qemu-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] vhost-pci and virtio-vhost-user


From: Jason Wang
Subject: Re: [Qemu-devel] vhost-pci and virtio-vhost-user
Date: Mon, 22 Jan 2018 11:54:41 +0800
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.5.0



On 2018年01月20日 01:20, Stefan Hajnoczi wrote:
I don't propose any new idea. I just want to know what's the advantage of
vhost-pci over zerocopy. Both needs one time of copy, the difference is the
vhost-pci did it inside a guest but zerocopy did in on host.
Exitless VM2VM communication is desirable if you cannot run software on
the host or if both endpoints are already in VMs.  In that case running
one thing in a VM and another on the host doesn't make sense.

Well, I must have missed anything, I don't see why we can not run virtio-net backend on host. Especially it only does L2 stuffs, higher level of service could be provided by another VM for sure. So it looks to me virtio-vhost-user is just a split device implementation which is irreverent to the service it could provide.

Maybe you can provide a concrete examples of virtio-vhost-user and its advantages?


The obvious environment where this applies is in the cloud where
everything is a VM.

So a typical setup makes the VMs can already talk to each other through ethernet(virtio-net). Virtio-vhost-user looks much less flexible than exist stuffs. The only possible advantage of virtio-vhost-user is its performance or security which still need to be proved.

Thanks



reply via email to

[Prev in Thread] Current Thread [Next in Thread]