uhci: Verify queue has not been changed by guest
According to the spec a guest can unlink a qh, and then as soon as frindex has changed by 1 since the unlink, assume it is idle and re-use it. However for various reasons, we cannot simply consider a qh as unlinked if we've not seen it for 1 frame. This means that it is possible for a guest to re-use / restart the queue while we still see its old state. This patch adds a safety check for this, and "early" retires queues when they were changed by the guest. Signed-off-by: NHans de Goede <hdegoede@redhat.com> Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
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