The internal user of libxl__async_exec_start et al now gets an rc as
well as the process's exit status.
For now this is always either 0 or ERROR_FAIL, but with ao
abort requests this will possibly be ABORTED or TIMEDOUT too.
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
---
v4: Improve doc comment as suggested by Ian C.
v2: New patch due to rebause; v1 had changes to device_hotplug_*
scripts instead.
Callback now gets unambiguous information about error situation:
previously, if only thing that went wrong was that child died
badly, rc would be FAILED, which was unambigously; now rc=0.
Add a comment document the meaning of the rc and status parameters
to the callback.
Add two members in libxl_domain_remus_info:
netbuf: whether netbuf is enabled
netbufscript: the path of the script which will be run to setup
and tear down the guest's interface.
Add cmdline switches to 'xl remus' command to enable or disable
network buffering and a domain-specific hotplug script to setup
network buffering.
Add a new config var 'remus.default.netbufscript' to xl.conf, that
allows the user to override the default global script used to
setup network buffering.
Note: Network buffering is enabled by default. Disabling network
buffering requires enabling unsafe mode.
Signed-off-by: Shriram Rajagopalan <rshriram@cs.ubc.ca>
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Reviewed-by: Wen Congyang <wency@cn.fujitsu.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This patch adds the machinery required for protecting a guest's
network device state. This patch comprises of two parts:
1. Hotplug scripts: The remus-netbuf-setup script is responsible for
setting up and tearing down the necessary infrastructure required for
network output buffering. This script should be invoked by libxl for
each of the guest's network interfaces, when starting or stopping Remus.
Apart from returning success/failure indication via the usual hotplug
entries in xenstore, this script also writes to xenstore, the name of
the REMUS_IFB device to be used to control the vif's network output.
The script relies on libnl3 command line utilities to perform various
setup/teardown functions. The script is confined to Linux platforms only
since NetBSD does not seem to have libnl3.
2. Remus network device: Implements the interfaces required by the
remus abstract device layer. A note about the implementation:
a) init_subkind_nic() & cleanup_subkind_nic() are called once per Remus
invocation. They establish and free netlink related state respectively.
b) setup() and teardown are called for each vif attached to the
guest.
During setup():
i) The hotplug script is called to setup a network buffer on a
given vif. The script chooses an available IFB device from
the system, redirects vif egress traffic to the IFB device
and sets up the plug qdisc (output buffer) on the IFB device.
The name of the IFB device is communicated via xenstore to
libxl.
ii) Libxl obtains a handle to the plug qdisc using the libnl3 API
and subsequently controls output buffering using this handle
in the checkpoint callbacks.
During teardown(), the hotplug scripts are called again to remove
the vif->ifb traffic redirection, release the ifb and the plug
qdisc associated with it.
c) The checkpoint callbacks [postsuspend(), preresume() and commit()]
are implemented as synchronous ops as the netlink calls associated
with the qdisc subsystem are very fast.
Signed-off-by: Shriram Rajagopalan <rshriram@cs.ubc.ca>
Signed-off-by: Yang Hongyang <yanghy@cn.fujitsu.com>
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Libnl3 is required for controlling Remus network buffering.
This patch adds dependency on libnl3 (>= 3.2.8) to autoconf scripts.
It also provides the ability to configure tools without libnl3 support
i.e., without network buffering support.
When there is no network buffering support, libxl__netbuffer_enabled()
returns 0, otherwise returns 1. The callers of this api will be
introduced in the rest of the series.
NOTE: This patch changes tools/configure.ac, please rerun
autogen.sh while applying the patch.
Signed-off-by: Shriram Rajagopalan <rshriram@cs.ubc.ca>
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Yang Hongyang <yanghy@cn.fujitsu.com>
Reviewed-by: Wen Congyang <wency@cn.fujitsu.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Wen Congyang
Ian Jackson
Yang Hongyang