#983 closed enhancement (fixed)
AF_VSOCK support
Reported by: | Antoine Martin | Owned by: | Smo |
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Priority: | major | Milestone: | 0.17 |
Component: | core | Version: | 0.15.x |
Keywords: | Cc: |
Description
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.
Links:
Usage:
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 >>>
Attachments (3)
Change History (17)
comment:1 Changed 6 years ago by
Milestone: | 0.17 → 0.18 |
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Status: | new → assigned |
Changed 6 years ago by
Attachment: | vsock.patch added |
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patch attempting to force AF_VSOCK into the python socket class
comment:3 Changed 6 years ago by
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 http://qemu-project.org/Features/VirtioVsock), or a newer kernel source and apply 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)
comment:4 Changed 6 years ago by
Milestone: | 0.18 → 0.17 |
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Owner: | changed from Antoine Martin to Smo |
Status: | assigned → new |
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.
Usage:
- on the host, load the vsock module and make it accessible by non-privileged users (better than running qemu as root... will do for now):
modprobe vhost_vsock chmod 666 /dev/vhost-vsock
- start a session with a vsock bind (here using a specific port, "auto" will assign one):
xpra start :100 --start-child="xterm" --bind-vsock=auto:2000
- start a guest in qemu, use the vhost-vsock option
vhost-vsock-pci,id=vhost-vsock-pci0,addr=M.0,guest-cid=N
, ie:/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
- in the guest, connect to the vsock using:
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.
Debugging:
-d network
- test scripts from r12310
- netcat-vsock: https://github.com/stefanha/linux/blob/vsock-extras/nc-vsock.c
comment:6 Changed 6 years ago by
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
comment:8 Changed 6 years ago by
VSOCK is included in kernel 4.8, here was the pull request: vhost: new features for 4.8
comment:9 Changed 6 years ago by
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?
Changed 6 years ago by
Attachment: | kvm-AF_VSOCK-status.email added |
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email sent to the AF_VSOCK maintainer and kvm ML
comment:10 Changed 6 years ago by
Seems that even qemu 2.7 in Fedora 25 does not have vsock builtin.
I've pinged an email to the maintainer. (attached)
comment:11 Changed 6 years ago by
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.
comment:12 Changed 6 years ago by
Reply: Re: AF_VSOCK status in qemu upstream: you can use qemu.git/master .. I have also made a copr repository for Fedora available here with qemu-kvm, kernel, and other packages with virtio-vsock support : https://copr.fedorainfracloud.org/coprs/stefanha/vsock/
comment:13 Changed 5 years ago by
Resolution: | → fixed |
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Status: | new → closed |
This has been tested, see #1387 for a follow up - closing.
comment:14 Changed 17 months ago by
this ticket has been moved to: https://github.com/Xpra-org/xpra/issues/983
Links: