Re: [RFC PATCH 0/3] vsock: support network namespace

2019-12-03 Thread Stefano Garzarella
On Tue, Dec 03, 2019 at 09:26:49AM +, Stefan Hajnoczi wrote:
> On Thu, Nov 28, 2019 at 06:15:16PM +0100, Stefano Garzarella wrote:
> > Hi,
> > now that we have multi-transport upstream, I started to take a look to
> > support network namespace (netns) in vsock.
> > 
> > As we partially discussed in the multi-transport proposal [1], it could
> > be nice to support network namespace in vsock to reach the following
> > goals:
> > - isolate host applications from guest applications using the same ports
> >   with CID_ANY
> > - assign the same CID of VMs running in different network namespaces
> > - partition VMs between VMMs or at finer granularity
> > 
> > This preliminary implementation provides the following behavior:
> > - packets received from the host (received by G2H transports) are
> >   assigned to the default netns (init_net)
> > - packets received from the guest (received by H2G - vhost-vsock) are
> >   assigned to the netns of the process that opens /dev/vhost-vsock
> >   (usually the VMM, qemu in my tests, opens the /dev/vhost-vsock)
> > - for vmci I need some suggestions, because I don't know how to do
> >   and test the same in the vmci driver, for now vmci uses the
> >   init_net
> > - loopback packets are exchanged only in the same netns
> > 
> > Questions:
> > 1. Should we make configurable the netns (now it is init_net) where
> >packets from the host should be delivered?
> 
> Yes, it should be possible to have multiple G2H (e.g. virtio-vsock)
> devices and to assign them to different net namespaces.  Something like
> net/core/dev.c:dev_change_net_namespace() will eventually be needed.
> 

Make sense, but for now we support only one G2H.
How we can provide this feature to the userspace?
Should we interface vsock with ip-link(8)?

I don't know if initially we can provide through sysfs a way to set the
netns of the only G2H loaded.

> > 2. Should we provide an ioctl in vhost-vsock to configure the netns
> >to use? (instead of using the netns of the process that opens
> >/dev/vhost-vsock)
> 
> Creating the vhost-vsock instance in the process' net namespace makes
> sense.  Maybe wait for a use case before adding an ioctl.
> 

Agree.

> > 3. Should we provide a way to disable the netns support in vsock?
> 
> The code should follow CONFIG_NET_NS semantics.  I'm not sure what they
> are exactly since struct net is always defined, regardless of whether
> network namespaces are enabled.

I think that if CONFIG_NET_NS is not defined, all sockets and processes
are assigned to init_net and this RFC should work in this case, but I'll
try this case before v1.

I was thinking about the Kata's use case, I don't know if they launch the
VM in a netns and even the runtime in the host runs inside the same netns.

I'll send an e-mail to kata mailing list.

Thanks,
Stefano

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Re: [RFC PATCH 0/3] vsock: support network namespace

2019-12-03 Thread Stefan Hajnoczi
On Thu, Nov 28, 2019 at 06:15:16PM +0100, Stefano Garzarella wrote:
> Hi,
> now that we have multi-transport upstream, I started to take a look to
> support network namespace (netns) in vsock.
> 
> As we partially discussed in the multi-transport proposal [1], it could
> be nice to support network namespace in vsock to reach the following
> goals:
> - isolate host applications from guest applications using the same ports
>   with CID_ANY
> - assign the same CID of VMs running in different network namespaces
> - partition VMs between VMMs or at finer granularity
> 
> This preliminary implementation provides the following behavior:
> - packets received from the host (received by G2H transports) are
>   assigned to the default netns (init_net)
> - packets received from the guest (received by H2G - vhost-vsock) are
>   assigned to the netns of the process that opens /dev/vhost-vsock
>   (usually the VMM, qemu in my tests, opens the /dev/vhost-vsock)
> - for vmci I need some suggestions, because I don't know how to do
>   and test the same in the vmci driver, for now vmci uses the
>   init_net
> - loopback packets are exchanged only in the same netns
> 
> Questions:
> 1. Should we make configurable the netns (now it is init_net) where
>packets from the host should be delivered?

Yes, it should be possible to have multiple G2H (e.g. virtio-vsock)
devices and to assign them to different net namespaces.  Something like
net/core/dev.c:dev_change_net_namespace() will eventually be needed.

> 2. Should we provide an ioctl in vhost-vsock to configure the netns
>to use? (instead of using the netns of the process that opens
>/dev/vhost-vsock)

Creating the vhost-vsock instance in the process' net namespace makes
sense.  Maybe wait for a use case before adding an ioctl.

> 3. Should we provide a way to disable the netns support in vsock?

The code should follow CONFIG_NET_NS semantics.  I'm not sure what they
are exactly since struct net is always defined, regardless of whether
network namespaces are enabled.


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[RFC PATCH 0/3] vsock: support network namespace

2019-11-28 Thread Stefano Garzarella
Hi,
now that we have multi-transport upstream, I started to take a look to
support network namespace (netns) in vsock.

As we partially discussed in the multi-transport proposal [1], it could
be nice to support network namespace in vsock to reach the following
goals:
- isolate host applications from guest applications using the same ports
  with CID_ANY
- assign the same CID of VMs running in different network namespaces
- partition VMs between VMMs or at finer granularity

This preliminary implementation provides the following behavior:
- packets received from the host (received by G2H transports) are
  assigned to the default netns (init_net)
- packets received from the guest (received by H2G - vhost-vsock) are
  assigned to the netns of the process that opens /dev/vhost-vsock
  (usually the VMM, qemu in my tests, opens the /dev/vhost-vsock)
- for vmci I need some suggestions, because I don't know how to do
  and test the same in the vmci driver, for now vmci uses the
  init_net
- loopback packets are exchanged only in the same netns

Questions:
1. Should we make configurable the netns (now it is init_net) where
   packets from the host should be delivered?
2. Should we provide an ioctl in vhost-vsock to configure the netns
   to use? (instead of using the netns of the process that opens
   /dev/vhost-vsock)
3. Should we provide a way to disable the netns support in vsock?
4. Jorgen: Do you think can be useful support it in vmci host
   driver?

I tested the series in this way:
l0_host$ qemu-system-x86_64 -m 4G -M accel=kvm -smp 4 \
-drive file=/tmp/vsockvm0.img,if=virtio --nographic \
-device vhost-vsock-pci,guest-cid=3

l1_vm$ ip netns add ns1
l1_vm$ ip netns add ns2
 # same CID on different netns
l1_vm$ ip netns exec ns1 qemu-system-x86_64 -m 1G -M accel=kvm -smp 2 \
-drive file=/tmp/vsockvm1.img,if=virtio --nographic \
-device vhost-vsock-pci,guest-cid=4
l1_vm$ ip netns exec ns2 qemu-system-x86_64 -m 1G -M accel=kvm -smp 2 \
-drive file=/tmp/vsockvm2.img,if=virtio --nographic \
-device vhost-vsock-pci,guest-cid=4

 # all iperf3 listen on CID_ANY and port 5201, but in different netns
l1_vm$ ./iperf3 --vsock -s # connection from l0 or guests started
   # on default netns (init_net)
l1_vm$ ip netns exec ns1 ./iperf3 --vsock -s
l1_vm$ ip netns exec ns1 ./iperf3 --vsock -s

l0_host$ ./iperf3 --vsock -c 3
l2_vm1$ ./iperf3 --vsock -c 2
l2_vm2$ ./iperf3 --vsock -c 2

This series is on top of the vsock-loopback series (not yet merged),
and it is available in the Git repository at:

  git://github.com/stefano-garzarella/linux.git vsock-netns

Any comments are really appreciated!

Thanks,
Stefano

[1] https://www.spinics.net/lists/netdev/msg575792.html

Stefano Garzarella (3):
  vsock: add network namespace support
  vsock/virtio_transport_common: handle netns of received packets
  vhost/vsock: use netns of process that opens the vhost-vsock device

 drivers/vhost/vsock.c   | 29 ---
 include/linux/virtio_vsock.h|  2 ++
 include/net/af_vsock.h  |  6 +++--
 net/vmw_vsock/af_vsock.c| 31 ++---
 net/vmw_vsock/hyperv_transport.c|  5 ++--
 net/vmw_vsock/virtio_transport.c|  2 ++
 net/vmw_vsock/virtio_transport_common.c | 12 --
 net/vmw_vsock/vmci_transport.c  |  5 ++--
 8 files changed, 67 insertions(+), 25 deletions(-)

-- 
2.23.0

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