1 files changed, 22 insertions, 9 deletions

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index d4d52f5a1cf7..688936044dc9 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -246,11 +246,21 @@ xmaddr_t arbitrary_virt_to_machine(void *vaddr)
 {
         unsigned long address = (unsigned long)vaddr;
         unsigned int level;
-        pte_t *pte = lookup_address(address, &level);
-        unsigned offset = address & ~PAGE_MASK;
+        pte_t *pte;
+        unsigned offset;
 
-        BUG_ON(pte == NULL);
+        /*
+         * if the PFN is in the linear mapped vaddr range, we can just use
+         * the (quick) virt_to_machine() p2m lookup
+         */
+        if (virt_addr_valid(vaddr))
+                return virt_to_machine(vaddr);
 
+        /* otherwise we have to do a (slower) full page-table walk */
+
+        pte = lookup_address(address, &level);
+        BUG_ON(pte == NULL);
+        offset = address & ~PAGE_MASK;
         return XMADDR(((phys_addr_t)pte_mfn(*pte) << PAGE_SHIFT) + offset);
 }
 
@@ -410,7 +420,7 @@ void xen_ptep_modify_prot_commit(struct mm_struct *mm, unsigned long addr,
 
         xen_mc_batch();
 
-        u.ptr = virt_to_machine(ptep).maddr | MMU_PT_UPDATE_PRESERVE_AD;
+        u.ptr = arbitrary_virt_to_machine(ptep).maddr | MMU_PT_UPDATE_PRESERVE_AD;
         u.val = pte_val_ma(pte);
         xen_extend_mmu_update(&u);
 
@@ -840,13 +850,16 @@ static int xen_pin_page(struct mm_struct *mm, struct page *page,
    read-only, and can be pinned. */
 static void __xen_pgd_pin(struct mm_struct *mm, pgd_t *pgd)
 {
+        vm_unmap_aliases();
+
         xen_mc_batch();
 
-        if (xen_pgd_walk(mm, xen_pin_page, USER_LIMIT)) {
-                /* re-enable interrupts for kmap_flush_unused */
+         if (xen_pgd_walk(mm, xen_pin_page, USER_LIMIT)) {
+                /* re-enable interrupts for flushing */
                 xen_mc_issue(0);
+
                 kmap_flush_unused();
-                vm_unmap_aliases();
+
                 xen_mc_batch();
         }
 
@@ -864,7 +877,7 @@ static void __xen_pgd_pin(struct mm_struct *mm, pgd_t *pgd)
 #else /* CONFIG_X86_32 */
 #ifdef CONFIG_X86_PAE
         /* Need to make sure unshared kernel PMD is pinnable */
-        xen_pin_page(mm, virt_to_page(pgd_page(pgd[pgd_index(TASK_SIZE)])),
+        xen_pin_page(mm, pgd_page(pgd[pgd_index(TASK_SIZE)]),
                      PT_PMD);
 #endif
         xen_do_pin(MMUEXT_PIN_L3_TABLE, PFN_DOWN(__pa(pgd)));
@@ -981,7 +994,7 @@ static void __xen_pgd_unpin(struct mm_struct *mm, pgd_t *pgd)
 
 #ifdef CONFIG_X86_PAE
         /* Need to make sure unshared kernel PMD is unpinned */
-        xen_unpin_page(mm, virt_to_page(pgd_page(pgd[pgd_index(TASK_SIZE)])),
+        xen_unpin_page(mm, pgd_page(pgd[pgd_index(TASK_SIZE)]),
                        PT_PMD);
 #endif