RE: [Qemu-devel] [PATCH] Share Vmware communication port betweendevices

[Dor Laor]

>> Hi,
>>
>> Some more information about the VMware backdoor can be found at:
>> http://chitchat.at.infoseek.co.jp/vmware/backdoor.html
>
>Are there interesting apps that make use of this?  I really don't like
>the idea of supporting this PV protocol if we're not going to get
>interesting apps out of it.  The project you referenced earlier didn't
>have source code available (you had to request it privately) and I don't
>think it's being generally used.
>
>The problem with this particular protocol is that it's inherently
>x86-specific b/c it depends on doing PIO in userspace.  If we're just
>looking to get this functionality, it would be better to do it as a PCI
>device or something that could actually work on non-x86 architectures.

Actually we have implemented such device + driver in qemu for kvm.
You can check out the code, currently is uses ioport too but is accessed
by guest pci driver.
It is called vmchannel device. From the guest view it's a pci device.
From the host view it's a qemu device that can be contacted as a socket/file/..
It is used for mgmt proposes.
--Dor