KVM: x86/mmu: Move kvm_mmu_(get|put)_root to TDP MMU

The TDP MMU is almost the only user of kvm_mmu_get_root and
kvm_mmu_put_root. There is only one use of put_root in mmu.c for the
legacy / shadow MMU. Open code that one use and move the get / put
functions to the TDP MMU so they can be extended in future commits.

No functional change intended.

Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <20210401233736.638171-3-bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 6395ab9..585073d 100644 (file)
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -3120,12 +3120,10 @@ static void mmu_free_root_page(struct kvm *kvm, hpa_t *root_hpa,
 
        sp = to_shadow_page(*root_hpa & PT64_BASE_ADDR_MASK);
 
-       if (kvm_mmu_put_root(kvm, sp)) {
-               if (is_tdp_mmu_page(sp))
-                       kvm_tdp_mmu_free_root(kvm, sp);
-               else if (sp->role.invalid)
-                       kvm_mmu_prepare_zap_page(kvm, sp, invalid_list);
-       }
+       if (is_tdp_mmu_page(sp) && kvm_tdp_mmu_put_root(kvm, sp))
+               kvm_tdp_mmu_free_root(kvm, sp);
+       else if (!--sp->root_count && sp->role.invalid)
+               kvm_mmu_prepare_zap_page(kvm, sp, invalid_list);
 
        *root_hpa = INVALID_PAGE;
 }

diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h
index 9f51382..8135b6d 100644 (file)
--- a/arch/x86/kvm/mmu/mmu_internal.h
+++ b/arch/x86/kvm/mmu/mmu_internal.h
@@ -123,22 +123,6 @@ bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm,
 void kvm_flush_remote_tlbs_with_address(struct kvm *kvm,
                                        u64 start_gfn, u64 pages);
 
-static inline void kvm_mmu_get_root(struct kvm *kvm, struct kvm_mmu_page *sp)
-{
-       BUG_ON(!sp->root_count);
-       lockdep_assert_held(&kvm->mmu_lock);
-
-       ++sp->root_count;
-}
-
-static inline bool kvm_mmu_put_root(struct kvm *kvm, struct kvm_mmu_page *sp)
-{
-       lockdep_assert_held(&kvm->mmu_lock);
-       --sp->root_count;
-
-       return !sp->root_count;
-}
-
 /*
  * Return values of handle_mmio_page_fault, mmu.page_fault, and fast_page_fault().
  *

diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index 5f517ef..de2c830 100644 (file)
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -43,7 +43,7 @@ void kvm_mmu_uninit_tdp_mmu(struct kvm *kvm)
 
 static void tdp_mmu_put_root(struct kvm *kvm, struct kvm_mmu_page *root)
 {
-       if (kvm_mmu_put_root(kvm, root))
+       if (kvm_tdp_mmu_put_root(kvm, root))
                kvm_tdp_mmu_free_root(kvm, root);
 }
 
@@ -55,7 +55,7 @@ static inline bool tdp_mmu_next_root_valid(struct kvm *kvm,
        if (list_entry_is_head(root, &kvm->arch.tdp_mmu_roots, link))
                return false;
 
-       kvm_mmu_get_root(kvm, root);
+       kvm_tdp_mmu_get_root(kvm, root);
        return true;
 
 }
@@ -154,7 +154,7 @@ hpa_t kvm_tdp_mmu_get_vcpu_root_hpa(struct kvm_vcpu *vcpu)
        /* Check for an existing root before allocating a new one. */
        for_each_tdp_mmu_root(kvm, root, kvm_mmu_role_as_id(role)) {
                if (root->role.word == role.word) {
-                       kvm_mmu_get_root(kvm, root);
+                       kvm_tdp_mmu_get_root(kvm, root);
                        goto out;
                }
        }

diff --git a/arch/x86/kvm/mmu/tdp_mmu.h b/arch/x86/kvm/mmu/tdp_mmu.h
index 1105099..8476ad3 100644 (file)
--- a/arch/x86/kvm/mmu/tdp_mmu.h
+++ b/arch/x86/kvm/mmu/tdp_mmu.h
@@ -8,6 +8,24 @@
 hpa_t kvm_tdp_mmu_get_vcpu_root_hpa(struct kvm_vcpu *vcpu);
 void kvm_tdp_mmu_free_root(struct kvm *kvm, struct kvm_mmu_page *root);
 
+static inline void kvm_tdp_mmu_get_root(struct kvm *kvm,
+                                       struct kvm_mmu_page *root)
+{
+       BUG_ON(!root->root_count);
+       lockdep_assert_held(&kvm->mmu_lock);
+
+       ++root->root_count;
+}
+
+static inline bool kvm_tdp_mmu_put_root(struct kvm *kvm,
+                                       struct kvm_mmu_page *root)
+{
+       lockdep_assert_held(&kvm->mmu_lock);
+       --root->root_count;
+
+       return !root->root_count;
+}
+
 bool __kvm_tdp_mmu_zap_gfn_range(struct kvm *kvm, int as_id, gfn_t start,
                                 gfn_t end, bool can_yield, bool flush);
 static inline bool kvm_tdp_mmu_zap_gfn_range(struct kvm *kvm, int as_id,