[Qemu-devel] Regression "Warning: more nics requested than this machine supports"

[Markus Armbruster]

Watch this:

    $ qemu-system-x86_64 -nodefaults -enable-kvm -m 384 -vnc :0 -S -netdev 
user,id=net0 -device e1000,netdev=net0
    Warning: more nics requested than this machine supports; some have been 
ignored
    (qemu) info network
    Devices not on any VLAN:
      net0: net=10.0.2.0, restricted=n peer=e1000.0
      e1000.0: model=e1000,macaddr=52:54:00:12:34:56 peer=net0

Culprit is

commit f68b9d672b90dedc79aeb9b44607f484dbe46a6b
Author: Peter Maydell <address@hidden>
Date:   Tue Mar 22 18:39:40 2011 +0000

    net: Improve the warnings for dubious command line option combinations
    
    Improve the warnings we give if the user specified a combination of -net
    options which don't make much sense:
     * Don't warn about anything if the config is the implicit default
       "-net user -net nic" rather than one specified by the user (this will
       only kick in for boards with no NIC or if CONFIG_SLIRP is not set)
     * Diagnose the case where the user asked for NICs which the board
       didn't instantiate (for example where the user asked for two NICs
       but the board only supports one)
    
    Signed-off-by: Peter Maydell <address@hidden>
    Signed-off-by: Aurelien Jarno <address@hidden>

Its count of requested NICs is blissfully unaware of -device.  In my
example, it comes up with nb_nics == 0 and seen_nics == 1.