KVM: MMU: introduce kvm_mmu_gfn_{allow,disallow}_lpage

Abstract the common operations from account_shadowed() and
unaccount_shadowed(), then introduce kvm_mmu_gfn_disallow_lpage()
and kvm_mmu_gfn_allow_lpage()

These two functions will be used by page tracking in the later patch

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 06dd4abfeaa39e1ce4fdceb6164c072476e93be4..566639dd13b3f560e16f830b80f150c8c3de076c 100644 (file)
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -776,21 +776,39 @@ static struct kvm_lpage_info *lpage_info_slot(gfn_t gfn,
        return &slot->arch.lpage_info[level - 2][idx];
 }
 
+static void update_gfn_disallow_lpage_count(struct kvm_memory_slot *slot,
+                                           gfn_t gfn, int count)
+{
+       struct kvm_lpage_info *linfo;
+       int i;
+
+       for (i = PT_DIRECTORY_LEVEL; i <= PT_MAX_HUGEPAGE_LEVEL; ++i) {
+               linfo = lpage_info_slot(gfn, slot, i);
+               linfo->disallow_lpage += count;
+               WARN_ON(linfo->disallow_lpage < 0);
+       }
+}
+
+void kvm_mmu_gfn_disallow_lpage(struct kvm_memory_slot *slot, gfn_t gfn)
+{
+       update_gfn_disallow_lpage_count(slot, gfn, 1);
+}
+
+void kvm_mmu_gfn_allow_lpage(struct kvm_memory_slot *slot, gfn_t gfn)
+{
+       update_gfn_disallow_lpage_count(slot, gfn, -1);
+}
+
 static void account_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp)
 {
        struct kvm_memslots *slots;
        struct kvm_memory_slot *slot;
-       struct kvm_lpage_info *linfo;
        gfn_t gfn;
-       int i;
 
        gfn = sp->gfn;
        slots = kvm_memslots_for_spte_role(kvm, sp->role);
        slot = __gfn_to_memslot(slots, gfn);
-       for (i = PT_DIRECTORY_LEVEL; i <= PT_MAX_HUGEPAGE_LEVEL; ++i) {
-               linfo = lpage_info_slot(gfn, slot, i);
-               linfo->disallow_lpage += 1;
-       }
+       kvm_mmu_gfn_disallow_lpage(slot, gfn);
        kvm->arch.indirect_shadow_pages++;
 }
 
@@ -798,18 +816,12 @@ static void unaccount_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp)
 {
        struct kvm_memslots *slots;
        struct kvm_memory_slot *slot;
-       struct kvm_lpage_info *linfo;
        gfn_t gfn;
-       int i;
 
        gfn = sp->gfn;
        slots = kvm_memslots_for_spte_role(kvm, sp->role);
        slot = __gfn_to_memslot(slots, gfn);
-       for (i = PT_DIRECTORY_LEVEL; i <= PT_MAX_HUGEPAGE_LEVEL; ++i) {
-               linfo = lpage_info_slot(gfn, slot, i);
-               linfo->disallow_lpage -= 1;
-               WARN_ON(linfo->disallow_lpage < 0);
-       }
+       kvm_mmu_gfn_allow_lpage(slot, gfn);
        kvm->arch.indirect_shadow_pages--;
 }
 

diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index 55ffb7b0f95e9f82a97e8fd4ab7caf4f720fc335..de92bed207f1007fb8b7315899bc613b6115330f 100644 (file)
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -174,4 +174,7 @@ static inline bool permission_fault(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
 
 void kvm_mmu_invalidate_zap_all_pages(struct kvm *kvm);
 void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end);
+
+void kvm_mmu_gfn_disallow_lpage(struct kvm_memory_slot *slot, gfn_t gfn);
+void kvm_mmu_gfn_allow_lpage(struct kvm_memory_slot *slot, gfn_t gfn);
 #endif