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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH 05/10 V7] remus: Remus network buffering core and APIs to setup/teardown
From: Shriram Rajagopalan <rshriram@xxxxxxxxx>
This patch introduces remus-netbuf-setup hotplug script responsible for
setting up and tearing down the necessary infrastructure required for
network output buffering in Remus. This script is intended to be invoked
by libxl for each guest interface, 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 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.
The following steps are taken during setup:
a) call the hotplug script for each vif to setup its network buffer
b) establish a dedicated remus context containing libnl related
state (netlink sockets, qdisc caches, etc.,)
c) Obtain handles to plug qdiscs installed on the IFB devices
chosen by the hotplug scripts.
And during teardown, the netlink resources are released, followed by
invocation of hotplug scripts to remove the IFB devices.
Signed-off-by: Shriram Rajagopalan <rshriram@xxxxxxxxx>
Signed-off-by: Lai Jiangshan <laijs@xxxxxxxxxxxxxx>
Reviewed-by: Wen Congyang <wency@xxxxxxxxxxxxxx>
---
docs/misc/xenstore-paths.markdown | 4 +
tools/hotplug/Linux/Makefile | 1 +
tools/hotplug/Linux/remus-netbuf-setup | 183 ++++++++++++
tools/libxl/Makefile | 2 +
tools/libxl/libxl_dom.c | 7 +-
tools/libxl/libxl_internal.h | 17 ++
tools/libxl/libxl_netbuffer.c | 481 ++++++++++++++++++++++++++++++++
tools/libxl/libxl_nonetbuffer.c | 11 +
tools/libxl/libxl_remus.c | 41 +++
9 files changed, 742 insertions(+), 5 deletions(-)
create mode 100644 tools/hotplug/Linux/remus-netbuf-setup
create mode 100644 tools/libxl/libxl_remus.c
diff --git a/docs/misc/xenstore-paths.markdown
b/docs/misc/xenstore-paths.markdown
index 70ab7f4..7a0d2c9 100644
--- a/docs/misc/xenstore-paths.markdown
+++ b/docs/misc/xenstore-paths.markdown
@@ -385,6 +385,10 @@ The guest's virtual time offset from UTC in seconds.
The device model version for a domain.
+#### /libxl/$DOMID/remus/netbuf/$DEVID/ifb = STRING [n,INTERNAL]
+
+IFB device used by Remus to buffer network output from the associated vif.
+
[BLKIF]:
http://xenbits.xen.org/docs/unstable/hypercall/include,public,io,blkif.h.html
[FBIF]:
http://xenbits.xen.org/docs/unstable/hypercall/include,public,io,fbif.h.html
[HVMPARAMS]:
http://xenbits.xen.org/docs/unstable/hypercall/include,public,hvm,params.h.html
diff --git a/tools/hotplug/Linux/Makefile b/tools/hotplug/Linux/Makefile
index 47655f6..6139c1f 100644
--- a/tools/hotplug/Linux/Makefile
+++ b/tools/hotplug/Linux/Makefile
@@ -16,6 +16,7 @@ XEN_SCRIPTS += network-nat vif-nat
XEN_SCRIPTS += vif-openvswitch
XEN_SCRIPTS += vif2
XEN_SCRIPTS += vif-setup
+XEN_SCRIPTS-$(CONFIG_REMUS_NETBUF) += remus-netbuf-setup
XEN_SCRIPTS += block
XEN_SCRIPTS += block-enbd block-nbd
XEN_SCRIPTS-$(CONFIG_BLKTAP1) += blktap
diff --git a/tools/hotplug/Linux/remus-netbuf-setup
b/tools/hotplug/Linux/remus-netbuf-setup
new file mode 100644
index 0000000..3467db2
--- /dev/null
+++ b/tools/hotplug/Linux/remus-netbuf-setup
@@ -0,0 +1,183 @@
+#!/bin/bash
+#============================================================================
+# ${XEN_SCRIPT_DIR}/remus-netbuf-setup
+#
+# Script for attaching a network buffer to the specified vif (in any mode).
+# The hotplugging system will call this script when starting remus via libxl
+# API, libxl_domain_remus_start.
+#
+# Usage:
+# remus-netbuf-setup (setup|teardown)
+#
+# Environment vars:
+# vifname vif interface name (required).
+# XENBUS_PATH path in Xenstore, where the IFB device details will be stored
+# or read from (required).
+# (libxl passes /libxl/<domid>/remus/netbuf/<devid>)
+# IFB ifb interface to be cleaned up (required). [for teardown op only]
+
+# Written to the store: (setup operation)
+# XENBUS_PATH/ifb=<ifbdevName> the IFB device serving
+# as the intermediate buffer through which the interface's network output
+# can be controlled.
+#
+# To install a network buffer on a guest vif (vif1.0) using ifb (ifb0)
+# we need to do the following
+#
+# ip link set dev ifb0 up
+# tc qdisc add dev vif1.0 ingress
+# tc filter add dev vif1.0 parent ffff: proto ip \
+# prio 10 u32 match u32 0 0 action mirred egress redirect dev ifb0
+# nl-qdisc-add --dev=ifb0 --parent root plug
+# nl-qdisc-add --dev=ifb0 --parent root --update plug --limit=10000000
+# (10MB limit on buffer)
+#
+# So order of operations when installing a network buffer on vif1.0
+# 1. find a free ifb and bring up the device
+# 2. redirect traffic from vif1.0 to ifb:
+# 2.1 add ingress qdisc to vif1.0 (to capture outgoing packets from guest)
+# 2.2 use tc filter command with actions mirred egress + redirect
+# 3. install plug_qdisc on ifb device, with which we can buffer/release
+# guest's network output from vif1.0
+#
+#
+
+#============================================================================
+
+# Unlike other vif scripts, vif-common is not needed here as it executes vif
+#specific setup code such as renaming.
+dir=$(dirname "$0")
+. "$dir/xen-hotplug-common.sh"
+
+findCommand "$@"
+
+if [ "$command" != "setup" -a "$command" != "teardown" ]
+then
+ echo "Invalid command: $command"
+ log err "Invalid command: $command"
+ exit 1
+fi
+
+evalVariables "$@"
+
+: ${vifname:?}
+: ${XENBUS_PATH:?}
+
+check_libnl_tools() {
+ if ! command -v nl-qdisc-list > /dev/null 2>&1; then
+ fatal "Unable to find nl-qdisc-list tool"
+ fi
+ if ! command -v nl-qdisc-add > /dev/null 2>&1; then
+ fatal "Unable to find nl-qdisc-add tool"
+ fi
+ if ! command -v nl-qdisc-delete > /dev/null 2>&1; then
+ fatal "Unable to find nl-qdisc-delete tool"
+ fi
+}
+
+# We only check for modules. We don't load them.
+# User/Admin is supposed to load ifb during boot time,
+# ensuring that there are enough free ifbs in the system.
+# Other modules will be loaded automatically by tc commands.
+check_modules() {
+ for m in ifb sch_plug sch_ingress act_mirred cls_u32
+ do
+ if ! modinfo $m > /dev/null 2>&1; then
+ fatal "Unable to find $m kernel module"
+ fi
+ done
+}
+
+setup_ifb() {
+
+ for ifb in `ifconfig -a -s|egrep ^ifb|cut -d ' ' -f1`
+ do
+ local installed=`nl-qdisc-list -d $ifb`
+ [ -n "$installed" ] && continue
+ IFB="$ifb"
+ break
+ done
+
+ if [ -z "$IFB" ]
+ then
+ fatal "Unable to find a free IFB device for $vifname"
+ fi
+
+ do_or_die ip link set dev "$IFB" up
+}
+
+redirect_vif_traffic() {
+ local vif=$1
+ local ifb=$2
+
+ do_or_die tc qdisc add dev "$vif" ingress
+
+ tc filter add dev "$vif" parent ffff: proto ip prio 10 \
+ u32 match u32 0 0 action mirred egress redirect dev "$ifb" >/dev/null
2>&1
+
+ if [ $? -ne 0 ]
+ then
+ do_without_error tc qdisc del dev "$vif" ingress
+ fatal "Failed to redirect traffic from $vif to $ifb"
+ fi
+}
+
+add_plug_qdisc() {
+ local vif=$1
+ local ifb=$2
+
+ nl-qdisc-add --dev="$ifb" --parent root plug >/dev/null 2>&1
+ if [ $? -ne 0 ]
+ then
+ do_without_error tc qdisc del dev "$vif" ingress
+ fatal "Failed to add plug qdisc to $ifb"
+ fi
+
+ #set ifb buffering limit in bytes. Its okay if this command fails
+ nl-qdisc-add --dev="$ifb" --parent root \
+ --update plug --limit=10000000 >/dev/null 2>&1
+}
+
+teardown_netbuf() {
+ local vif=$1
+ local ifb=$2
+
+ if [ "$ifb" ]; then
+ do_without_error ip link set dev "$ifb" down
+ do_without_error nl-qdisc-delete --dev="$ifb" --parent root plug
>/dev/null 2>&1
+ xenstore-rm -t "$XENBUS_PATH/ifb" 2>/dev/null || true
+ fi
+ do_without_error tc qdisc del dev "$vif" ingress
+ xenstore-rm -t "$XENBUS_PATH/hotplug-status" 2>/dev/null || true
+}
+
+xs_write_failed() {
+ local vif=$1
+ local ifb=$2
+ teardown_netbuf "$vifname" "$IFB"
+ fatal "failed to write ifb name to xenstore"
+}
+
+case "$command" in
+ setup)
+ check_libnl_tools
+ check_modules
+
+ claim_lock "pickifb"
+ setup_ifb
+ redirect_vif_traffic "$vifname" "$IFB"
+ add_plug_qdisc "$vifname" "$IFB"
+ release_lock "pickifb"
+
+ #not using xenstore_write that automatically exits on error
+ #because we need to cleanup
+ _xenstore_write "$XENBUS_PATH/ifb" "$IFB" || xs_write_failed
"$vifname" "$IFB"
+ success
+ ;;
+ teardown)
+ : ${IFB:?}
+ teardown_netbuf "$vifname" "$IFB"
+ ;;
+esac
+
+log debug "Successful remus-netbuf-setup $command for $vifname, ifb $IFB."
diff --git a/tools/libxl/Makefile b/tools/libxl/Makefile
index 84a467c..218f55e 100644
--- a/tools/libxl/Makefile
+++ b/tools/libxl/Makefile
@@ -52,6 +52,8 @@ else
LIBXL_OBJS-y += libxl_nonetbuffer.o
endif
+LIBXL_OBJS-y += libxl_remus.o
+
LIBXL_OBJS-$(CONFIG_X86) += libxl_cpuid.o libxl_x86.o
LIBXL_OBJS-$(CONFIG_ARM) += libxl_nocpuid.o libxl_arm.o
diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c
index 8d63f90..e3e9f6f 100644
--- a/tools/libxl/libxl_dom.c
+++ b/tools/libxl/libxl_dom.c
@@ -753,9 +753,6 @@ int libxl__toolstack_restore(uint32_t domid, const uint8_t
*buf,
/*==================== Domain suspend (save) ====================*/
-static void domain_suspend_done(libxl__egc *egc,
- libxl__domain_suspend_state *dss, int rc);
-
/*----- complicated callback, called by xc_domain_save -----*/
/*
@@ -1508,8 +1505,8 @@ static void save_device_model_datacopier_done(libxl__egc
*egc,
dss->save_dm_callback(egc, dss, our_rc);
}
-static void domain_suspend_done(libxl__egc *egc,
- libxl__domain_suspend_state *dss, int rc)
+void domain_suspend_done(libxl__egc *egc,
+ libxl__domain_suspend_state *dss, int rc)
{
STATE_AO_GC(dss->ao);
diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index 2f64382..4006174 100644
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -2313,6 +2313,23 @@ typedef struct libxl__remus_state {
_hidden int libxl__netbuffer_enabled(libxl__gc *gc);
+_hidden void domain_suspend_done(libxl__egc *egc,
+ libxl__domain_suspend_state *dss,
+ int rc);
+
+_hidden void libxl__remus_setup_done(libxl__egc *egc,
+ libxl__domain_suspend_state *dss,
+ int rc);
+
+_hidden void libxl__remus_netbuf_setup(libxl__egc *egc,
+ libxl__domain_suspend_state *dss);
+
+_hidden void libxl__remus_teardown_done(libxl__egc *egc,
+ libxl__domain_suspend_state *dss);
+
+_hidden void libxl__remus_netbuf_teardown(libxl__egc *egc,
+ libxl__domain_suspend_state *dss);
+
struct libxl__domain_suspend_state {
/* set by caller of libxl__domain_suspend */
libxl__ao *ao;
diff --git a/tools/libxl/libxl_netbuffer.c b/tools/libxl/libxl_netbuffer.c
index 8e23d75..2c77076 100644
--- a/tools/libxl/libxl_netbuffer.c
+++ b/tools/libxl/libxl_netbuffer.c
@@ -17,11 +17,492 @@
#include "libxl_internal.h"
+#include <netlink/cache.h>
+#include <netlink/socket.h>
+#include <netlink/attr.h>
+#include <netlink/route/link.h>
+#include <netlink/route/route.h>
+#include <netlink/route/qdisc.h>
+#include <netlink/route/qdisc/plug.h>
+
+typedef struct libxl__remus_netbuf_state {
+ struct rtnl_qdisc **netbuf_qdisc_list;
+ struct nl_sock *nlsock;
+ struct nl_cache *qdisc_cache;
+ const char **vif_list;
+ const char **ifb_list;
+ uint32_t num_netbufs;
+ uint32_t unused;
+} libxl__remus_netbuf_state;
+
int libxl__netbuffer_enabled(libxl__gc *gc)
{
return 1;
}
+/* If the device has a vifname, then use that instead of
+ * the vifX.Y format.
+ */
+static const char *get_vifname(libxl__gc *gc, uint32_t domid,
+ libxl_device_nic *nic)
+{
+ const char *vifname = NULL;
+ const char *path;
+ int rc;
+
+ path = libxl__sprintf(gc, "%s/backend/vif/%d/%d/vifname",
+ libxl__xs_get_dompath(gc, 0), domid, nic->devid);
+ rc = libxl__xs_read_checked(gc, XBT_NULL, path, &vifname);
+ if (!rc && !vifname) {
+ /* use the default name */
+ vifname = libxl__device_nic_devname(gc, domid,
+ nic->devid,
+ nic->nictype);
+ }
+
+ return vifname;
+}
+
+static const char **get_guest_vif_list(libxl__gc *gc, uint32_t domid,
+ int *num_vifs)
+{
+ libxl_device_nic *nics = NULL;
+ int nb, i = 0;
+ const char **vif_list = NULL;
+
+ *num_vifs = 0;
+ nics = libxl_device_nic_list(CTX, domid, &nb);
+ if (!nics)
+ return NULL;
+
+ /* Ensure that none of the vifs are backed by driver domains */
+ for (i = 0; i < nb; i++) {
+ if (nics[i].backend_domid != LIBXL_TOOLSTACK_DOMID) {
+ const char *vifname = get_vifname(gc, domid, &nics[i]);
+
+ if (!vifname)
+ vifname = "(unknown)";
+ LOG(ERROR, "vif %s has driver domain (%u) as its backend. "
+ "Network buffering is not supported with driver domains",
+ vifname, nics[i].backend_domid);
+ *num_vifs = -1;
+ goto out;
+ }
+ }
+
+ GCNEW_ARRAY(vif_list, nb);
+ for (i = 0; i < nb; ++i) {
+ vif_list[i] = get_vifname(gc, domid, &nics[i]);
+ if (!vif_list[i]) {
+ vif_list = NULL;
+ goto out;
+ }
+ }
+ *num_vifs = nb;
+
+ out:
+ for (i = 0; i < nb; i++)
+ libxl_device_nic_dispose(&nics[i]);
+ free(nics);
+ return vif_list;
+}
+
+static void free_qdiscs(libxl__remus_netbuf_state *netbuf_state)
+{
+ int i;
+ struct rtnl_qdisc *qdisc = NULL;
+
+ /* free qdiscs */
+ for (i = 0; i < netbuf_state->num_netbufs; i++) {
+ qdisc = netbuf_state->netbuf_qdisc_list[i];
+ if (!qdisc)
+ break;
+
+ nl_object_put((struct nl_object *)qdisc);
+ netbuf_state->netbuf_qdisc_list[i] = NULL;
+ }
+
+ /* free qdisc cache */
+ if (netbuf_state->qdisc_cache) {
+ nl_cache_clear(netbuf_state->qdisc_cache);
+ nl_cache_free(netbuf_state->qdisc_cache);
+ netbuf_state->qdisc_cache = NULL;
+ }
+
+ /* close & free nlsock */
+ if (netbuf_state->nlsock) {
+ nl_close(netbuf_state->nlsock);
+ nl_socket_free(netbuf_state->nlsock);
+ netbuf_state->nlsock = NULL;
+ }
+}
+
+static int init_qdiscs(libxl__gc *gc,
+ libxl__remus_state *remus_state)
+{
+ int i, ret, ifindex;
+ struct rtnl_link *ifb = NULL;
+ struct rtnl_qdisc *qdisc = NULL;
+
+ /* Convenience aliases */
+ libxl__remus_netbuf_state * const netbuf_state = remus_state->netbuf_state;
+ const int num_netbufs = netbuf_state->num_netbufs;
+ const char ** const ifb_list = netbuf_state->ifb_list;
+
+ /* Now that we have brought up IFB devices with plug qdisc for
+ * each vif, lets get a netlink handle on the plug qdisc for use
+ * during checkpointing.
+ */
+ netbuf_state->nlsock = nl_socket_alloc();
+ if (!netbuf_state->nlsock) {
+ LOG(ERROR, "cannot allocate nl socket");
+ goto out;
+ }
+
+ ret = nl_connect(netbuf_state->nlsock, NETLINK_ROUTE);
+ if (ret) {
+ LOG(ERROR, "failed to open netlink socket: %s",
+ nl_geterror(ret));
+ goto out;
+ }
+
+ /* get list of all qdiscs installed on network devs. */
+ ret = rtnl_qdisc_alloc_cache(netbuf_state->nlsock,
+ &netbuf_state->qdisc_cache);
+ if (ret) {
+ LOG(ERROR, "failed to allocate qdisc cache: %s",
+ nl_geterror(ret));
+ goto out;
+ }
+
+ /* list of handles to plug qdiscs */
+ GCNEW_ARRAY(netbuf_state->netbuf_qdisc_list, num_netbufs);
+
+ for (i = 0; i < num_netbufs; ++i) {
+
+ /* get a handle to the IFB interface */
+ ifb = NULL;
+ ret = rtnl_link_get_kernel(netbuf_state->nlsock, 0,
+ ifb_list[i], &ifb);
+ if (ret) {
+ LOG(ERROR, "cannot obtain handle for %s: %s", ifb_list[i],
+ nl_geterror(ret));
+ goto out;
+ }
+
+ ifindex = rtnl_link_get_ifindex(ifb);
+ if (!ifindex) {
+ LOG(ERROR, "interface %s has no index", ifb_list[i]);
+ goto out;
+ }
+
+ /* Get a reference to the root qdisc installed on the IFB, by
+ * querying the qdisc list we obtained earlier. The netbufscript
+ * sets up the plug qdisc as the root qdisc, so we don't have to
+ * search the entire qdisc tree on the IFB dev.
+
+ * There is no need to explicitly free this qdisc as its just a
+ * reference from the qdisc cache we allocated earlier.
+ */
+ qdisc = rtnl_qdisc_get_by_parent(netbuf_state->qdisc_cache, ifindex,
+ TC_H_ROOT);
+
+ if (qdisc) {
+ const char *tc_kind = rtnl_tc_get_kind(TC_CAST(qdisc));
+ /* Sanity check: Ensure that the root qdisc is a plug qdisc. */
+ if (!tc_kind || strcmp(tc_kind, "plug")) {
+ nl_object_put((struct nl_object *)qdisc);
+ LOG(ERROR, "plug qdisc is not installed on %s", ifb_list[i]);
+ goto out;
+ }
+ netbuf_state->netbuf_qdisc_list[i] = qdisc;
+ } else {
+ LOG(ERROR, "Cannot get qdisc handle from ifb %s", ifb_list[i]);
+ goto out;
+ }
+ rtnl_link_put(ifb);
+ }
+
+ return 0;
+
+ out:
+ if (ifb)
+ rtnl_link_put(ifb);
+ free_qdiscs(netbuf_state);
+ return ERROR_FAIL;
+}
+
+static void netbuf_setup_timeout_cb(libxl__egc *egc,
+ libxl__ev_time *ev,
+ const struct timeval *requested_abs)
+{
+ libxl__remus_state *remus_state = CONTAINER_OF(ev, *remus_state, timeout);
+
+ /* Convenience aliases */
+ const int devid = remus_state->dev_id;
+ libxl__remus_netbuf_state *const netbuf_state = remus_state->netbuf_state;
+ const char *const vif = netbuf_state->vif_list[devid];
+
+ STATE_AO_GC(remus_state->dss->ao);
+
+ libxl__ev_time_deregister(gc, &remus_state->timeout);
+ assert(libxl__ev_child_inuse(&remus_state->child));
+
+ LOG(DEBUG, "killing hotplug script %s (on vif %s) because of timeout",
+ remus_state->netbufscript, vif);
+
+ if (kill(remus_state->child.pid, SIGKILL)) {
+ LOGEV(ERROR, errno, "unable to kill hotplug script %s [%ld]",
+ remus_state->netbufscript,
+ (unsigned long)remus_state->child.pid);
+ }
+
+ return;
+}
+
+/* the script needs the following env & args
+ * $vifname
+ * $XENBUS_PATH (/libxl/<domid>/remus/netbuf/<devid>/)
+ * $IFB (for teardown)
+ * setup/teardown as command line arg.
+ * In return, the script writes the name of IFB device (during setup) to be
+ * used for output buffering into XENBUS_PATH/ifb
+ */
+static int exec_netbuf_script(libxl__gc *gc, libxl__remus_state *remus_state,
+ char *op, libxl__ev_child_callback *death)
+{
+ int arraysize, nr = 0;
+ char **env = NULL, **args = NULL;
+ pid_t pid;
+
+ /* Convenience aliases */
+ libxl__ev_child *const child = &remus_state->child;
+ libxl__ev_time *const timeout = &remus_state->timeout;
+ char *const script = libxl__strdup(gc, remus_state->netbufscript);
+ const uint32_t domid = remus_state->dss->domid;
+ const int devid = remus_state->dev_id;
+ libxl__remus_netbuf_state *const netbuf_state = remus_state->netbuf_state;
+ const char *const vif = netbuf_state->vif_list[devid];
+ const char *const ifb = netbuf_state->ifb_list[devid];
+
+ arraysize = 7;
+ GCNEW_ARRAY(env, arraysize);
+ env[nr++] = "vifname";
+ env[nr++] = libxl__strdup(gc, vif);
+ env[nr++] = "XENBUS_PATH";
+ env[nr++] = GCSPRINTF("%s/remus/netbuf/%d",
+ libxl__xs_libxl_path(gc, domid), devid);
+ if (!strcmp(op, "teardown")) {
+ env[nr++] = "IFB";
+ env[nr++] = libxl__strdup(gc, ifb);
+ }
+ env[nr++] = NULL;
+ assert(nr <= arraysize);
+
+ arraysize = 3; nr = 0;
+ GCNEW_ARRAY(args, arraysize);
+ args[nr++] = script;
+ args[nr++] = op;
+ args[nr++] = NULL;
+ assert(nr == arraysize);
+
+ /* Set hotplug timeout */
+ if (libxl__ev_time_register_rel(gc, timeout,
+ netbuf_setup_timeout_cb,
+ LIBXL_HOTPLUG_TIMEOUT * 1000)) {
+ LOG(ERROR, "unable to register timeout for "
+ "netbuf setup script %s on vif %s", script, vif);
+ return ERROR_FAIL;
+ }
+
+ LOG(DEBUG, "Calling netbuf script: %s %s on vif %s",
+ script, op, vif);
+
+ /* Fork and exec netbuf script */
+ pid = libxl__ev_child_fork(gc, child, death);
+ if (pid == -1) {
+ LOG(ERROR, "unable to fork netbuf script %s", script);
+ return ERROR_FAIL;
+ }
+
+ if (!pid) {
+ /* child: Launch netbuf script */
+ libxl__exec(gc, -1, -1, -1, args[0], args, env);
+ /* notreached */
+ abort();
+ }
+
+ return 0;
+}
+
+static void netbuf_setup_script_cb(libxl__egc *egc,
+ libxl__ev_child *child,
+ pid_t pid, int status)
+{
+ libxl__remus_state *remus_state = CONTAINER_OF(child, *remus_state, child);
+ const char *out_path_base, *hotplug_error = NULL;
+ int rc = ERROR_FAIL;
+
+ /* Convenience aliases */
+ const uint32_t domid = remus_state->dss->domid;
+ const int devid = remus_state->dev_id;
+ libxl__remus_netbuf_state *const netbuf_state = remus_state->netbuf_state;
+ const char *const vif = netbuf_state->vif_list[devid];
+ const char **const ifb = &netbuf_state->ifb_list[devid];
+
+ STATE_AO_GC(remus_state->dss->ao);
+
+ libxl__ev_time_deregister(gc, &remus_state->timeout);
+
+ out_path_base = GCSPRINTF("%s/remus/netbuf/%d",
+ libxl__xs_libxl_path(gc, domid), devid);
+
+ rc = libxl__xs_read_checked(gc, XBT_NULL,
+ GCSPRINTF("%s/hotplug-error", out_path_base),
+ &hotplug_error);
+ if (rc)
+ goto out;
+
+ if (hotplug_error) {
+ LOG(ERROR, "netbuf script %s setup failed for vif %s: %s",
+ remus_state->netbufscript,
+ netbuf_state->vif_list[devid], hotplug_error);
+ rc = ERROR_FAIL;
+ goto out;
+ }
+
+ if (status) {
+ libxl_report_child_exitstatus(CTX, LIBXL__LOG_ERROR,
+ remus_state->netbufscript,
+ pid, status);
+ rc = ERROR_FAIL;
+ goto out;
+ }
+
+ rc = libxl__xs_read_checked(gc, XBT_NULL,
+ GCSPRINTF("%s/remus/netbuf/%d/ifb",
+ libxl__xs_libxl_path(gc, domid),
+ devid),
+ ifb);
+ if (rc)
+ goto out;
+
+ if (!(*ifb)) {
+ LOG(ERROR, "Cannot get ifb dev name for domain %u dev %s",
+ domid, vif);
+ rc = ERROR_FAIL;
+ goto out;
+ }
+
+ LOG(DEBUG, "%s will buffer packets from vif %s", *ifb, vif);
+ remus_state->dev_id++;
+ if (remus_state->dev_id < netbuf_state->num_netbufs) {
+ rc = exec_netbuf_script(gc, remus_state,
+ "setup", netbuf_setup_script_cb);
+ if (rc)
+ goto out;
+
+ return;
+ }
+
+ rc = init_qdiscs(gc, remus_state);
+ out:
+ libxl__remus_setup_done(egc, remus_state->dss, rc);
+}
+
+/* Scan through the list of vifs belonging to domid and
+ * invoke the netbufscript to setup the IFB device & plug qdisc
+ * for each vif. Then scan through the list of IFB devices to obtain
+ * a handle on the plug qdisc installed on these IFB devices.
+ * Network output buffering is controlled via these qdiscs.
+ */
+void libxl__remus_netbuf_setup(libxl__egc *egc,
+ libxl__domain_suspend_state *dss)
+{
+ libxl__remus_netbuf_state *netbuf_state = NULL;
+ int num_netbufs = 0;
+ int rc = ERROR_FAIL;
+
+ /* Convenience aliases */
+ const uint32_t domid = dss->domid;
+ libxl__remus_state *const remus_state = dss->remus_state;
+
+ STATE_AO_GC(dss->ao);
+
+ GCNEW(netbuf_state);
+ netbuf_state->vif_list = get_guest_vif_list(gc, domid, &num_netbufs);
+ if (!num_netbufs) {
+ rc = 0;
+ goto out;
+ }
+
+ if (num_netbufs < 0) goto out;
+
+ GCNEW_ARRAY(netbuf_state->ifb_list, num_netbufs);
+ netbuf_state->num_netbufs = num_netbufs;
+ remus_state->netbuf_state = netbuf_state;
+ remus_state->dev_id = 0;
+ if (exec_netbuf_script(gc, remus_state, "setup",
+ netbuf_setup_script_cb))
+ goto out;
+ return;
+
+ out:
+ libxl__remus_setup_done(egc, dss, rc);
+}
+
+static void netbuf_teardown_script_cb(libxl__egc *egc,
+ libxl__ev_child *child,
+ pid_t pid, int status)
+{
+ libxl__remus_state *remus_state = CONTAINER_OF(child, *remus_state, child);
+
+ /* Convenience aliases */
+ libxl__remus_netbuf_state *const netbuf_state = remus_state->netbuf_state;
+
+ STATE_AO_GC(remus_state->dss->ao);
+
+ libxl__ev_time_deregister(gc, &remus_state->timeout);
+
+ if (status) {
+ libxl_report_child_exitstatus(CTX, LIBXL__LOG_ERROR,
+ remus_state->netbufscript,
+ pid, status);
+ }
+
+ remus_state->dev_id++;
+ if (remus_state->dev_id < netbuf_state->num_netbufs) {
+ if (exec_netbuf_script(gc, remus_state,
+ "teardown", netbuf_teardown_script_cb))
+ goto out;
+ return;
+ }
+
+ out:
+ libxl__remus_teardown_done(egc, remus_state->dss);
+}
+
+/* Note: This function will be called in the same gc context as
+ * libxl__remus_netbuf_setup, created during the libxl_domain_remus_start
+ * API call.
+ */
+void libxl__remus_netbuf_teardown(libxl__egc *egc,
+ libxl__domain_suspend_state *dss)
+{
+ /* Convenience aliases */
+ libxl__remus_state *const remus_state = dss->remus_state;
+ libxl__remus_netbuf_state *const netbuf_state = remus_state->netbuf_state;
+
+ STATE_AO_GC(dss->ao);
+
+ free_qdiscs(netbuf_state);
+
+ remus_state->dev_id = 0;
+ if (exec_netbuf_script(gc, remus_state, "teardown",
+ netbuf_teardown_script_cb))
+ libxl__remus_teardown_done(egc, dss);
+}
+
/*
* Local variables:
* mode: C
diff --git a/tools/libxl/libxl_nonetbuffer.c b/tools/libxl/libxl_nonetbuffer.c
index 6aa4bf1..559d0a6 100644
--- a/tools/libxl/libxl_nonetbuffer.c
+++ b/tools/libxl/libxl_nonetbuffer.c
@@ -22,6 +22,17 @@ int libxl__netbuffer_enabled(libxl__gc *gc)
return 0;
}
+/* Remus network buffer related stubs */
+void libxl__remus_netbuf_setup(libxl__egc *egc,
+ libxl__domain_suspend_state *dss)
+{
+}
+
+void libxl__remus_netbuf_teardown(libxl__egc *egc,
+ libxl__domain_suspend_state *dss)
+{
+}
+
/*
* Local variables:
* mode: C
diff --git a/tools/libxl/libxl_remus.c b/tools/libxl/libxl_remus.c
new file mode 100644
index 0000000..4e40412
--- /dev/null
+++ b/tools/libxl/libxl_remus.c
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2014
+ * Author Shriram Rajagopalan <rshriram@xxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation; version 2.1 only. with the special
+ * exception on linking described in file LICENSE.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ */
+
+#include "libxl_osdeps.h" /* must come before any other headers */
+
+#include "libxl_internal.h"
+
+/*----- remus setup/teardown code -----*/
+
+void libxl__remus_setup_done(libxl__egc *egc,
+ libxl__domain_suspend_state *dss,
+ int rc)
+{
+ STATE_AO_GC(dss->ao);
+ if (!rc) {
+ libxl__domain_suspend(egc, dss);
+ return;
+ }
+
+ LOG(ERROR, "Remus: failed to setup network buffering"
+ " for guest with domid %u", dss->domid);
+ domain_suspend_done(egc, dss, rc);
+}
+
+void libxl__remus_teardown_done(libxl__egc *egc,
+ libxl__domain_suspend_state *dss)
+{
+ dss->callback(egc, dss, dss->remus_state->saved_rc);
+}
--
1.7.1
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