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, 29 insertions, 15 deletions

diff --git a/sys/netinet/in_pcb.h b/sys/netinet/in_pcb.h
index f5b713bd6ac6..d8ac3bff0b08 100644
--- a/sys/netinet/in_pcb.h
+++ b/sys/netinet/in_pcb.h
@@ -41,6 +41,7 @@
 
 #ifdef _KERNEL
 #include <sys/rwlock.h>
+#include <net/vnet.h>
 #endif
 
 #define	in6pcb		inpcb	/* for KAME src sync over BSD*'s */
@@ -450,21 +451,34 @@ void 	inp_4tuple_get(struct inpcb *inp, uint32_t *laddr, uint16_t *lp,
 #define	INP_CHECK_SOCKAF(so, af)	(INP_SOCKAF(so) == af)
 
 #ifdef _KERNEL
-#ifdef VIMAGE_GLOBALS
-extern int	ipport_reservedhigh;
-extern int	ipport_reservedlow;
-extern int	ipport_lowfirstauto;
-extern int	ipport_lowlastauto;
-extern int	ipport_firstauto;
-extern int	ipport_lastauto;
-extern int	ipport_hifirstauto;
-extern int	ipport_hilastauto;
-extern int	ipport_randomized;
-extern int	ipport_randomcps;
-extern int	ipport_randomtime;
-extern int	ipport_stoprandom;
-extern int	ipport_tcpallocs;
-#endif
+VNET_DECLARE(int, ipport_reservedhigh);
+VNET_DECLARE(int, ipport_reservedlow);
+VNET_DECLARE(int, ipport_lowfirstauto);
+VNET_DECLARE(int, ipport_lowlastauto);
+VNET_DECLARE(int, ipport_firstauto);
+VNET_DECLARE(int, ipport_lastauto);
+VNET_DECLARE(int, ipport_hifirstauto);
+VNET_DECLARE(int, ipport_hilastauto);
+VNET_DECLARE(int, ipport_randomized);
+VNET_DECLARE(int, ipport_randomcps);
+VNET_DECLARE(int, ipport_randomtime);
+VNET_DECLARE(int, ipport_stoprandom);
+VNET_DECLARE(int, ipport_tcpallocs);
+
+#define	V_ipport_reservedhigh	VNET_GET(ipport_reservedhigh)
+#define	V_ipport_reservedlow	VNET_GET(ipport_reservedlow)
+#define	V_ipport_lowfirstauto	VNET_GET(ipport_lowfirstauto)
+#define	V_ipport_lowlastauto	VNET_GET(ipport_lowlastauto)
+#define	V_ipport_firstauto	VNET_GET(ipport_firstauto)
+#define	V_ipport_lastauto	VNET_GET(ipport_lastauto)
+#define	V_ipport_hifirstauto	VNET_GET(ipport_hifirstauto)
+#define	V_ipport_hilastauto	VNET_GET(ipport_hilastauto)
+#define	V_ipport_randomized	VNET_GET(ipport_randomized)
+#define	V_ipport_randomcps	VNET_GET(ipport_randomcps)
+#define	V_ipport_randomtime	VNET_GET(ipport_randomtime)
+#define	V_ipport_stoprandom	VNET_GET(ipport_stoprandom)
+#define	V_ipport_tcpallocs	VNET_GET(ipport_tcpallocs)
+
 extern struct callout ipport_tick_callout;
 
 void	in_pcbpurgeif0(struct inpcbinfo *, struct ifnet *);