From 50d6e424348162df7ef871da1db76fab6681f414 Mon Sep 17 00:00:00 2001
From: Kip Macy <kmacy@FreeBSD.org>
Date: Sun, 19 Oct 2008 01:35:27 +0000
Subject: [PATCH] - Forward port flush of page table updates on context switch
 or userret - Forward port vfork XEN hack

---
 sys/kern/kern_fork.c  | 9 +++++++--
 sys/kern/kern_synch.c | 9 +++++++++
 sys/kern/subr_trap.c  | 9 +++++++++
 3 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/sys/kern/kern_fork.c b/sys/kern/kern_fork.c
index e5a3779ec5ca..673913b6fa84 100644
--- a/sys/kern/kern_fork.c
+++ b/sys/kern/kern_fork.c
@@ -117,10 +117,15 @@ vfork(td, uap)
 	struct thread *td;
 	struct vfork_args *uap;
 {
-	int error;
+	int error, flags;
 	struct proc *p2;
 
-	error = fork1(td, RFFDG | RFPROC | RFPPWAIT | RFMEM, 0, &p2);
+#ifdef XEN
+	flags = RFFDG | RFPROC; /* validate that this is still an issue */
+#else
+	flags = RFFDG | RFPROC | RFPPWAIT | RFMEM;
+#endif		
+	error = fork1(td, flags, 0, &p2);
 	if (error == 0) {
 		td->td_retval[0] = p2->p_pid;
 		td->td_retval[1] = 0;
diff --git a/sys/kern/kern_synch.c b/sys/kern/kern_synch.c
index 4f1205d17156..53e3ced77721 100644
--- a/sys/kern/kern_synch.c
+++ b/sys/kern/kern_synch.c
@@ -65,6 +65,12 @@ __FBSDID("$FreeBSD$");
 
 #include <machine/cpu.h>
 
+#ifdef XEN
+#include <vm/vm.h>
+#include <vm/vm_param.h>
+#include <vm/pmap.h>
+#endif
+
 static void synch_setup(void *dummy);
 SYSINIT(synch_setup, SI_SUB_KICK_SCHEDULER, SI_ORDER_FIRST, synch_setup,
     NULL);
@@ -431,6 +437,9 @@ mi_switch(int flags, struct thread *newtd)
 		    "mi_switch: %p(%s) prio %d inhibit %d wmesg %s lock %s",
 		    td, td->td_name, td->td_priority,
 		    td->td_inhibitors, td->td_wmesg, td->td_lockname);
+#endif
+#ifdef XEN
+	PT_UPDATES_FLUSH();
 #endif
 	sched_switch(td, newtd, flags);
 	CTR3(KTR_SCHED, "mi_switch: running %p(%s) prio %d",
diff --git a/sys/kern/subr_trap.c b/sys/kern/subr_trap.c
index 3d1948dce4e1..e7e8120c912e 100644
--- a/sys/kern/subr_trap.c
+++ b/sys/kern/subr_trap.c
@@ -73,6 +73,12 @@ __FBSDID("$FreeBSD$");
 #include <machine/cpu.h>
 #include <machine/pcb.h>
 
+#ifdef XEN
+#include <vm/vm.h>
+#include <vm/vm_param.h>
+#include <vm/pmap.h>
+#endif
+
 #include <security/mac/mac_framework.h>
 
 /*
@@ -118,6 +124,9 @@ userret(struct thread *td, struct trapframe *frame)
 	sched_userret(td);
 	KASSERT(td->td_locks == 0,
 	    ("userret: Returning with %d locks held.", td->td_locks));
+#ifdef XEN
+	PT_UPDATES_FLUSH();
+#endif
 }
 
 /*