1 files changed, 46 insertions, 28 deletions

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 8b9ee27805fd..27ee26aedf94 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -95,7 +95,7 @@ struct shared_info *HYPERVISOR_shared_info = (void *)&dummy_shared_info;
  *
  * 0: not available, 1: available
  */
-static int have_vcpu_info_placement = 0;
+static int have_vcpu_info_placement = 1;
 
 static void __init xen_vcpu_setup(int cpu)
 {
@@ -103,6 +103,7 @@ static void __init xen_vcpu_setup(int cpu)
         int err;
         struct vcpu_info *vcpup;
 
+        BUG_ON(HYPERVISOR_shared_info == &dummy_shared_info);
         per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
 
         if (!have_vcpu_info_placement)
@@ -666,10 +667,10 @@ static void xen_release_pt_init(u32 pfn)
         make_lowmem_page_readwrite(__va(PFN_PHYS(pfn)));
 }
 
-static void pin_pagetable_pfn(unsigned level, unsigned long pfn)
+static void pin_pagetable_pfn(unsigned cmd, unsigned long pfn)
 {
         struct mmuext_op op;
-        op.cmd = level;
+        op.cmd = cmd;
         op.arg1.mfn = pfn_to_mfn(pfn);
         if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF))
                 BUG();
@@ -686,7 +687,8 @@ static void xen_alloc_ptpage(struct mm_struct *mm, u32 pfn, unsigned level)
 
                 if (!PageHighMem(page)) {
                         make_lowmem_page_readonly(__va(PFN_PHYS(pfn)));
-                        pin_pagetable_pfn(level, pfn);
+                        if (level == PT_PTE)
+                                pin_pagetable_pfn(MMUEXT_PIN_L1_TABLE, pfn);
                 } else
                         /* make sure there are no stray mappings of
                            this page */
@@ -696,27 +698,39 @@ static void xen_alloc_ptpage(struct mm_struct *mm, u32 pfn, unsigned level)
 
 static void xen_alloc_pt(struct mm_struct *mm, u32 pfn)
 {
-        xen_alloc_ptpage(mm, pfn, MMUEXT_PIN_L1_TABLE);
+        xen_alloc_ptpage(mm, pfn, PT_PTE);
 }
 
 static void xen_alloc_pd(struct mm_struct *mm, u32 pfn)
 {
-        xen_alloc_ptpage(mm, pfn, MMUEXT_PIN_L2_TABLE);
+        xen_alloc_ptpage(mm, pfn, PT_PMD);
 }
 
 /* This should never happen until we're OK to use struct page */
-static void xen_release_pt(u32 pfn)
+static void xen_release_ptpage(u32 pfn, unsigned level)
 {
         struct page *page = pfn_to_page(pfn);
 
         if (PagePinned(page)) {
                 if (!PageHighMem(page)) {
-                        pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, pfn);
+                        if (level == PT_PTE)
+                                pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, pfn);
                         make_lowmem_page_readwrite(__va(PFN_PHYS(pfn)));
                 }
+                ClearPagePinned(page);
         }
 }
 
+static void xen_release_pt(u32 pfn)
+{
+        xen_release_ptpage(pfn, PT_PTE);
+}
+
+static void xen_release_pd(u32 pfn)
+{
+        xen_release_ptpage(pfn, PT_PMD);
+}
+
 #ifdef CONFIG_HIGHPTE
 static void *xen_kmap_atomic_pte(struct page *page, enum km_type type)
 {
@@ -805,33 +819,43 @@ static __init void xen_pagetable_setup_start(pgd_t *base)
                           PFN_DOWN(__pa(xen_start_info->pt_base)));
 }
 
-static __init void xen_pagetable_setup_done(pgd_t *base)
+static __init void setup_shared_info(void)
 {
-        /* This will work as long as patching hasn't happened yet
-           (which it hasn't) */
-        pv_mmu_ops.alloc_pt = xen_alloc_pt;
-        pv_mmu_ops.alloc_pd = xen_alloc_pd;
-        pv_mmu_ops.release_pt = xen_release_pt;
-        pv_mmu_ops.release_pd = xen_release_pt;
-        pv_mmu_ops.set_pte = xen_set_pte;
-
         if (!xen_feature(XENFEAT_auto_translated_physmap)) {
+                unsigned long addr = fix_to_virt(FIX_PARAVIRT_BOOTMAP);
+
                 /*
                  * Create a mapping for the shared info page.
                  * Should be set_fixmap(), but shared_info is a machine
                  * address with no corresponding pseudo-phys address.
                  */
-                set_pte_mfn(fix_to_virt(FIX_PARAVIRT_BOOTMAP),
+                set_pte_mfn(addr,
                             PFN_DOWN(xen_start_info->shared_info),
                             PAGE_KERNEL);
 
-                HYPERVISOR_shared_info =
-                        (struct shared_info *)fix_to_virt(FIX_PARAVIRT_BOOTMAP);
-
+                HYPERVISOR_shared_info = (struct shared_info *)addr;
         } else
                 HYPERVISOR_shared_info =
                         (struct shared_info *)__va(xen_start_info->shared_info);
 
+#ifndef CONFIG_SMP
+        /* In UP this is as good a place as any to set up shared info */
+        xen_setup_vcpu_info_placement();
+#endif
+}
+
+static __init void xen_pagetable_setup_done(pgd_t *base)
+{
+        /* This will work as long as patching hasn't happened yet
+           (which it hasn't) */
+        pv_mmu_ops.alloc_pt = xen_alloc_pt;
+        pv_mmu_ops.alloc_pd = xen_alloc_pd;
+        pv_mmu_ops.release_pt = xen_release_pt;
+        pv_mmu_ops.release_pd = xen_release_pd;
+        pv_mmu_ops.set_pte = xen_set_pte;
+
+        setup_shared_info();
+
         /* Actually pin the pagetable down, but we can't set PG_pinned
            yet because the page structures don't exist yet. */
         {
@@ -1182,15 +1206,9 @@ asmlinkage void __init xen_start_kernel(void)
         x86_write_percpu(xen_cr3, __pa(pgd));
         x86_write_percpu(xen_current_cr3, __pa(pgd));
 
-#ifdef CONFIG_SMP
         /* Don't do the full vcpu_info placement stuff until we have a
-           possible map. */
+           possible map and a non-dummy shared_info. */
         per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
-#else
-        /* May as well do it now, since there's no good time to call
-           it later on UP. */
-        xen_setup_vcpu_info_placement();
-#endif
 
         pv_info.kernel_rpl = 1;
         if (xen_feature(XENFEAT_supervisor_mode_kernel))