On Sun, Nov 09, 2014 at 05:39:05PM +0800, Fam Zheng wrote: > This fixes a hanging issue during guest shutdown. > > The device is left enabled even though we removed it and disabled msix > during shutdown. If the virtio device happens to get a new event right > at this point, seeing msix is disabled, it may try to notify us with an > IRQ, which is totally unexpected thus will not be handled. In this > case the guest hangs. > > Let's reset the device so that it will not generate any interrupts. > > Link: https://bugzilla.redhat.com/show_bug.cgi?id=1128424 > Cc: Ulrich Obergfell <uobergfe@xxxxxxxxxx> > Signed-off-by: Fam Zheng <famz@xxxxxxxxxx> This needs some careful thought. vp_reset isn't safe unless there's a guarantee that nothing is accessing the device at the same time, which normally needs coordination with the function-specific driver. For example, for virtio net, you will notice that on remove path we do unregister_netdev before reset for this reason. What guarantees it in this case? > --- > drivers/virtio/virtio_pci.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c > index d34ebfa..cd7be6f 100644 > --- a/drivers/virtio/virtio_pci.c > +++ b/drivers/virtio/virtio_pci.c > @@ -743,6 +743,14 @@ out: > return err; > } > > +static void virtio_pci_shutdown(struct pci_dev *pci_dev) > +{ > + struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev); > + > + vp_reset(&vp_dev->vdev); > +} > + > + > static void virtio_pci_remove(struct pci_dev *pci_dev) > { > struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev); > @@ -794,6 +802,7 @@ static struct pci_driver virtio_pci_driver = { > .id_table = virtio_pci_id_table, > .probe = virtio_pci_probe, > .remove = virtio_pci_remove, > + .shutdown = virtio_pci_shutdown, > #ifdef CONFIG_PM_SLEEP > .driver.pm = &virtio_pci_pm_ops, > #endif > -- > 1.9.3 _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
