virtio: set pci bus master enable bit

commit bc505f373979692d51a86d40925f77a8b09d17b9 upstream.

As all virtio devices perform DMA, we
must enable bus mastering for them to be
spec compliant.

This patch fixes hotplug of virtio devices
with Linux guests and qemu 0.11-0.12.

Tested-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Cc: maximilian attems <max@stro.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c
index 5fed28387b3f6e2638a9aae922f9f054bc5e5c9d..d10c85764ee3be2200a73da7045ff0fd21689cc3 100644 (file)
--- a/drivers/virtio/virtio_pci.c
+++ b/drivers/virtio/virtio_pci.c
@@ -647,6 +647,7 @@ static int __devinit virtio_pci_probe(struct pci_dev *pci_dev,
                goto out_req_regions;
 
        pci_set_drvdata(pci_dev, vp_dev);
+       pci_set_master(pci_dev);
 
        /* we use the subsystem vendor/device id as the virtio vendor/device
         * id.  this allows us to use the same PCI vendor/device id for all