From adda0ad56bd28d5a809051cbd190fda5798ec4e4 Mon Sep 17 00:00:00 2001 From: Akihiko Odaki Date: Fri, 30 May 2025 14:18:53 +0900 Subject: virtio-net: Add queues for RSS during migration virtio_net_pre_load_queues() inspects vdev->guest_features to tell if VIRTIO_NET_F_RSS or VIRTIO_NET_F_MQ is enabled to infer the required number of queues. This works for VIRTIO_NET_F_MQ but it doesn't for VIRTIO_NET_F_RSS because only the lowest 32 bits of vdev->guest_features is set at the point and VIRTIO_NET_F_RSS uses bit 60 while VIRTIO_NET_F_MQ uses bit 22. Instead of inferring the required number of queues from vdev->guest_features, use the number loaded from the vm state. This change also has a nice side effect to remove a duplicate peer queue pair change by circumventing virtio_net_set_multiqueue(). Also update the comment in include/hw/virtio/virtio.h to prevent an implementation of pre_load_queues() from refering to any fields being loaded during migration by accident in the future. Fixes: 8c49756825da ("virtio-net: Add only one queue pair when realizing") Tested-by: Lei Yang Cc: qemu-stable@nongnu.org Signed-off-by: Akihiko Odaki Signed-off-by: Jason Wang --- hw/net/virtio-net.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) (limited to 'hw/net/virtio-net.c') diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c index eb93607b8c..351377c025 100644 --- a/hw/net/virtio-net.c +++ b/hw/net/virtio-net.c @@ -3022,11 +3022,10 @@ static void virtio_net_del_queue(VirtIONet *n, int index) virtio_del_queue(vdev, index * 2 + 1); } -static void virtio_net_change_num_queue_pairs(VirtIONet *n, int new_max_queue_pairs) +static void virtio_net_change_num_queues(VirtIONet *n, int new_num_queues) { VirtIODevice *vdev = VIRTIO_DEVICE(n); int old_num_queues = virtio_get_num_queues(vdev); - int new_num_queues = new_max_queue_pairs * 2 + 1; int i; assert(old_num_queues >= 3); @@ -3062,16 +3061,14 @@ static void virtio_net_set_multiqueue(VirtIONet *n, int multiqueue) int max = multiqueue ? n->max_queue_pairs : 1; n->multiqueue = multiqueue; - virtio_net_change_num_queue_pairs(n, max); + virtio_net_change_num_queues(n, max * 2 + 1); virtio_net_set_queue_pairs(n); } -static int virtio_net_pre_load_queues(VirtIODevice *vdev) +static int virtio_net_pre_load_queues(VirtIODevice *vdev, uint32_t n) { - virtio_net_set_multiqueue(VIRTIO_NET(vdev), - virtio_has_feature(vdev->guest_features, VIRTIO_NET_F_RSS) || - virtio_has_feature(vdev->guest_features, VIRTIO_NET_F_MQ)); + virtio_net_change_num_queues(VIRTIO_NET(vdev), n); return 0; } -- cgit 1.4.1