On 2020/4/27 下午10:25, Stefano Garzarella wrote:
Hi David, Michael, Stefan,
I'm restarting to work on this topic since Kata guys are interested to
have that, especially on the guest side.
While working on the v2 I had few doubts, and I'd like to have your
suggestions:
1. netns assigned to the device inside the guest
Currently I assigned this device to 'init_net'. Maybe it is better
if we allow the user to decide which netns assign to the device
or to disable this new feature to have the same behavior as before
(host reachable from any netns).
I think we can handle this in the vsock core and not in the single
transports.
The simplest way that I found, is to add a new
IOCTL_VM_SOCKETS_ASSIGN_G2H_NETNS to /dev/vsock to enable the feature
and assign the device to the same netns of the process that do the
ioctl(), but I'm not sure it is clean enough.
Maybe it is better to add new rtnetlink messages, but I'm not sure if
it is feasible since we don't have a netdev device.
What do you suggest?
As we've discussed, it should be a netdev probably in either guest or
host side. And it would be much simpler if we want do implement
namespace then. No new API is needed.
Thanks
2. netns assigned in the host
As Michael suggested, I added a new /dev/vhost-vsock-netns to allow
userspace application to use this new feature, leaving to
/dev/vhost-vsock the previous behavior (guest reachable from any
netns).
I like this approach, but I had these doubts:
- I need to allocate a new minor for that device (e.g.
VHOST_VSOCK_NETNS_MINOR) or is there an alternative way that I can
use?
- It is vhost-vsock specific, should we provide something handled in
the vsock core, maybe centralizing the CID allocation and adding a
new IOCTL or rtnetlink message like for the guest side?
(maybe it could be a second step, and for now we can continue with
the new device)
Thanks for the help,
Stefano
On Thu, Jan 16, 2020 at 06:24:25PM +0100, Stefano Garzarella wrote:
RFC -> v1:
* added 'netns' module param to vsock.ko to enable the
network namespace support (disabled by default)
* added 'vsock_net_eq()' to check the "net" assigned to a socket
only when 'netns' support is enabled
RFC: https://patchwork.ozlabs.org/cover/1202235/
Now that we have multi-transport upstream, I started to take a look to
support network namespace 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 new feature is disabled by default, because it changes vsock's
behavior with network namespaces and could break existing applications.
It can be enabled with the new 'netns' module parameter of vsock.ko.
This 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
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$ echo 1 > /sys/module/vsock/parameters/netns
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
[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 | 7 +++--
net/vmw_vsock/af_vsock.c | 41 +++++++++++++++++++------
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, 78 insertions(+), 25 deletions(-)
--
2.24.1
