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>

3 files changed, 64 insertions, 1 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) {
diff --git a/net/vhost-user.c b/net/vhost-user.c
index b7bf0d2042..bc8e82a092 100644
--- a/net/vhost-user.c
+++ b/net/vhost-user.c
@@ -12,7 +12,9 @@
 #include "clients.h"
 #include "net/vhost_net.h"
 #include "net/vhost-user.h"
+#include "hw/virtio/vhost.h"
 #include "hw/virtio/vhost-user.h"
+#include "standard-headers/linux/virtio_net.h"
 #include "chardev/char-fe.h"
 #include "qapi/error.h"
 #include "qapi/qapi-commands-net.h"
@@ -22,6 +24,46 @@
 #include "qemu/option.h"
 #include "trace.h"
 
+static const int user_feature_bits[] = {
+    VIRTIO_F_NOTIFY_ON_EMPTY,
+    VIRTIO_F_NOTIFICATION_DATA,
+    VIRTIO_RING_F_INDIRECT_DESC,
+    VIRTIO_RING_F_EVENT_IDX,
+
+    VIRTIO_F_ANY_LAYOUT,
+    VIRTIO_F_VERSION_1,
+    VIRTIO_NET_F_CSUM,
+    VIRTIO_NET_F_GUEST_CSUM,
+    VIRTIO_NET_F_GSO,
+    VIRTIO_NET_F_GUEST_TSO4,
+    VIRTIO_NET_F_GUEST_TSO6,
+    VIRTIO_NET_F_GUEST_ECN,
+    VIRTIO_NET_F_GUEST_UFO,
+    VIRTIO_NET_F_HOST_TSO4,
+    VIRTIO_NET_F_HOST_TSO6,
+    VIRTIO_NET_F_HOST_ECN,
+    VIRTIO_NET_F_HOST_UFO,
+    VIRTIO_NET_F_MRG_RXBUF,
+    VIRTIO_NET_F_MTU,
+    VIRTIO_F_IOMMU_PLATFORM,
+    VIRTIO_F_RING_PACKED,
+    VIRTIO_F_RING_RESET,
+    VIRTIO_F_IN_ORDER,
+    VIRTIO_NET_F_RSS,
+    VIRTIO_NET_F_RSC_EXT,
+    VIRTIO_NET_F_HASH_REPORT,
+    VIRTIO_NET_F_GUEST_USO4,
+    VIRTIO_NET_F_GUEST_USO6,
+    VIRTIO_NET_F_HOST_USO,
+
+    /* This bit implies RARP isn't sent by QEMU out of band */
+    VIRTIO_NET_F_GUEST_ANNOUNCE,
+
+    VIRTIO_NET_F_MQ,
+
+    VHOST_INVALID_FEATURE_BIT
+};
+
 typedef struct NetVhostUserState {
     NetClientState nc;
     CharBackend chr; /* only queue index 0 */
@@ -96,6 +138,7 @@ static int vhost_user_start(int queues, NetClientState *ncs[],
         options.opaque      = be;
         options.busyloop_timeout = 0;
         options.nvqs = 2;
+        options.feature_bits = user_feature_bits;
         net = vhost_net_init(&options);
         if (!net) {
             error_report("failed to init vhost_net for queue %d", i);
diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
index 0b86c917ed..cbbea0eb71 100644
--- a/net/vhost-vdpa.c
+++ b/net/vhost-vdpa.c
@@ -55,7 +55,7 @@ typedef struct VhostVDPAState {
  * with the exception of VHOST_INVALID_FEATURE_BIT,
  * which should always be the last entry.
  */
-const int vdpa_feature_bits[] = {
+static const int vdpa_feature_bits[] = {
     VIRTIO_F_ANY_LAYOUT,
     VIRTIO_F_IOMMU_PLATFORM,
     VIRTIO_F_NOTIFY_ON_EMPTY,
@@ -201,6 +201,7 @@ static int vhost_vdpa_add(NetClientState *ncs, void *be,
     options.opaque      = be;
     options.busyloop_timeout = 0;
     options.nvqs = nvqs;
+    options.feature_bits = vdpa_feature_bits;
 
     net = vhost_net_init(&options);
     if (!net) {