On Mon, Dec 17, 2012 at 05:24:48PM +0100, Paolo Bonzini wrote:
> virtio-pci devices do not perform a full reset when zero is written
> to the status byte. While PCI-specific status is initialized, the
> reset does not propagate down the qdev bus hierarchy. Because of
> this, a virtio reset does not cancel in-flight I/O for virtio-scsi
> (where the cancellation is handled automatically by the SCSI
> devices underneath virtio-scsi-pci).
>
> Reported-by: Bryan Venteicher <bry...@daemoninthecloset.org>
> Cc: Michael S. Tsirkin <m...@redhat.com>
> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
I would still prefer this logic to reside in virtio.c instead of being
duplicated in each bus.
My idea was to simply call qdev_reset_all on the binding from virtio.c
but other ideas wellcome.
> ---
> hw/virtio-pci.c | 28 ++++++++++------------------
> 1 file changed, 10 insertions(+), 18 deletions(-)
>
> diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c
> index a7c75fe..2cf5282 100644
> --- a/hw/virtio-pci.c
> +++ b/hw/virtio-pci.c
> @@ -268,12 +268,10 @@ static void virtio_ioport_write(void *opaque, uint32_t
> addr, uint32_t val)
> case VIRTIO_PCI_QUEUE_PFN:
> pa = (hwaddr)val << VIRTIO_PCI_QUEUE_ADDR_SHIFT;
> if (pa == 0) {
> - virtio_reset(proxy->vdev);
> - virtio_pci_stop_ioeventfd(proxy);
> - msix_unuse_all_vectors(&proxy->pci_dev);
> - }
> - else
> + qdev_reset_all(&proxy->pci_dev.qdev);
> + } else {
> virtio_queue_set_addr(vdev, vdev->queue_sel, pa);
> + }
> break;
> case VIRTIO_PCI_QUEUE_SEL:
> if (val < VIRTIO_PCI_QUEUE_MAX)
> @@ -285,22 +283,16 @@ static void virtio_ioport_write(void *opaque, uint32_t
> addr, uint32_t val)
> }
> break;
> case VIRTIO_PCI_STATUS:
> - if (vdev->status == 0) {
> - virtio_reset(proxy->vdev);
> - }
> -
> - if (!(val & VIRTIO_CONFIG_S_DRIVER_OK)) {
> - virtio_pci_stop_ioeventfd(proxy);
> - }
> -
> virtio_set_status(vdev, val & 0xFF);
>
> - if (val & VIRTIO_CONFIG_S_DRIVER_OK) {
> - virtio_pci_start_ioeventfd(proxy);
> - }
> -
> if (vdev->status == 0) {
> - msix_unuse_all_vectors(&proxy->pci_dev);
> + qdev_reset_all(&proxy->pci_dev.qdev);
> + } else {
> + if (!(val & VIRTIO_CONFIG_S_DRIVER_OK)) {
> + virtio_pci_stop_ioeventfd(proxy);
> + } else {
> + virtio_pci_start_ioeventfd(proxy);
> + }
> }
>
> /* Linux before 2.6.34 sets the device as OK without enabling
> --
> 1.8.0.2
>
