From: Jason Wang Date: Wed, 17 Sep 2025 06:30:45 +0000 (+0800) Subject: vhost-net: flush batched before enabling notifications X-Git-Tag: v6.17~20^2~4 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=e430451613c7a27beeadd00d707bcf7ceec6328e;p=thirdparty%2Fkernel%2Fstable.git vhost-net: flush batched before enabling notifications Commit 8c2e6b26ffe2 ("vhost/net: Defer TX queue re-enable until after sendmsg") tries to defer the notification enabling by moving the logic out of the loop after the vhost_tx_batch() when nothing new is spotted. This caused unexpected side effects as the new logic is reused for several other error conditions. A previous patch reverted 8c2e6b26ffe2. Now, bring the performance back up by flushing batched buffers before enabling notifications. Reported-by: Jon Kohler Cc: stable@vger.kernel.org Fixes: 8c2e6b26ffe2 ("vhost/net: Defer TX queue re-enable until after sendmsg") Signed-off-by: Jason Wang Signed-off-by: Michael S. Tsirkin Message-Id: <20250917063045.2042-3-jasowang@redhat.com> --- diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 57efd5c55f89e..35ded43304319 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -780,6 +780,11 @@ static void handle_tx_copy(struct vhost_net *net, struct socket *sock) break; /* Nothing new? Wait for eventfd to tell us they refilled. */ if (head == vq->num) { + /* Flush batched packets to handle pending RX + * work (if busyloop_intr is set) and to avoid + * unnecessary virtqueue kicks. + */ + vhost_tx_batch(net, nvq, sock, &msg); if (unlikely(busyloop_intr)) { vhost_poll_queue(&vq->poll); } else if (unlikely(vhost_enable_notify(&net->dev,