VSock: Initial datagram implementation for Argo.

vsock-argo/README.md

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+---
+
+# Work In Progress
+
+This software is still under development and should be considered experimental.
+It is currently developed for x86-64 and has not been built or tested for ARM
+targets.
+
+---
+
+# VSOCK module for Xen/Argo
+
+[vsock(7)](http://man7.org/linux/man-pages/man7/vsock.7.html) is an address
+family to facilitate communication between virtual machines.
+[Argo](https://xenbits.xenproject.org/docs/unstable/designs/argo.html) is an
+interdomain communication mechanism for Xen.
+
+This module implements Argo primitives under the Vsock address family to allow
+socket communication between Xen domains.
+
+## Getting started
+
+### Linux module
+
+Building `vsock_argo_transport` will require your Linux kernel headers. It can
+be built as an out-of-tree module. A convenience Makefile is provided:
+```bash
+ $ make -C module
+```
+
+The module itself will require VSock support in the kernel:
+```bash
+ $ zgrep CONFIG_VSOCKETS /proc/config.gz
+CONFIG_VSOCKETS=m
+CONFIG_VSOCKETS_DIAG=m
+ $ sudo modprobe vsock
+```
+
+It is possible that another VSock transport driver was already loaded, you will
+need to remove it, e.g:
+```bash
+ $ lsmod | grep vsock
+vmw_vsock_vmci_transport    32768  0
+vmw_vmci               77824  1 vmw_vsock_vmci_transport
+vsock                  40960  1 vmw_vsock_vmci_transport
+ $ sudo rmmod vmw_vsock_vmci_transport
+```
+Then load the module and confirm the operation succeeded.
+```bash
+ $ sudo insmod module/vsock_argo_transport.ko
+ $ dmesg -H | grep argo
+[  +0.000017] vsock_argo_transport registered.
+```
+
+### Test client
+
+A test `netcat` like utility is provided to simplify send and receive operation
+using VSock datagram over Argo, the tool is call `hatch` and roughly follows
+the `netcat` usage.
+
+<sup><sub>Ship cargo, packets, are usualy passed through a `hatch`, hence the
+name... Since Argo is an old mythological ship.</sub></sub>
+
+It builds using autotools:
+```bash
+ $ cd test/hatch
+ $ autoreconf -i
+ $ mkdir dist ; ./configure --prefix=$(pwd)/dist
+ ...
+ $ make install
+ $ ./dist/bin/hatch -h
+Basic usage:
+        hatch domid port
+        hatch -r -p local_port
+Options:
+        -r, --recv      receive mode, wait for incoming packets.
+        -p, --port      set local port number.
+        -D              enable debug output on stderr.
+```
+
+## Testing
+
+Argo was released with Xen 4.12.0, but is still experimental feature. You will
+likely need to rebuild Xen to enable argo and change its cmdline. I recommend
+following the way your distribution packages Xen (PKGBUILD, sbuild, etc) and
+amend with the changes described below. The following is only provided as an
+example:
+```bash
+ $ git clone git://xenbits.xen.org/xen.git
+ $ cd xen
+ $ git checkout -b stable-4.12 origin/stable-4.12
+ $ echo 'CONFIG_ARGO=y' >> xen/.config
+ $ PYTHON=/usr/bin/python2 ./configure --prefix=/usr --sbindir=/usr/bin --with-sysconfig-leaf-dir=conf.d --with-rundir=/run --enable-systemd--with-extra-qemuu-configure-args="--disable-bluez --disable-gtk --disable-vte --disable-werror --disable-virglrenderer --disable-libnfs --disable-glusterfs --disable-numa --disable-smartcard --disable-fdt --enable-spice --enable-usb-redir --with-sdlabi=1.2"
+ $ yes "" | make XEN_CONFIG_EXPERT=y -C xen oldconfig
+ $ make XEN_CONFIG_EXPERT=y LANG=C PYTHON=python2 dist
+```
+
+Install and configure the previously built Xen to suit your distribution. This
+is beyond the scope of this document.
+
+Add `argo=true,mac-permissive=1` to your Xen cmdline and reboot on the freshly
+built Xen with Argo support.
+
+You will need at least 1 Xen guest, other than dom0, to test
+`vsock_argo_transport.ko`. No guest specific guest configuration is required,
+e.g:
+```
+type = "pvh"
+kernel="/var/lib/machines/vm0/boot/vmlinuz-linux"
+ramdisk="/var/lib/machines/vm0/boot/initramfs-linux.img"
+root="/dev/xvda"
+extra="earlyprintk=xen console=tty0 console=hvc0,115200n8 rw quiet"
+name = "vm0.pvh"
+memory = 512
+maxmem = 512
+vcpus = 2
+vfb = [ "type=vfb, vnc=1, vnclisten=0.0.0.0, vncdisplay=1" ]
+vif = [ 'mac=00:16:3e:01:01:01, bridge=br0' ]
+disk = [ '/dev/vg0/vm0,raw,xvda,rw' ]
+```
+
+Start and log into the guest to load `vsock_argo_transport.ko`. `hatch` can be
+used as netcat using the domain-id as address and a port.
+```bash
+user@dom0 $ hatch -r -p 1234 > /tmp/file
+ ^C
+user@dom0 $ md5sum file
+b061b7954fbcb8b17cc7e2e8a5754269  file
+```
+```bash
+user@vm0 $ md5sum file
+b061b7954fbcb8b17cc7e2e8a5754269  file
+user@vm0 $ hatch 0 1234 < file
+```

vsock-argo/module/.gitignore

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+*.ko
+*.ko.cmd
+*.mod.o
+*.mod.c
+modules.order
+Module.symvers
+*.o
+*.o.d
+*.o.cmd
+.tmp_versions

vsock-argo/module/Kbuild

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+obj-m += vsock_argo_transport.o
+vsock_argo_transport-y += argo_transport.o argo_ring.o
+
+ccflags-y := -I$(src)/include
+ccflags-$(CONFIG_X86) += -I$(src)/asm-x86

vsock-argo/module/Makefile

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+ifneq ($(KERNELRELEASE),)
+# kbuild part of makefile
+include Kbuild
+
+else
+# normal makefile
+KERNEL_VERSION ?= `uname -r`
+KERNEL_SRC ?= /lib/modules/$(KERNEL_VERSION)/build
+INSTALL_HDR_PATH ?= /usr
+
+default:
+	$(MAKE) -C $(KERNEL_SRC) M=$$PWD
+
+clean:
+	$(MAKE) -C $(KERNEL_SRC) M=$$PWD clean
+
+modules_install:
+	$(MAKE) -C $(KERNEL_SRC) M=$$PWD modules_install
+
+endif