN3cUy5 YeIn45bN2udPyiZuy35VAFtPVsyesRw= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-611-Us67bDswOFG8AA-cnFVmqw-1; Thu, 13 Nov 2025 03:53:39 -0500 X-MC-Unique: Us67bDswOFG8AA-cnFVmqw-1 X-Mimecast-MFC-AGG-ID: Us67bDswOFG8AA-cnFVmqw_1763024018 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 3602119560A1; Thu, 13 Nov 2025 08:53:38 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.56]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 8C8171955F1B; Thu, 13 Nov 2025 08:53:34 +0000 (UTC) Date: Thu, 13 Nov 2025 08:53:30 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Peter Xu Cc: Jason Wang , eduardo@habkost.net, marcel.apfelbaum@gmail.com, philmd@linaro.org, wangyanan55@huawei.com, zhao1.liu@intel.com, mst@redhat.com, qemu-devel@nongnu.org, farosas@suse.de, jinpu.wang@ionos.com, thuth@redhat.com Subject: Re: [RFC PATCH] virtio-net: introduce strict peer feature check Message-ID: References: <20251107020149.3223-1-jasowang@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/2.2.14 (2025-02-20) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Wed, Nov 12, 2025 at 04:55:42PM -0500, Peter Xu wrote: > On Fri, Nov 07, 2025 at 10:01:49AM +0800, Jason Wang wrote: > > We used to clear features silently in virtio_net_get_features() even > > if it is required. This complicates the live migration compatibility > > as the management layer may think the feature is enabled but in fact > > not. > > > > Let's add a strict feature check to make sure if there's a mismatch > > between the required feature and peer, fail the get_features() > > immediately instead of waiting until the migration to fail. This > > offload the migration compatibility completely to the management > > layer. > > > > Signed-off-by: Jason Wang > > Jason, thanks for help looking into the problem! > > Am I right that after this patch applied, whenever a new QEMU boots with > the new machine types (e.g. having USO* by default ON), will fail to boot > on an old kernel that doesn't support USO*, but ask the users to turn off > USO* features explicitly in the virtio-net devices? What kernel version are we talking about where there will be incompatibility ? Is it old enough that it pre-dates our platform support matrix requirements ? Ubuntu 22.04 and RHEL-9 are currently our targets with the oldest kernels that we need to retain compatibility with as the bare min. I would expect machine types to work on these old platforms without users to having to manually disable default set features. > > Thanks, > > > --- > > hw/core/machine.c | 1 + > > hw/net/virtio-net.c | 153 +++++++++++++++++++++++++-------- > > include/hw/virtio/virtio-net.h | 1 + > > 3 files changed, 119 insertions(+), 36 deletions(-) > > > > diff --git a/hw/core/machine.c b/hw/core/machine.c > > index 681adbb7ac..a9e43c4990 100644 > > --- a/hw/core/machine.c > > +++ b/hw/core/machine.c > > @@ -40,6 +40,7 @@ > > > > GlobalProperty hw_compat_10_1[] = { > > { TYPE_ACPI_GED, "x-has-hest-addr", "false" }, > > + { TYPE_VIRTIO_NET, "strict-peer-feature-check", "false"}, > > }; > > const size_t hw_compat_10_1_len = G_N_ELEMENTS(hw_compat_10_1); > > > > diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c > > index 33116712eb..3acc5ed4a6 100644 > > --- a/hw/net/virtio-net.c > > +++ b/hw/net/virtio-net.c > > @@ -3090,53 +3090,120 @@ static void virtio_net_get_features(VirtIODevice *vdev, uint64_t *features, > > virtio_add_feature_ex(features, VIRTIO_NET_F_MAC); > > > > if (!peer_has_vnet_hdr(n)) { > > - virtio_clear_feature_ex(features, VIRTIO_NET_F_CSUM); > > - virtio_clear_feature_ex(features, VIRTIO_NET_F_HOST_TSO4); > > - virtio_clear_feature_ex(features, VIRTIO_NET_F_HOST_TSO6); > > - virtio_clear_feature_ex(features, VIRTIO_NET_F_HOST_ECN); > > - > > - virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_CSUM); > > - virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_TSO4); > > - virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_TSO6); > > - virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_ECN); > > - > > - virtio_clear_feature_ex(features, VIRTIO_NET_F_HOST_USO); > > - virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_USO4); > > - virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_USO6); > > - > > - virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO); > > - virtio_clear_feature_ex(features, VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO); > > - virtio_clear_feature_ex(features, > > - VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO_CSUM); > > - virtio_clear_feature_ex(features, > > - VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO_CSUM); > > + if (n->strict_peer_feature_check) { > > + if (virtio_has_feature_ex(features, VIRTIO_NET_F_CSUM) | > > + virtio_has_feature_ex(features, VIRTIO_NET_F_HOST_TSO4) | > > + virtio_has_feature_ex(features, VIRTIO_NET_F_HOST_TSO6) | > > + virtio_has_feature_ex(features, VIRTIO_NET_F_HOST_ECN) | > > + virtio_has_feature_ex(features, VIRTIO_NET_F_GUEST_CSUM) | > > + virtio_has_feature_ex(features, VIRTIO_NET_F_GUEST_TSO4) | > > + virtio_has_feature_ex(features, VIRTIO_NET_F_GUEST_TSO6) | > > + virtio_has_feature_ex(features, VIRTIO_NET_F_GUEST_ECN) | > > + virtio_has_feature_ex(features, VIRTIO_NET_F_HOST_USO) | > > + virtio_has_feature_ex(features, VIRTIO_NET_F_GUEST_USO4) | > > + virtio_has_feature_ex(features, VIRTIO_NET_F_GUEST_USO6) | > > + virtio_has_feature_ex(features, > > + VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO) | > > + virtio_has_feature_ex(features, > > + VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO) | > > + virtio_has_feature_ex(features, > > + VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO_CSUM) | > > + virtio_has_feature_ex(features, > > + VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO_CSUM) | > > + virtio_has_feature_ex(features, > > + VIRTIO_NET_F_HASH_REPORT)) { > > + error_setg(errp, "virtio_net: peer doesn't support vnet hdr"); > > + return; > > + } > > + } else { > > + virtio_clear_feature_ex(features, VIRTIO_NET_F_CSUM); > > + virtio_clear_feature_ex(features, VIRTIO_NET_F_HOST_TSO4); > > + virtio_clear_feature_ex(features, VIRTIO_NET_F_HOST_TSO6); > > + virtio_clear_feature_ex(features, VIRTIO_NET_F_HOST_ECN); > > + > > + virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_CSUM); > > + virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_TSO4); > > + virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_TSO6); > > + virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_ECN); > > + > > + virtio_clear_feature_ex(features, VIRTIO_NET_F_HOST_USO); > > + virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_USO4); > > + virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_USO6); > > + > > + virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO); > > + virtio_clear_feature_ex(features, VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO); > > + virtio_clear_feature_ex(features, > > + VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO_CSUM); > > + virtio_clear_feature_ex(features, > > + VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO_CSUM); > > > > - virtio_clear_feature_ex(features, VIRTIO_NET_F_HASH_REPORT); > > + virtio_clear_feature_ex(features, VIRTIO_NET_F_HASH_REPORT); > > + } > > } > > > > if (!peer_has_vnet_hdr(n) || !peer_has_ufo(n)) { > > - virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_UFO); > > - virtio_clear_feature_ex(features, VIRTIO_NET_F_HOST_UFO); > > + if (n->strict_peer_feature_check) { > > + if (virtio_has_feature_ex(features, VIRTIO_NET_F_GUEST_UFO) | > > + virtio_has_feature_ex(features, VIRTIO_NET_F_HOST_UFO)) { > > + error_setg(errp, "virtio_net: peer doesn't support UFO"); > > + return; > > + } > > + } else { > > + virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_UFO); > > + virtio_clear_feature_ex(features, VIRTIO_NET_F_HOST_UFO); > > + } > > } > > if (!peer_has_uso(n)) { > > - virtio_clear_feature_ex(features, VIRTIO_NET_F_HOST_USO); > > - virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_USO4); > > - virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_USO6); > > + if (n->strict_peer_feature_check) { > > + if (virtio_has_feature_ex(features, VIRTIO_NET_F_HOST_USO) | > > + virtio_has_feature_ex(features, VIRTIO_NET_F_GUEST_USO4) | > > + virtio_has_feature_ex(features, VIRTIO_NET_F_GUEST_USO6)) { > > + error_setg(errp, "virtio_net: peer doesn't support USO"); > > + return; > > + } > > + } else { > > + virtio_clear_feature_ex(features, VIRTIO_NET_F_HOST_USO); > > + virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_USO4); > > + virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_USO6); > > + } > > } > > > > if (!peer_has_tunnel(n)) { > > - virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO); > > - virtio_clear_feature_ex(features, VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO); > > - virtio_clear_feature_ex(features, > > - VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO_CSUM); > > - virtio_clear_feature_ex(features, > > - VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO_CSUM); > > + if (n->strict_peer_feature_check) { > > + if (virtio_has_feature_ex(features, > > + VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO) | > > + virtio_has_feature_ex(features, > > + VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO) | > > + virtio_has_feature_ex(features, > > + VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO_CSUM) | > > + virtio_has_feature_ex(features, > > + VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO_CSUM)) { > > + error_setg(errp, "virtio_net: peer doesn't support tunnel GSO"); > > + return; > > + } > > + } else { > > + virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO); > > + virtio_clear_feature_ex(features, VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO); > > + virtio_clear_feature_ex(features, > > + VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO_CSUM); > > + virtio_clear_feature_ex(features, > > + VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO_CSUM); > > + } > > } > > > > if (!get_vhost_net(nc->peer)) { > > if (!use_own_hash) { > > - virtio_clear_feature_ex(features, VIRTIO_NET_F_HASH_REPORT); > > - virtio_clear_feature_ex(features, VIRTIO_NET_F_RSS); > > + if (n->strict_peer_feature_check) { > > + if (virtio_has_feature_ex(features, VIRTIO_NET_F_HASH_REPORT) | > > + virtio_has_feature_ex(features, VIRTIO_NET_F_RSS)) { > > + error_setg(errp, > > + "virtio_net: peer doesn't support RSS/HASH_REPORT"); > > + return; > > + } > > + } else { > > + virtio_clear_feature_ex(features, VIRTIO_NET_F_HASH_REPORT); > > + virtio_clear_feature_ex(features, VIRTIO_NET_F_RSS); > > + } > > } else if (virtio_has_feature_ex(features, VIRTIO_NET_F_RSS)) { > > virtio_net_load_ebpf(n, errp); > > } > > @@ -3145,14 +3212,26 @@ static void virtio_net_get_features(VirtIODevice *vdev, uint64_t *features, > > } > > > > if (!use_peer_hash) { > > - virtio_clear_feature_ex(features, VIRTIO_NET_F_HASH_REPORT); > > + if (n->strict_peer_feature_check && > > + virtio_has_feature_ex(features, VIRTIO_NET_F_HASH_REPORT)) { > > + error_setg(errp, "virtio_net: peer doesn't HASH_REPORT"); > > + return; > > + } else { > > + virtio_clear_feature_ex(features, VIRTIO_NET_F_HASH_REPORT); > > + } > > > > if (!use_own_hash || !virtio_net_attach_ebpf_to_backend(n->nic, -1)) { > > if (!virtio_net_load_ebpf(n, errp)) { > > return; > > } > > > > - virtio_clear_feature_ex(features, VIRTIO_NET_F_RSS); > > + if (n->strict_peer_feature_check && > > + virtio_has_feature_ex(features, VIRTIO_NET_F_RSS)) { > > + error_setg(errp, "virtio_net: fail to attach eBPF for RSS"); > > + return; > > + } else { > > + virtio_clear_feature_ex(features, VIRTIO_NET_F_RSS); > > + } > > } > > } > > > > @@ -4313,6 +4392,8 @@ static const Property virtio_net_properties[] = { > > host_features_ex, > > VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO_CSUM, > > false), > > + DEFINE_PROP_BOOL("strict-peer-feature-check", VirtIONet, > > + strict_peer_feature_check, true), > > }; > > > > static void virtio_net_class_init(ObjectClass *klass, const void *data) > > diff --git a/include/hw/virtio/virtio-net.h b/include/hw/virtio/virtio-net.h > > index 5b8ab7bda7..abd4ca4bb0 100644 > > --- a/include/hw/virtio/virtio-net.h > > +++ b/include/hw/virtio/virtio-net.h > > @@ -222,6 +222,7 @@ struct VirtIONet { > > /* primary failover device is hidden*/ > > bool failover_primary_hidden; > > bool failover; > > + bool strict_peer_feature_check; > > DeviceListener primary_listener; > > QDict *primary_opts; > > bool primary_opts_from_json; > > -- > > 2.34.1 > > > > -- > Peter Xu > With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|