[Qemu-devel] [PATCH] Don't notify virtio devices before S_DRIVER_OK

[Mark McLoughlin <markmc@redhat.com>]

Current Linux guests oops if the host notifies of a
config change before a driver has been bound to the
device.

It's pretty pointless for us to do notify of config
changes before status is S_DRIVER_OK anyway, so let's
just not do it.

Signed-off-by: Mark McLoughlin <markmc@redhat.com>
---
 qemu/hw/virtio.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/qemu/hw/virtio.c b/qemu/hw/virtio.c
index 35f4669..78bcc2e 100644
--- a/qemu/hw/virtio.c
+++ b/qemu/hw/virtio.c
@@ -738,6 +738,9 @@ void virtio_notify(VirtIODevice *vdev, VirtQueue *vq)
 
 void virtio_notify_config(VirtIODevice *vdev)
 {
+    if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK))
+        return;
+
     vdev->isr |= 0x03;
     virtio_update_irq(vdev);
 }
-- 
1.6.0.6