[PATCH 3.2 34/92] kvm: free resources after canceling async_pf

Ben Hutchings
2014-06-07T01:26:29Z

From: Radim Krčmář <rkrcmar@redhat.com>

commit 28b441e24088081c1e213139d1303b451a34a4f4 upstream.

When we cancel 'async_pf_execute()', we should behave as if the work was
never scheduled in 'kvm_setup_async_pf()'.
Fixes a bug when we can't unload module because the vm wasn't destroyed.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
virt/kvm/async_pf.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

--- a/virt/kvm/async_pf.c
+++ b/virt/kvm/async_pf.c
@@ -101,8 +101,11 @@ void kvm_clear_async_pf_completion_queue
typeof(*work), queue);
cancel_work_sync(&work->work);
list_del(&work->queue);
- if (!work->done) /* work was canceled */
+ if (!work->done) { /* work was canceled */
+ mmdrop(work->mm);
+ kvm_put_kvm(vcpu->kvm); /* == work->vcpu->kvm */
kmem_cache_free(async_pf_cache, work);
+ }
}

spin_lock(&vcpu->async_pf.lock);