Test vhost-net !!

Test vhost-net !!

[Onkar Mahajan]

Hi ,
   How do I test if vhost-net is actually enabled and working ?

Regards,
Onkar

Re: Test vhost-net !!

[Jean-Philippe Menil]

Le 07/04/2011 09:18, Onkar Mahajan a écrit :
> Hi ,
>     How do I test if vhost-net is actually enabled and working ?
>
> Regards,
> Onkar
> --
> To unsubscribe from this list: send the line "unsubscribe kvm" in
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Hi,

you must modprobe the vhost_net module on your host:

root@ayrshire:~# lsmod | grep vhost
vhost_net              18197  17
macvtap                 7452  1 vhost_net
tun                    15387  35 vhost_net

and you need to pass "vhost-on" on your command line:
http://www.linux-kvm.org/page/VhostNet

When the guest start, you will see some process like theses on your host:
root@ayrshire:~# ps aux | grep vhost-
root      4336  0.0  0.0      0     0 ?        S    Mar16   1:36 
[vhost-4329]
root      4337  0.3  0.0      0     0 ?        S    Mar16 100:15 
[vhost-4329]
root      4454 16.9  0.0      0     0 ?        S    Mar16 5331:54 
[vhost-4444]
root      4455  0.0  0.0      0     0 ?        S    Mar16   4:52 
[vhost-4444]
root      4456  1.2  0.0      0     0 ?        S    Mar16 404:57 
[vhost-4444]
root      4457  0.0  0.0      0     0 ?        S    Mar16   1:45 
[vhost-4444]
root      4458  9.0  0.0      0     0 ?        S    Mar16 2855:00 
[vhost-4444]
root      4459  0.0  0.0      0     0 ?        S    Mar16   0:51 
[vhost-4444]
root      4460  4.6  0.0      0     0 ?        S    Mar16 1465:50 
[vhost-4444]
root      4461  0.0  0.0      0     0 ?        S    Mar16   4:02 
[vhost-4444]
root      4462  3.4  0.0      0     0 ?        S    Mar16 1068:59 
[vhost-4444]
root      4463  0.0  0.0      0     0 ?        S    Mar16   0:49 
[vhost-4444]
root      4464  1.5  0.0      0     0 ?        S    Mar16 473:23 
[vhost-4444]
root      4465  0.0  0.0      0     0 ?        S    Mar16   0:40 
[vhost-4444]
root      4466  5.8  0.0      0     0 ?        S    Mar16 1835:21 
[vhost-4444]
root      4503  0.0  0.0      0     0 ?        S    Mar16   1:39 
[vhost-4498]
root      4504  0.0  0.0      0     0 ?        S    Mar16   1:44 
[vhost-4498]
root     24288  0.0  0.0   9664   840 pts/1    S+   09:31   0:00 grep vhost-

Regards.

-- 
Jean-Philippe Menil - Pôle réseau Service IRTS
DSI Université de Nantes
jean-philippe.menil@univ-nantes.fr
Tel : 02.53.48.49.27 - Fax : 02.53.48.49.09

Re: Test vhost-net !!

[Asdo]

On 04/07/2011 09:33 AM, Jean-Philippe Menil wrote:
> Le 07/04/2011 09:18, Onkar Mahajan a écrit :
>> Hi ,
>>     How do I test if vhost-net is actually enabled and working ? Hi,
>> ...
>
> you must modprobe the vhost_net module on your host:
> ...
> and you need to pass "vhost-on" on your command line:
> http://www.linux-kvm.org/page/VhostNet
> ...
> Regards.
>

Are you really able to make vhost_net work?

I compiled from source KVM 0.13.0 and recently also 0.14.0 on intel xeon
54xx and 56xx, on newly installed Ubuntu with vanilla kernel 2.6.37, and
when I tried to enable vhost_net (modprobe the module then restart KVM)
the emulation was going 100x slower than normal, so I had to disable it.
See my old message in this ML "vhost disables kvm acceleration"

What did you do to make it work? Did you compile KVM from sources? On
what kernel? AMD or Intel?
Also, are you not using libvirt maybe?

Thank you

Re: Test vhost-net !!

[Jean-Philippe Menil]

Le 09/04/2011 16:25, Asdo a écrit :
> On 04/07/2011 09:33 AM, Jean-Philippe Menil wrote:
>> Le 07/04/2011 09:18, Onkar Mahajan a écrit :
>>> Hi ,
>>>      How do I test if vhost-net is actually enabled and working ? Hi,
>>> ...
>>
>> you must modprobe the vhost_net module on your host:
>> ...
>> and you need to pass "vhost-on" on your command line:
>> http://www.linux-kvm.org/page/VhostNet
>> ...
>> Regards.
>>
>
> Are you really able to make vhost_net work?
>
> I compiled from source KVM 0.13.0 and recently also 0.14.0 on intel xeon
> 54xx and 56xx, on newly installed Ubuntu with vanilla kernel 2.6.37, and
> when I tried to enable vhost_net (modprobe the module then restart KVM)
> the emulation was going 100x slower than normal, so I had to disable it.
> See my old message in this ML "vhost disables kvm acceleration"
>
> What did you do to make it work? Did you compile KVM from sources? On
> what kernel? AMD or Intel?
> Also, are you not using libvirt maybe?
>
> Thank you
>
> --
> To unsubscribe from this list: send the line "unsubscribe kvm" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
Hmm, something must be wrong in your configuration.
I use successfully vhost_net module on 2.6.38 with qemu-kvm 0.14.0 
compiled from sources. Run fine on amd, must run fine on intel too.
If you use libvirt, you must restart the libvirt dameon after modprobe 
the vhost_net module, otherwise libvirt don't append the vhost=on parameter.

Can you provide your command line? and what guest are you running?

-- 
Jean-Philippe Menil - Pôle réseau Service IRTS
DSI Université de Nantes
jean-philippe.menil@univ-nantes.fr
Tel : 02.53.48.49.27 - Fax : 02.53.48.49.09