Introduce and use a sysinit-based initialization scheme for virtual

network stacks, VNET_SYSINIT:

- Add VNET_SYSINIT and VNET_SYSUNINIT macros to declare events that will
  occur each time a network stack is instantiated and destroyed.  In the
  !VIMAGE case, these are simply mapped into regular SYSINIT/SYSUNINIT.
  For the VIMAGE case, we instead use SYSINIT's to track their order and
  properties on registration, using them for each vnet when created/
  destroyed, or immediately on module load for already-started vnets.
- Remove vnet_modinfo mechanism that existed to serve this purpose
  previously, as well as its dependency scheme: we now just use the
  SYSINIT ordering scheme.
- Implement VNET_DOMAIN_SET() to allow protocol domains to declare that
  they want init functions to be called for each virtual network stack
  rather than just once at boot, compiling down to DOMAIN_SET() in the
  non-VIMAGE case.
- Walk all virtualized kernel subsystems and make use of these instead
  of modinfo or DOMAIN_SET() for init/uninit events.  In some cases,
  convert modular components from using modevent to using sysinit (where
  appropriate).  In some cases, do minor rejuggling of SYSINIT ordering
  to make room for or better manage events.

Portions submitted by:	jhb (VNET_SYSINIT), bz (cleanup)
Discussed with:		jhb, bz, julian, zec
Reviewed by:		bz
Approved by:		re (VIMAGE blanket)

1 files changed, 51 insertions, 0 deletions

diff --git a/sys/net/vnet.h b/sys/net/vnet.h
index aec448a..8877bab 100644
--- a/sys/net/vnet.h
+++ b/sys/net/vnet.h
@@ -46,6 +46,43 @@
 
 #ifdef _KERNEL
 #ifdef VIMAGE
+#include <sys/kernel.h>
+
+/*
+ * SYSINIT/SYSUNINIT variants that provide per-vnet constructors and
+ * destructors.
+ */
+struct vnet_sysinit {
+	enum sysinit_sub_id	subsystem;
+	enum sysinit_elem_order	order;
+	sysinit_cfunc_t		func;
+	const void		*arg;
+	TAILQ_ENTRY(vnet_sysinit) link;
+};
+
+#define	VNET_SYSINIT(ident, subsystem, order, func, arg)		\
+	static struct vnet_sysinit ident ## _vnet_init = {		\
+		subsystem,						\
+		order,							\
+		(sysinit_cfunc_t)(sysinit_nfunc_t)func,			\
+		(arg)							\
+	};								\
+	SYSINIT(vnet_init_ ## ident, subsystem, order,			\
+	    vnet_register_sysinit, &ident ## _vnet_init);		\
+	SYSUNINIT(vnet_init_ ## ident, subsystem, order,		\
+	    vnet_deregister_sysinit, &ident ## _vnet_init)
+
+#define	VNET_SYSUNINIT(ident, subsystem, order, func, arg)		\
+	static struct vnet_sysinit ident ## _vnet_uninit = {		\
+		subsystem,						\
+		order,							\
+		(sysinit_cfunc_t)(sysinit_nfunc_t)func,			\
+		(arg)							\
+	};								\
+	SYSINIT(vnet_uninit_ ## ident, subsystem, order,		\
+	    vnet_register_sysuninit, &ident ## _vnet_uninit);		\
+	SYSUNINIT(vnet_uninit_ ## ident, subsystem, order,		\
+	    vnet_deregister_sysuninit, &ident ## _vnet_uninit)
 
 #if defined(__arm__)
 __asm__(".section " VNET_SETNAME ", \"aw\", %progbits");
@@ -121,6 +158,16 @@ void	 vnet_data_free(void *start_arg, int size);
 struct vnet;
 void	 vnet_data_init(struct vnet *vnet);
 void	 vnet_data_destroy(struct vnet *vnet);
+void	 vnet_sysinit(void);
+void	 vnet_sysuninit(void);
+
+/*
+ * Interfaces for managing per-vnet constructors and destructors.
+ */
+void	vnet_register_sysinit(void *arg);
+void	vnet_register_sysuninit(void *arg);
+void	vnet_deregister_sysinit(void *arg);
+void	vnet_deregister_sysuninit(void *arg);
 
 #else /* !VIMAGE */
 
@@ -132,6 +179,10 @@ void	 vnet_data_destroy(struct vnet *vnet);
 #define	VNET_DECLARE(t, n)	extern t n
 #define	VNET_DEFINE(t, n)	t n
 #define	_VNET_PTR(b, n)		&VNET_NAME(n)
+#define	VNET_SYSINIT(ident, subsystem, order, func, arg)		\
+	SYSINIT(ident, subsystem, order, func, arg)
+#define	VNET_SYSUNINIT(ident, subsystem, order, func, arg)		\
+	SYSUNINIT(ident, subsystem, order, func, arg)
 
 #ifdef SYSCTL_OID
 #define	SYSCTL_VNET_INT(parent, nbr, name, access, ptr, val, descr)	\