1 files changed, 13 insertions, 6 deletions

diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c
index 68023e509fcc..4de3cbc0746d 100644
--- a/drivers/virtio/virtio_pci.c
+++ b/drivers/virtio/virtio_pci.c
@@ -89,6 +89,7 @@ struct virtio_pci_device {
                                       const char *name,
                                       u16 msix_vec);
         void (*del_vq)(struct virtio_pci_vq_info *info);
+        u16 (*config_vector)(struct virtio_pci_device *vp_dev, u16 vector);
 };
 
 /* Constants for MSI-X */
@@ -271,6 +272,15 @@ static irqreturn_t vp_interrupt(int irq, void *opaque)
         return vp_vring_interrupt(irq, opaque);
 }
 
+static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
+{
+        /* Setup the vector used for configuration events */
+        iowrite16(vector, vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
+        /* Verify we had enough resources to assign the vector */
+        /* Will also flush the write out to device */
+        return ioread16(vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
+}
+
 static void vp_free_vectors(struct virtio_device *vdev)
 {
         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
@@ -290,10 +300,7 @@ static void vp_free_vectors(struct virtio_device *vdev)
 
         if (vp_dev->msix_enabled) {
                 /* Disable the vector used for configuration */
-                iowrite16(VIRTIO_MSI_NO_VECTOR,
-                          vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
-                /* Flush the write out to device */
-                ioread16(vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
+                vp_dev->config_vector(vp_dev, VIRTIO_MSI_NO_VECTOR);
 
                 pci_disable_msix(vp_dev->pci_dev);
                 vp_dev->msix_enabled = 0;
@@ -357,9 +364,8 @@ static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors,
                 goto error;
         ++vp_dev->msix_used_vectors;
 
-        iowrite16(v, vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
+        v = vp_dev->config_vector(vp_dev, v);
         /* Verify we had enough resources to assign the vector */
-        v = ioread16(vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
         if (v == VIRTIO_MSI_NO_VECTOR) {
                 err = -EBUSY;
                 goto error;
@@ -770,6 +776,7 @@ static int virtio_pci_probe(struct pci_dev *pci_dev,
         vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor;
         vp_dev->vdev.id.device = pci_dev->subsystem_device;
 
+        vp_dev->config_vector = vp_config_vector;
         vp_dev->setup_vq = setup_vq;
         vp_dev->del_vq = del_vq;