[PATCH 2/7] kvm-vfio: Decouple only when we match a group

From: Alex Williamson <alex.williamson@redhat.com>
To: kvm@vger.kernel.org
Cc: Paolo Bonzini <pbonzini@redhat.com>,
	alex.williamson@redhat.com, linux-kernel@vger.kernel.org,
	eric.auger@redhat.com
Subject: [PATCH 2/7] kvm-vfio: Decouple only when we match a group
Date: Fri, 09 Jun 2017 15:59:44 -0600	[thread overview]
Message-ID: <20170609215944.31986.32841.stgit@gimli.home> (raw)
In-Reply-To: <20170609215816.31986.89321.stgit@gimli.home>

Unset-KVM and decrement-assignment only when we find the group in our
list.  Otherwise we can get out of sync if the user triggers this for
groups that aren't currently on our list.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
---
 virt/kvm/vfio.c |    6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c
index d32f239eb471..db9036ef8c73 100644
--- a/virt/kvm/vfio.c
+++ b/virt/kvm/vfio.c
@@ -201,18 +201,16 @@ static int kvm_vfio_set_group(struct kvm_device *dev, long attr, u64 arg)
 				continue;
 
 			list_del(&kvg->node);
+			kvm_arch_end_assignment(dev->kvm);
+			kvm_vfio_group_set_kvm(kvg->vfio_group, NULL);
 			kvm_vfio_group_put_external_user(kvg->vfio_group);
 			kfree(kvg);
 			ret = 0;
 			break;
 		}
 
-		kvm_arch_end_assignment(dev->kvm);
-
 		mutex_unlock(&kv->lock);
 
-		kvm_vfio_group_set_kvm(vfio_group, NULL);
-
 		kvm_vfio_group_put_external_user(vfio_group);
 
 		kvm_vfio_update_coherency(dev);
