KVM: convert slots_lock to a mutex

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

arch/ia64/kvm/kvm-ia64.c

@@ -1834,7 +1834,7 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
 	struct kvm_memory_slot *memslot;
 	int is_dirty = 0;
 
-	down_write(&kvm->slots_lock);
+	mutex_lock(&kvm->slots_lock);
 	spin_lock(&kvm->arch.dirty_log_lock);
 
 	r = kvm_ia64_sync_dirty_log(kvm, log);
@@ -1854,7 +1854,7 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
 	}
 	r = 0;
 out:
-	up_write(&kvm->slots_lock);
+	mutex_unlock(&kvm->slots_lock);
 	spin_unlock(&kvm->arch.dirty_log_lock);
 	return r;
 }

arch/powerpc/kvm/book3s.c

@@ -857,7 +857,7 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
 	int is_dirty = 0;
 	int r, n;
 
-	down_write(&kvm->slots_lock);
+	mutex_lock(&kvm->slots_lock);
 
 	r = kvm_get_dirty_log(kvm, log, &is_dirty);
 	if (r)
@@ -879,7 +879,7 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
 
 	r = 0;
 out:
-	up_write(&kvm->slots_lock);
+	mutex_unlock(&kvm->slots_lock);
 	return r;
 }
 

arch/x86/kvm/i8254.c

@@ -605,7 +605,7 @@ static const struct kvm_io_device_ops speaker_dev_ops = {
 	.write    = speaker_ioport_write,
 };
 
-/* Caller must have writers lock on slots_lock */
+/* Caller must hold slots_lock */
 struct kvm_pit *kvm_create_pit(struct kvm *kvm, u32 flags)
 {
 	struct kvm_pit *pit;

arch/x86/kvm/i8259.c

@@ -533,9 +533,9 @@ struct kvm_pic *kvm_create_pic(struct kvm *kvm)
 	 * Initialize PIO device
 	 */
 	kvm_iodevice_init(&s->dev, &picdev_ops);
-	down_write(&kvm->slots_lock);
+	mutex_lock(&kvm->slots_lock);
 	ret = kvm_io_bus_register_dev(kvm, KVM_PIO_BUS, &s->dev);
-	up_write(&kvm->slots_lock);
+	mutex_unlock(&kvm->slots_lock);
 	if (ret < 0) {
 		kfree(s);
 		return NULL;

arch/x86/kvm/vmx.c

@@ -2223,7 +2223,7 @@ static int alloc_apic_access_page(struct kvm *kvm)
 	struct kvm_userspace_memory_region kvm_userspace_mem;
 	int r = 0;
 
-	down_write(&kvm->slots_lock);
+	mutex_lock(&kvm->slots_lock);
 	if (kvm->arch.apic_access_page)
 		goto out;
 	kvm_userspace_mem.slot = APIC_ACCESS_PAGE_PRIVATE_MEMSLOT;
@@ -2236,7 +2236,7 @@ static int alloc_apic_access_page(struct kvm *kvm)
 
 	kvm->arch.apic_access_page = gfn_to_page(kvm, 0xfee00);
 out:
-	up_write(&kvm->slots_lock);
+	mutex_unlock(&kvm->slots_lock);
 	return r;
 }
 
@@ -2245,7 +2245,7 @@ static int alloc_identity_pagetable(struct kvm *kvm)
 	struct kvm_userspace_memory_region kvm_userspace_mem;
 	int r = 0;
 
-	down_write(&kvm->slots_lock);
+	mutex_lock(&kvm->slots_lock);
 	if (kvm->arch.ept_identity_pagetable)
 		goto out;
 	kvm_userspace_mem.slot = IDENTITY_PAGETABLE_PRIVATE_MEMSLOT;
@@ -2260,7 +2260,7 @@ static int alloc_identity_pagetable(struct kvm *kvm)
 	kvm->arch.ept_identity_pagetable = gfn_to_page(kvm,
 			kvm->arch.ept_identity_map_addr >> PAGE_SHIFT);
 out:
-	up_write(&kvm->slots_lock);
+	mutex_unlock(&kvm->slots_lock);
 	return r;
 }
 

arch/x86/kvm/x86.c

@@ -2208,14 +2208,14 @@ static int kvm_vm_ioctl_set_nr_mmu_pages(struct kvm *kvm,
 	if (kvm_nr_mmu_pages < KVM_MIN_ALLOC_MMU_PAGES)
 		return -EINVAL;
 
-	down_write(&kvm->slots_lock);
+	mutex_lock(&kvm->slots_lock);
 	spin_lock(&kvm->mmu_lock);
 
 	kvm_mmu_change_mmu_pages(kvm, kvm_nr_mmu_pages);
 	kvm->arch.n_requested_mmu_pages = kvm_nr_mmu_pages;
 
 	spin_unlock(&kvm->mmu_lock);
-	up_write(&kvm->slots_lock);
+	mutex_unlock(&kvm->slots_lock);
 	return 0;
 }
 
@@ -2292,7 +2292,7 @@ static int kvm_vm_ioctl_set_memory_alias(struct kvm *kvm,
 	if (!aliases)
 		goto out;
 
-	down_write(&kvm->slots_lock);
+	mutex_lock(&kvm->slots_lock);
 
 	/* invalidate any gfn reference in case of deletion/shrinking */
 	memcpy(aliases, kvm->arch.aliases, sizeof(struct kvm_mem_aliases));
@@ -2328,7 +2328,7 @@ static int kvm_vm_ioctl_set_memory_alias(struct kvm *kvm,
 	r = 0;
 
 out_unlock:
-	up_write(&kvm->slots_lock);
+	mutex_unlock(&kvm->slots_lock);
 out:
 	return r;
 }
@@ -2462,7 +2462,7 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
 	unsigned long is_dirty = 0;
 	unsigned long *dirty_bitmap = NULL;
 
-	down_write(&kvm->slots_lock);
+	mutex_lock(&kvm->slots_lock);
 
 	r = -EINVAL;
 	if (log->slot >= KVM_MEMORY_SLOTS)
@@ -2512,7 +2512,7 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
 out_free:
 	vfree(dirty_bitmap);
 out:
-	up_write(&kvm->slots_lock);
+	mutex_unlock(&kvm->slots_lock);
 	return r;
 }
 
@@ -2625,7 +2625,7 @@ long kvm_arch_vm_ioctl(struct file *filp,
 				   sizeof(struct kvm_pit_config)))
 			goto out;
 	create_pit:
-		down_write(&kvm->slots_lock);
+		mutex_lock(&kvm->slots_lock);
 		r = -EEXIST;
 		if (kvm->arch.vpit)
 			goto create_pit_unlock;
@@ -2634,7 +2634,7 @@ long kvm_arch_vm_ioctl(struct file *filp,
 		if (kvm->arch.vpit)
 			r = 0;
 	create_pit_unlock:
-		up_write(&kvm->slots_lock);
+		mutex_unlock(&kvm->slots_lock);
 		break;
 	case KVM_IRQ_LINE_STATUS:
 	case KVM_IRQ_LINE: {

include/linux/kvm_host.h

@@ -161,7 +161,7 @@ struct kvm_memslots {
 struct kvm {
 	spinlock_t mmu_lock;
 	spinlock_t requests_lock;
-	struct rw_semaphore slots_lock;
+	struct mutex slots_lock;
 	struct mm_struct *mm; /* userspace tied to this vm */
 	struct kvm_memslots *memslots;
 	struct srcu_struct srcu;

virt/kvm/coalesced_mmio.c

@@ -110,9 +110,9 @@ int kvm_coalesced_mmio_init(struct kvm *kvm)
 	dev->kvm = kvm;
 	kvm->coalesced_mmio_dev = dev;
 
-	down_write(&kvm->slots_lock);
+	mutex_lock(&kvm->slots_lock);
 	ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, &dev->dev);
-	up_write(&kvm->slots_lock);
+	mutex_unlock(&kvm->slots_lock);
 	if (ret < 0)
 		goto out_free_dev;
 
@@ -140,16 +140,16 @@ int kvm_vm_ioctl_register_coalesced_mmio(struct kvm *kvm,
 	if (dev == NULL)
 		return -EINVAL;
 
-	down_write(&kvm->slots_lock);
+	mutex_lock(&kvm->slots_lock);
 	if (dev->nb_zones >= KVM_COALESCED_MMIO_ZONE_MAX) {
-		up_write(&kvm->slots_lock);
+		mutex_unlock(&kvm->slots_lock);
 		return -ENOBUFS;
 	}
 
 	dev->zone[dev->nb_zones] = *zone;
 	dev->nb_zones++;
 
-	up_write(&kvm->slots_lock);
+	mutex_unlock(&kvm->slots_lock);
 	return 0;
 }
 
@@ -163,7 +163,7 @@ int kvm_vm_ioctl_unregister_coalesced_mmio(struct kvm *kvm,
 	if (dev == NULL)
 		return -EINVAL;
 
-	down_write(&kvm->slots_lock);
+	mutex_lock(&kvm->slots_lock);
 
 	i = dev->nb_zones;
 	while(i) {
@@ -181,7 +181,7 @@ int kvm_vm_ioctl_unregister_coalesced_mmio(struct kvm *kvm,
 		i--;
 	}
 
-	up_write(&kvm->slots_lock);
+	mutex_unlock(&kvm->slots_lock);
 
 	return 0;
 }

virt/kvm/eventfd.c

@@ -508,7 +508,7 @@ kvm_assign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
 	else
 		p->wildcard = true;
 
-	down_write(&kvm->slots_lock);
+	mutex_lock(&kvm->slots_lock);
 
 	/* Verify that there isnt a match already */
 	if (ioeventfd_check_collision(kvm, p)) {
@@ -524,12 +524,12 @@ kvm_assign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
 
 	list_add_tail(&p->list, &kvm->ioeventfds);
 
-	up_write(&kvm->slots_lock);
+	mutex_unlock(&kvm->slots_lock);
 
 	return 0;
 
 unlock_fail:
-	up_write(&kvm->slots_lock);
+	mutex_unlock(&kvm->slots_lock);
 
 fail:
 	kfree(p);
@@ -551,7 +551,7 @@ kvm_deassign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
 	if (IS_ERR(eventfd))
 		return PTR_ERR(eventfd);
 
-	down_write(&kvm->slots_lock);
+	mutex_lock(&kvm->slots_lock);
 
 	list_for_each_entry_safe(p, tmp, &kvm->ioeventfds, list) {
 		bool wildcard = !(args->flags & KVM_IOEVENTFD_FLAG_DATAMATCH);
@@ -571,7 +571,7 @@ kvm_deassign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
 		break;
 	}
 
-	up_write(&kvm->slots_lock);
+	mutex_unlock(&kvm->slots_lock);
 
 	eventfd_ctx_put(eventfd);
 

virt/kvm/ioapic.c

@@ -372,9 +372,9 @@ int kvm_ioapic_init(struct kvm *kvm)
 	kvm_ioapic_reset(ioapic);
 	kvm_iodevice_init(&ioapic->dev, &ioapic_mmio_ops);
 	ioapic->kvm = kvm;
-	down_write(&kvm->slots_lock);
+	mutex_lock(&kvm->slots_lock);
 	ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, &ioapic->dev);
-	up_write(&kvm->slots_lock);
+	mutex_unlock(&kvm->slots_lock);
 	if (ret < 0)
 		kfree(ioapic);
 

virt/kvm/kvm_main.c

@@ -429,7 +429,7 @@ static struct kvm *kvm_create_vm(void)
 	kvm_eventfd_init(kvm);
 	mutex_init(&kvm->lock);
 	mutex_init(&kvm->irq_lock);
-	init_rwsem(&kvm->slots_lock);
+	mutex_init(&kvm->slots_lock);
 	atomic_set(&kvm->users_count, 1);
 	spin_lock(&kvm_lock);
 	list_add(&kvm->vm_list, &vm_list);
@@ -763,9 +763,9 @@ int kvm_set_memory_region(struct kvm *kvm,
 {
 	int r;
 
-	down_write(&kvm->slots_lock);
+	mutex_lock(&kvm->slots_lock);
 	r = __kvm_set_memory_region(kvm, mem, user_alloc);
-	up_write(&kvm->slots_lock);
+	mutex_unlock(&kvm->slots_lock);
 	return r;
 }
 EXPORT_SYMBOL_GPL(kvm_set_memory_region);
@@ -1997,7 +1997,7 @@ int kvm_io_bus_read(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
 	return -EOPNOTSUPP;
 }
 
-/* Caller must have write lock on slots_lock. */
+/* Caller must hold slots_lock. */
 int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx,
 			    struct kvm_io_device *dev)
 {
@@ -2019,7 +2019,7 @@ int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx,
 	return 0;
 }
 
-/* Caller must have write lock on slots_lock. */
+/* Caller must hold slots_lock. */
 int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
 			      struct kvm_io_device *dev)
 {