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)

1 files changed, 26 insertions, 34 deletions

diff --git a/sys/netinet6/ip6_input.c b/sys/netinet6/ip6_input.c
index b9d594c..78c0901 100644
--- a/sys/netinet6/ip6_input.c
+++ b/sys/netinet6/ip6_input.c
@@ -96,7 +96,6 @@ __FBSDID("$FreeBSD$");
 #ifdef INET
 #include <netinet/ip.h>
 #include <netinet/ip_icmp.h>
-#include <netinet/vinet.h>
 #endif /* INET */
 #include <netinet/ip6.h>
 #include <netinet6/in6_var.h>
@@ -106,7 +105,6 @@ __FBSDID("$FreeBSD$");
 #include <netinet6/scope6_var.h>
 #include <netinet6/in6_ifattach.h>
 #include <netinet6/nd6.h>
-#include <netinet6/vinet6.h>
 
 #ifdef IPSEC
 #include <netipsec/ipsec.h>
@@ -127,28 +125,30 @@ static struct netisr_handler ip6_nh = {
 	.nh_policy = NETISR_POLICY_FLOW,
 };
 
-#ifndef VIMAGE
-#ifndef VIMAGE_GLOBALS
-struct vnet_inet6 vnet_inet6_0;
-#endif
-#endif
-
-#ifdef VIMAGE_GLOBALS
-struct in6_ifaddrhead in6_ifaddrhead;
-struct ip6stat ip6stat;
-
-extern struct callout in6_tmpaddrtimer_ch;
-
-extern int dad_init;
-extern int pmtu_expire;
-extern int pmtu_probe;
-extern u_long rip6_sendspace;
-extern u_long rip6_recvspace;
-extern int icmp6errppslim;
-extern int icmp6_nodeinfo;
-extern int udp6_sendspace;
-extern int udp6_recvspace;
-#endif
+VNET_DEFINE(struct in6_ifaddrhead, in6_ifaddrhead);
+VNET_DEFINE(struct ip6stat, ip6stat);
+
+VNET_DECLARE(struct callout, in6_tmpaddrtimer_ch);
+VNET_DECLARE(int, dad_init);
+VNET_DECLARE(int, pmtu_expire);
+VNET_DECLARE(int, pmtu_probe);
+VNET_DECLARE(u_long, rip6_sendspace);
+VNET_DECLARE(u_long, rip6_recvspace);
+VNET_DECLARE(int, icmp6errppslim);
+VNET_DECLARE(int, icmp6_nodeinfo);
+VNET_DECLARE(int, udp6_sendspace);
+VNET_DECLARE(int, udp6_recvspace);
+
+#define	V_in6_tmpaddrtimer_ch		VNET_GET(in6_tmpaddrtimer_ch)
+#define	V_dad_init			VNET_GET(dad_init)
+#define	V_pmtu_expire			VNET_GET(pmtu_expire)
+#define	V_pmtu_probe			VNET_GET(pmtu_probe)
+#define	V_rip6_sendspace		VNET_GET(rip6_sendspace)
+#define	V_rip6_recvspace		VNET_GET(rip6_recvspace)
+#define	V_icmp6errppslim		VNET_GET(icmp6errppslim)
+#define	V_icmp6_nodeinfo		VNET_GET(icmp6_nodeinfo)
+#define	V_udp6_sendspace		VNET_GET(udp6_sendspace)
+#define	V_udp6_recvspace		VNET_GET(udp6_recvspace)
 
 struct rwlock in6_ifaddr_lock;
 RW_SYSINIT(in6_ifaddr_lock, &in6_ifaddr_lock, "in6_ifaddr_lock");
@@ -162,13 +162,13 @@ static int ip6_hopopts_input(u_int32_t *, u_int32_t *, struct mbuf **, int *);
 static struct mbuf *ip6_pullexthdr(struct mbuf *, size_t, int);
 #endif
 
-#ifndef VIMAGE_GLOBALS
+#ifdef VIMAGE
+/* XXX only has to stay for .vmi_dependson elsewhere. */
 static void vnet_inet6_register(void);
  
 static const vnet_modinfo_t vnet_inet6_modinfo = {
 	.vmi_id		= VNET_MOD_INET6,
 	.vmi_name	= "inet6",
-	.vmi_size	= sizeof(struct vnet_inet6),
 	.vmi_dependson	= VNET_MOD_INET	/* XXX revisit - TCP/UDP needs this? */
 };
  
@@ -189,7 +189,6 @@ SYSINIT(inet6, SI_SUB_PROTO_BEGIN, SI_ORDER_FIRST, vnet_inet6_register, 0);
 void
 ip6_init(void)
 {
-	INIT_VNET_INET6(curvnet);
 	struct ip6protosw *pr;
 	int i;
 
@@ -311,7 +310,6 @@ ip6_init(void)
 void
 ip6_destroy()
 {
-	INIT_VNET_INET6(curvnet);
 
 	nd6_destroy();
 	callout_drain(&V_in6_tmpaddrtimer_ch);
@@ -321,7 +319,6 @@ ip6_destroy()
 static int
 ip6_init2_vnet(const void *unused __unused)
 {
-	INIT_VNET_INET6(curvnet);
 
 	/* nd6_timer_init */
 	callout_init(&V_nd6_timer_ch, 0);
@@ -351,8 +348,6 @@ SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL);
 void
 ip6_input(struct mbuf *m)
 {
-	INIT_VNET_NET(curvnet);
-	INIT_VNET_INET6(curvnet);
 	struct ip6_hdr *ip6;
 	int off = sizeof(struct ip6_hdr), nest;
 	u_int32_t plen;
@@ -967,7 +962,6 @@ static int
 ip6_hopopts_input(u_int32_t *plenp, u_int32_t *rtalertp,
     struct mbuf **mp, int *offp)
 {
-	INIT_VNET_INET6(curvnet);
 	struct mbuf *m = *mp;
 	int off = *offp, hbhlen;
 	struct ip6_hbh *hbh;
@@ -1023,7 +1017,6 @@ int
 ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen,
     u_int32_t *rtalertp, u_int32_t *plenp)
 {
-	INIT_VNET_INET6(curvnet);
 	struct ip6_hdr *ip6;
 	int optlen = 0;
 	u_int8_t *opt = opthead;
@@ -1156,7 +1149,6 @@ ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen,
 int
 ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off)
 {
-	INIT_VNET_INET6(curvnet);
 	struct ip6_hdr *ip6;
 
 	switch (IP6OPT_TYPE(*optp)) {