net: Consolidate vhost feature bits into vhost_net structure

Previously, the vhost_net_get_feature_bits() function in
hw/net/vhost_net.c used a large switch statement to determine
the appropriate feature bits based on the NetClientDriver type.

This created unnecessary coupling between the generic vhost layer
and specific network backends (like TAP, vhost-user, and
vhost-vdpa).

This patch moves the definition of vhost feature bits directly into the
vhost_net structure for each relevant network client.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/net/tap.c b/net/tap.c
index 4beba6d7a7..a33eb23212 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -42,11 +42,29 @@
 #include "qemu/error-report.h"
 #include "qemu/main-loop.h"
 #include "qemu/sockets.h"
+#include "hw/virtio/vhost.h"
 
 #include "net/tap.h"
 
 #include "net/vhost_net.h"
 
+static const int kernel_feature_bits[] = {
+    VIRTIO_F_NOTIFY_ON_EMPTY,
+    VIRTIO_RING_F_INDIRECT_DESC,
+    VIRTIO_RING_F_EVENT_IDX,
+    VIRTIO_NET_F_MRG_RXBUF,
+    VIRTIO_F_VERSION_1,
+    VIRTIO_NET_F_MTU,
+    VIRTIO_F_IOMMU_PLATFORM,
+    VIRTIO_F_RING_PACKED,
+    VIRTIO_F_RING_RESET,
+    VIRTIO_F_IN_ORDER,
+    VIRTIO_F_NOTIFICATION_DATA,
+    VIRTIO_NET_F_RSC_EXT,
+    VIRTIO_NET_F_HASH_REPORT,
+    VHOST_INVALID_FEATURE_BIT
+};
+
 typedef struct TAPState {
     NetClientState nc;
     int fd;
@@ -725,6 +743,7 @@ static void net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer,
         }
         options.opaque = (void *)(uintptr_t)vhostfd;
         options.nvqs = 2;
+        options.feature_bits = kernel_feature_bits;
 
         s->vhost_net = vhost_net_init(&options);
         if (!s->vhost_net) {