Win2012-64r2 guest doesn't set bus mastering correctly, it caused guest network down, this patch ignored it for e1000 nic for workarounding the guest issue.
Patch 1 is an update version of: http://lists.gnu.org/archive/html/qemu-devel/2014-12/msg00048.html transmit packets are also defered in latest version. Amos Kong (1): e1000: unconditionally enable bus mastering Michael S. Tsirkin (1): e1000: defer packets until BM enabled hw/net/e1000.c | 34 +++++++++++++++++++++++++++++++++- 1 file changed, 33 insertions(+), 1 deletion(-) -- 2.1.0
