[v9,14/20] virtio-net: Report RSS warning at device realization

Commit Message

Akihiko Odaki April 3, 2024, 11:11 a.m. UTC

Warning about RSS fallback at device realization allows the user to
notice the configuration problem early.

Signed-off-by: Akihiko Odaki <[e-mail]>
---
 hw/net/virtio-net.c | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

Patch

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 3d53eba88cfc..86929c9e1fad 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -1261,10 +1261,12 @@  static bool virtio_net_attach_epbf_rss(VirtIONet *n)
 
     if (!ebpf_rss_set_all(&n->ebpf_rss, &config,
                           n->rss_data.indirections_table, n->rss_data.key)) {
+        error_report("Failed to configure eBPF RSS");
         return false;
     }
 
     if (!virtio_net_attach_ebpf_to_backend(n->nic, n->ebpf_rss.program_fd)) {
+        error_report("Failed to attach eBPF to backend");
         return false;
     }
 
@@ -1279,16 +1281,10 @@  static void virtio_net_detach_epbf_rss(VirtIONet *n)
 static void virtio_net_commit_rss_config(VirtIONet *n)
 {
     if (n->rss_data.enabled) {
-        n->rss_data.enabled_software_rss = n->rss_data.populate_hash;
+        n->rss_data.enabled_software_rss = n->rss_data.populate_hash ||
+                                           !virtio_net_attach_epbf_rss(n);
         if (n->rss_data.populate_hash) {
             virtio_net_detach_epbf_rss(n);
-        } else if (!virtio_net_attach_epbf_rss(n)) {
-            if (get_vhost_net(qemu_get_queue(n->nic)->peer)) {
-                warn_report("Can't load eBPF RSS for vhost");
-            } else {
-                warn_report("Can't load eBPF RSS - fallback to software RSS");
-                n->rss_data.enabled_software_rss = true;
-            }
         }
 
         trace_virtio_net_rss_enable(n->rss_data.hash_types,
@@ -3802,9 +3798,14 @@  static void virtio_net_device_realize(DeviceState *dev, Error **errp)
     net_rx_pkt_init(&n->rx_pkt);
 
     if (virtio_has_feature(n->host_features, VIRTIO_NET_F_RSS) &&
-        !virtio_net_load_ebpf(n) && get_vhost_net(nc->peer)) {
-        virtio_net_device_unrealize(dev);
-        error_setg(errp, "Can't load eBPF RSS for vhost");
+        !virtio_net_load_ebpf(n)) {
+        if (get_vhost_net(nc->peer)) {
+            error_setg(errp, "Can't load eBPF RSS for vhost");
+            virtio_net_device_unrealize(dev);
+            return;
+        }
+
+        warn_report("Can't load eBPF RSS - fallback to software RSS");
     }
 }