[Qemu-devel] [PATCH] virtio-net: count VIRTIO_NET_F_MAC when calculating config_len

[Jason Wang]

Commit 14f9b664 (hw/virtio-net.c: set config size using host features) tries to
calculate config size based on the host features. But it forgets the
VIRTIO_NET_F_MAC were always set for qemu later. This will lead a zero config
len for virtio-net device when both VIRTIO_NET_F_STATUS and VIRTIO_NET_F_MQ were
disabled form command line. Then qemu will crash when user tries to read the
config of virtio-net.

Fix this by counting VIRTIO_NET_F_MAC and make sure the config at least contains
the mac address.

Cc: Jesse Larrew <address@hidden>
Signed-off-by: Jason Wang <address@hidden>
---
 hw/net/virtio-net.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 70c8fce..33a70ef 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -1264,7 +1264,8 @@ static void virtio_net_guest_notifier_mask(VirtIODevice 
*vdev, int idx,
 
 void virtio_net_set_config_size(VirtIONet *n, uint32_t host_features)
 {
-    int i, config_size = 0;
+    /* VIRTIO_NET_F_MAC can't be disabled from qemu side */
+    int i, config_size = feature_sizes[0].end;
     for (i = 0; feature_sizes[i].flags != 0; i++) {
         if (host_features & feature_sizes[i].flags) {
             config_size = MAX(feature_sizes[i].end, config_size);
-- 
1.7.1