[PATCH 1/2] virtio-pci: add setup_vqs flag in vp_try_to_find_vqs

[zanghongyong@huawei.com]

From: Hongyong Zang <zanghongyong@huawei.com>

changes in vp_try_to_find_vqs:
Virtio-serial's probe() calls it to request irqs and setup vqs of port0 and
controls; add_port() calls it to set up vqs of io_port.
it will not create virtqueue if the name is null.

Signed-off-by: Hongyong Zang <zanghongyong@huawei.com>
---
 drivers/virtio/virtio_pci.c |   17 +++++++++++++----
 1 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c
index baabb79..1f98c36 100644
--- a/drivers/virtio/virtio_pci.c
+++ b/drivers/virtio/virtio_pci.c
@@ -492,9 +492,11 @@ static void vp_del_vqs(struct virtio_device *vdev)
 	list_for_each_entry_safe(vq, n, &vdev->vqs, list) {
 		info = vq->priv;
 		if (vp_dev->per_vq_vectors &&
-			info->msix_vector != VIRTIO_MSI_NO_VECTOR)
+			info->msix_vector != VIRTIO_MSI_NO_VECTOR) {
 			free_irq(vp_dev->msix_entries[info->msix_vector].vector,
 				 vq);
+			vp_dev->msix_used_vectors--;
+		}
 		vp_del_vq(vq);
 	}
 	vp_dev->per_vq_vectors = false;
@@ -511,7 +513,10 @@ static int vp_try_to_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 {
 	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 	u16 msix_vec;
-	int i, err, nvectors, allocated_vectors;
+	int i, err, nvectors;
+
+	if (vp_dev->msix_used_vectors)
+		goto setup_vqs;
 
 	if (!use_msix) {
 		/* Old style: one normal interrupt for change and all vqs. */
@@ -536,12 +541,16 @@ static int vp_try_to_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 	}
 
 	vp_dev->per_vq_vectors = per_vq_vectors;
-	allocated_vectors = vp_dev->msix_used_vectors;
+
+setup_vqs:
 	for (i = 0; i < nvqs; ++i) {
+		if (names[i] == NULL)
+			continue;
+
 		if (!callbacks[i] || !vp_dev->msix_enabled)
 			msix_vec = VIRTIO_MSI_NO_VECTOR;
 		else if (vp_dev->per_vq_vectors)
-			msix_vec = allocated_vectors++;
+			msix_vec = vp_dev->msix_used_vectors++;
 		else
 			msix_vec = VP_MSIX_VQ_VECTOR;
 		vqs[i] = setup_vq(vdev, i, callbacks[i], names[i], msix_vec);
-- 
1.7.1