On 2020/6/10 下午5:52, Stefano Garzarella wrote:
On Wed, Jun 10, 2020 at 05:42:54AM -0400, Michael S. Tsirkin wrote:
On Wed, Jun 10, 2020 at 10:57:26AM +0200, Stefano Garzarella wrote:
On Wed, Jun 10, 2020 at 01:43:51PM +0800, Jason Wang wrote:
Spec said: The driver uses this to selectively prevent the device from
executing requests from this virtqueue. 1 - enabled; 0 - disabled.
Though write 0 to queue_enable is forbidden by the spec, we should not
assume that the value is 1.
Fix this by ignore the write value other than 1.
Signed-off-by: Jason Wang <jasow...@redhat.com>
---
Changes from V1:
- fix typo
- warn wrong value through virtio_error
---
hw/virtio/virtio-pci.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index d028c17c24..7bc8c1c056 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -1273,16 +1273,20 @@ static void virtio_pci_common_write(void *opaque,
hwaddr addr,
virtio_queue_set_vector(vdev, vdev->queue_sel, val);
break;
case VIRTIO_PCI_COMMON_Q_ENABLE:
- virtio_queue_set_num(vdev, vdev->queue_sel,
- proxy->vqs[vdev->queue_sel].num);
- virtio_queue_set_rings(vdev, vdev->queue_sel,
+ if (val == 1) {
Does it have to be 1 or can it be any value other than 0?
Thanks,
Stefano
spec says 1
I was confused by "The driver MUST NOT write a 0 to queue_enable.",
interpreting it as "can write anything other than 0".
Yes, the spec is unclear about what happens if we write a value other
than 0 or 1.
Maybe we should clarify that only 1 is allowed. Or writing value other
than 1 may cause unexpected result.
But as Jason also wrote in the commit message, the driver should write
1 to enable, so
Reviewed-by: Stefano Garzarella <sgarz...@redhat.com>
Thanks
Thanks,
Stefano
