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, 20 insertions, 25 deletions

diff --git a/sys/netinet6/in6_rmx.c b/sys/netinet6/in6_rmx.c
index f05a093..b378f5a 100644
--- a/sys/netinet6/in6_rmx.c
+++ b/sys/netinet6/in6_rmx.c
@@ -101,7 +101,6 @@ __FBSDID("$FreeBSD$");
 
 #include <netinet/icmp6.h>
 #include <netinet6/nd6.h>
-#include <netinet6/vinet6.h>
 
 #include <netinet/tcp.h>
 #include <netinet/tcp_seq.h>
@@ -206,22 +205,22 @@ in6_matroute(void *v_arg, struct radix_node_head *head)
 
 SYSCTL_DECL(_net_inet6_ip6);
 
-#ifdef VIMAGE_GLOBALS
-static int rtq_reallyold6;
-static int rtq_minreallyold6;
-static int rtq_toomany6;
-#endif
-
-SYSCTL_V_INT(V_NET, vnet_inet6, _net_inet6_ip6, IPV6CTL_RTEXPIRE,
-    rtexpire, CTLFLAG_RW, rtq_reallyold6 , 0, "");
+static VNET_DEFINE(int, rtq_reallyold6);
+static VNET_DEFINE(int, rtq_minreallyold6);
+static VNET_DEFINE(int, rtq_toomany6);
 
-SYSCTL_V_INT(V_NET, vnet_inet6, _net_inet6_ip6, IPV6CTL_RTMINEXPIRE,
-    rtminexpire, CTLFLAG_RW, rtq_minreallyold6 , 0, "");
+#define	V_rtq_reallyold6		VNET_GET(rtq_reallyold6)
+#define	V_rtq_minreallyold6		VNET_GET(rtq_minreallyold6)
+#define	V_rtq_toomany6			VNET_GET(rtq_toomany6)
 
-SYSCTL_V_INT(V_NET, vnet_inet6, _net_inet6_ip6, IPV6CTL_RTMAXCACHE,
-    rtmaxcache, CTLFLAG_RW, rtq_toomany6 , 0, "");
+SYSCTL_VNET_INT(_net_inet6_ip6, IPV6CTL_RTEXPIRE, rtexpire, CTLFLAG_RW,
+    &VNET_NAME(rtq_reallyold6) , 0, "");
 
+SYSCTL_VNET_INT(_net_inet6_ip6, IPV6CTL_RTMINEXPIRE, rtminexpire, CTLFLAG_RW,
+    &VNET_NAME(rtq_minreallyold6) , 0, "");
 
+SYSCTL_VNET_INT(_net_inet6_ip6, IPV6CTL_RTMAXCACHE, rtmaxcache, CTLFLAG_RW,
+    &VNET_NAME(rtq_toomany6) , 0, "");
 
 struct rtqk_arg {
 	struct radix_node_head *rnh;
@@ -241,7 +240,6 @@ struct rtqk_arg {
 static int
 in6_rtqkill(struct radix_node *rn, void *rock)
 {
-	INIT_VNET_INET6(curvnet);
 	struct rtqk_arg *ap = rock;
 	struct rtentry *rt = (struct rtentry *)rn;
 	int err;
@@ -280,16 +278,16 @@ in6_rtqkill(struct radix_node *rn, void *rock)
 }
 
 #define RTQ_TIMEOUT	60*10	/* run no less than once every ten minutes */
-#ifdef VIMAGE_GLOBALS
-static int rtq_timeout6;
-static struct callout rtq_timer6;
-#endif
+static VNET_DEFINE(int, rtq_timeout6);
+static VNET_DEFINE(struct callout, rtq_timer6);
+
+#define	V_rtq_timeout6			VNET_GET(rtq_timeout6)
+#define	V_rtq_timer6			VNET_GET(rtq_timer6)
 
 static void
 in6_rtqtimo(void *rock)
 {
 	CURVNET_SET_QUIET((struct vnet *) rock);
-	INIT_VNET_INET6(curvnet);
 	struct radix_node_head *rnh;
 	struct rtqk_arg arg;
 	struct timeval atv;
@@ -349,9 +347,9 @@ struct mtuex_arg {
 	struct radix_node_head *rnh;
 	time_t nextstop;
 };
-#ifdef VIMAGE_GLOBALS
-static struct callout rtq_mtutimer;
-#endif
+
+static VNET_DEFINE(struct callout, rtq_mtutimer);
+#define	V_rtq_mtutimer			VNET_GET(rtq_mtutimer)
 
 static int
 in6_mtuexpire(struct radix_node *rn, void *rock)
@@ -381,7 +379,6 @@ static void
 in6_mtutimo(void *rock)
 {
 	CURVNET_SET_QUIET((struct vnet *) rock);
-	INIT_VNET_INET6(curvnet);
 	struct radix_node_head *rnh;
 	struct mtuex_arg arg;
 	struct timeval atv;
@@ -418,7 +415,6 @@ in6_mtutimo(void *rock)
 int
 in6_inithead(void **head, int off)
 {
-	INIT_VNET_INET6(curvnet);
 	struct radix_node_head *rnh;
 
 	if (!rn_inithead(head, offsetof(struct sockaddr_in6, sin6_addr) << 3))
@@ -447,7 +443,6 @@ in6_inithead(void **head, int off)
 int
 in6_detachhead(void **head, int off)
 {
-	INIT_VNET_INET6(curvnet);
 
 	callout_drain(&V_rtq_timer6);
 	callout_drain(&V_rtq_mtutimer);