From 40558266b1bcea744427118fd6f848a9e31364e2 Mon Sep 17 00:00:00 2001 From: Akihiko Odaki Date: Mon, 21 Apr 2025 21:17:20 +0900 Subject: [PATCH] virtio: Call set_features during reset virtio-net expects set_features() will be called when the feature set used by the guest changes to update the number of virtqueues but it is not called during reset, which will clear all features, leaving the queues added for VIRTIO_NET_F_MQ or VIRTIO_NET_F_RSS. Not only these extra queues are visible to the guest, they will cause segmentation fault during migration. Call set_features() during reset to remove those queues for virtio-net as we call set_status(). It will also prevent similar bugs for virtio-net and other devices in the future. Fixes: f9d6dbf0bf6e ("virtio-net: remove virtio queues if the guest doesn't support multiqueue") Buglink: https://issues.redhat.com/browse/RHEL-73842 Cc: qemu-stable@nongnu.org Signed-off-by: Akihiko Odaki Message-Id: <20250421-reset-v2-1-e4c1ead88ea1@daynix.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin (cherry picked from commit 0caed25cd171c611781589b5402161d27d57229c) Signed-off-by: Michael Tokarev --- hw/virtio/virtio.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 85110bce37..755260981e 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -2316,6 +2316,8 @@ void virtio_queue_enable(VirtIODevice *vdev, uint32_t queue_index) } } +static int virtio_set_features_nocheck(VirtIODevice *vdev, uint64_t val); + void virtio_reset(void *opaque) { VirtIODevice *vdev = opaque; @@ -2346,7 +2348,7 @@ void virtio_reset(void *opaque) vdev->start_on_kick = false; vdev->started = false; vdev->broken = false; - vdev->guest_features = 0; + virtio_set_features_nocheck(vdev, 0); vdev->queue_sel = 0; vdev->status = 0; vdev->disabled = false; -- 2.39.5