KVM: x86/mmu: Fix comment mentioning skip_4k

[linux-2.6-microblaze.git] / arch / x86 / kvm / mmu / tdp_mmu.c

diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index 88f69a6..237317b 100644 (file)
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -388,7 +388,7 @@ static void handle_removed_tdp_mmu_page(struct kvm *kvm, tdp_ptep_t pt,
 }
 
 /**
- * handle_changed_spte - handle bookkeeping associated with an SPTE change
+ * __handle_changed_spte - handle bookkeeping associated with an SPTE change
  * @kvm: kvm instance
  * @as_id: the address space of the paging structure the SPTE was a part of
  * @gfn: the base GFN that was mapped by the SPTE
@@ -444,6 +444,13 @@ static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
 
        trace_kvm_tdp_mmu_spte_changed(as_id, gfn, level, old_spte, new_spte);
 
+       if (is_large_pte(old_spte) != is_large_pte(new_spte)) {
+               if (is_large_pte(old_spte))
+                       atomic64_sub(1, (atomic64_t*)&kvm->stat.lpages);
+               else
+                       atomic64_add(1, (atomic64_t*)&kvm->stat.lpages);
+       }
+
        /*
         * The only times a SPTE should be changed from a non-present to
         * non-present state is when an MMIO entry is installed/modified/
@@ -1009,6 +1016,14 @@ int kvm_tdp_mmu_map(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
                }
 
                if (!is_shadow_present_pte(iter.old_spte)) {
+                       /*
+                        * If SPTE has been forzen by another thread, just
+                        * give up and retry, avoiding unnecessary page table
+                        * allocation and free.
+                        */
+                       if (is_removed_spte(iter.old_spte))
+                               break;
+
                        sp = alloc_tdp_mmu_page(vcpu, iter.gfn, iter.level);
                        child_pt = sp->spt;
 
@@ -1177,9 +1192,9 @@ bool kvm_tdp_mmu_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
 }
 
 /*
- * Remove write access from all the SPTEs mapping GFNs [start, end). If
- * skip_4k is set, SPTEs that map 4k pages, will not be write-protected.
- * Returns true if an SPTE has been changed and the TLBs need to be flushed.
+ * Remove write access from all SPTEs at or above min_level that map GFNs
+ * [start, end). Returns true if an SPTE has been changed and the TLBs need to
+ * be flushed.
  */
 static bool wrprot_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
                             gfn_t start, gfn_t end, int min_level)