tap: forbid creating multiqueue tap when hub is used
Obviously, hub does not support multiqueue tap. So this patch forbids creating
multiple queue tap when hub is used to prevent the crash when command line such
as "-net tap,queues=2" is used.
Cc: qemu-stable@nongnu.org
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/net/tap.c b/net/tap.c
index 48c254e..daab350 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -693,6 +693,13 @@
queues = tap->has_queues ? tap->queues : 1;
vhostfdname = tap->has_vhostfd ? tap->vhostfd : NULL;
+ /* QEMU vlans does not support multiqueue tap, in this case peer is set.
+ * For -netdev, peer is always NULL. */
+ if (peer && (tap->has_queues || tap->has_fds || tap->has_vhostfds)) {
+ error_report("Multiqueue tap cannnot be used with QEMU vlans");
+ return -1;
+ }
+
if (tap->has_fd) {
if (tap->has_ifname || tap->has_script || tap->has_downscript ||
tap->has_vnet_hdr || tap->has_helper || tap->has_queues ||
