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, 22 insertions, 48 deletions

diff --git a/sys/netinet/if_ether.c b/sys/netinet/if_ether.c
index 97ea108..bf5f124 100644
--- a/sys/netinet/if_ether.c
+++ b/sys/netinet/if_ether.c
@@ -65,7 +65,6 @@ __FBSDID("$FreeBSD$");
 #include <netinet/in_var.h>
 #include <net/if_llatbl.h>
 #include <netinet/if_ether.h>
-#include <netinet/vinet.h>
 
 #include <net/if_arc.h>
 #include <net/iso88025.h>
@@ -83,28 +82,33 @@ SYSCTL_DECL(_net_link_ether);
 SYSCTL_NODE(_net_link_ether, PF_INET, inet, CTLFLAG_RW, 0, "");
 
 /* timer values */
-#ifdef VIMAGE_GLOBALS
-static int	arpt_keep; /* once resolved, good for 20 more minutes */
-static int	arp_maxtries;
-int	useloopback; /* use loopback interface for local traffic */
-static int	arp_proxyall;
-#endif
-
-SYSCTL_V_INT(V_NET, vnet_inet, _net_link_ether_inet, OID_AUTO, max_age,
-    CTLFLAG_RW, arpt_keep, 0, "ARP entry lifetime in seconds");
-
-SYSCTL_V_INT(V_NET, vnet_inet, _net_link_ether_inet, OID_AUTO, maxtries,
-	CTLFLAG_RW, arp_maxtries, 0,
+static VNET_DEFINE(int, arpt_keep) = (20*60);	/* once resolved, good for 20
+						 * minutes */
+static VNET_DEFINE(int, arp_maxtries) = 5;
+static VNET_DEFINE(int, useloopback) = 1;	/* use loopback interface for
+						 * local traffic */
+static VNET_DEFINE(int, arp_proxyall);
+
+#define	V_arpt_keep		VNET_GET(arpt_keep)
+#define	V_arp_maxtries		VNET_GET(arp_maxtries)
+#define	V_useloopback		VNET_GET(useloopback)
+#define	V_arp_proxyall		VNET_GET(arp_proxyall)
+
+SYSCTL_VNET_INT(_net_link_ether_inet, OID_AUTO, max_age, CTLFLAG_RW,
+	&VNET_NAME(arpt_keep), 0,
+	"ARP entry lifetime in seconds");
+
+SYSCTL_VNET_INT(_net_link_ether_inet, OID_AUTO, maxtries, CTLFLAG_RW,
+	&VNET_NAME(arp_maxtries), 0,
 	"ARP resolution attempts before returning error");
-SYSCTL_V_INT(V_NET, vnet_inet, _net_link_ether_inet, OID_AUTO, useloopback,
-	CTLFLAG_RW, useloopback, 0,
+SYSCTL_VNET_INT(_net_link_ether_inet, OID_AUTO, useloopback, CTLFLAG_RW,
+	&VNET_NAME(useloopback), 0,
 	"Use the loopback interface for local traffic");
-SYSCTL_V_INT(V_NET, vnet_inet, _net_link_ether_inet, OID_AUTO, proxyall,
-	CTLFLAG_RW, arp_proxyall, 0,
+SYSCTL_VNET_INT(_net_link_ether_inet, OID_AUTO, proxyall, CTLFLAG_RW,
+	&VNET_NAME(arp_proxyall), 0,
 	"Enable proxy ARP for all suitable requests");
 
 static void	arp_init(void);
-static int	arp_iattach(const void *);
 void		arprequest(struct ifnet *,
 			struct in_addr *, struct in_addr *, u_char *);
 static void	arpintr(struct mbuf *);
@@ -120,15 +124,6 @@ static const struct netisr_handler arp_nh = {
 	.nh_policy = NETISR_POLICY_SOURCE,
 };
 
-#ifndef VIMAGE_GLOBALS
-static const vnet_modinfo_t vnet_arp_modinfo = {
-	.vmi_id		= VNET_MOD_ARP,
-	.vmi_name	= "arp",
-	.vmi_dependson	= VNET_MOD_INET,
-	.vmi_iattach	= arp_iattach
-};
-#endif /* !VIMAGE_GLOBALS */
-
 #ifdef AF_INET
 void arp_ifscrub(struct ifnet *ifp, uint32_t addr);
 
@@ -263,7 +258,6 @@ int
 arpresolve(struct ifnet *ifp, struct rtentry *rt0, struct mbuf *m,
 	struct sockaddr *dst, u_char *desten, struct llentry **lle)
 {
-	INIT_VNET_INET(ifp->if_vnet);
 	struct llentry *la = 0;
 	u_int flags = 0;
 	int error, renew;
@@ -482,7 +476,6 @@ in_arpinput(struct mbuf *m)
 	sin.sin_len = sizeof(struct sockaddr_in);
 	sin.sin_family = AF_INET;
 	sin.sin_addr.s_addr = 0;
-	INIT_VNET_INET(ifp->if_vnet);
 
 	if (ifp->if_bridge)
 		bridged = 1;
@@ -825,29 +818,10 @@ arp_ifinit2(struct ifnet *ifp, struct ifaddr *ifa, u_char *enaddr)
 	ifa->ifa_rtrequest = NULL;
 }
 
-static int
-arp_iattach(const void *unused __unused)
-{
-	INIT_VNET_INET(curvnet);
-
-	V_arpt_keep = (20*60); /* once resolved, good for 20 more minutes */
-	V_arp_maxtries = 5;
-	V_useloopback = 1; /* use loopback interface for local traffic */
-	V_arp_proxyall = 0;
-
-	return (0);
-}
-
 static void
 arp_init(void)
 {
 
-#ifndef VIMAGE_GLOBALS
-	vnet_mod_register(&vnet_arp_modinfo);
-#else
-	arp_iattach(NULL);
-#endif
-
 	netisr_register(&arp_nh);
 }
 SYSINIT(arp, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, arp_init, 0);