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, 0 insertions, 12 deletions

diff --git a/sys/netinet/ip_mroute.c b/sys/netinet/ip_mroute.c
index 3c3c014238aa..b8957f42e421 100644
--- a/sys/netinet/ip_mroute.c
+++ b/sys/netinet/ip_mroute.c
@@ -111,7 +111,6 @@ __FBSDID("$FreeBSD$");
 #include <netinet/pim.h>
 #include <netinet/pim_var.h>
 #include <netinet/udp.h>
-#include <netinet/vinet.h>
 
 #include <machine/in_cksum.h>
 
@@ -379,7 +378,6 @@ mfc_find(struct in_addr *o, struct in_addr *g)
 static int
 X_ip_mrouter_set(struct socket *so, struct sockopt *sopt)
 {
-    INIT_VNET_INET(curvnet);
     int	error, optval;
     vifi_t	vifi;
     struct	vifctl vifc;
@@ -602,7 +600,6 @@ ip_mrouter_reset(void)
 static void
 if_detached_event(void *arg __unused, struct ifnet *ifp)
 {
-    INIT_VNET_INET(curvnet);
     vifi_t vifi;
     int i;
 
@@ -651,7 +648,6 @@ if_detached_event(void *arg __unused, struct ifnet *ifp)
 static int
 ip_mrouter_init(struct socket *so, int version)
 {
-    INIT_VNET_INET(curvnet);
 
     CTR3(KTR_IPMF, "%s: so_type %d, pr_protocol %d", __func__,
         so->so_type, so->so_proto->pr_protocol);
@@ -699,7 +695,6 @@ ip_mrouter_init(struct socket *so, int version)
 static int
 X_ip_mrouter_done(void)
 {
-    INIT_VNET_INET(curvnet);
     vifi_t vifi;
     int i;
     struct ifnet *ifp;
@@ -1220,7 +1215,6 @@ static int
 X_ip_mforward(struct ip *ip, struct ifnet *ifp, struct mbuf *m,
     struct ip_moptions *imo)
 {
-    INIT_VNET_INET(curvnet);
     struct mfc *rt;
     int error;
     vifi_t vifi;
@@ -1475,7 +1469,6 @@ expire_upcalls(void *unused)
 static int
 ip_mdq(struct mbuf *m, struct ifnet *ifp, struct mfc *rt, vifi_t xmt_vif)
 {
-    INIT_VNET_INET(curvnet);
     struct ip  *ip = mtod(m, struct ip *);
     vifi_t vifi;
     int plen = ip->ip_len;
@@ -1709,7 +1702,6 @@ X_ip_rsvp_force_done(struct socket *so __unused)
 static void
 X_rsvp_input(struct mbuf *m, int off __unused)
 {
-	INIT_VNET_INET(curvnet);
 
 	if (!V_rsvp_on)
 		m_freem(m);
@@ -2044,7 +2036,6 @@ bw_meter_prepare_upcall(struct bw_meter *x, struct timeval *nowp)
 static void
 bw_upcalls_send(void)
 {
-    INIT_VNET_INET(curvnet);
     struct mbuf *m;
     int len = bw_upcalls_n * sizeof(bw_upcalls[0]);
     struct sockaddr_in k_igmpsrc = { sizeof k_igmpsrc, AF_INET };
@@ -2401,7 +2392,6 @@ static int
 pim_register_send_upcall(struct ip *ip, struct vif *vifp,
     struct mbuf *mb_copy, struct mfc *rt)
 {
-    INIT_VNET_INET(curvnet);
     struct mbuf *mb_first;
     int len = ntohs(ip->ip_len);
     struct igmpmsg *im;
@@ -2454,7 +2444,6 @@ static int
 pim_register_send_rp(struct ip *ip, struct vif *vifp, struct mbuf *mb_copy,
     struct mfc *rt)
 {
-    INIT_VNET_INET(curvnet);
     struct mbuf *mb_first;
     struct ip *ip_outer;
     struct pim_encap_pimhdr *pimhdr;
@@ -2795,7 +2784,6 @@ SYSCTL_NODE(_net_inet_ip, OID_AUTO, mfctable, CTLFLAG_RD, sysctl_mfctable,
 static int
 ip_mroute_modevent(module_t mod, int type, void *unused)
 {
-    INIT_VNET_INET(curvnet);
 
     switch (type) {
     case MOD_LOAD: