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Yang Hongyang
6e1b7ac4ed
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>
xen-bugtool =========== The xen-bugtool command line application will collate the Xen dmesg output, details of the hardware configuration of your machine, information about the build of Xen that you are using, plus, if you allow it, various logs. The information collated can either be posted to a Xen Bugzilla bug (this bug must already exist in the system, and you must be a registered user there), or it can be saved as a .tar.bz2 for sending or archiving. The collated logs may contain private information, and if you are at all worried about that, you should not use this tool, or you should explicitly exclude those logs from the archive. xen-bugtool is wholly interactive, so simply run it, and answer the questions.