KVM: MMU: Make walk_addr_generic capable for two-level walking
Joerg Roedel [Fri, 10 Sep 2010 15:30:52 +0000 (17:30 +0200)]
This patch uses kvm_read_guest_page_tdp to make the
walk_addr_generic functions suitable for two-level page
table walking.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

arch/x86/kvm/paging_tmpl.h

index eefe363..f4e09d3 100644 (file)
@@ -124,6 +124,8 @@ static int FNAME(walk_addr_generic)(struct guest_walker *walker,
        unsigned index, pt_access, uninitialized_var(pte_access);
        gpa_t pte_gpa;
        bool eperm, present, rsvd_fault;
+       int offset;
+       u32 access = 0;
 
        trace_kvm_mmu_pagetable_walk(addr, write_fault, user_fault,
                                     fetch_fault);
@@ -153,12 +155,14 @@ walk:
                index = PT_INDEX(addr, walker->level);
 
                table_gfn = gpte_to_gfn(pte);
-               pte_gpa = gfn_to_gpa(table_gfn);
-               pte_gpa += index * sizeof(pt_element_t);
+               offset    = index * sizeof(pt_element_t);
+               pte_gpa   = gfn_to_gpa(table_gfn) + offset;
                walker->table_gfn[walker->level - 1] = table_gfn;
                walker->pte_gpa[walker->level - 1] = pte_gpa;
 
-               if (kvm_read_guest(vcpu->kvm, pte_gpa, &pte, sizeof(pte))) {
+               if (kvm_read_guest_page_mmu(vcpu, mmu, table_gfn, &pte,
+                                           offset, sizeof(pte),
+                                           PFERR_USER_MASK|PFERR_WRITE_MASK)) {
                        present = false;
                        break;
                }
@@ -209,15 +213,27 @@ walk:
                                is_large_pte(pte) &&
                                mmu->root_level == PT64_ROOT_LEVEL)) {
                        int lvl = walker->level;
+                       gpa_t real_gpa;
+                       gfn_t gfn;
 
-                       walker->gfn = gpte_to_gfn_lvl(pte, lvl);
-                       walker->gfn += (addr & PT_LVL_OFFSET_MASK(lvl))
-                                       >> PAGE_SHIFT;
+                       gfn = gpte_to_gfn_lvl(pte, lvl);
+                       gfn += (addr & PT_LVL_OFFSET_MASK(lvl)) >> PAGE_SHIFT;
 
                        if (PTTYPE == 32 &&
                            walker->level == PT_DIRECTORY_LEVEL &&
                            is_cpuid_PSE36())
-                               walker->gfn += pse36_gfn_delta(pte);
+                               gfn += pse36_gfn_delta(pte);
+
+                       access |= write_fault ? PFERR_WRITE_MASK : 0;
+                       access |= fetch_fault ? PFERR_FETCH_MASK : 0;
+                       access |= user_fault  ? PFERR_USER_MASK  : 0;
+
+                       real_gpa = mmu->translate_gpa(vcpu, gfn_to_gpa(gfn),
+                                                     access);
+                       if (real_gpa == UNMAPPED_GVA)
+                               return 0;
+
+                       walker->gfn = real_gpa >> PAGE_SHIFT;
 
                        break;
                }