Re: [Qemu-devel] vio-net driver

[Charles . Tsai-蔡清海-研究發展部]

Hi Brian,

Do you have any finding for VirtIO Net driver problem?
The latest Ubuntu release(v 12.04) still comes with Qemu 0.14.1.
Did you find any debug report for VirtIO Net driver on qemu 0.14.1?
If we need to upgrade qemu, is there any installation package available over 
the web?
Last time, my co-worker upgraded the Qemu by compiling the  source code.
I am wondering that my co-worker might have done something wrong during the 
upgrade process that caused software conflict. Please let me know the easiest 
way to upgrade Qemu for Ubuntu without any hassle.

Thanks.

-----Original Message-----
From: Charles.Tsai-蔡清海-研究發展部 
Sent: Wednesday, June 06, 2012 11:48 AM
To: 'Brian Jackson'; address@hidden
Subject: RE: [Qemu-devel] vio-net driver

Hi Brian,

        Here are the information from our system.

        We launched the VM using the following XML file.
        The kernel version is 3.0.0.12
        The Qemu version is 1.0.0(we upgraded it. Default one is 0.14.1)

===================================================================
<domain type='kvm'>
  <name>MONITOR</name>
  <uuid>c34f950d-6784-468b-ab1d-d7a4bff3522c</uuid>
  <memory>2097152</memory>
  <currentMemory>2097152</currentMemory>
  <vcpu>1</vcpu>
  <os>
    <type arch='x86_64' machine='pc'>hvm</type>
    <boot dev='network'/>
    <bootmenu enable='no'/>
  </os>
  <features>
    <acpi/>
    <apic/>
    <pae/>
  </features>
  <clock offset='utc'/>
  <on_poweroff>destroy</on_poweroff>
  <on_reboot>restart</on_reboot>
  <on_crash>restart</on_crash>
  <devices>
    <emulator>/usr/bin/kvm</emulator>
    <disk type='file' device='disk'>
      <driver name='qemu' type='raw' cache='none'/>
      <source file='/opt/cloudena/cloudena_boot/vms/monitor/monitor.img'/>
      <target dev='vda' bus='virtio'/>
    </disk>
    <interface type='bridge'>
      <mac address='00:00:00:00:00:02'/>
      <source bridge='deploy'/>
      <model type='virtio'/>
    </interface>
    <serial type='pty'>
      <source path='/dev/pts/12'/>
      <target port='0'/>
      <alias name='serial0'/>
    </serial>
    <console type='pty' tty='/dev/pts/12'>
      <source path='/dev/pts/12'/>
      <target type='serial' port='0'/>
      <alias name='serial0'/>
    </console>
    <input type='mouse' bus='ps2'/>
    <graphics type='vnc' port='-1' autoport='yes' listen='0.0.0.0'/>
    <video>
      <model type='cirrus' vram='9216' heads='1'/>
      <alias name='video0'/>
    </video>
    <memballoon model='virtio'>
      <alias name='balloon0'/>
    </memballoon>
  </devices>
</domain>

-----Original Message-----
From: Brian Jackson [mailto:address@hidden
Sent: Wednesday, June 06, 2012 2:30 AM
To: address@hidden
Cc: Charles.Tsai-蔡清海-研究發展部
Subject: Re: [Qemu-devel] vio-net driver

On Tuesday, June 05, 2012 12:17:17 AM Charles.Tsai-蔡清海-研究發展部 wrote:
> We recently ran an Ubuntu 11.10 VM which was installed with VirtIO NIC 
> driver. The VirtIO net driver came from the Ubuntu's default package.
> The VM we installed was configured as a bridge mode. When we ran the 
> Iperf test against the VM, the network interface of the VM was fairly 
> unstable.
> Sometimes, the network interface of the VM could not receive the 
> packets and we needed to bright the network interface down and up in 
> order to make it work. After we replaced the VirtIo Net driver with 
> ne2k driver and it worked quite stably now.


The normal answer is "update to the latest kernel (host and guest) and qemu/kvm.



> 
> 
> 
> We know that the performance of virtIO is much better than ne2k in virtual
> environment. We would like to use virtio driver instead. If this is the
> virtio driver issue, can you tell us where to get the latest virtIO driver
> for Ubuntu VM? Otherwise, tell us how to make the virtio net driver work
> in Ubuntu VM if you have ever had similar issue before.
> 
> The version of Qemu installed in Ubuntu is 1.0


I have to imagine they are backporting 1.0 branch fixes to that, but even then  
nothing pops out in my memory about problems like that with 1.0. Older 
versions are a different story. You might try telling us host kernel version, 
guest kernel version (we don't all have a matrix for what random distro 
version has what kernel/qemu/kvm versions). Also, the command line used to run 
the guest is almost always a requirement for help.