When using the ProxyServer, or just when connecting to/from a virtual machine in general, it would be very nice to support VSOCK. One could also envisage running virtual machines without any networking whatsoever (or even the host, and let the VM have the NIC instead), only the VSOCK would be used for display forwarding.
qemu ... -device vhost-vsock-pci,id=vhost-vsock-pci0
.svm_family = AF_VSOCK, .svm_cid = VMADDR_CID_HOST, .svm_port = 1234,
Not sure about the kernel + python support.
/usr/include/bits/socket.h:#define PF_VSOCK 40 /* vSockets. */ /usr/include/bits/socket.h:#define AF_VSOCK PF_VSOCK
This may require cythonizing:
>>> s=socket.socket(40) >>> s.bind((1234, )) Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/usr/lib64/python2.7/socket.py", line 228, in meth return getattr(self._sock,name)(*args) socket.error: getsockaddrarg: bad family >>>
patch attempting to force AF_VSOCK into the python socket class
The vsock bits have been reverted in December 2015: VSOCK: revert virtio-vsock until device spec is finalized, which makes it very hard to test. And it's not immediately obvious because you get this unhelpful error:
qemu-system-x86_64: -device vhost-vsock-pci,id=vh0,addr=4.0,guest-cid=4: vhost-vsock: failed to open vhost device: Unknown error -2
You then have to figure out with strace that the device does not exist..
To fix this, you either have to download the kernel tree they are using (see RFC,v5,4/5 VSOCK: Introduce vhost_vsock.ko. (for example the Fedora rawhide kernels - the patch applies cleanly there still, bar the maintainers file which can be skipped anyway)
Once I figured out that you MUST use the kernel and qemu versions from http://qemu-project.org/Features/VirtioVsock (other combinations may or may not work - this one definitely does, the patched kernel is needed at both ends too), it wasn't too difficult: done in r12309. It is very fast. The latency goes from ~12ms to 0. Packets come in 256KB chunks at about 1.1GB/s with fairly low CPU usage.
modprobe vhost_vsock chmod 666 /dev/vhost-vsock
xpra start :100 --start-child="xterm" --bind-vsock=auto:2000
/usr/local/bin/qemu-system-x86_64 --enable-kvm -m 2048 -name Fedora-24 \ -drive file=./Fedora-24-x86_64.raw,if=virtio,index=0,format=raw \ -device vhost-vsock-pci,id=vhost-vsock-pci0,addr=4.0,guest-cid=4
modprobe vsock xpra attach vsock:host:2000
Note: I thought the connections using vsock were from guest to host only, but that is not the case: Re: AF_VSOCK status (will need re-testing).
@smo: let's discuss.
See also ticket:1159#comment:1 for the new
Conversely, you can run a server in the guest and connect to it using the assigned CID. Re-using the same qemu command line as comment:4 (guest-cid=4). The guest can start a server:
xpra start :100 --start-child="xterm" --bind-vsock=auto:10000
And we can connect to it from the host using:
xpra attach vhost:4:10000
r12698 adds it to the man page.
VSOCK is included in kernel 4.8, here was the pull request: vhost: new features for 4.8
Just a quick update to this old ticket.
Looks like the kernel modules are there now with Fedora 24 which is what I run on my workstation.
After loading vhost_vsock module and trying to make use of it in qemu results in
'vhost-vsock-pci' is not a valid device model name
Does qemu perhaps have to be configured with an option to enable vsock support?
email sent to the AF_VSOCK maintainer and kvm ML
Seems that even qemu 2.7 in Fedora 25 does not have vsock builtin. I've pinged an email to the maintainer. (attached)
Got the answer from the 2.8 release notes http://wiki.qemu.org/ChangeLog/2.8#virtio: New device vhost-vsock.
You should be able to test with the 2.8 RC.
This has been tested, see #1387 for a follow up - closing.
this ticket has been moved to: https://github.com/Xpra-org/xpra/issues/983