Build on Jeff Roberson's linker-set based dynamic per-CPU allocator

(DPCPU), as suggested by Peter Wemm, and implement a new per-virtual
network stack memory allocator.  Modify vnet to use the allocator
instead of monolithic global container structures (vinet, ...).  This
change solves many binary compatibility problems associated with
VIMAGE, and restores ELF symbols for virtualized global variables.

Each virtualized global variable exists as a "reference copy", and also
once per virtual network stack.  Virtualized global variables are
tagged at compile-time, placing the in a special linker set, which is
loaded into a contiguous region of kernel memory.  Virtualized global
variables in the base kernel are linked as normal, but those in modules
are copied and relocated to a reserved portion of the kernel's vnet
region with the help of a the kernel linker.

Virtualized global variables exist in per-vnet memory set up when the
network stack instance is created, and are initialized statically from
the reference copy.  Run-time access occurs via an accessor macro, which
converts from the current vnet and requested symbol to a per-vnet
address.  When "options VIMAGE" is not compiled into the kernel, normal
global ELF symbols will be used instead and indirection is avoided.

This change restores static initialization for network stack global
variables, restores support for non-global symbols and types, eliminates
the need for many subsystem constructors, eliminates large per-subsystem
structures that caused many binary compatibility issues both for
monitoring applications (netstat) and kernel modules, removes the
per-function INIT_VNET_*() macros throughout the stack, eliminates the
need for vnet_symmap ksym(2) munging, and eliminates duplicate
definitions of virtualized globals under VIMAGE_GLOBALS.

Bump __FreeBSD_version and update UPDATING.

Portions submitted by:  bz
Reviewed by:            bz, zec
Discussed with:         gnn, jamie, jeff, jhb, julian, sam
Suggested by:           peter
Approved by:            re (kensmith)

7 files changed, 29 insertions, 101 deletions

diff --git a/sys/netgraph/atm/ng_atm.c b/sys/netgraph/atm/ng_atm.c
index e5e1e2e..7296aa1 100644
--- a/sys/netgraph/atm/ng_atm.c
+++ b/sys/netgraph/atm/ng_atm.c
@@ -1407,7 +1407,6 @@ ng_atm_mod_event(module_t mod, int event, void *data)
 		VNET_LIST_RLOCK();
 		VNET_FOREACH(vnet_iter) {
 			CURVNET_SET_QUIET(vnet_iter);
-			INIT_VNET_NET(vnet_iter);
 			TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
 				if (ifp->if_type == IFT_ATM)
 					ng_atm_attach(ifp);
@@ -1431,7 +1430,6 @@ ng_atm_mod_event(module_t mod, int event, void *data)
 		VNET_LIST_RLOCK();
 		VNET_FOREACH(vnet_iter) {
 			CURVNET_SET_QUIET(vnet_iter);
-			INIT_VNET_NET(vnet_iter);
 			TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
 				if (ifp->if_type == IFT_ATM)
 					ng_atm_detach(ifp);
diff --git a/sys/netgraph/netgraph.h b/sys/netgraph/netgraph.h
index 5a0418e..37ef833 100644
--- a/sys/netgraph/netgraph.h
+++ b/sys/netgraph/netgraph.h
@@ -1218,36 +1218,4 @@ typedef void *meta_p;
 		    ("%s: negative td_ng_outbound", __func__));		\
 	} while (0)
 
-/* Virtualization macros */
-#define	INIT_VNET_NETGRAPH(vnet) \
-	INIT_FROM_VNET(vnet, VNET_MOD_NETGRAPH, \
-	    struct vnet_netgraph, vnet_netgraph)
-
-#define	VNET_NETGRAPH(sym)	VSYM(vnet_netgraph, sym)
-
-struct vnet_netgraph {
-	LIST_HEAD(, ng_node)	 _ng_ID_hash[NG_ID_HASH_SIZE];
-	LIST_HEAD(, ng_node)	 _ng_name_hash[NG_NAME_HASH_SIZE];
-	LIST_HEAD(, ng_node)	 _ng_nodelist;
-	ng_ID_t			 _nextID;
-	struct unrhdr		*_ng_iface_unit;
-	struct unrhdr		*_ng_eiface_unit;
-	struct unrhdr		*_ng_wormhole_unit;
-};
-
-#ifndef VIMAGE
-#ifndef VIMAGE_GLOBALS
-extern struct vnet_netgraph vnet_netgraph_0;
-#endif
-#endif
-
-/* Symbol translation macros */
-#define	V_nextID		VNET_NETGRAPH(nextID)
-#define	V_ng_ID_hash		VNET_NETGRAPH(ng_ID_hash)
-#define	V_ng_eiface_unit	VNET_NETGRAPH(ng_eiface_unit)
-#define	V_ng_iface_unit		VNET_NETGRAPH(ng_iface_unit)
-#define	V_ng_name_hash		VNET_NETGRAPH(ng_name_hash)
-#define	V_ng_nodelist		VNET_NETGRAPH(ng_nodelist)
-#define	V_ng_wormhole_unit	VNET_NETGRAPH(ng_wormhole_unit)
-
 #endif /* _NETGRAPH_NETGRAPH_H_ */
diff --git a/sys/netgraph/ng_base.c b/sys/netgraph/ng_base.c
index a495701..9eb99d5 100644
--- a/sys/netgraph/ng_base.c
+++ b/sys/netgraph/ng_base.c
@@ -68,6 +68,7 @@
 #include <machine/cpu.h>
 
 #include <net/netisr.h>
+#include <net/vnet.h>
 
 #include <netgraph/ng_message.h>
 #include <netgraph/netgraph.h>
@@ -75,16 +76,9 @@
 
 MODULE_VERSION(netgraph, NG_ABI_VERSION);
 
-#ifndef VIMAGE
-#ifndef VIMAGE_GLOBALS
-struct vnet_netgraph vnet_netgraph_0;
-#endif
-#endif
-
 /* Mutex to protect topology events. */
 static struct mtx	ng_topo_mtx;
 
-static vnet_attach_fn vnet_netgraph_iattach;
 #ifdef VIMAGE
 static vnet_detach_fn vnet_netgraph_idetach;
 #endif
@@ -182,9 +176,9 @@ static struct mtx	ng_typelist_mtx;
 
 /* Hash related definitions */
 /* XXX Don't need to initialise them because it's a LIST */
-#ifdef VIMAGE_GLOBALS
-static LIST_HEAD(, ng_node) ng_ID_hash[NG_ID_HASH_SIZE];
-#endif
+static VNET_DEFINE(LIST_HEAD(, ng_node), ng_ID_hash[NG_ID_HASH_SIZE]);
+#define	V_ng_ID_hash			VNET_GET(ng_ID_hash)
+
 static struct mtx	ng_idhash_mtx;
 /* Method to find a node.. used twice so do it here */
 #define NG_IDHASH_FN(ID) ((ID) % (NG_ID_HASH_SIZE))
@@ -200,9 +194,9 @@ static struct mtx	ng_idhash_mtx;
 		}							\
 	} while (0)
 
-#ifdef VIMAGE_GLOBALS
-static LIST_HEAD(, ng_node) ng_name_hash[NG_NAME_HASH_SIZE];
-#endif
+static VNET_DEFINE(LIST_HEAD(, ng_node), ng_name_hash[NG_NAME_HASH_SIZE]);
+#define	V_ng_name_hash			VNET_GET(ng_name_hash)
+
 static struct mtx	ng_namehash_mtx;
 #define NG_NAMEHASH(NAME, HASH)				\
 	do {						\
@@ -370,9 +364,8 @@ ng_alloc_node(void)
 #define TRAP_ERROR()
 #endif
 
-#ifdef VIMAGE_GLOBALS
-static	ng_ID_t nextID;
-#endif
+static VNET_DEFINE(ng_ID_t, nextID) = 1;
+#define	V_nextID			VNET_GET(nextID)
 
 #ifdef INVARIANTS
 #define CHECK_DATA_MBUF(m)	do {					\
@@ -634,7 +627,6 @@ ng_make_node(const char *typename, node_p *nodepp)
 int
 ng_make_node_common(struct ng_type *type, node_p *nodepp)
 {
-	INIT_VNET_NETGRAPH(curvnet);
 	node_p node;
 
 	/* Require the node type to have been already installed */
@@ -819,7 +811,6 @@ ng_unref_node(node_p node)
 static node_p
 ng_ID2noderef(ng_ID_t ID)
 {
-	INIT_VNET_NETGRAPH(curvnet);
 	node_p node;
 	mtx_lock(&ng_idhash_mtx);
 	NG_IDHASH_FIND(ID, node);
@@ -845,7 +836,6 @@ ng_node2ID(node_p node)
 int
 ng_name_node(node_p node, const char *name)
 {
-	INIT_VNET_NETGRAPH(curvnet);
 	int i, hash;
 	node_p node2;
 
@@ -896,7 +886,6 @@ ng_name_node(node_p node, const char *name)
 node_p
 ng_name2noderef(node_p here, const char *name)
 {
-	INIT_VNET_NETGRAPH(curvnet);
 	node_p node;
 	ng_ID_t temp;
 	int	hash;
@@ -2457,7 +2446,6 @@ ng_apply_item(node_p node, item_p item, int rw)
 static int
 ng_generic_msg(node_p here, item_p item, hook_p lasthook)
 {
-	INIT_VNET_NETGRAPH(curvnet);
 	int error = 0;
 	struct ng_mesg *msg;
 	struct ng_mesg *resp = NULL;
@@ -3080,37 +3068,24 @@ ng_mod_event(module_t mod, int event, void *data)
 	return (error);
 }
 
-#ifndef VIMAGE_GLOBALS
+#ifdef VIMAGE
 static const vnet_modinfo_t vnet_netgraph_modinfo = {
 	.vmi_id		= VNET_MOD_NETGRAPH,
 	.vmi_name	= "netgraph",
-	.vmi_size	= sizeof(struct vnet_netgraph),
 	.vmi_dependson	= VNET_MOD_LOIF,
-	.vmi_iattach	= vnet_netgraph_iattach,
-#ifdef VIMAGE
 	.vmi_idetach	= vnet_netgraph_idetach
-#endif
 };
 #endif
 
-static int
-vnet_netgraph_iattach(const void *unused __unused)
-{
-	INIT_VNET_NETGRAPH(curvnet);
-
-	V_nextID = 1;
-
-	return (0);
-}
-
 #ifdef VIMAGE 
 static int
 vnet_netgraph_idetach(const void *unused __unused)
 {
-	INIT_VNET_NETGRAPH(curvnet);
+#if 0
 	node_p node, last_killed = NULL;
 
-	while ((node = LIST_FIRST(&V_ng_nodelist)) != NULL) {
+	/* XXXRW: utterly bogus. */
+	while ((node = LIST_FIRST(&V_ng_allnodes)) != NULL) {
 		if (node == last_killed) {
 			/* This should never happen */
 			node->nd_flags |= NGF_REALLY_DIE;
@@ -3118,13 +3093,14 @@ vnet_netgraph_idetach(const void *unused __unused)
 			    node->nd_name);
 			ng_rmnode(node, NULL, NULL, 0);
 			/* This must never happen */
-			if (node == LIST_FIRST(&V_ng_nodelist))
+			if (node == LIST_FIRST(&V_ng_allnodes))
 				panic("netgraph node %s won't die",
 				    node->nd_name);
 		}
 		ng_rmnode(node, NULL, NULL, 0);
 		last_killed = node;
 	}
+#endif
 
 	return (0);
 }
@@ -3144,10 +3120,8 @@ ngb_mod_event(module_t mod, int event, void *data)
 	switch (event) {
 	case MOD_LOAD:
 		/* Initialize everything. */
-#ifndef VIMAGE_GLOBALS
+#ifdef VIMAGE
 		vnet_mod_register(&vnet_netgraph_modinfo);
-#else
-		vnet_netgraph_iattach(NULL);
 #endif
 		NG_WORKLIST_LOCK_INIT();
 		mtx_init(&ng_typelist_mtx, "netgraph types mutex", NULL,
diff --git a/sys/netgraph/ng_eiface.c b/sys/netgraph/ng_eiface.c
index 27b4b45..9969924 100644
--- a/sys/netgraph/ng_eiface.c
+++ b/sys/netgraph/ng_eiface.c
@@ -116,11 +116,10 @@ NETGRAPH_INIT(eiface, &typestruct);
 static vnet_attach_fn ng_eiface_iattach;
 static vnet_detach_fn ng_eiface_idetach;
 
-#ifdef VIMAGE_GLOBALS
-static struct unrhdr	*ng_eiface_unit;
-#endif
+static VNET_DEFINE(struct unrhdr *, ng_eiface_unit);
+#define	V_ng_eiface_unit		VNET_GET(ng_eiface_unit)
 
-#ifndef VIMAGE_GLOBALS
+#ifdef VIMAGE
 static vnet_modinfo_t vnet_ng_eiface_modinfo = {
 	.vmi_id		= VNET_MOD_NG_EIFACE,
 	.vmi_name	= "ng_eiface",
@@ -351,7 +350,6 @@ ng_eiface_print_ioctl(struct ifnet *ifp, int command, caddr_t data)
 static int
 ng_eiface_constructor(node_p node)
 {
-	INIT_VNET_NETGRAPH(curvnet);
 	struct ifnet *ifp;
 	priv_p priv;
 	u_char eaddr[6] = {0,0,0,0,0,0};
@@ -563,7 +561,6 @@ ng_eiface_rcvdata(hook_p hook, item_p item)
 static int
 ng_eiface_rmnode(node_p node)
 {
-	INIT_VNET_NETGRAPH(curvnet);
 	const priv_p priv = NG_NODE_PRIVATE(node);
 	struct ifnet *const ifp = priv->ifp;
 
@@ -604,14 +601,14 @@ ng_eiface_mod_event(module_t mod, int event, void *data)
 
 	switch (event) {
 	case MOD_LOAD:
-#ifndef VIMAGE_GLOBALS
+#ifdef VIMAGE
 		vnet_mod_register(&vnet_ng_eiface_modinfo);
 #else
 		ng_eiface_iattach(NULL);
 #endif
 		break;
 	case MOD_UNLOAD:
-#ifndef VIMAGE_GLOBALS
+#ifdef VIMAGE
 		vnet_mod_deregister(&vnet_ng_eiface_modinfo);
 #else
 		ng_eiface_idetach(NULL);
@@ -626,7 +623,6 @@ ng_eiface_mod_event(module_t mod, int event, void *data)
 
 static int ng_eiface_iattach(const void *unused)
 {
-	INIT_VNET_NETGRAPH(curvnet);
 
 	V_ng_eiface_unit = new_unrhdr(0, 0xffff, NULL);
 
@@ -635,7 +631,6 @@ static int ng_eiface_iattach(const void *unused)
 
 static int ng_eiface_idetach(const void *unused)
 {
-	INIT_VNET_NETGRAPH(curvnet);
 
 	delete_unrhdr(V_ng_eiface_unit);
 
diff --git a/sys/netgraph/ng_ether.c b/sys/netgraph/ng_ether.c
index 2be3b883..09a8615 100644
--- a/sys/netgraph/ng_ether.c
+++ b/sys/netgraph/ng_ether.c
@@ -74,7 +74,7 @@
 
 static vnet_attach_fn ng_ether_iattach;
 
-#ifndef VIMAGE_GLOBALS
+#ifdef VIMAGE
 static vnet_modinfo_t vnet_ng_ether_modinfo = {
 	.vmi_id		= VNET_MOD_NG_ETHER,
 	.vmi_name	= "ng_ether",
@@ -783,7 +783,7 @@ ng_ether_mod_event(module_t mod, int event, void *data)
 		ng_ether_input_orphan_p = ng_ether_input_orphan;
 		ng_ether_link_state_p = ng_ether_link_state;
 
-#ifndef VIMAGE_GLOBALS
+#ifdef VIMAGE
 		vnet_mod_register(&vnet_ng_ether_modinfo);
 #else
 		error = ng_ether_iattach(NULL);
@@ -800,7 +800,7 @@ ng_ether_mod_event(module_t mod, int event, void *data)
 		 * is MOD_UNLOAD, so there's no need to detach any nodes.
 		 */
 
-#ifndef VIMAGE_GLOBALS
+#ifdef VIMAGE
 		vnet_mod_deregister(&vnet_ng_ether_modinfo);
 #endif
 
@@ -823,7 +823,6 @@ ng_ether_mod_event(module_t mod, int event, void *data)
 
 static int ng_ether_iattach(const void *unused)
 {
-	INIT_VNET_NET(curvnet);
 	struct ifnet *ifp;
 
 	/* Create nodes for any already-existing Ethernet interfaces. */
diff --git a/sys/netgraph/ng_gif.c b/sys/netgraph/ng_gif.c
index 6f2657e..f099d61 100644
--- a/sys/netgraph/ng_gif.c
+++ b/sys/netgraph/ng_gif.c
@@ -565,7 +565,6 @@ ng_gif_mod_event(module_t mod, int event, void *data)
 		VNET_LIST_RLOCK();
 		VNET_FOREACH(vnet_iter) {
 			CURVNET_SET_QUIET(vnet_iter); /* XXX revisit quiet */
-			INIT_VNET_NET(curvnet);
 			TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
 				if (ifp->if_type == IFT_GIF)
 					ng_gif_attach(ifp);
diff --git a/sys/netgraph/ng_iface.c b/sys/netgraph/ng_iface.c
index cd65ad3..7743b2b 100644
--- a/sys/netgraph/ng_iface.c
+++ b/sys/netgraph/ng_iface.c
@@ -212,11 +212,10 @@ NETGRAPH_INIT(iface, &typestruct);
 static vnet_attach_fn ng_iface_iattach;
 static vnet_detach_fn ng_iface_idetach;
 
-#ifdef VIMAGE_GLOBALS
-static struct unrhdr	*ng_iface_unit;
-#endif
+static VNET_DEFINE(struct unrhdr *, ng_iface_unit);
+#define	V_ng_iface_unit			VNET_GET(ng_iface_unit)
 
-#ifndef VIMAGE_GLOBALS
+#ifdef VIMAGE
 static vnet_modinfo_t vnet_ng_iface_modinfo = {
 	.vmi_id		= VNET_MOD_NG_IFACE,
 	.vmi_name	= "ng_iface",
@@ -542,7 +541,6 @@ ng_iface_print_ioctl(struct ifnet *ifp, int command, caddr_t data)
 static int
 ng_iface_constructor(node_p node)
 {
-	INIT_VNET_NETGRAPH(curvnet);
 	struct ifnet *ifp;
 	priv_p priv;
 
@@ -806,7 +804,6 @@ ng_iface_rcvdata(hook_p hook, item_p item)
 static int
 ng_iface_shutdown(node_p node)
 {
-	INIT_VNET_NETGRAPH(curvnet);
 	const priv_p priv = NG_NODE_PRIVATE(node);
 
 	/*
@@ -852,14 +849,14 @@ ng_iface_mod_event(module_t mod, int event, void *data)
 
 	switch (event) {
 	case MOD_LOAD:
-#ifndef VIMAGE_GLOBALS
+#ifdef VIMAGE
 		vnet_mod_register(&vnet_ng_iface_modinfo);
 #else
 		ng_iface_iattach(NULL);
 #endif
 		break;
 	case MOD_UNLOAD:
-#ifndef VIMAGE_GLOBALS
+#ifdef VIMAGE
 		vnet_mod_deregister(&vnet_ng_iface_modinfo);
 #else
 		ng_iface_idetach(NULL);
@@ -874,7 +871,6 @@ ng_iface_mod_event(module_t mod, int event, void *data)
 
 static int ng_iface_iattach(const void *unused)
 {
-	INIT_VNET_NETGRAPH(curvnet);
 
 	V_ng_iface_unit = new_unrhdr(0, 0xffff, NULL);
 
@@ -883,7 +879,6 @@ static int ng_iface_iattach(const void *unused)
 
 static int ng_iface_idetach(const void *unused)
 {
-	INIT_VNET_NETGRAPH(curvnet);
 
 	delete_unrhdr(V_ng_iface_unit);