3 files changed, 26 insertions, 19 deletions

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 0c376a2d9f98..832765c0fb8c 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -1036,10 +1036,9 @@ static void xen_pgd_pin(struct mm_struct *mm)
  */
 void xen_mm_pin_all(void)
 {
-        unsigned long flags;
         struct page *page;
 
-        spin_lock_irqsave(&pgd_lock, flags);
+        spin_lock(&pgd_lock);
 
         list_for_each_entry(page, &pgd_list, lru) {
                 if (!PagePinned(page)) {
@@ -1048,7 +1047,7 @@ void xen_mm_pin_all(void)
                 }
         }
 
-        spin_unlock_irqrestore(&pgd_lock, flags);
+        spin_unlock(&pgd_lock);
 }
 
 /*
@@ -1149,10 +1148,9 @@ static void xen_pgd_unpin(struct mm_struct *mm)
  */
 void xen_mm_unpin_all(void)
 {
-        unsigned long flags;
         struct page *page;
 
-        spin_lock_irqsave(&pgd_lock, flags);
+        spin_lock(&pgd_lock);
 
         list_for_each_entry(page, &pgd_list, lru) {
                 if (PageSavePinned(page)) {
@@ -1162,7 +1160,7 @@ void xen_mm_unpin_all(void)
                 }
         }
 
-        spin_unlock_irqrestore(&pgd_lock, flags);
+        spin_unlock(&pgd_lock);
 }
 
 void xen_activate_mm(struct mm_struct *prev, struct mm_struct *next)
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index 65f21f4b3962..00fe5604c593 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -374,21 +374,15 @@ void __init xen_build_dynamic_phys_to_machine(void)
                  * As long as the mfn_list has enough entries to completely
                  * fill a p2m page, pointing into the array is ok. But if
                  * not the entries beyond the last pfn will be undefined.
-                 * And guessing that the 'what-ever-there-is' does not take it
-                 * too kindly when changing it to invalid markers, a new page
-                 * is allocated, initialized and filled with the valid part.
                  */
                 if (unlikely(pfn + P2M_PER_PAGE > max_pfn)) {
                         unsigned long p2midx;
-                        unsigned long *p2m = extend_brk(PAGE_SIZE, PAGE_SIZE);
-                        p2m_init(p2m);
-
-                        for (p2midx = 0; pfn + p2midx < max_pfn; p2midx++) {
-                                p2m[p2midx] = mfn_list[pfn + p2midx];
-                        }
-                        p2m_top[topidx][mididx] = p2m;
-                } else
-                        p2m_top[topidx][mididx] = &mfn_list[pfn];
+
+                        p2midx = max_pfn % P2M_PER_PAGE;
+                        for ( ; p2midx < P2M_PER_PAGE; p2midx++)
+                                mfn_list[pfn + p2midx] = INVALID_P2M_ENTRY;
+                }
+                p2m_top[topidx][mididx] = &mfn_list[pfn];
         }
 
         m2p_override_init();
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 54d93791ddb9..fa0269a99377 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -229,8 +229,13 @@ char * __init xen_memory_setup(void)
         e820.nr_map = 0;
         xen_extra_mem_start = mem_end;
         for (i = 0; i < memmap.nr_entries; i++) {
-                unsigned long long end = map[i].addr + map[i].size;
+                unsigned long long end;
 
+                /* Guard against non-page aligned E820 entries. */
+                if (map[i].type == E820_RAM)
+                        map[i].size -= (map[i].size + map[i].addr) % PAGE_SIZE;
+
+                end = map[i].addr + map[i].size;
                 if (map[i].type == E820_RAM && end > mem_end) {
                         /* RAM off the end - may be partially included */
                         u64 delta = min(map[i].size, end - mem_end);
@@ -239,6 +244,15 @@ char * __init xen_memory_setup(void)
                         end -= delta;
 
                         extra_pages += PFN_DOWN(delta);
+                        /*
+                         * Set RAM below 4GB that is not for us to be unusable.
+                         * This prevents "System RAM" address space from being
+                         * used as potential resource for I/O address (happens
+                         * when 'allocate_resource' is called).
+                         */
+                        if (delta &&
+                                (xen_initial_domain() && end < 0x100000000ULL))
+                                e820_add_region(end, delta, E820_UNUSABLE);
                 }
 
                 if (map[i].size > 0 && end > xen_extra_mem_start)
@@ -407,6 +421,7 @@ void __init xen_arch_setup(void)
         boot_cpu_data.hlt_works_ok = 1;
 #endif
         pm_idle = default_idle;
+        boot_option_idle_override = IDLE_HALT;
 
         fiddle_vdso();
 }