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author | Izik Eidus <izike@qumranet.com> | 2008-03-30 15:01:25 +0200 |
---|---|---|
committer | Avi Kivity <avi@qumranet.com> | 2008-04-27 11:00:56 +0200 |
commit | d39f13b0da7fa7f705fbe6c80995205d0380bc7a (patch) | |
tree | febc1458c6225c70ca4c435047acf279fd77b019 /virt | |
parent | KVM: function declaration parameter name cleanup (diff) | |
download | linux-d39f13b0da7fa7f705fbe6c80995205d0380bc7a.tar.xz linux-d39f13b0da7fa7f705fbe6c80995205d0380bc7a.zip |
KVM: add vm refcounting
the main purpose of adding this functions is the abilaty to release the
spinlock that protect the kvm list while still be able to do operations
on a specific kvm in a safe way.
Signed-off-by: Izik Eidus <izike@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Diffstat (limited to 'virt')
-rw-r--r-- | virt/kvm/kvm_main.c | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 41d4b6519136..93ed78b015c0 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -193,6 +193,7 @@ static struct kvm *kvm_create_vm(void) mutex_init(&kvm->lock); kvm_io_bus_init(&kvm->mmio_bus); init_rwsem(&kvm->slots_lock); + atomic_set(&kvm->users_count, 1); spin_lock(&kvm_lock); list_add(&kvm->vm_list, &vm_list); spin_unlock(&kvm_lock); @@ -242,11 +243,25 @@ static void kvm_destroy_vm(struct kvm *kvm) mmdrop(mm); } +void kvm_get_kvm(struct kvm *kvm) +{ + atomic_inc(&kvm->users_count); +} +EXPORT_SYMBOL_GPL(kvm_get_kvm); + +void kvm_put_kvm(struct kvm *kvm) +{ + if (atomic_dec_and_test(&kvm->users_count)) + kvm_destroy_vm(kvm); +} +EXPORT_SYMBOL_GPL(kvm_put_kvm); + + static int kvm_vm_release(struct inode *inode, struct file *filp) { struct kvm *kvm = filp->private_data; - kvm_destroy_vm(kvm); + kvm_put_kvm(kvm); return 0; } |