KVM: Simplify kvm_free_memslot() and all its descendents

Now that all callers of kvm_free_memslot() pass NULL for @dont, remove
the param from the top-level routine and all arch's implementations.

No functional change intended.
Tested-by: Christoffer Dall <christoffer.dall@arm.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/mips/include/asm/kvm_host.h

@@ -1133,7 +1133,7 @@ extern unsigned long kvm_mips_get_ramsize(struct kvm *kvm);
 static inline void kvm_arch_hardware_unsetup(void) {}
 static inline void kvm_arch_sync_events(struct kvm *kvm) {}
 static inline void kvm_arch_free_memslot(struct kvm *kvm,
-		struct kvm_memory_slot *free, struct kvm_memory_slot *dont) {}
+					 struct kvm_memory_slot *slot) {}
 static inline void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen) {}
 static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
 static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) {}

arch/powerpc/include/asm/kvm_ppc.h

@@ -200,8 +200,7 @@ extern void kvm_free_hpt_cma(struct page *page, unsigned long nr_pages);
 extern int kvmppc_core_init_vm(struct kvm *kvm);
 extern void kvmppc_core_destroy_vm(struct kvm *kvm);
 extern void kvmppc_core_free_memslot(struct kvm *kvm,
-				     struct kvm_memory_slot *free,
-				     struct kvm_memory_slot *dont);
+				     struct kvm_memory_slot *slot);
 extern int kvmppc_core_prepare_memory_region(struct kvm *kvm,
 				struct kvm_memory_slot *memslot,
 				const struct kvm_userspace_memory_region *mem,
@@ -291,8 +290,7 @@ struct kvmppc_ops {
 	int (*test_age_hva)(struct kvm *kvm, unsigned long hva);
 	void (*set_spte_hva)(struct kvm *kvm, unsigned long hva, pte_t pte);
 	void (*mmu_destroy)(struct kvm_vcpu *vcpu);
-	void (*free_memslot)(struct kvm_memory_slot *free,
-			     struct kvm_memory_slot *dont);
+	void (*free_memslot)(struct kvm_memory_slot *slot);
 	int (*init_vm)(struct kvm *kvm);
 	void (*destroy_vm)(struct kvm *kvm);
 	int (*get_smmu_info)(struct kvm *kvm, struct kvm_ppc_smmu_info *info);

arch/powerpc/kvm/book3s.c

@@ -804,10 +804,9 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
 	return kvm->arch.kvm_ops->get_dirty_log(kvm, log);
 }
 
-void kvmppc_core_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
-			      struct kvm_memory_slot *dont)
+void kvmppc_core_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot)
 {
-	kvm->arch.kvm_ops->free_memslot(free, dont);
+	kvm->arch.kvm_ops->free_memslot(slot);
 }
 
 void kvmppc_core_flush_memslot(struct kvm *kvm, struct kvm_memory_slot *memslot)

arch/powerpc/kvm/book3s_hv.c

@@ -4447,13 +4447,10 @@ static int kvm_vm_ioctl_get_dirty_log_hv(struct kvm *kvm,
 	return r;
 }
 
-static void kvmppc_core_free_memslot_hv(struct kvm_memory_slot *free,
-					struct kvm_memory_slot *dont)
+static void kvmppc_core_free_memslot_hv(struct kvm_memory_slot *slot)
 {
-	if (!dont || free->arch.rmap != dont->arch.rmap) {
-		vfree(free->arch.rmap);
-		free->arch.rmap = NULL;
-	}
+	vfree(slot->arch.rmap);
+	slot->arch.rmap = NULL;
 }
 
 static int kvmppc_core_prepare_memory_region_hv(struct kvm *kvm,

arch/powerpc/kvm/book3s_pr.c

@@ -1942,8 +1942,7 @@ static void kvmppc_core_commit_memory_region_pr(struct kvm *kvm,
 	return;
 }
 
-static void kvmppc_core_free_memslot_pr(struct kvm_memory_slot *free,
-					struct kvm_memory_slot *dont)
+static void kvmppc_core_free_memslot_pr(struct kvm_memory_slot *slot)
 {
 	return;
 }

arch/powerpc/kvm/booke.c

@@ -1771,8 +1771,7 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
 	return -ENOTSUPP;
 }
 
-void kvmppc_core_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
-			      struct kvm_memory_slot *dont)
+void kvmppc_core_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot)
 {
 }
 

arch/powerpc/kvm/powerpc.c

@@ -685,10 +685,9 @@ long kvm_arch_dev_ioctl(struct file *filp,
 	return -EINVAL;
 }
 
-void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
-			   struct kvm_memory_slot *dont)
+void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot)
 {
-	kvmppc_core_free_memslot(kvm, free, dont);
+	kvmppc_core_free_memslot(kvm, slot);
 }
 
 int kvm_arch_prepare_memory_region(struct kvm *kvm,

arch/s390/include/asm/kvm_host.h

@@ -921,7 +921,7 @@ static inline void kvm_arch_hardware_disable(void) {}
 static inline void kvm_arch_sync_events(struct kvm *kvm) {}
 static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
 static inline void kvm_arch_free_memslot(struct kvm *kvm,
-		struct kvm_memory_slot *free, struct kvm_memory_slot *dont) {}
+					 struct kvm_memory_slot *slot) {}
 static inline void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen) {}
 static inline void kvm_arch_flush_shadow_all(struct kvm *kvm) {}
 static inline void kvm_arch_flush_shadow_memslot(struct kvm *kvm,

arch/x86/include/asm/kvm_page_track.h

@@ -49,8 +49,7 @@ struct kvm_page_track_notifier_node {
 void kvm_page_track_init(struct kvm *kvm);
 void kvm_page_track_cleanup(struct kvm *kvm);
 
-void kvm_page_track_free_memslot(struct kvm_memory_slot *free,
-				 struct kvm_memory_slot *dont);
+void kvm_page_track_free_memslot(struct kvm_memory_slot *slot);
 int kvm_page_track_create_memslot(struct kvm_memory_slot *slot,
 				  unsigned long npages);
 

arch/x86/kvm/mmu/page_track.c

@@ -19,17 +19,14 @@
 
 #include "mmu.h"
 
-void kvm_page_track_free_memslot(struct kvm_memory_slot *free,
-				 struct kvm_memory_slot *dont)
+void kvm_page_track_free_memslot(struct kvm_memory_slot *slot)
 {
 	int i;
 
-	for (i = 0; i < KVM_PAGE_TRACK_MAX; i++)
-		if (!dont || free->arch.gfn_track[i] !=
-		      dont->arch.gfn_track[i]) {
-			kvfree(free->arch.gfn_track[i]);
-			free->arch.gfn_track[i] = NULL;
-		}
+	for (i = 0; i < KVM_PAGE_TRACK_MAX; i++) {
+		kvfree(slot->arch.gfn_track[i]);
+		slot->arch.gfn_track[i] = NULL;
+	}
 }
 
 int kvm_page_track_create_memslot(struct kvm_memory_slot *slot,
@@ -48,7 +45,7 @@ int kvm_page_track_create_memslot(struct kvm_memory_slot *slot,
 	return 0;
 
 track_free:
-	kvm_page_track_free_memslot(slot, NULL);
+	kvm_page_track_free_memslot(slot);
 	return -ENOMEM;
 }
 

arch/x86/kvm/x86.c

@@ -9850,27 +9850,22 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
 	kvm_hv_destroy_vm(kvm);
 }
 
-void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
-			   struct kvm_memory_slot *dont)
+void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot)
 {
 	int i;
 
 	for (i = 0; i < KVM_NR_PAGE_SIZES; ++i) {
-		if (!dont || free->arch.rmap[i] != dont->arch.rmap[i]) {
-			kvfree(free->arch.rmap[i]);
-			free->arch.rmap[i] = NULL;
-		}
+		kvfree(slot->arch.rmap[i]);
+		slot->arch.rmap[i] = NULL;
+
 		if (i == 0)
 			continue;
 
-		if (!dont || free->arch.lpage_info[i - 1] !=
-			     dont->arch.lpage_info[i - 1]) {
-			kvfree(free->arch.lpage_info[i - 1]);
-			free->arch.lpage_info[i - 1] = NULL;
-		}
+		kvfree(slot->arch.lpage_info[i - 1]);
+		slot->arch.lpage_info[i - 1] = NULL;
 	}
 
-	kvm_page_track_free_memslot(free, dont);
+	kvm_page_track_free_memslot(slot);
 }
 
 static int kvm_alloc_memslot_metadata(struct kvm_memory_slot *slot,
@@ -10069,7 +10064,7 @@ void kvm_arch_commit_memory_region(struct kvm *kvm,
 
 	/* Free the arrays associated with the old memslot. */
 	if (change == KVM_MR_MOVE)
-		kvm_arch_free_memslot(kvm, old, NULL);
+		kvm_arch_free_memslot(kvm, old);
 }
 
 void kvm_arch_flush_shadow_all(struct kvm *kvm)

include/linux/kvm_host.h

@@ -669,8 +669,7 @@ int kvm_set_memory_region(struct kvm *kvm,
 			  const struct kvm_userspace_memory_region *mem);
 int __kvm_set_memory_region(struct kvm *kvm,
 			    const struct kvm_userspace_memory_region *mem);
-void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
-			   struct kvm_memory_slot *dont);
+void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot);
 void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen);
 int kvm_arch_prepare_memory_region(struct kvm *kvm,
 				struct kvm_memory_slot *memslot,

virt/kvm/arm/mmu.c

@@ -2349,8 +2349,7 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
 	return ret;
 }
 
-void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
-			   struct kvm_memory_slot *dont)
+void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot)
 {
 }
 

virt/kvm/kvm_main.c

@@ -580,18 +580,14 @@ static void kvm_destroy_dirty_bitmap(struct kvm_memory_slot *memslot)
 	memslot->dirty_bitmap = NULL;
 }
 
-/*
- * Free any memory in @free but not in @dont.
- */
-static void kvm_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
-			      struct kvm_memory_slot *dont)
+static void kvm_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot)
 {
-	if (!dont || free->dirty_bitmap != dont->dirty_bitmap)
-		kvm_destroy_dirty_bitmap(free);
+	kvm_destroy_dirty_bitmap(slot);
 
-	kvm_arch_free_memslot(kvm, free, dont);
+	kvm_arch_free_memslot(kvm, slot);
 
-	free->npages = 0;
+	slot->flags = 0;
+	slot->npages = 0;
 }
 
 static void kvm_free_memslots(struct kvm *kvm, struct kvm_memslots *slots)
@@ -602,7 +598,7 @@ static void kvm_free_memslots(struct kvm *kvm, struct kvm_memslots *slots)
 		return;
 
 	kvm_for_each_memslot(memslot, slots)
-		kvm_free_memslot(kvm, memslot, NULL);
+		kvm_free_memslot(kvm, memslot);
 
 	kvfree(slots);
 }
@@ -1060,7 +1056,7 @@ static int kvm_delete_memslot(struct kvm *kvm,
 	if (r)
 		return r;
 
-	kvm_free_memslot(kvm, old, NULL);
+	kvm_free_memslot(kvm, old);
 	return 0;
 }