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)

8 files changed, 119 insertions, 226 deletions

diff --git a/sys/kern/kern_linker.c b/sys/kern/kern_linker.c
index 9775059..1768e69 100644
--- a/sys/kern/kern_linker.c
+++ b/sys/kern/kern_linker.c
@@ -1334,23 +1334,8 @@ kldsym(struct thread *td, struct kldsym_args *uap)
 				break;
 			}
 		}
-#ifndef VIMAGE_GLOBALS
-		/*
-		 * If the symbol is not found in global namespace,
-		 * try to look it up in the current vimage namespace.
-		 */
-		if (lf == NULL) {
-			CURVNET_SET(TD_TO_VNET(td));
-			error = vi_symlookup(&lookup, symstr);
-			CURVNET_RESTORE();
-			if (error == 0)
-				error = copyout(&lookup, uap->data,
-						sizeof(lookup));
-		}
-#else
 		if (lf == NULL)
 			error = ENOENT;
-#endif
 	}
 	KLD_UNLOCK();
 out:
diff --git a/sys/kern/kern_poll.c b/sys/kern/kern_poll.c
index d9cf49f..5396240 100644
--- a/sys/kern/kern_poll.c
+++ b/sys/kern/kern_poll.c
@@ -545,7 +545,6 @@ ether_poll_deregister(struct ifnet *ifp)
 static int
 poll_switch(SYSCTL_HANDLER_ARGS)
 {
-	INIT_VNET_NET(curvnet);
 	struct ifnet *ifp;
 	int error;
 	int val = polling;
diff --git a/sys/kern/kern_sysctl.c b/sys/kern/kern_sysctl.c
index 9e61544..94e45f1 100644
--- a/sys/kern/kern_sysctl.c
+++ b/sys/kern/kern_sysctl.c
@@ -59,6 +59,8 @@ __FBSDID("$FreeBSD$");
 #include <sys/ktrace.h>
 #endif
 
+#include <net/vnet.h>
+
 #include <security/mac/mac_framework.h>
 
 #include <vm/vm.h>
@@ -936,33 +938,9 @@ sysctl_handle_int(SYSCTL_HANDLER_ARGS)
 	return (error);
 }
 
-#ifdef VIMAGE
-int
-sysctl_handle_v_int(SYSCTL_HANDLER_ARGS)
-{
-	int tmpout, error = 0;
- 
-	SYSCTL_RESOLVE_V_ARG1();
- 
-	/*
-	 * Attempt to get a coherent snapshot by making a copy of the data.
-	 */
-	tmpout = *(int *)arg1;
-	error = SYSCTL_OUT(req, &tmpout, sizeof(int));
-
-	if (error || !req->newptr)
-		return (error);
-
-	if (!arg1)
-		error = EPERM;
-	else
-		error = SYSCTL_IN(req, arg1, sizeof(int));
-	return (error);
-}
-#endif
-
 /*
  * Based on on sysctl_handle_int() convert milliseconds into ticks.
+ * Note: this is used by TCP.
  */
 
 int
@@ -970,8 +948,11 @@ sysctl_msec_to_ticks(SYSCTL_HANDLER_ARGS)
 {
 	int error, s, tt;
 
-	SYSCTL_RESOLVE_V_ARG1();
-
+#ifdef VIMAGE
+	if (arg1 != NULL)
+		arg1 = (void *)(TD_TO_VNET(req->td)->vnet_data_base +
+		    (uintptr_t)arg1);
+#endif
 	tt = *(int *)arg1;
 	s = (int)((int64_t)tt * 1000 / hz);
 
@@ -1097,47 +1078,6 @@ retry:
 	return (error);
 }
 
-#ifdef VIMAGE
-int
-sysctl_handle_v_string(SYSCTL_HANDLER_ARGS)
-{
-	int error=0;
-	char *tmparg;
-	size_t outlen;
-
-	SYSCTL_RESOLVE_V_ARG1();
-
-	/*
-	 * Attempt to get a coherent snapshot by copying to a
-	 * temporary kernel buffer.
-	 */
-retry:
-	outlen = strlen((char *)arg1)+1;
-	tmparg = malloc(outlen, M_SYSCTLTMP, M_WAITOK);
-
-	if (strlcpy(tmparg, (char *)arg1, outlen) >= outlen) {
-		free(tmparg, M_SYSCTLTMP);
-		goto retry;
-	}
-
-	error = SYSCTL_OUT(req, tmparg, outlen);
-	free(tmparg, M_SYSCTLTMP);
-
-	if (error || !req->newptr)
-		return (error);
-
-	if ((req->newlen - req->newidx) >= arg2) {
-		error = EINVAL;
-	} else {
-		arg2 = (req->newlen - req->newidx);
-		error = SYSCTL_IN(req, arg1, arg2);
-		((char *)arg1)[arg2] = '\0';
-	}
-
-	return (error);
-}
-#endif
-
 /*
  * Handle any kind of opaque data.
  * arg1 points to it, arg2 is the size.
@@ -1175,35 +1115,6 @@ retry:
 	return (error);
 }
 
-#ifdef VIMAGE
-int
-sysctl_handle_v_opaque(SYSCTL_HANDLER_ARGS)
-{
-	int error, tries;
-	u_int generation;
-	struct sysctl_req req2;
-
-	SYSCTL_RESOLVE_V_ARG1();
-
-	tries = 0;
-	req2 = *req;
-retry:
-	generation = curthread->td_generation;
-	error = SYSCTL_OUT(req, arg1, arg2);
-	if (error)
-		return (error);
-	tries++;
-	if (generation != curthread->td_generation && tries < 3) {
-		*req = req2;
-		goto retry;
-	}
-
-	error = SYSCTL_IN(req, arg1, arg2);
-
-	return (error);
-}
-#endif
-
 /*
  * Transfer functions to/from kernel space.
  * XXX: rather untested at this point
diff --git a/sys/kern/kern_uuid.c b/sys/kern/kern_uuid.c
index a0c26b9..cd88538 100644
--- a/sys/kern/kern_uuid.c
+++ b/sys/kern/kern_uuid.c
@@ -89,7 +89,6 @@ MTX_SYSINIT(uuid_lock, &uuid_mutex, "UUID generator mutex lock", MTX_DEF);
 static void
 uuid_node(uint16_t *node)
 {
-	INIT_VNET_NET(curvnet);
 	struct ifnet *ifp;
 	struct ifaddr *ifa;
 	struct sockaddr_dl *sdl;
diff --git a/sys/kern/kern_vimage.c b/sys/kern/kern_vimage.c
index 9ee3e1d..daa9b9f 100644
--- a/sys/kern/kern_vimage.c
+++ b/sys/kern/kern_vimage.c
@@ -53,8 +53,6 @@ __FBSDID("$FreeBSD$");
 #include <net/route.h>
 #include <net/vnet.h>
 
-#ifndef VIMAGE_GLOBALS
-
 MALLOC_DEFINE(M_VIMAGE, "vimage", "vimage resource container");
 MALLOC_DEFINE(M_VNET, "vnet", "network stack control block");
 MALLOC_DEFINE(M_VPROCG, "vprocg", "process group control block");
@@ -65,13 +63,11 @@ static void vnet_mod_complete_registration(struct vnet_modlink *);
 static int vnet_mod_constructor(struct vnet_modlink *);
 static int vnet_mod_destructor(struct vnet_modlink *);
 
-#ifdef VIMAGE
 static struct vimage *vi_alloc(struct vimage *, char *);
 static int vi_destroy(struct vimage *);
 static struct vimage *vimage_get_next(struct vimage *, struct vimage *, int);
 static void vimage_relative_name(struct vimage *, struct vimage *,
     char *, int);
-#endif
 
 #define	VNET_LIST_WLOCK()						\
 	mtx_lock(&vnet_list_refc_mtx);					\
@@ -81,17 +77,11 @@ static void vimage_relative_name(struct vimage *, struct vimage *,
 #define	VNET_LIST_WUNLOCK()						\
 	mtx_unlock(&vnet_list_refc_mtx);
 
-#ifdef VIMAGE
 struct vimage_list_head vimage_head;
 struct vnet_list_head vnet_head;
 struct vprocg_list_head vprocg_head;
-#else
-#ifndef VIMAGE_GLOBALS
 struct vprocg vprocg_0;
-#endif
-#endif
 
-#ifdef VIMAGE
 struct cv vnet_list_condvar;
 struct mtx vnet_list_refc_mtx;
 int vnet_list_refc = 0;
@@ -100,9 +90,7 @@ static u_int last_vi_id = 0;
 static u_int last_vprocg_id = 0;
 
 struct vnet *vnet0;
-#endif
 
-#ifdef VIMAGE
 
 /*
  * Move an ifnet to or from another vnet, specified by the jail id.  If a
@@ -396,8 +384,6 @@ vimage_get_next(struct vimage *top, struct vimage *where, int recurse)
 	return (NULL);
 }
 
-#endif /* VIMAGE */ /* User interface block */
-
 
 /*
  * Kernel interfaces and handlers.
@@ -540,25 +526,11 @@ vnet_mod_constructor(struct vnet_modlink *vml)
 	if (vml->vml_iarg)
 		printf("/%s", vml->vml_iname);
 	printf(": ");
-#ifdef VIMAGE
-	if (vmi->vmi_size)
-		printf("malloc(%zu); ", vmi->vmi_size);
-#endif
 	if (vmi->vmi_iattach != NULL)
 		printf("iattach()");
 	printf("\n");
 #endif
 
-#ifdef VIMAGE
-	if (vmi->vmi_size) {
-		void *mem = malloc(vmi->vmi_size, M_VNET,
-		    M_NOWAIT | M_ZERO);
-		if (mem == NULL) /* XXX should return error, not panic. */
-			panic("malloc for %s\n", vmi->vmi_name);
-		curvnet->mod_data[vmi->vmi_id] = mem;
-	}
-#endif
-
 	if (vmi->vmi_iattach != NULL)
 		vmi->vmi_iattach(vml->vml_iarg);
 
@@ -577,63 +549,15 @@ vnet_mod_destructor(struct vnet_modlink *vml)
 	printf(": ");
 	if (vmi->vmi_idetach != NULL)
 		printf("idetach(); ");
-#ifdef VIMAGE
-	if (vmi->vmi_size)
-		printf("free()");
-#endif
 	printf("\n");
 #endif
 
 	if (vmi->vmi_idetach)
 		vmi->vmi_idetach(vml->vml_iarg);
 
-#ifdef VIMAGE
-	if (vmi->vmi_size) {
-		if (curvnet->mod_data[vmi->vmi_id] == NULL)
-			panic("vi_destroy: %s\n", vmi->vmi_name);
-		free(curvnet->mod_data[vmi->vmi_id], M_VNET);
-		curvnet->mod_data[vmi->vmi_id] = NULL;
-	}
-#endif
-
 	return (0);
 }
 
-/*
- * vi_symlookup() attempts to resolve name to address queries for
- * variables which have been moved from global namespace to virtualization
- * container structures, but are still directly accessed from legacy
- * userspace processes via kldsym(2) and kmem(4) interfaces.
- */
-int
-vi_symlookup(struct kld_sym_lookup *lookup, char *symstr)
-{
-	struct vnet_modlink *vml;
-	struct vnet_symmap *mapentry;
-
-	TAILQ_FOREACH(vml, &vnet_modlink_head, vml_mod_le) {
-		if (vml->vml_modinfo->vmi_symmap == NULL)
-			continue;
-		for (mapentry = vml->vml_modinfo->vmi_symmap;
-		    mapentry->name != NULL; mapentry++) {
-			if (strcmp(symstr, mapentry->name) == 0) {
-#ifdef VIMAGE
-				lookup->symvalue =
-				    (u_long) curvnet->mod_data[
-				    vml->vml_modinfo->vmi_id];
-				lookup->symvalue += mapentry->offset;
-#else
-				lookup->symvalue = (u_long) mapentry->offset;
-#endif
-				lookup->symsize = mapentry->size;
-				return (0);
-			}
-		}
-	}
-	return (ENOENT);
-}
-
-#ifdef VIMAGE
 struct vnet *
 vnet_alloc(void)
 {
@@ -642,6 +566,7 @@ vnet_alloc(void)
 
 	vnet = malloc(sizeof(struct vnet), M_VNET, M_WAITOK | M_ZERO);
 	vnet->vnet_magic_n = VNET_MAGIC_N;
+	vnet_data_init(vnet);
 
 	/* Initialize / attach vnet module instances. */
 	CURVNET_SET_QUIET(vnet);
@@ -669,7 +594,6 @@ vnet_destroy(struct vnet *vnet)
 	VNET_LIST_WUNLOCK();
 
 	CURVNET_SET_QUIET(vnet);
-	INIT_VNET_NET(vnet);
 
 	/* Return all inherited interfaces to their parent vnets. */
 	TAILQ_FOREACH_SAFE(ifp, &V_ifnet, if_link, nifp) {
@@ -685,10 +609,22 @@ vnet_destroy(struct vnet *vnet)
 	CURVNET_RESTORE();
 
 	/* Hopefully, we are OK to free the vnet container itself. */
+	vnet_data_destroy(vnet);
 	vnet->vnet_magic_n = 0xdeadbeef;
 	free(vnet, M_VNET);
 }
 
+void
+vnet_foreach(void (*vnet_foreach_fn)(struct vnet *, void *), void *arg)
+{
+	struct vnet *vnet;
+
+	VNET_LIST_RLOCK();
+	LIST_FOREACH(vnet, &vnet_head, vnet_le)
+		vnet_foreach_fn(vnet, arg);
+	VNET_LIST_RUNLOCK();
+}
+
 static struct vimage *
 vi_alloc(struct vimage *parent, char *name)
 {
@@ -757,7 +693,6 @@ vi_destroy(struct vimage *vip)
 
 	return (0);
 }
-#endif /* VIMAGE */
 
 static void
 vi_init(void *unused)
@@ -766,7 +701,6 @@ vi_init(void *unused)
 	TAILQ_INIT(&vnet_modlink_head);
 	TAILQ_INIT(&vnet_modpending_head);
 
-#ifdef VIMAGE
 	LIST_INIT(&vimage_head);
 	LIST_INIT(&vprocg_head);
 	LIST_INIT(&vnet_head);
@@ -783,7 +717,6 @@ vi_init(void *unused)
 	 * curvnet recursions.
 	 */
 	curvnet = prison0.pr_vnet = vnet0 = LIST_FIRST(&vnet_head);
-#endif
 }
 
 static void
@@ -791,9 +724,7 @@ vi_init_done(void *unused)
 {
 	struct vnet_modlink *vml_iter;
 
-#ifdef VIMAGE
 	curvnet = NULL;
-#endif
 
 	if (TAILQ_EMPTY(&vnet_modpending_head))
 		return;
@@ -809,45 +740,21 @@ vi_init_done(void *unused)
 
 SYSINIT(vimage, SI_SUB_VIMAGE, SI_ORDER_FIRST, vi_init, NULL);
 SYSINIT(vimage_done, SI_SUB_VIMAGE_DONE, SI_ORDER_FIRST, vi_init_done, NULL);
-#endif /* !VIMAGE_GLOBALS */
 
-#ifdef VIMAGE
 #ifdef DDB
-static void
-db_vnet_ptr(void *arg)
-{
-
-	if (arg)
-		db_printf(" %p", arg);
-	else
-#if SIZE_MAX == UINT32_MAX /* 32-bit arch */
-		db_printf("          0");
-#else /* 64-bit arch, most probaly... */
-		db_printf("                  0");
-#endif
-}
-
 DB_SHOW_COMMAND(vnets, db_show_vnets)
 {
 	VNET_ITERATOR_DECL(vnet_iter);
 
 #if SIZE_MAX == UINT32_MAX /* 32-bit arch */
 	db_printf("      vnet ifs socks");
-	db_printf("        net       inet      inet6      ipsec   netgraph\n");
 #else /* 64-bit arch, most probaly... */
 	db_printf("              vnet ifs socks");
-	db_printf("                net               inet              inet6              ipsec           netgraph\n");
 #endif
 	VNET_FOREACH(vnet_iter) {
 		db_printf("%p %3d %5d",
 		    vnet_iter, vnet_iter->ifcnt, vnet_iter->sockcnt);
-		db_vnet_ptr(vnet_iter->mod_data[VNET_MOD_NET]);
-		db_vnet_ptr(vnet_iter->mod_data[VNET_MOD_INET]);
-		db_vnet_ptr(vnet_iter->mod_data[VNET_MOD_INET6]);
-		db_vnet_ptr(vnet_iter->mod_data[VNET_MOD_IPSEC]);
-		db_vnet_ptr(vnet_iter->mod_data[VNET_MOD_NETGRAPH]);
 		db_printf("\n");
 	}
 }
 #endif
-#endif /* VIMAGE */
diff --git a/sys/kern/link_elf.c b/sys/kern/link_elf.c
index cd0f3e9..b389ace 100644
--- a/sys/kern/link_elf.c
+++ b/sys/kern/link_elf.c
@@ -49,6 +49,8 @@ __FBSDID("$FreeBSD$");
 
 #include <machine/elf.h>
 
+#include <net/vnet.h>
+
 #include <security/mac/mac_framework.h>
 
 #include <vm/vm.h>
@@ -111,6 +113,11 @@ typedef struct elf_file {
     Elf_Addr		pcpu_start;	/* Pre-relocation pcpu set start. */
     Elf_Addr		pcpu_stop;	/* Pre-relocation pcpu set stop. */
     Elf_Addr		pcpu_base;	/* Relocated pcpu set address. */
+#ifdef VIMAGE
+    Elf_Addr		vnet_start;	/* Pre-relocation vnet set start. */
+    Elf_Addr		vnet_stop;	/* Pre-relocation vnet set stop. */
+    Elf_Addr		vnet_base;	/* Relocated vnet set address. */
+#endif
 #ifdef GDB
     struct link_map	gdb;		/* hooks for gdb */
 #endif
@@ -506,6 +513,36 @@ parse_dpcpu(elf_file_t ef)
     return (0);
 }
 
+#ifdef VIMAGE
+static int
+parse_vnet(elf_file_t ef)
+{ 
+    int count;
+    int error;
+
+    ef->vnet_start = 0;
+    ef->vnet_stop = 0;
+    error = link_elf_lookup_set(&ef->lf, "vnet", (void ***)&ef->vnet_start,
+                               (void ***)&ef->vnet_stop, &count);
+    /* Error just means there is no vnet data set to relocate. */
+    if (error)
+        return (0);
+    count *= sizeof(void *);
+    /*
+     * Allocate space in the primary vnet area.  Copy in our initialization
+     * from the data section and then initialize all per-vnet storage from
+     * that.
+     */
+    ef->vnet_base = (Elf_Addr)(uintptr_t)vnet_data_alloc(count);
+    if (ef->vnet_base == (Elf_Addr)NULL)
+        return (ENOSPC);
+    memcpy((void *)ef->vnet_base, (void *)ef->vnet_start, count);
+    vnet_data_copy((void *)ef->vnet_base, count);
+
+    return (0);
+}
+#endif
+
 static int
 link_elf_link_preload(linker_class_t cls,
 		      const char* filename, linker_file_t *result)
@@ -553,6 +590,10 @@ link_elf_link_preload(linker_class_t cls,
     error = parse_dynamic(ef);
     if (error == 0)
         error = parse_dpcpu(ef);
+#ifdef VIMAGE
+    if (error == 0)
+	error = parse_vnet(ef);
+#endif
     if (error) {
 	linker_file_unload(lf, LINKER_UNLOAD_FORCE);
 	return error;
@@ -838,6 +879,11 @@ link_elf_load_file(linker_class_t cls, const char* filename,
     error = parse_dpcpu(ef);
     if (error)
         goto out;
+#ifdef VIMAGE
+    error = parse_vnet(ef);
+    if (error)
+        goto out;
+#endif
     link_elf_reloc_local(lf);
 
     VOP_UNLOCK(nd.ni_vp, 0);
@@ -942,6 +988,10 @@ elf_relocaddr(linker_file_t lf, Elf_Addr x)
     ef = (elf_file_t)lf;
     if (x >= ef->pcpu_start && x < ef->pcpu_stop)
 	return ((x - ef->pcpu_start) + ef->pcpu_base);
+#ifdef VIMAGE
+    if (x >= ef->vnet_start && x < ef->vnet_stop)
+	return ((x - ef->vnet_start) + ef->vnet_base);
+#endif
     return (x);
 }
 
@@ -954,6 +1004,11 @@ link_elf_unload_file(linker_file_t file)
     if (ef->pcpu_base) {
         dpcpu_free((void *)ef->pcpu_base, ef->pcpu_stop - ef->pcpu_start);
     }
+#ifdef VIMAGE
+    if (ef->vnet_base) {
+        vnet_data_free((void *)ef->vnet_base, ef->vnet_stop - ef->vnet_start);
+    }
+#endif
 #ifdef GDB
     if (ef->gdb.l_ld) {
 	GDB_STATE(RT_DELETE);
diff --git a/sys/kern/link_elf_obj.c b/sys/kern/link_elf_obj.c
index 9d4d70c..afcdd63 100644
--- a/sys/kern/link_elf_obj.c
+++ b/sys/kern/link_elf_obj.c
@@ -45,6 +45,8 @@ __FBSDID("$FreeBSD$");
 
 #include <machine/elf.h>
 
+#include <net/vnet.h>
+
 #include <security/mac/mac_framework.h>
 
 #include <vm/vm.h>
@@ -346,6 +348,21 @@ link_elf_link_preload(linker_class_t cls, const char *filename,
 				    ef->progtab[pb].size);
 				dpcpu_copy(dpcpu, shdr[i].sh_size);
 				ef->progtab[pb].addr = dpcpu;
+#ifdef VIMAGE
+			} else if (ef->progtab[pb].name != NULL &&
+			    !strcmp(ef->progtab[pb].name, "set_vnet")) {
+				void *vnet_data;
+
+				vnet_data = vnet_data_alloc(shdr[i].sh_size);
+				if (vnet_data == NULL) {
+					error = ENOSPC;
+					goto out;
+				}
+				memcpy(vnet_data, ef->progtab[pb].addr,
+				    ef->progtab[pb].size);
+				vnet_data_copy(vnet_data, shdr[i].sh_size);
+				ef->progtab[pb].addr = vnet_data;
+#endif
 			}
 
 			/* Update all symbol values with the offset. */
@@ -737,6 +754,12 @@ link_elf_load_file(linker_class_t cls, const char *filename,
 			    !strcmp(ef->progtab[pb].name, "set_pcpu"))
 				ef->progtab[pb].addr =
 				    dpcpu_alloc(shdr[i].sh_size);
+#ifdef VIMAGE
+			else if (ef->progtab[pb].name != NULL &&
+			    !strcmp(ef->progtab[pb].name, "set_vnet"))
+				ef->progtab[pb].addr =
+				    vnet_data_alloc(shdr[i].sh_size);
+#endif
 			else
 				ef->progtab[pb].addr =
 				    (void *)(uintptr_t)mapbase;
@@ -758,10 +781,21 @@ link_elf_load_file(linker_class_t cls, const char *filename,
 					error = EINVAL;
 					goto out;
 				}
-				/* Initialize the per-cpu area. */
-				if (ef->progtab[pb].addr != (void *)mapbase)
+				/* Initialize the per-cpu or vnet area. */
+				if (ef->progtab[pb].addr != (void *)mapbase &&
+				    !strcmp(ef->progtab[pb].name, "set_pcpu"))
 					dpcpu_copy(ef->progtab[pb].addr,
 					    shdr[i].sh_size);
+#ifdef VIMAGE
+				else if (ef->progtab[pb].addr !=
+				    (void *)mapbase &&
+				    !strcmp(ef->progtab[pb].name, "set_vnet"))
+					vnet_data_copy(ef->progtab[pb].addr,
+					    shdr[i].sh_size);
+#endif
+				else
+					panic("link_elf_load_file: unexpected "
+					    "progbits type");
 			} else
 				bzero(ef->progtab[pb].addr, shdr[i].sh_size);
 
@@ -877,6 +911,11 @@ link_elf_unload_file(linker_file_t file)
 			if (!strcmp(ef->progtab[i].name, "set_pcpu"))
 				dpcpu_free(ef->progtab[i].addr,
 				    ef->progtab[i].size);
+#ifdef VIMAGE
+			else if (!strcmp(ef->progtab[i].name, "set_vnet"))
+				vnet_data_free(ef->progtab[i].addr,
+				    ef->progtab[i].size);
+#endif
 		}
 	}
 	if (ef->preloaded) {
diff --git a/sys/kern/uipc_domain.c b/sys/kern/uipc_domain.c
index 9ee6047..88322d5 100644
--- a/sys/kern/uipc_domain.c
+++ b/sys/kern/uipc_domain.c
@@ -106,14 +106,12 @@ struct pr_usrreqs nousrreqs = {
 	.pru_sopoll =		pru_sopoll_notsupp,
 };
 
-#ifndef VIMAGE_GLOBALS
+#ifdef VIMAGE
 vnet_modinfo_t vnet_domain_modinfo = {
 	.vmi_id		= VNET_MOD_DOMAIN,
 	.vmi_name	= "domain",
 	.vmi_iattach	= net_init_domain,
-#ifdef VIMAGE
 	.vmi_idetach	= net_detach_domain,
-#endif
 };
 #endif
 
@@ -249,7 +247,7 @@ net_add_domain(void *data)
 		    "domainfinalize()\n", dp->dom_name);
 #endif
 	mtx_unlock(&dom_mtx);
-#ifndef VIMAGE_GLOBALS
+#ifdef VIMAGE
 	vnet_mod_register_multi(&vnet_domain_modinfo, dp, dp->dom_name);
 #else
 	net_init_domain(dp);