From 33b78a30a3e8e1cf16ef423bf2e78caf3d560985 Mon Sep 17 00:00:00 2001 From: Laurent Vivier Date: Wed, 9 Jul 2025 10:24:22 +0200 Subject: net: Allow network backends to advertise max TX queue size This commit refactors how the maximum transmit queue size for virtio-net devices is determined, making the mechanism more generic and extensible. Previously, virtio_net_max_tx_queue_size() contained hardcoded checks for specific network backend types (vhost-user and vhost-vdpa) to determine their supported maximum queue size. This created direct dependencies and would require modifications for every new backend that supports variable queue sizes. To improve flexibility, a new max_tx_queue_size field is added to the vhost_net structure. This allows each network backend to advertise its supported maximum transmit queue size directly. The virtio_net_max_tx_queue_size() function now retrieves the max TX queue size from the vhost_net struct, if available and set. Otherwise, it defaults to VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE. Signed-off-by: Laurent Vivier Signed-off-by: Jason Wang --- hw/net/virtio-net.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) (limited to 'hw/net/virtio-net.c') diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c index e3400f18c8..39fc280839 100644 --- a/hw/net/virtio-net.c +++ b/hw/net/virtio-net.c @@ -670,22 +670,22 @@ static void virtio_net_set_mrg_rx_bufs(VirtIONet *n, int mergeable_rx_bufs, static int virtio_net_max_tx_queue_size(VirtIONet *n) { NetClientState *peer = n->nic_conf.peers.ncs[0]; + struct vhost_net *net; - /* - * Backends other than vhost-user or vhost-vdpa don't support max queue - * size. - */ if (!peer) { - return VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE; + goto default_value; } - switch(peer->info->type) { - case NET_CLIENT_DRIVER_VHOST_USER: - case NET_CLIENT_DRIVER_VHOST_VDPA: - return VIRTQUEUE_MAX_SIZE; - default: - return VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE; - }; + net = get_vhost_net(peer); + + if (!net || !net->max_tx_queue_size) { + goto default_value; + } + + return net->max_tx_queue_size; + +default_value: + return VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE; } static int peer_attach(VirtIONet *n, int index) -- cgit 1.4.1