1 files changed, 73 insertions, 9 deletions

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 5e92b61ad574..832765c0fb8c 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -46,6 +46,7 @@
 #include <linux/module.h>
 #include <linux/gfp.h>
 #include <linux/memblock.h>
+#include <linux/seq_file.h>
 
 #include <asm/pgtable.h>
 #include <asm/tlbflush.h>
@@ -416,8 +417,12 @@ static pteval_t pte_pfn_to_mfn(pteval_t val)
         if (val & _PAGE_PRESENT) {
                 unsigned long pfn = (val & PTE_PFN_MASK) >> PAGE_SHIFT;
                 pteval_t flags = val & PTE_FLAGS_MASK;
-                unsigned long mfn = pfn_to_mfn(pfn);
+                unsigned long mfn;
 
+                if (!xen_feature(XENFEAT_auto_translated_physmap))
+                        mfn = get_phys_to_machine(pfn);
+                else
+                        mfn = pfn;
                 /*
                  * If there's no mfn for the pfn, then just create an
                  * empty non-present pte.  Unfortunately this loses
@@ -427,8 +432,18 @@ static pteval_t pte_pfn_to_mfn(pteval_t val)
                 if (unlikely(mfn == INVALID_P2M_ENTRY)) {
                         mfn = 0;
                         flags = 0;
+                } else {
+                        /*
+                         * Paramount to do this test _after_ the
+                         * INVALID_P2M_ENTRY as INVALID_P2M_ENTRY &
+                         * IDENTITY_FRAME_BIT resolves to true.
+                         */
+                        mfn &= ~FOREIGN_FRAME_BIT;
+                        if (mfn & IDENTITY_FRAME_BIT) {
+                                mfn &= ~IDENTITY_FRAME_BIT;
+                                flags |= _PAGE_IOMAP;
+                        }
                 }
-
                 val = ((pteval_t)mfn << PAGE_SHIFT) | flags;
         }
 
@@ -532,6 +547,41 @@ pte_t xen_make_pte(pteval_t pte)
 }
 PV_CALLEE_SAVE_REGS_THUNK(xen_make_pte);
 
+#ifdef CONFIG_XEN_DEBUG
+pte_t xen_make_pte_debug(pteval_t pte)
+{
+        phys_addr_t addr = (pte & PTE_PFN_MASK);
+        phys_addr_t other_addr;
+        bool io_page = false;
+        pte_t _pte;
+
+        if (pte & _PAGE_IOMAP)
+                io_page = true;
+
+        _pte = xen_make_pte(pte);
+
+        if (!addr)
+                return _pte;
+
+        if (io_page &&
+            (xen_initial_domain() || addr >= ISA_END_ADDRESS)) {
+                other_addr = pfn_to_mfn(addr >> PAGE_SHIFT) << PAGE_SHIFT;
+                WARN(addr != other_addr,
+                        "0x%lx is using VM_IO, but it is 0x%lx!\n",
+                        (unsigned long)addr, (unsigned long)other_addr);
+        } else {
+                pteval_t iomap_set = (_pte.pte & PTE_FLAGS_MASK) & _PAGE_IOMAP;
+                other_addr = (_pte.pte & PTE_PFN_MASK);
+                WARN((addr == other_addr) && (!io_page) && (!iomap_set),
+                        "0x%lx is missing VM_IO (and wasn't fixed)!\n",
+                        (unsigned long)addr);
+        }
+
+        return _pte;
+}
+PV_CALLEE_SAVE_REGS_THUNK(xen_make_pte_debug);
+#endif
+
 pgd_t xen_make_pgd(pgdval_t pgd)
 {
         pgd = pte_pfn_to_mfn(pgd);
@@ -986,10 +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)) {
@@ -998,7 +1047,7 @@ void xen_mm_pin_all(void)
                 }
         }
 
-        spin_unlock_irqrestore(&pgd_lock, flags);
+        spin_unlock(&pgd_lock);
 }
 
 /*
@@ -1099,10 +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)) {
@@ -1112,7 +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)
@@ -1942,6 +1990,9 @@ __init void xen_ident_map_ISA(void)
 
 static __init void xen_post_allocator_init(void)
 {
+#ifdef CONFIG_XEN_DEBUG
+        pv_mmu_ops.make_pte = PV_CALLEE_SAVE(xen_make_pte_debug);
+#endif
         pv_mmu_ops.set_pte = xen_set_pte;
         pv_mmu_ops.set_pmd = xen_set_pmd;
         pv_mmu_ops.set_pud = xen_set_pud;
@@ -2074,7 +2125,7 @@ static void xen_zap_pfn_range(unsigned long vaddr, unsigned int order,
                         in_frames[i] = virt_to_mfn(vaddr);
 
                 MULTI_update_va_mapping(mcs.mc, vaddr, VOID_PTE, 0);
-                set_phys_to_machine(virt_to_pfn(vaddr), INVALID_P2M_ENTRY);
+                __set_phys_to_machine(virt_to_pfn(vaddr), INVALID_P2M_ENTRY);
 
                 if (out_frames)
                         out_frames[i] = virt_to_pfn(vaddr);
@@ -2353,6 +2404,18 @@ EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);
 
 #ifdef CONFIG_XEN_DEBUG_FS
 
+static int p2m_dump_open(struct inode *inode, struct file *filp)
+{
+        return single_open(filp, p2m_dump_show, NULL);
+}
+
+static const struct file_operations p2m_dump_fops = {
+        .open           = p2m_dump_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = single_release,
+};
+
 static struct dentry *d_mmu_debug;
 
 static int __init xen_mmu_debugfs(void)
@@ -2408,6 +2471,7 @@ static int __init xen_mmu_debugfs(void)
         debugfs_create_u32("prot_commit_batched", 0444, d_mmu_debug,
                            &mmu_stats.prot_commit_batched);
 
+        debugfs_create_file("p2m", 0600, d_mmu_debug, NULL, &p2m_dump_fops);
         return 0;
 }
 fs_initcall(xen_mmu_debugfs);