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, 9 insertions, 31 deletions

diff --git a/sys/netipsec/xform_ipip.c b/sys/netipsec/xform_ipip.c
index d9cf8c6..8de23ec 100644
--- a/sys/netipsec/xform_ipip.c
+++ b/sys/netipsec/xform_ipip.c
@@ -68,7 +68,6 @@
 #ifdef MROUTING
 #include <netinet/ip_mroute.h>
 #endif
-#include <netinet/vinet.h>
 
 #include <netipsec/ipsec.h>
 #include <netipsec/xform.h>
@@ -92,31 +91,27 @@
  * We can control the acceptance of IP4 packets by altering the sysctl
  * net.inet.ipip.allow value.  Zero means drop them, all else is acceptance.
  */
-#ifdef VIMAGE_GLOBALS
-int	ipip_allow;
-struct	ipipstat ipipstat;
-#endif
+VNET_DEFINE(int, ipip_allow) = 0;
+VNET_DEFINE(struct ipipstat, ipipstat);
 
 SYSCTL_DECL(_net_inet_ipip);
-SYSCTL_V_INT(V_NET, vnet_ipsec, _net_inet_ipip, OID_AUTO,
-	ipip_allow,	CTLFLAG_RW,	ipip_allow,	0, "");
-SYSCTL_V_STRUCT(V_NET, vnet_ipsec, _net_inet_ipip, IPSECCTL_STATS,
-	stats,		CTLFLAG_RD,	ipipstat,	ipipstat, "");
+SYSCTL_VNET_INT(_net_inet_ipip, OID_AUTO,
+	ipip_allow,	CTLFLAG_RW,	&VNET_NAME(ipip_allow),	0, "");
+SYSCTL_VNET_STRUCT(_net_inet_ipip, IPSECCTL_STATS,
+	stats,		CTLFLAG_RD,	&VNET_NAME(ipipstat),	ipipstat, "");
 
 /* XXX IPCOMP */
 #define	M_IPSEC	(M_AUTHIPHDR|M_AUTHIPDGM|M_DECRYPTED)
 
 static void _ipip_input(struct mbuf *m, int iphlen, struct ifnet *gifp);
-static int ipe4_iattach(const void *);
 
-#ifndef VIMAGE_GLOBALS
+#ifdef VIMAGE
 static const vnet_modinfo_t vnet_ipip_modinfo = {
 	.vmi_id		= VNET_MOD_IPIP,
 	.vmi_name	= "ipsec_ipip",
 	.vmi_dependson	= VNET_MOD_IPSEC,
-	.vmi_iattach	= ipe4_iattach
 };
-#endif /* !VIMAGE_GLOBALS */
+#endif
 
 #ifdef INET6
 /*
@@ -169,8 +164,6 @@ ip4_input(struct mbuf *m, int off)
 static void
 _ipip_input(struct mbuf *m, int iphlen, struct ifnet *gifp)
 {
-	INIT_VNET_NET(curvnet);
-	INIT_VNET_IPSEC(curvnet);
 #ifdef INET
 	register struct sockaddr_in *sin;
 #endif
@@ -424,10 +417,6 @@ ipip_output(
 	int protoff
 )
 {
-	INIT_VNET_IPSEC(curvnet);
-#ifdef INET
-	INIT_VNET_INET(curvnet);
-#endif /* INET */
 	struct secasvar *sav;
 	u_int8_t tp, otos;
 	struct secasindex *saidx;
@@ -708,15 +697,6 @@ ipe4_encapcheck(const struct mbuf *m, int off, int proto, void *arg)
 	return ((m->m_flags & M_IPSEC) != 0 ? 1 : 0);
 }
 
-static int
-ipe4_iattach(const void *unused __unused)
-{
-	INIT_VNET_IPSEC(curvnet);
-
-	V_ipip_allow = 0;
-	return (0);
-}
-
 static void
 ipe4_attach(void)
 {
@@ -730,10 +710,8 @@ ipe4_attach(void)
 	(void) encap_attach_func(AF_INET6, -1,
 		ipe4_encapcheck, (struct protosw *)&ipe6_protosw, NULL);
 #endif
-#ifndef VIMAGE_GLOBALS
+#ifdef VIMAGE
 	vnet_mod_register(&vnet_ipip_modinfo);
-#else
-	ipe4_iattach(NULL);
 #endif
 }
 SYSINIT(ipe4_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ipe4_attach, NULL);