From 4fe096a6fad61ab721fd29324d48383c7f427ac9 Mon Sep 17 00:00:00 2001 From: Laurent Vivier Date: Mon, 5 Jun 2023 16:21:25 +0200 Subject: [PATCH 7/9] virtio-net: correctly report maximum tx_queue_size value MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Laurent Vivier RH-MergeRequest: 191: virtio-net: correctly report maximum tx_queue_size value RH-Bugzilla: 2040509 RH-Acked-by: Stefano Garzarella RH-Acked-by: Eugenio Pérez RH-Commit: [1/1] afb944c6d75fe476ac86fe267b1cca5f272dfbbd (lvivier/qemu-kvm-centos) BZ: https://bugzilla.redhat.com/show_bug.cgi?id=2040509 Maximum value for tx_queue_size depends on the backend type. 1024 for vDPA/vhost-user, 256 for all the others. The value is returned by virtio_net_max_tx_queue_size() to set the parameter: n->net_conf.tx_queue_size = MIN(virtio_net_max_tx_queue_size(n), n->net_conf.tx_queue_size); But the parameter checking uses VIRTQUEUE_MAX_SIZE (1024). So the parameter is silently ignored and ethtool reports a different value than the one provided by the user. ... -netdev tap,... -device virtio-net,tx_queue_size=1024 # ethtool -g enp0s2 Ring parameters for enp0s2: Pre-set maximums: RX: 256 RX Mini: n/a RX Jumbo: n/a TX: 256 Current hardware settings: RX: 256 RX Mini: n/a RX Jumbo: n/a TX: 256 ... -netdev vhost-user,... -device virtio-net,tx_queue_size=2048 Invalid tx_queue_size (= 2048), must be a power of 2 between 256 and 1024 With this patch the correct maximum value is checked and displayed. For vDPA/vhost-user: Invalid tx_queue_size (= 2048), must be a power of 2 between 256 and 1024 For all the others: Invalid tx_queue_size (= 512), must be a power of 2 between 256 and 256 Fixes: 2eef278b9e63 ("virtio-net: fix tx queue size for !vhost-user") Cc: mst@redhat.com Cc: qemu-stable@nongnu.org Signed-off-by: Laurent Vivier Signed-off-by: Jason Wang (cherry picked from commit 4271f4038372f174dbafffacca1a748d058a03ba) --- hw/net/virtio-net.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c index 447f669921..ae1e6a5e3d 100644 --- a/hw/net/virtio-net.c +++ b/hw/net/virtio-net.c @@ -3628,12 +3628,12 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp) } if (n->net_conf.tx_queue_size < VIRTIO_NET_TX_QUEUE_MIN_SIZE || - n->net_conf.tx_queue_size > VIRTQUEUE_MAX_SIZE || + n->net_conf.tx_queue_size > virtio_net_max_tx_queue_size(n) || !is_power_of_2(n->net_conf.tx_queue_size)) { error_setg(errp, "Invalid tx_queue_size (= %" PRIu16 "), " "must be a power of 2 between %d and %d", n->net_conf.tx_queue_size, VIRTIO_NET_TX_QUEUE_MIN_SIZE, - VIRTQUEUE_MAX_SIZE); + virtio_net_max_tx_queue_size(n)); virtio_cleanup(vdev); return; } -- 2.39.3