kvm-tools: can't seem to set guest_mac and KVM_GET_SUPPORTED_CPUID failed.

David Evensky
2011-11-17T01:00:28Z

There was a patch (quoted below) that changed networking at the end of September. When I
try to set the guest_mac from the usage in the patch and an admittaly too
brief a look at the code, the guest's mac address isn't being set. I'm using:

sudo /path/to/linux-kvm/tools/kvm/kvm run -c 1 -m 256 -k /path/to/bzImage-3.0.8 \
-i /path/to/initramfs-host.img --console serial -p ' console=ttyS0 ' -n tap,guest_mac=00:11:11:11:11:11

In the guest I get:

# ifconfig eth0
eth0 Link encap:Ethernet HWaddr 02:15:15:15:15:15
inet addr:192.168.122.237 Bcast:192.168.122.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:24 errors:0 dropped:2 overruns:0 frame:0
TX packets:2 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:1874 (1.8 KiB) TX bytes:656 (656.0 B)

which is the default.

Also, when I start the guest I sometimes get the following error message:

# kvm run -k /path/to/bzImage-3.0.8 -m 256 -c 1 --name guest-15757
KVM_GET_SUPPORTED_CPUID failed: Argument list too long

I haven't seen that before.

Thanks,
\dae

On Sat, Sep 24, 2011 at 12:17:51PM +0300, Sasha Levin wrote:
> This patch adds support for multiple network devices. The command line syntax
> changes to the following:
>
> --network/-n [mode=[tap/user/none]] [guest_ip=[guest ip]] [host_ip=
> [host_ip]] [guest_mac=[guest_mac]] [script=[script]]
>
> Each of the parameters is optional, and the config defaults to a TAP based
> networking with a random MAC.
> ...