On both qemu (no-kqemu) and qemu-kvm (no-kvm or with kvm) release
0.9.0 the following happens when using ne2000 (default) emulation:
UG: waring at kernel/softirq.c:138/local_bh_enable() (Not tainted)
[<c042b0cf>] local_bh_enable+ /0x92
[..........] cond_resched_sof +0x2c/0x42
[..........] release_sock+0x4f/0 9d
[..........] inet_stream_connect+0x116/0x1ff
[..........] autoremove_wake_function+0x0/0x35
[..........] sys_connect+0x82/0xad
[..........] d_instantiate+0x5c/ x60
[..........] sock_attach_fd+0x70/0xcf
[..........] selinux_file_alloc_security+0x1f/0x40
[..........] get_empty_filp+0x99/0x151
[..........] __sock_create+0x16e/0x1a8
[..........] fd_install+0x1e/0x47
[..........] sock_map_fd+0x41/0x47
[..........] sys_socketcall+0xac/0x261
[..........] syscall_call+0x7/0xb
The virtual host runs fedora 7, kernel-2.6.21-1.3194.fc7. When
using windows-XP as a virtual host a network hang also occurs, but
I have no details about it.
The mentioned problems (for both Linux and Windows XP) do not
occur when using rtl8139 emulation.