xen: fix Xen domU boot with batched mprotect

[linux-2.6-omap-h63xx.git] / arch / x86 / xen / mmu.c

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index d4d52f5a1cf7bae392801e19367030ebe58ccf79..aba77b2b7d1853a188f42696e92255091de041b2 100644 (file)
--- 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);