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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>
55 lines
1.3 KiB
C
55 lines
1.3 KiB
C
/*
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* Copyright (C) 2014
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* Author Shriram Rajagopalan <rshriram@cs.ubc.ca>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as published
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* by the Free Software Foundation; version 2.1 only. with the special
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* exception on linking described in file LICENSE.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*/
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#include "libxl_osdeps.h" /* must come before any other headers */
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#include "libxl_internal.h"
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int libxl__netbuffer_enabled(libxl__gc *gc)
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{
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return 0;
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}
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int init_subkind_nic(libxl__remus_devices_state *rds)
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{
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return 0;
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}
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void cleanup_subkind_nic(libxl__remus_devices_state *rds)
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{
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return;
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}
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static void nic_setup(libxl__egc *egc, libxl__remus_device *dev)
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{
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STATE_AO_GC(dev->rds->ao);
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dev->aodev.rc = ERROR_FAIL;
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dev->aodev.callback(egc, &dev->aodev);
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}
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const libxl__remus_device_instance_ops remus_device_nic = {
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.kind = LIBXL__DEVICE_KIND_VIF,
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.setup = nic_setup,
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};
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/*
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* Local variables:
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* mode: C
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* c-basic-offset: 4
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* indent-tabs-mode: nil
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* End:
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*/
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