Merge remote-tracking branch 'torvalds/master' into perf/core

[linux-2.6-microblaze.git] / virt / kvm / kvm_main.c

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 9869598..b50dbe2 100644 (file)
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -892,6 +892,8 @@ static void kvm_destroy_vm_debugfs(struct kvm *kvm)
 
 static int kvm_create_vm_debugfs(struct kvm *kvm, int fd)
 {
+       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;
@@ -903,8 +905,20 @@ static int kvm_create_vm_debugfs(struct kvm *kvm, int fd)
                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);
+       mutex_lock(&kvm_debugfs_lock);
+       dent = debugfs_lookup(dir_name, kvm_debugfs_dir);
+       if (dent) {
+               pr_warn_ratelimited("KVM: debugfs: duplicate directory %s\n", dir_name);
+               dput(dent);
+               mutex_unlock(&kvm_debugfs_lock);
+               return 0;
+       }
+       dent = debugfs_create_dir(dir_name, kvm_debugfs_dir);
+       mutex_unlock(&kvm_debugfs_lock);
+       if (IS_ERR(dent))
+               return 0;
 
+       kvm->debugfs_dentry = dent;
        kvm->debugfs_stat_data = kcalloc(kvm_debugfs_num_entries,
                                         sizeof(*kvm->debugfs_stat_data),
                                         GFP_KERNEL_ACCOUNT);
@@ -3110,6 +3124,7 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu)
                                        ++vcpu->stat.generic.halt_poll_invalid;
                                goto out;
                        }
+                       cpu_relax();
                        poll_end = cur = ktime_get();
                } while (kvm_vcpu_can_poll(cur, stop));
        }
@@ -4390,6 +4405,16 @@ struct compat_kvm_dirty_log {
        };
 };
 
+struct compat_kvm_clear_dirty_log {
+       __u32 slot;
+       __u32 num_pages;
+       __u64 first_page;
+       union {
+               compat_uptr_t dirty_bitmap; /* one bit per page */
+               __u64 padding2;
+       };
+};
+
 static long kvm_vm_compat_ioctl(struct file *filp,
                           unsigned int ioctl, unsigned long arg)
 {
@@ -4399,6 +4424,24 @@ static long kvm_vm_compat_ioctl(struct file *filp,
        if (kvm->mm != current->mm)
                return -EIO;
        switch (ioctl) {
+#ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
+       case KVM_CLEAR_DIRTY_LOG: {
+               struct compat_kvm_clear_dirty_log compat_log;
+               struct kvm_clear_dirty_log log;
+
+               if (copy_from_user(&compat_log, (void __user *)arg,
+                                  sizeof(compat_log)))
+                       return -EFAULT;
+               log.slot         = compat_log.slot;
+               log.num_pages    = compat_log.num_pages;
+               log.first_page   = compat_log.first_page;
+               log.padding2     = compat_log.padding2;
+               log.dirty_bitmap = compat_ptr(compat_log.dirty_bitmap);
+
+               r = kvm_vm_ioctl_clear_dirty_log(kvm, &log);
+               break;
+       }
+#endif
        case KVM_GET_DIRTY_LOG: {
                struct compat_kvm_dirty_log compat_log;
                struct kvm_dirty_log log;
@@ -5172,7 +5215,7 @@ static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm)
        }
        add_uevent_var(env, "PID=%d", kvm->userspace_pid);
 
-       if (!IS_ERR_OR_NULL(kvm->debugfs_dentry)) {
+       if (kvm->debugfs_dentry) {
                char *tmp, *p = kmalloc(PATH_MAX, GFP_KERNEL_ACCOUNT);
 
                if (p) {