diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index b1fa8f11c95b..1c9c973a7dd9 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -412,6 +412,8 @@ struct kvm { #endif long tlbs_dirty; struct list_head devices; + struct dentry *debugfs_dentry; + struct kvm_stat_data **debugfs_stat_data; }; #define kvm_err(fmt, ...) \ @@ -991,6 +993,11 @@ enum kvm_stat_kind { KVM_STAT_VCPU, }; +struct kvm_stat_data { + int offset; + struct kvm *kvm; +}; + struct kvm_stats_debugfs_item { const char *name; int offset; diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index dd4ac9d9e8f5..37af23052470 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -63,6 +63,9 @@ #define CREATE_TRACE_POINTS #include +/* Worst case buffer size needed for holding an integer. */ +#define ITOA_MAX_LEN 12 + MODULE_AUTHOR("Qumranet"); MODULE_LICENSE("GPL"); @@ -100,6 +103,9 @@ static __read_mostly struct preempt_ops kvm_preempt_ops; struct dentry *kvm_debugfs_dir; EXPORT_SYMBOL_GPL(kvm_debugfs_dir); +static int kvm_debugfs_num_entries; +static const struct file_operations *stat_fops_per_vm[]; + static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl, unsigned long arg); #ifdef CONFIG_KVM_COMPAT @@ -542,6 +548,58 @@ static void kvm_free_memslots(struct kvm *kvm, struct kvm_memslots *slots) kvfree(slots); } +static void kvm_destroy_vm_debugfs(struct kvm *kvm) +{ + int i; + + if (!kvm->debugfs_dentry) + return; + + debugfs_remove_recursive(kvm->debugfs_dentry); + + for (i = 0; i < kvm_debugfs_num_entries; i++) + kfree(kvm->debugfs_stat_data[i]); + kfree(kvm->debugfs_stat_data); +} + +static int kvm_create_vm_debugfs(struct kvm *kvm, int fd) +{ + char dir_name[ITOA_MAX_LEN * 2]; + struct kvm_stat_data *stat_data; + struct kvm_stats_debugfs_item *p; + + if (!debugfs_initialized()) + return 0; + + snprintf(dir_name, sizeof(dir_name), "%d-%d", task_pid_nr(current), fd); + kvm->debugfs_dentry = debugfs_create_dir(dir_name, + kvm_debugfs_dir); + if (!kvm->debugfs_dentry) + return -ENOMEM; + + kvm->debugfs_stat_data = kcalloc(kvm_debugfs_num_entries, + sizeof(*kvm->debugfs_stat_data), + GFP_KERNEL); + if (!kvm->debugfs_stat_data) + return -ENOMEM; + + for (p = debugfs_entries; p->name; p++) { + stat_data = kzalloc(sizeof(*stat_data), GFP_KERNEL); + if (!stat_data) + return -ENOMEM; + + stat_data->kvm = kvm; + stat_data->offset = p->offset; + kvm->debugfs_stat_data[p - debugfs_entries] = stat_data; + if (!debugfs_create_file(p->name, 0444, + kvm->debugfs_dentry, + stat_data, + stat_fops_per_vm[p->kind])) + return -ENOMEM; + } + return 0; +} + static struct kvm *kvm_create_vm(unsigned long type) { int r, i; @@ -647,6 +705,7 @@ static void kvm_destroy_vm(struct kvm *kvm) int i; struct mm_struct *mm = kvm->mm; + kvm_destroy_vm_debugfs(kvm); kvm_arch_sync_events(kvm); spin_lock(&kvm_lock); list_del(&kvm->vm_list); @@ -2999,8 +3058,15 @@ static int kvm_dev_ioctl_create_vm(unsigned long type) } #endif r = anon_inode_getfd("kvm-vm", &kvm_vm_fops, kvm, O_RDWR | O_CLOEXEC); - if (r < 0) + if (r < 0) { kvm_put_kvm(kvm); + return r; + } + + if (kvm_create_vm_debugfs(kvm, r) < 0) { + kvm_put_kvm(kvm); + return -ENOMEM; + } return r; } @@ -3425,15 +3491,114 @@ static struct notifier_block kvm_cpu_notifier = { .notifier_call = kvm_cpu_hotplug, }; +static int kvm_debugfs_open(struct inode *inode, struct file *file, + int (*get)(void *, u64 *), int (*set)(void *, u64), + const char *fmt) +{ + struct kvm_stat_data *stat_data = (struct kvm_stat_data *) + inode->i_private; + + /* The debugfs files are a reference to the kvm struct which + * is still valid when kvm_destroy_vm is called. + * To avoid the race between open and the removal of the debugfs + * directory we test against the users count. + */ + if (!atomic_add_unless(&stat_data->kvm->users_count, 1, 0)) + return -ENOENT; + + if (simple_attr_open(inode, file, get, set, fmt)) { + kvm_put_kvm(stat_data->kvm); + return -ENOMEM; + } + + return 0; +} + +static int kvm_debugfs_release(struct inode *inode, struct file *file) +{ + struct kvm_stat_data *stat_data = (struct kvm_stat_data *) + inode->i_private; + + simple_attr_release(inode, file); + kvm_put_kvm(stat_data->kvm); + + return 0; +} + +static int vm_stat_get_per_vm(void *data, u64 *val) +{ + struct kvm_stat_data *stat_data = (struct kvm_stat_data *)data; + + *val = *(u32 *)((void *)stat_data->kvm + stat_data->offset); + + return 0; +} + +static int vm_stat_get_per_vm_open(struct inode *inode, struct file *file) +{ + __simple_attr_check_format("%llu\n", 0ull); + return kvm_debugfs_open(inode, file, vm_stat_get_per_vm, + NULL, "%llu\n"); +} + +static const struct file_operations vm_stat_get_per_vm_fops = { + .owner = THIS_MODULE, + .open = vm_stat_get_per_vm_open, + .release = kvm_debugfs_release, + .read = simple_attr_read, + .write = simple_attr_write, + .llseek = generic_file_llseek, +}; + +static int vcpu_stat_get_per_vm(void *data, u64 *val) +{ + int i; + struct kvm_stat_data *stat_data = (struct kvm_stat_data *)data; + struct kvm_vcpu *vcpu; + + *val = 0; + + kvm_for_each_vcpu(i, vcpu, stat_data->kvm) + *val += *(u32 *)((void *)vcpu + stat_data->offset); + + return 0; +} + +static int vcpu_stat_get_per_vm_open(struct inode *inode, struct file *file) +{ + __simple_attr_check_format("%llu\n", 0ull); + return kvm_debugfs_open(inode, file, vcpu_stat_get_per_vm, + NULL, "%llu\n"); +} + +static const struct file_operations vcpu_stat_get_per_vm_fops = { + .owner = THIS_MODULE, + .open = vcpu_stat_get_per_vm_open, + .release = kvm_debugfs_release, + .read = simple_attr_read, + .write = simple_attr_write, + .llseek = generic_file_llseek, +}; + +static const struct file_operations *stat_fops_per_vm[] = { + [KVM_STAT_VCPU] = &vcpu_stat_get_per_vm_fops, + [KVM_STAT_VM] = &vm_stat_get_per_vm_fops, +}; + static int vm_stat_get(void *_offset, u64 *val) { unsigned offset = (long)_offset; struct kvm *kvm; + struct kvm_stat_data stat_tmp = {.offset = offset}; + u64 tmp_val; *val = 0; spin_lock(&kvm_lock); - list_for_each_entry(kvm, &vm_list, vm_list) - *val += *(u32 *)((void *)kvm + offset); + list_for_each_entry(kvm, &vm_list, vm_list) { + stat_tmp.kvm = kvm; + vm_stat_get_per_vm((void *)&stat_tmp, &tmp_val); + *val += tmp_val; + } spin_unlock(&kvm_lock); return 0; } @@ -3444,15 +3609,16 @@ static int vcpu_stat_get(void *_offset, u64 *val) { unsigned offset = (long)_offset; struct kvm *kvm; - struct kvm_vcpu *vcpu; - int i; + struct kvm_stat_data stat_tmp = {.offset = offset}; + u64 tmp_val; *val = 0; spin_lock(&kvm_lock); - list_for_each_entry(kvm, &vm_list, vm_list) - kvm_for_each_vcpu(i, vcpu, kvm) - *val += *(u32 *)((void *)vcpu + offset); - + list_for_each_entry(kvm, &vm_list, vm_list) { + stat_tmp.kvm = kvm; + vcpu_stat_get_per_vm((void *)&stat_tmp, &tmp_val); + *val += tmp_val; + } spin_unlock(&kvm_lock); return 0; } @@ -3473,7 +3639,8 @@ static int kvm_init_debug(void) if (kvm_debugfs_dir == NULL) goto out; - for (p = debugfs_entries; p->name; ++p) { + kvm_debugfs_num_entries = 0; + for (p = debugfs_entries; p->name; ++p, kvm_debugfs_num_entries++) { if (!debugfs_create_file(p->name, 0444, kvm_debugfs_dir, (void *)(long)p->offset, stat_fops[p->kind]))