semantic: 0.176
other: 0.150
network: 0.089
graphic: 0.086
KVM: 0.084
PID: 0.070
device: 0.068
socket: 0.067
performance: 0.046
debug: 0.039
files: 0.036
permissions: 0.035
boot: 0.033
vnc: 0.019
debug: 0.608
network: 0.131
KVM: 0.114
PID: 0.037
other: 0.020
performance: 0.016
socket: 0.016
semantic: 0.015
files: 0.015
device: 0.009
vnc: 0.006
boot: 0.006
graphic: 0.004
permissions: 0.003

Silently fail with wrong vde socket dir

Hi,

Using qemu 0.12.5, kvm silently fail with exit code 1 when using -net vde and a wrong path for sock. Actually, the sock option is mean to be the socket dir of the vde_switch, not the socket itself.

With -net vde,sock=/var/run/vde/vde0/ctl , strace ends with the following messages :

connect(7, {sa_family=AF_FILE, path="/var/run/vde/vde0/ctl/ctl"}, 110) = -1 ENOTDIR (Not a directory)
close(7)                                = 0
close(8)                                = 0
exit_group(1)                           = ?
root ~# 

Please add a meaningful message.

Regards,
Étienne

Hello,

Could you please provide more data, what kinda of system and version are you running on?

Jes


There's no need to add any more specific information.  The bug's in the code in qemu.

net/vde.c:

static int net_vde_init(VLANState *vlan, const char *model,
                        const char *name, const char *sock,
                        int port, const char *group, int mode)
{
...
    vde = vde_open(init_sock, (char *)"QEMU", &args);
    if (!vde){
        return -1;
    }
...
}

There's no message generated there.  Callers merely pass the failure up the road, where it's finally handled as exit(1).  If _anything_ is wrong in vde_open() (which can fail due to variety of reasons, including wrong path to the listening socket and what not), nothing will indicate that, just a trivial, silent exit.

Given that you know what the problem is, it would probably have been faster to post a patch than just updating the bug and marking it confirmed....

A fix for this problem has finally been contributed here:
https://git.qemu.org/?p=qemu.git;a=commitdiff;h=7587855cd23755a7a6bd