KVM: x86/mmu: Detect write #PF to shadow pages during FNAME(fetch) walk

[linux-2.6-microblaze.git] / arch / x86 / kvm / mmu / paging_tmpl.h

diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
index 5d29582..f57d907 100644 (file)
--- a/arch/x86/kvm/mmu/paging_tmpl.h
+++ b/arch/x86/kvm/mmu/paging_tmpl.h
@@ -685,6 +685,9 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault,
 
                if (sp != ERR_PTR(-EEXIST))
                        link_shadow_page(vcpu, it.sptep, sp);
+
+               if (fault->write && table_gfn == fault->gfn)
+                       fault->write_fault_to_shadow_pgtable = true;
        }
 
        kvm_mmu_hugepage_adjust(vcpu, fault);
@@ -741,17 +744,13 @@ out_gpte_changed:
  * created when kvm establishes shadow page table that stop kvm using large
  * page size. Do it early can avoid unnecessary #PF and emulation.
  *
- * @write_fault_to_shadow_pgtable will return true if the fault gfn is
- * currently used as its page table.
- *
  * Note: the PDPT page table is not checked for PAE-32 bit guest. It is ok
  * since the PDPT is always shadowed, that means, we can not use large page
  * size to map the gfn which is used as PDPT.
  */
 static bool
 FNAME(is_self_change_mapping)(struct kvm_vcpu *vcpu,
-                             struct guest_walker *walker, bool user_fault,
-                             bool *write_fault_to_shadow_pgtable)
+                             struct guest_walker *walker, bool user_fault)
 {
        int level;
        gfn_t mask = ~(KVM_PAGES_PER_HPAGE(walker->level) - 1);
@@ -765,7 +764,6 @@ FNAME(is_self_change_mapping)(struct kvm_vcpu *vcpu,
                gfn_t gfn = walker->gfn ^ walker->table_gfn[level - 1];
 
                self_changed |= !(gfn & mask);
-               *write_fault_to_shadow_pgtable |= !gfn;
        }
 
        return self_changed;
@@ -826,7 +824,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
                return r;
 
        is_self_change_mapping = FNAME(is_self_change_mapping)(vcpu,
-             &walker, fault->user, &fault->write_fault_to_shadow_pgtable);
+             &walker, fault->user);
 
        if (is_self_change_mapping)
                fault->max_level = PG_LEVEL_4K;