6.12-stable review patch. If anyone has any objections, please let me know.
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From: Junnan Wu junnan01.wu@samsung.com
[ Upstream commit 55eff109e76a14e5ed10c8c3c3978d20a35e2a4d ]
When executing suspend to ram twice in a row, the `rx_buf_nr` and `rx_buf_max_nr` increase to three times vq->num_free. Then after virtqueue_get_buf and `rx_buf_nr` decreased in function virtio_transport_rx_work, the condition to fill rx buffer (rx_buf_nr < rx_buf_max_nr / 2) will never be met.
It is because that `rx_buf_nr` and `rx_buf_max_nr` are initialized only in virtio_vsock_probe(), but they should be reset whenever virtqueues are recreated, like after a suspend/resume.
Move the `rx_buf_nr` and `rx_buf_max_nr` initialization in virtio_vsock_vqs_init(), so we are sure that they are properly initialized, every time we initialize the virtqueues, either when we load the driver or after a suspend/resume.
To prevent erroneous atomic load operations on the `queued_replies` in the virtio_transport_send_pkt_work() function which may disrupt the scheduling of vsock->rx_work when transmitting reply-required socket packets, this atomic variable must undergo synchronized initialization alongside the preceding two variables after a suspend/resume.
Fixes: bd50c5dc182b ("vsock/virtio: add support for device suspend/resume") Link: https://lore.kernel.org/virtualization/20250207052033.2222629-1-junnan01.wu@... Co-developed-by: Ying Gao ying01.gao@samsung.com Signed-off-by: Ying Gao ying01.gao@samsung.com Signed-off-by: Junnan Wu junnan01.wu@samsung.com Reviewed-by: Luigi Leonardi leonardi@redhat.com Acked-by: Michael S. Tsirkin mst@redhat.com Reviewed-by: Stefano Garzarella sgarzare@redhat.com Link: https://patch.msgid.link/20250214012200.1883896-1-junnan01.wu@samsung.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/vmw_vsock/virtio_transport.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c index b58c3818f284f..f0e48e6911fc4 100644 --- a/net/vmw_vsock/virtio_transport.c +++ b/net/vmw_vsock/virtio_transport.c @@ -670,6 +670,13 @@ static int virtio_vsock_vqs_init(struct virtio_vsock *vsock) }; int ret;
+ mutex_lock(&vsock->rx_lock); + vsock->rx_buf_nr = 0; + vsock->rx_buf_max_nr = 0; + mutex_unlock(&vsock->rx_lock); + + atomic_set(&vsock->queued_replies, 0); + ret = virtio_find_vqs(vdev, VSOCK_VQ_MAX, vsock->vqs, vqs_info, NULL); if (ret < 0) return ret; @@ -779,9 +786,6 @@ static int virtio_vsock_probe(struct virtio_device *vdev)
vsock->vdev = vdev;
- vsock->rx_buf_nr = 0; - vsock->rx_buf_max_nr = 0; - atomic_set(&vsock->queued_replies, 0);
mutex_init(&vsock->tx_lock); mutex_init(&vsock->rx_lock);