net/vhost-vdpa: Report hashing capability

Report hashing capability so that virtio-net can deliver the correct
capability information to the guest.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-Id: <20250530-vdpa-v1-2-5af4109b1c19@daynix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

2 files changed, 37 insertions, 0 deletions

diff --git a/net/net.c b/net/net.c
index 39d6f28..d0ae3db 100644
--- a/net/net.c
+++ b/net/net.c
@@ -573,6 +573,15 @@ void qemu_set_vnet_hdr_len(NetClientState *nc, int len)
     nc->info->set_vnet_hdr_len(nc, len);
 }
 
+bool qemu_get_vnet_hash_supported_types(NetClientState *nc, uint32_t *types)
+{
+    if (!nc || !nc->info->get_vnet_hash_supported_types) {
+        return false;
+    }
+
+    return nc->info->get_vnet_hash_supported_types(nc, types);
+}
+
 int qemu_set_vnet_le(NetClientState *nc, bool is_le)
 {
 #if HOST_BIG_ENDIAN
diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
index 58d7389..cb63e09 100644
--- a/net/vhost-vdpa.c
+++ b/net/vhost-vdpa.c
@@ -252,6 +252,32 @@ static bool vhost_vdpa_has_vnet_hdr(NetClientState *nc)
     return true;
 }
 
+static bool vhost_vdpa_get_vnet_hash_supported_types(NetClientState *nc,
+                                                     uint32_t *types)
+{
+    assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA);
+    VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc);
+    uint64_t features = s->vhost_vdpa.dev->features;
+    int fd = s->vhost_vdpa.shared->device_fd;
+    struct {
+        struct vhost_vdpa_config hdr;
+        uint32_t supported_hash_types;
+    } config;
+
+    if (!virtio_has_feature(features, VIRTIO_NET_F_HASH_REPORT) &&
+        !virtio_has_feature(features, VIRTIO_NET_F_RSS)) {
+        return false;
+    }
+
+    config.hdr.off = offsetof(struct virtio_net_config, supported_hash_types);
+    config.hdr.len = sizeof(config.supported_hash_types);
+
+    assert(!ioctl(fd, VHOST_VDPA_GET_CONFIG, &config));
+    *types = le32_to_cpu(config.supported_hash_types);
+
+    return true;
+}
+
 static bool vhost_vdpa_has_ufo(NetClientState *nc)
 {
     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA);
@@ -428,6 +454,7 @@ static NetClientInfo net_vhost_vdpa_info = {
         .stop = vhost_vdpa_net_client_stop,
         .cleanup = vhost_vdpa_cleanup,
         .has_vnet_hdr = vhost_vdpa_has_vnet_hdr,
+        .get_vnet_hash_supported_types = vhost_vdpa_get_vnet_hash_supported_types,
         .has_ufo = vhost_vdpa_has_ufo,
         .set_vnet_le = vhost_vdpa_set_vnet_le,
         .check_peer_type = vhost_vdpa_check_peer_type,
@@ -1284,6 +1311,7 @@ static NetClientInfo net_vhost_vdpa_cvq_info = {
     .stop = vhost_vdpa_net_cvq_stop,
     .cleanup = vhost_vdpa_cleanup,
     .has_vnet_hdr = vhost_vdpa_has_vnet_hdr,
+    .get_vnet_hash_supported_types = vhost_vdpa_get_vnet_hash_supported_types,
     .has_ufo = vhost_vdpa_has_ufo,
     .check_peer_type = vhost_vdpa_check_peer_type,
     .set_steering_ebpf = vhost_vdpa_set_steering_ebpf,