KVM: only allow one gsi per fd
Looks like repeatedly binding same fd to multiple gsi's with irqfd can use up a ton of kernel memory for irqfd structures. A simple fix is to allow each fd to only trigger one gsi: triggering a storm of interrupts in guest is likely useless anyway, and we can do it by binding a single gsi to many interrupts if we really want to. Cc: stable@kernel.org Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Acked-by: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
parent
82b7005f0e
commit
f1d1c309f3
|
@ -166,7 +166,7 @@ irqfd_ptable_queue_proc(struct file *file, wait_queue_head_t *wqh,
|
||||||
static int
|
static int
|
||||||
kvm_irqfd_assign(struct kvm *kvm, int fd, int gsi)
|
kvm_irqfd_assign(struct kvm *kvm, int fd, int gsi)
|
||||||
{
|
{
|
||||||
struct _irqfd *irqfd;
|
struct _irqfd *irqfd, *tmp;
|
||||||
struct file *file = NULL;
|
struct file *file = NULL;
|
||||||
struct eventfd_ctx *eventfd = NULL;
|
struct eventfd_ctx *eventfd = NULL;
|
||||||
int ret;
|
int ret;
|
||||||
|
@ -203,9 +203,20 @@ kvm_irqfd_assign(struct kvm *kvm, int fd, int gsi)
|
||||||
init_waitqueue_func_entry(&irqfd->wait, irqfd_wakeup);
|
init_waitqueue_func_entry(&irqfd->wait, irqfd_wakeup);
|
||||||
init_poll_funcptr(&irqfd->pt, irqfd_ptable_queue_proc);
|
init_poll_funcptr(&irqfd->pt, irqfd_ptable_queue_proc);
|
||||||
|
|
||||||
|
spin_lock_irq(&kvm->irqfds.lock);
|
||||||
|
|
||||||
|
ret = 0;
|
||||||
|
list_for_each_entry(tmp, &kvm->irqfds.items, list) {
|
||||||
|
if (irqfd->eventfd != tmp->eventfd)
|
||||||
|
continue;
|
||||||
|
/* This fd is used for another irq already. */
|
||||||
|
ret = -EBUSY;
|
||||||
|
spin_unlock_irq(&kvm->irqfds.lock);
|
||||||
|
goto fail;
|
||||||
|
}
|
||||||
|
|
||||||
events = file->f_op->poll(file, &irqfd->pt);
|
events = file->f_op->poll(file, &irqfd->pt);
|
||||||
|
|
||||||
spin_lock_irq(&kvm->irqfds.lock);
|
|
||||||
list_add_tail(&irqfd->list, &kvm->irqfds.items);
|
list_add_tail(&irqfd->list, &kvm->irqfds.items);
|
||||||
spin_unlock_irq(&kvm->irqfds.lock);
|
spin_unlock_irq(&kvm->irqfds.lock);
|
||||||
|
|
||||||
|
|
Loading…
Reference in New Issue