[PATCH 3/3] vhost: Check+skip uninitialized VQs in vhost_verify_ring_mappings

["Nicholas A. Bellinger" <nab@linux-iscsi.org>]

From: Nicholas Bellinger <nab@linux-iscsi.org>

With the virtio_queue_valid() checks in place to skip uninitialized VQs
within virtio-pci code, go ahead and skip the same uninitialized VQs
during vhost_verify_ring_mappings().

Note this patch does not prevent vhost_virtqueue_start() from executing
by checking virtio_queue_valid(), as other logic during seabios ->
virtio-scsi LLD guest hand-off appears to depend upon this execution.

Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Asias He <asias@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
---
 hw/vhost.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/hw/vhost.c b/hw/vhost.c
index 4d6aee3..3a71aee 100644
--- a/hw/vhost.c
+++ b/hw/vhost.c
@@ -314,6 +314,9 @@ static int vhost_verify_ring_mappings(struct vhost_dev *dev,
         hwaddr l;
         void *p;
 
+        if (!vq->ring_phys || !vq->ring_size) {
+            continue;
+        }
         if (!ranges_overlap(start_addr, size, vq->ring_phys, vq->ring_size)) {
             continue;
         }
-- 
1.7.2.5