From a1b0eebcd2925baec8ca60117f7a41925cb665e5 Mon Sep 17 00:00:00 2001
From: cperciva <cperciva@ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f>
Date: Thu, 6 Jan 2011 22:57:06 +0000
Subject: [PATCH] MFS r217056: Make i386_set_ldt work (rather than panic) on
 i386/XEN.

Approved by:	re (rwatson)


git-svn-id: svn://svn.freebsd.org/base/releng/8.2@217084 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
---
 sys/i386/i386/sys_machdep.c | 20 ++++++++++++++++----
 sys/i386/include/pmap.h     |  1 -
 sys/i386/include/segments.h |  1 +
 sys/i386/xen/pmap.c         |  4 ++++
 4 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/sys/i386/i386/sys_machdep.c b/sys/i386/i386/sys_machdep.c
index 2e7abdde..3fb231b7 100644
--- a/sys/i386/i386/sys_machdep.c
+++ b/sys/i386/i386/sys_machdep.c
@@ -450,6 +450,7 @@ user_ldt_alloc(struct mdproc *mdp, int len)
         new_ldt->ldt_refcnt = 1; 
         new_ldt->ldt_active = 0; 
  
+	mtx_lock_spin(&dt_lock);
         if ((pldt = mdp->md_ldt)) { 
                 if (len > pldt->ldt_len) 
                         len = pldt->ldt_len; 
@@ -458,8 +459,10 @@ user_ldt_alloc(struct mdproc *mdp, int len)
         } else { 
                 bcopy(ldt, new_ldt->ldt_base, PAGE_SIZE); 
         } 
+        mtx_unlock_spin(&dt_lock);  /* XXX kill once pmap locking fixed. */
         pmap_map_readonly(kernel_pmap, (vm_offset_t)new_ldt->ldt_base, 
                           new_ldt->ldt_len*sizeof(union descriptor)); 
+        mtx_lock_spin(&dt_lock);  /* XXX kill once pmap locking fixed. */
         return (new_ldt);
 } 
 #else
@@ -520,8 +523,13 @@ user_ldt_free(struct thread *td)
 	}
 
 	if (td == PCPU_GET(curthread)) {
+#ifdef XEN
+		i386_reset_ldt(&default_proc_ldt);
+		PCPU_SET(currentldt, (int)&default_proc_ldt);
+#else
 		lldt(_default_ldt);
 		PCPU_SET(currentldt, _default_ldt);
+#endif
 	}
 
 	mdp->md_ldt = NULL;
@@ -758,10 +766,14 @@ i386_set_ldt_data(struct thread *td, int start, int num,
 
 	mtx_assert(&dt_lock, MA_OWNED);
 
-	/* Fill in range */
-	bcopy(descs,
-	    &((union descriptor *)(pldt->ldt_base))[start],
-	    num * sizeof(union descriptor));
+	while (num) {
+		xen_update_descriptor(
+		    &((union descriptor *)(pldt->ldt_base))[start],
+		    descs);
+		num--;
+		start++;
+		descs++;
+	}
 	return (0);
 }
 #else
diff --git a/sys/i386/include/pmap.h b/sys/i386/include/pmap.h
index 3d44d220..7a45aab7 100644
--- a/sys/i386/include/pmap.h
+++ b/sys/i386/include/pmap.h
@@ -251,7 +251,6 @@ pte_load_store(pt_entry_t *ptep, pt_entry_t v)
 {
 	pt_entry_t r;
 
-	v = xpmap_ptom(v);
 	r = *ptep;
 	PT_SET_VA(ptep, v, TRUE);
 	return (r);
diff --git a/sys/i386/include/segments.h b/sys/i386/include/segments.h
index 2edcc590..bfc3bb9c 100644
--- a/sys/i386/include/segments.h
+++ b/sys/i386/include/segments.h
@@ -249,6 +249,7 @@ struct region_descriptor {
 #ifdef _KERNEL
 extern int	_default_ldt;
 #ifdef XEN
+extern struct proc_ldt default_proc_ldt;
 extern union descriptor *gdt;
 extern union descriptor *ldt;
 #else
diff --git a/sys/i386/xen/pmap.c b/sys/i386/xen/pmap.c
index 0d2450e2..ab4fe054 100644
--- a/sys/i386/xen/pmap.c
+++ b/sys/i386/xen/pmap.c
@@ -3710,7 +3710,9 @@ pmap_map_readonly(pmap_t pmap, vm_offset_t va, int len)
 	for (i = 0; i < npages; i++) {
 		pt_entry_t *pte;
 		pte = pmap_pte(pmap, (vm_offset_t)(va + i*PAGE_SIZE));
+		vm_page_lock_queues();
 		pte_store(pte, xpmap_mtop(*pte & ~(PG_RW|PG_M)));
+		vm_page_unlock_queues();
 		PMAP_MARK_PRIV(xpmap_mtop(*pte));
 		pmap_pte_release(pte);
 	}
@@ -3724,7 +3726,9 @@ pmap_map_readwrite(pmap_t pmap, vm_offset_t va, int len)
 		pt_entry_t *pte;
 		pte = pmap_pte(pmap, (vm_offset_t)(va + i*PAGE_SIZE));
 		PMAP_MARK_UNPRIV(xpmap_mtop(*pte));
+		vm_page_lock_queues();
 		pte_store(pte, xpmap_mtop(*pte) | (PG_RW|PG_M));
+		vm_page_unlock_queues();
 		pmap_pte_release(pte);
 	}
 }
-- 
2.42.0