Merge tag 'kvm-x86-mmu-6.16' of https://github.com/kvm-x86/linux into HEAD

KVM x86 MMU changes for 6.16:

 - Refine and harden handling of spurious faults.

 - Use kvm_x86_call() instead of open coding static_call().

Author: bonzini

arch/x86/kvm/mmu/mmu.c

@@ -3020,7 +3020,8 @@ static int mmu_set_spte(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot,
 	}
 
 	if (is_shadow_present_pte(*sptep)) {
-		if (prefetch)
+		if (prefetch && is_last_spte(*sptep, level) &&
+		    pfn == spte_to_pfn(*sptep))
 			return RET_PF_SPURIOUS;
 
 		/*
@@ -3034,7 +3035,7 @@ static int mmu_set_spte(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot,
 			child = spte_to_child_sp(pte);
 			drop_parent_pte(vcpu->kvm, child, sptep);
 			flush = true;
-		} else if (pfn != spte_to_pfn(*sptep)) {
+		} else if (WARN_ON_ONCE(pfn != spte_to_pfn(*sptep))) {
 			drop_spte(vcpu->kvm, sptep);
 			flush = true;
 		} else

arch/x86/kvm/mmu/tdp_mmu.c

@@ -378,7 +378,7 @@ static void remove_external_spte(struct kvm *kvm, gfn_t gfn, u64 old_spte,
 	/* Zapping leaf spte is allowed only when write lock is held. */
 	lockdep_assert_held_write(&kvm->mmu_lock);
 	/* Because write lock is held, operation should success. */
-	ret = static_call(kvm_x86_remove_external_spte)(kvm, gfn, level, old_pfn);
+	ret = kvm_x86_call(remove_external_spte)(kvm, gfn, level, old_pfn);
 	KVM_BUG_ON(ret, kvm);
 }
 
@@ -485,8 +485,8 @@ static void handle_removed_pt(struct kvm *kvm, tdp_ptep_t pt, bool shared)
 	}
 
 	if (is_mirror_sp(sp) &&
-	    WARN_ON(static_call(kvm_x86_free_external_spt)(kvm, base_gfn, sp->role.level,
-							  sp->external_spt))) {
+	    WARN_ON(kvm_x86_call(free_external_spt)(kvm, base_gfn, sp->role.level,
+						    sp->external_spt))) {
 		/*
 		 * Failed to free page table page in mirror page table and
 		 * there is nothing to do further.
@@ -538,12 +538,12 @@ static int __must_check set_external_spte_present(struct kvm *kvm, tdp_ptep_t sp
 	 * external page table, or leaf.
 	 */
 	if (is_leaf) {
-		ret = static_call(kvm_x86_set_external_spte)(kvm, gfn, level, new_pfn);
+		ret = kvm_x86_call(set_external_spte)(kvm, gfn, level, new_pfn);
 	} else {
 		void *external_spt = get_external_spt(gfn, new_spte, level);
 
 		KVM_BUG_ON(!external_spt, kvm);
-		ret = static_call(kvm_x86_link_external_spt)(kvm, gfn, level, external_spt);
+		ret = kvm_x86_call(link_external_spt)(kvm, gfn, level, external_spt);
 	}
 	if (ret)
 		__kvm_tdp_mmu_write_spte(sptep, old_spte);
@@ -1153,13 +1153,12 @@ static int tdp_mmu_map_handle_target_level(struct kvm_vcpu *vcpu,
 	if (WARN_ON_ONCE(sp->role.level != fault->goal_level))
 		return RET_PF_RETRY;
 
-	if (fault->prefetch && is_shadow_present_pte(iter->old_spte))
-		return RET_PF_SPURIOUS;
-
 	if (is_shadow_present_pte(iter->old_spte) &&
-	    is_access_allowed(fault, iter->old_spte) &&
-	    is_last_spte(iter->old_spte, iter->level))
+	    (fault->prefetch || is_access_allowed(fault, iter->old_spte)) &&
+	    is_last_spte(iter->old_spte, iter->level)) {
+		WARN_ON_ONCE(fault->pfn != spte_to_pfn(iter->old_spte));
 		return RET_PF_SPURIOUS;
+	}
 
 	if (unlikely(!fault->slot))
 		new_spte = make_mmio_spte(vcpu, iter->gfn, ACC_ALL);