From: Jason Wang <jasowang@redhat.com>
To: eduardo@habkost.net, marcel.apfelbaum@gmail.com,
philmd@linaro.org, wangyanan55@huawei.com, zhao1.liu@intel.com,
mst@redhat.com, jasowang@redhat.com, qemu-devel@nongnu.org,
peterx@redhat.com
Cc: farosas@suse.de, jinpu.wang@ionos.com, thuth@redhat.com,
berrange@redhat.com
Subject: [RFC PATCH] virtio-net: introduce strict peer feature check
Date: Fri, 7 Nov 2025 10:01:49 +0800 [thread overview]
Message-ID: <20251107020149.3223-1-jasowang@redhat.com> (raw)
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 <jasowang@redhat.com>
---
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
next reply other threads:[~2025-11-07 2:03 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-07 2:01 Jason Wang [this message]
2025-11-12 21:55 ` [RFC PATCH] virtio-net: introduce strict peer feature check Peter Xu
2025-11-13 0:31 ` Jason Wang
2025-11-13 15:51 ` Peter Xu
2025-11-13 8:53 ` Daniel P. Berrangé
2025-11-13 15:58 ` Peter Xu
2025-11-13 16:09 ` Michael S. Tsirkin
2025-11-13 16:37 ` Peter Xu
2025-11-13 16:47 ` Michael S. Tsirkin
2025-11-13 17:12 ` Peter Xu
2025-11-13 17:46 ` Michael S. Tsirkin
2025-11-13 19:32 ` Peter Xu
2025-11-14 1:51 ` Jason Wang
2025-11-16 6:45 ` Michael S. Tsirkin
2025-11-19 2:06 ` Jason Wang
2025-11-19 6:31 ` Michael S. Tsirkin
2025-11-14 5:48 ` Thomas Huth
2025-11-14 9:53 ` Jinpu Wang
2025-11-14 15:47 ` Peter Xu
2025-11-14 1:32 ` Jason Wang
2025-11-16 6:52 ` Michael S. Tsirkin
2025-11-17 4:31 ` Jason Wang
2025-11-17 8:57 ` Michael S. Tsirkin
2025-11-19 2:49 ` Jason Wang
2025-11-19 8:07 ` Michael S. Tsirkin
2025-11-20 1:45 ` Jason Wang
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