KVM: x86/mmu: Fold mmu_spte_age() into kvm_rmap_age_gfn_range()

Fold mmu_spte_age() into its sole caller now that aging and testing for
young SPTEs is handled in a common location, i.e. doesn't require more
helpers.

Opportunistically remove the use of mmu_spte_get_lockless(), as mmu_lock
is held (for write!), and marking SPTEs for access tracking outside of
mmu_lock is unsafe (at least, as written).  I.e. using the lockless
accessor is quite misleading.

No functional change intended.

Link: https://lore.kernel.org/r/20240809194335.1726916-16-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 9b977560677b90407725c87576709ab9b791eac5..24ca233d78cd87a5e3656f06b91042590436f199 100644 (file)
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -614,32 +614,6 @@ static u64 mmu_spte_get_lockless(u64 *sptep)
        return __get_spte_lockless(sptep);
 }
 
-/* Returns the Accessed status of the PTE and resets it at the same time. */
-static bool mmu_spte_age(u64 *sptep)
-{
-       u64 spte = mmu_spte_get_lockless(sptep);
-
-       if (!is_accessed_spte(spte))
-               return false;
-
-       if (spte_ad_enabled(spte)) {
-               clear_bit((ffs(shadow_accessed_mask) - 1),
-                         (unsigned long *)sptep);
-       } else {
-               /*
-                * Capture the dirty status of the page, so that it doesn't get
-                * lost when the SPTE is marked for access tracking.
-                */
-               if (is_writable_pte(spte))
-                       kvm_set_pfn_dirty(spte_to_pfn(spte));
-
-               spte = mark_spte_for_access_track(spte);
-               mmu_spte_update_no_track(sptep, spte);
-       }
-
-       return true;
-}
-
 static inline bool is_tdp_mmu_active(struct kvm_vcpu *vcpu)
 {
        return tdp_mmu_enabled && vcpu->arch.mmu->root_role.direct;
@@ -1641,10 +1615,30 @@ static bool kvm_rmap_age_gfn_range(struct kvm *kvm,
        for_each_slot_rmap_range(range->slot, PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL,
                                 range->start, range->end - 1, &iterator) {
                for_each_rmap_spte(iterator.rmap, &iter, sptep) {
-                       if (test_only && is_accessed_spte(*sptep))
+                       u64 spte = *sptep;
+
+                       if (!is_accessed_spte(spte))
+                               continue;
+
+                       if (test_only)
                                return true;
 
-                       young = mmu_spte_age(sptep);
+                       if (spte_ad_enabled(spte)) {
+                               clear_bit((ffs(shadow_accessed_mask) - 1),
+                                       (unsigned long *)sptep);
+                       } else {
+                               /*
+                                * Capture the dirty status of the page, so that
+                                * it doesn't get lost when the SPTE is marked
+                                * for access tracking.
+                                */
+                               if (is_writable_pte(spte))
+                                       kvm_set_pfn_dirty(spte_to_pfn(spte));
+
+                               spte = mark_spte_for_access_track(spte);
+                               mmu_spte_update_no_track(sptep, spte);
+                       }
+                       young = true;
                }
        }
        return young;