I'm worried that the network packet loss rate will increase after  reversing 
the order.
















为了让您的VPlat虚拟化故障得到高效的处理,请上报故障到: $VPlat技术支持。


芦志朋 luzhipeng






IT开发工程师 IT Development
Engineer
操作系统产品部/中心研究院/系统产品 OS Product Dept./Central R&D Institute/System Product









深圳市南山区科技南路55号中兴通讯研发大楼33楼 
33/F, R&D Building, ZTE
Corporation Hi-tech Road South, 
Hi-tech
Industrial Park Nanshan District, Shenzhen, P.R.China, 518057 
T: +86 755 xxxxxxxx F:+86 755 xxxxxxxx 
M: +86 xxxxxxxxxxx 
E: lu.zhip...@zte.com.cn 
www.zte.com.cn






原始邮件



发件人: <berra...@redhat.com>
收件人: <la...@laine.org>
抄送人: <libvir-list@redhat.com>芦志朋10108272
日 期 :2017年05月02日 16:30
主 题 :Re: [libvirt] [PATCH] qemu: change the name of tap device for a tapand 
bridge network





On Fri, Apr 28, 2017 at 01:08:45PM -0400, Laine Stump wrote:
> On 04/28/2017 05:33 AM, Daniel P. Berrange wrote:
> > On Fri, Apr 28, 2017 at 05:23:19PM +0800, ZhiPeng Lu wrote:
> >> Creating tap device and adding the device to bridge are not atomic 
operation.
> >> Similarly deleting tap device and removing it from bridge are not atomic 
operation.
> >> The Problem occurs when two vms start and shutdown. When one vm with the 
nic
> >> named "vnet0" stopping, it deleted tap device but not removing port from 
bridge.
> >> At this time, another vm created the tap device named "vnet0" and added 
port to the
> >> same bridge. Then, the first vm deleted the tap device from the same 
bridge.
> >> Finally, the tap device of the second vm don't attached to the bridge.
> >> So, we can add domid to vm's nic name. For example, the vm's domid is 1 
and vnet0
> >> is renamed to vnet1.0.
> > 
> > Surely deleting the NIC automatically removes it from the bridge so we
> > can just remove the code that delets the bridge port.
> 
> That is true when using a Linux host bridge, but I recall that for
> openvswitch (which I think is what ZhiPeng is using, based on an earlier
> patch), you must explicitly remove the port from the bridge - apparently
> the port is still there in openvswitch's table as some sort of "zombie"
> connection even after the tap device itself no longer exists.
> 
> 
> But instead of changing the naming scheme, maybe we should just delete
> the bridge port *before* deleting the tap device instead of after. (Am I
> recalling correctly that the tap device is deleted automatically when
> the qemu process is killed? If so, then what's needed is to move the
> loop in qemuProcessStop() that cleans up network interfaces so that it
> happens before qemuProcessKill() is called.

Agreed, we should just reverse the order.

Regards,
Daniel
-- 
|: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org         -o-            https://fstop138.berrange.com :|
|: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange :|

--
libvir-list mailing list
libvir-list@redhat.com
https://www.redhat.com/mailman/listinfo/libvir-list
--
libvir-list mailing list
libvir-list@redhat.com
https://www.redhat.com/mailman/listinfo/libvir-list

Reply via email to