1 files changed, 83 insertions, 80 deletions

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 32896c845ffe..26383e63d9dd 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -484,6 +484,10 @@ static void kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
 	vcpu->ready = false;
 	preempt_notifier_init(&vcpu->preempt_notifier, &kvm_preempt_ops);
 	vcpu->last_used_slot = NULL;
+
+	/* Fill the stats id string for the vcpu */
+	snprintf(vcpu->stats_id, sizeof(vcpu->stats_id), "kvm-%d/vcpu-%d",
+		 task_pid_nr(current), id);
 }
 
 static void kvm_vcpu_destroy(struct kvm_vcpu *vcpu)
@@ -698,30 +702,31 @@ static void kvm_mmu_notifier_change_pte(struct mmu_notifier *mn,
 
 	/*
 	 * .change_pte() must be surrounded by .invalidate_range_{start,end}().
-	 * If mmu_notifier_count is zero, then no in-progress invalidations,
-	 * including this one, found a relevant memslot at start(); rechecking
-	 * memslots here is unnecessary.  Note, a false positive (count elevated
-	 * by a different invalidation) is sub-optimal but functionally ok.
+	 * If mmu_invalidate_in_progress is zero, then no in-progress
+	 * invalidations, including this one, found a relevant memslot at
+	 * start(); rechecking memslots here is unnecessary.  Note, a false
+	 * positive (count elevated by a different invalidation) is sub-optimal
+	 * but functionally ok.
 	 */
 	WARN_ON_ONCE(!READ_ONCE(kvm->mn_active_invalidate_count));
-	if (!READ_ONCE(kvm->mmu_notifier_count))
+	if (!READ_ONCE(kvm->mmu_invalidate_in_progress))
 		return;
 
 	kvm_handle_hva_range(mn, address, address + 1, pte, kvm_set_spte_gfn);
 }
 
-void kvm_inc_notifier_count(struct kvm *kvm, unsigned long start,
-				   unsigned long end)
+void kvm_mmu_invalidate_begin(struct kvm *kvm, unsigned long start,
+			      unsigned long end)
 {
 	/*
 	 * The count increase must become visible at unlock time as no
 	 * spte can be established without taking the mmu_lock and
 	 * count is also read inside the mmu_lock critical section.
 	 */
-	kvm->mmu_notifier_count++;
-	if (likely(kvm->mmu_notifier_count == 1)) {
-		kvm->mmu_notifier_range_start = start;
-		kvm->mmu_notifier_range_end = end;
+	kvm->mmu_invalidate_in_progress++;
+	if (likely(kvm->mmu_invalidate_in_progress == 1)) {
+		kvm->mmu_invalidate_range_start = start;
+		kvm->mmu_invalidate_range_end = end;
 	} else {
 		/*
 		 * Fully tracking multiple concurrent ranges has diminishing
@@ -732,10 +737,10 @@ void kvm_inc_notifier_count(struct kvm *kvm, unsigned long start,
 		 * accumulate and persist until all outstanding invalidates
 		 * complete.
 		 */
-		kvm->mmu_notifier_range_start =
-			min(kvm->mmu_notifier_range_start, start);
-		kvm->mmu_notifier_range_end =
-			max(kvm->mmu_notifier_range_end, end);
+		kvm->mmu_invalidate_range_start =
+			min(kvm->mmu_invalidate_range_start, start);
+		kvm->mmu_invalidate_range_end =
+			max(kvm->mmu_invalidate_range_end, end);
 	}
 }
 
@@ -748,7 +753,7 @@ static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
 		.end		= range->end,
 		.pte		= __pte(0),
 		.handler	= kvm_unmap_gfn_range,
-		.on_lock	= kvm_inc_notifier_count,
+		.on_lock	= kvm_mmu_invalidate_begin,
 		.on_unlock	= kvm_arch_guest_memory_reclaimed,
 		.flush_on_ret	= true,
 		.may_block	= mmu_notifier_range_blockable(range),
@@ -759,7 +764,7 @@ static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
 	/*
 	 * Prevent memslot modification between range_start() and range_end()
 	 * so that conditionally locking provides the same result in both
-	 * functions.  Without that guarantee, the mmu_notifier_count
+	 * functions.  Without that guarantee, the mmu_invalidate_in_progress
 	 * adjustments will be imbalanced.
 	 *
 	 * Pairs with the decrement in range_end().
@@ -775,7 +780,8 @@ static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
 	 * any given time, and the caches themselves can check for hva overlap,
 	 * i.e. don't need to rely on memslot overlap checks for performance.
 	 * Because this runs without holding mmu_lock, the pfn caches must use
-	 * mn_active_invalidate_count (see above) instead of mmu_notifier_count.
+	 * mn_active_invalidate_count (see above) instead of
+	 * mmu_invalidate_in_progress.
 	 */
 	gfn_to_pfn_cache_invalidate_start(kvm, range->start, range->end,
 					  hva_range.may_block);
@@ -785,22 +791,22 @@ static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
 	return 0;
 }
 
-void kvm_dec_notifier_count(struct kvm *kvm, unsigned long start,
-				   unsigned long end)
+void kvm_mmu_invalidate_end(struct kvm *kvm, unsigned long start,
+			    unsigned long end)
 {
 	/*
 	 * This sequence increase will notify the kvm page fault that
 	 * the page that is going to be mapped in the spte could have
 	 * been freed.
 	 */
-	kvm->mmu_notifier_seq++;
+	kvm->mmu_invalidate_seq++;
 	smp_wmb();
 	/*
 	 * The above sequence increase must be visible before the
 	 * below count decrease, which is ensured by the smp_wmb above
-	 * in conjunction with the smp_rmb in mmu_notifier_retry().
+	 * in conjunction with the smp_rmb in mmu_invalidate_retry().
 	 */
-	kvm->mmu_notifier_count--;
+	kvm->mmu_invalidate_in_progress--;
 }
 
 static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn,
@@ -812,7 +818,7 @@ static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn,
 		.end		= range->end,
 		.pte		= __pte(0),
 		.handler	= (void *)kvm_null_fn,
-		.on_lock	= kvm_dec_notifier_count,
+		.on_lock	= kvm_mmu_invalidate_end,
 		.on_unlock	= (void *)kvm_null_fn,
 		.flush_on_ret	= false,
 		.may_block	= mmu_notifier_range_blockable(range),
@@ -833,7 +839,7 @@ static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn,
 	if (wake)
 		rcuwait_wake_up(&kvm->mn_memslots_update_rcuwait);
 
-	BUG_ON(kvm->mmu_notifier_count < 0);
+	BUG_ON(kvm->mmu_invalidate_in_progress < 0);
 }
 
 static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn,
@@ -1017,21 +1023,21 @@ static void kvm_destroy_vm_debugfs(struct kvm *kvm)
 	}
 }
 
-static int kvm_create_vm_debugfs(struct kvm *kvm, int fd)
+static int kvm_create_vm_debugfs(struct kvm *kvm, const char *fdname)
 {
 	static DEFINE_MUTEX(kvm_debugfs_lock);
 	struct dentry *dent;
 	char dir_name[ITOA_MAX_LEN * 2];
 	struct kvm_stat_data *stat_data;
 	const struct _kvm_stats_desc *pdesc;
-	int i, ret;
+	int i, ret = -ENOMEM;
 	int kvm_debugfs_num_entries = kvm_vm_stats_header.num_desc +
 				      kvm_vcpu_stats_header.num_desc;
 
 	if (!debugfs_initialized())
 		return 0;
 
-	snprintf(dir_name, sizeof(dir_name), "%d-%d", task_pid_nr(current), fd);
+	snprintf(dir_name, sizeof(dir_name), "%d-%s", task_pid_nr(current), fdname);
 	mutex_lock(&kvm_debugfs_lock);
 	dent = debugfs_lookup(dir_name, kvm_debugfs_dir);
 	if (dent) {
@@ -1050,13 +1056,13 @@ static int kvm_create_vm_debugfs(struct kvm *kvm, int fd)
 					 sizeof(*kvm->debugfs_stat_data),
 					 GFP_KERNEL_ACCOUNT);
 	if (!kvm->debugfs_stat_data)
-		return -ENOMEM;
+		goto out_err;
 
 	for (i = 0; i < kvm_vm_stats_header.num_desc; ++i) {
 		pdesc = &kvm_vm_stats_desc[i];
 		stat_data = kzalloc(sizeof(*stat_data), GFP_KERNEL_ACCOUNT);
 		if (!stat_data)
-			return -ENOMEM;
+			goto out_err;
 
 		stat_data->kvm = kvm;
 		stat_data->desc = pdesc;
@@ -1071,7 +1077,7 @@ static int kvm_create_vm_debugfs(struct kvm *kvm, int fd)
 		pdesc = &kvm_vcpu_stats_desc[i];
 		stat_data = kzalloc(sizeof(*stat_data), GFP_KERNEL_ACCOUNT);
 		if (!stat_data)
-			return -ENOMEM;
+			goto out_err;
 
 		stat_data->kvm = kvm;
 		stat_data->desc = pdesc;
@@ -1083,12 +1089,13 @@ static int kvm_create_vm_debugfs(struct kvm *kvm, int fd)
 	}
 
 	ret = kvm_arch_create_vm_debugfs(kvm);
-	if (ret) {
-		kvm_destroy_vm_debugfs(kvm);
-		return i;
-	}
+	if (ret)
+		goto out_err;
 
 	return 0;
+out_err:
+	kvm_destroy_vm_debugfs(kvm);
+	return ret;
 }
 
 /*
@@ -1119,7 +1126,7 @@ int __weak kvm_arch_create_vm_debugfs(struct kvm *kvm)
 	return 0;
 }
 
-static struct kvm *kvm_create_vm(unsigned long type)
+static struct kvm *kvm_create_vm(unsigned long type, const char *fdname)
 {
 	struct kvm *kvm = kvm_arch_alloc_vm();
 	struct kvm_memslots *slots;
@@ -1129,6 +1136,9 @@ static struct kvm *kvm_create_vm(unsigned long type)
 	if (!kvm)
 		return ERR_PTR(-ENOMEM);
 
+	/* KVM is pinned via open("/dev/kvm"), the fd passed to this ioctl(). */
+	__module_get(kvm_chardev_ops.owner);
+
 	KVM_MMU_LOCK_INIT(kvm);
 	mmgrab(current->mm);
 	kvm->mm = current->mm;
@@ -1155,6 +1165,9 @@ static struct kvm *kvm_create_vm(unsigned long type)
 	 */
 	kvm->debugfs_dentry = ERR_PTR(-ENOENT);
 
+	snprintf(kvm->stats_id, sizeof(kvm->stats_id), "kvm-%d",
+		 task_pid_nr(current));
+
 	if (init_srcu_struct(&kvm->srcu))
 		goto out_err_no_srcu;
 	if (init_srcu_struct(&kvm->irq_srcu))
@@ -1203,6 +1216,14 @@ static struct kvm *kvm_create_vm(unsigned long type)
 	if (r)
 		goto out_err_no_mmu_notifier;
 
+	r = kvm_coalesced_mmio_init(kvm);
+	if (r < 0)
+		goto out_no_coalesced_mmio;
+
+	r = kvm_create_vm_debugfs(kvm, fdname);
+	if (r)
+		goto out_err_no_debugfs;
+
 	r = kvm_arch_post_init_vm(kvm);
 	if (r)
 		goto out_err;
@@ -1214,19 +1235,13 @@ static struct kvm *kvm_create_vm(unsigned long type)
 	preempt_notifier_inc();
 	kvm_init_pm_notifier(kvm);
 
-	/*
-	 * When the fd passed to this ioctl() is opened it pins the module,
-	 * but try_module_get() also prevents getting a reference if the module
-	 * is in MODULE_STATE_GOING (e.g. if someone ran "rmmod --wait").
-	 */
-	if (!try_module_get(kvm_chardev_ops.owner)) {
-		r = -ENODEV;
-		goto out_err;
-	}
-
 	return kvm;
 
 out_err:
+	kvm_destroy_vm_debugfs(kvm);
+out_err_no_debugfs:
+	kvm_coalesced_mmio_free(kvm);
+out_no_coalesced_mmio:
 #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
 	if (kvm->mmu_notifier.ops)
 		mmu_notifier_unregister(&kvm->mmu_notifier, current->mm);
@@ -1245,6 +1260,7 @@ out_err_no_irq_srcu:
 out_err_no_srcu:
 	kvm_arch_free_vm(kvm);
 	mmdrop(current->mm);
+	module_put(kvm_chardev_ops.owner);
 	return ERR_PTR(r);
 }
 
@@ -2502,7 +2518,7 @@ static int hva_to_pfn_slow(unsigned long addr, bool *async, bool write_fault,
 {
 	unsigned int flags = FOLL_HWPOISON;
 	struct page *page;
-	int npages = 0;
+	int npages;
 
 	might_sleep();
 
@@ -3393,10 +3409,8 @@ static int kvm_vcpu_check_block(struct kvm_vcpu *vcpu)
 	int ret = -EINTR;
 	int idx = srcu_read_lock(&vcpu->kvm->srcu);
 
-	if (kvm_arch_vcpu_runnable(vcpu)) {
-		kvm_make_request(KVM_REQ_UNHALT, vcpu);
+	if (kvm_arch_vcpu_runnable(vcpu))
 		goto out;
-	}
 	if (kvm_cpu_has_pending_timer(vcpu))
 		goto out;
 	if (signal_pending(current))
@@ -3916,10 +3930,6 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
 	if (r)
 		goto unlock_vcpu_destroy;
 
-	/* Fill the stats id string for the vcpu */
-	snprintf(vcpu->stats_id, sizeof(vcpu->stats_id), "kvm-%d/vcpu-%d",
-		 task_pid_nr(current), id);
-
 	/* Now it's all set up, let userspace reach it */
 	kvm_get_kvm(kvm);
 	r = create_vcpu_fd(vcpu);
@@ -4368,7 +4378,7 @@ void kvm_unregister_device_ops(u32 type)
 static int kvm_ioctl_create_device(struct kvm *kvm,
 				   struct kvm_create_device *cd)
 {
-	const struct kvm_device_ops *ops = NULL;
+	const struct kvm_device_ops *ops;
 	struct kvm_device *dev;
 	bool test = cd->flags & KVM_CREATE_DEVICE_TEST;
 	int type;
@@ -4886,28 +4896,25 @@ EXPORT_SYMBOL_GPL(file_is_kvm);
 
 static int kvm_dev_ioctl_create_vm(unsigned long type)
 {
-	int r;
+	char fdname[ITOA_MAX_LEN + 1];
+	int r, fd;
 	struct kvm *kvm;
 	struct file *file;
 
-	kvm = kvm_create_vm(type);
-	if (IS_ERR(kvm))
-		return PTR_ERR(kvm);
-#ifdef CONFIG_KVM_MMIO
-	r = kvm_coalesced_mmio_init(kvm);
-	if (r < 0)
-		goto put_kvm;
-#endif
-	r = get_unused_fd_flags(O_CLOEXEC);
-	if (r < 0)
-		goto put_kvm;
+	fd = get_unused_fd_flags(O_CLOEXEC);
+	if (fd < 0)
+		return fd;
 
-	snprintf(kvm->stats_id, sizeof(kvm->stats_id),
-			"kvm-%d", task_pid_nr(current));
+	snprintf(fdname, sizeof(fdname), "%d", fd);
+
+	kvm = kvm_create_vm(type, fdname);
+	if (IS_ERR(kvm)) {
+		r = PTR_ERR(kvm);
+		goto put_fd;
+	}
 
 	file = anon_inode_getfile("kvm-vm", &kvm_vm_fops, kvm, O_RDWR);
 	if (IS_ERR(file)) {
-		put_unused_fd(r);
 		r = PTR_ERR(file);
 		goto put_kvm;
 	}
@@ -4918,18 +4925,15 @@ static int kvm_dev_ioctl_create_vm(unsigned long type)
 	 * cases it will be called by the final fput(file) and will take
 	 * care of doing kvm_put_kvm(kvm).
 	 */
-	if (kvm_create_vm_debugfs(kvm, r) < 0) {
-		put_unused_fd(r);
-		fput(file);
-		return -ENOMEM;
-	}
 	kvm_uevent_notify_change(KVM_EVENT_CREATE_VM, kvm);
 
-	fd_install(r, file);
-	return r;
+	fd_install(fd, file);
+	return fd;
 
 put_kvm:
 	kvm_put_kvm(kvm);
+put_fd:
+	put_unused_fd(fd);
 	return r;
 }
 
@@ -5875,7 +5879,7 @@ int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
 
 	r = kvm_async_pf_init();
 	if (r)
-		goto out_free_5;
+		goto out_free_4;
 
 	kvm_chardev_ops.owner = module;
 
@@ -5899,10 +5903,9 @@ int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
 
 out_unreg:
 	kvm_async_pf_deinit();
-out_free_5:
+out_free_4:
 	for_each_possible_cpu(cpu)
 		free_cpumask_var(per_cpu(cpu_kick_mask, cpu));
-out_free_4:
 	kmem_cache_destroy(kvm_vcpu_cache);
 out_free_3:
 	unregister_reboot_notifier(&kvm_reboot_notifier);