From 66453cff9e5e75344c601cd7674c8ef5fefee8a6 Mon Sep 17 00:00:00 2001 From: Greg Kurz Date: Wed, 17 May 2017 10:17:51 +0200 Subject: virtio: allow broken device to notify guest According to section 2.1.2 of the virtio-1 specification: "The device SHOULD set DEVICE_NEEDS_RESET when it enters an error state that a reset is needed. If DRIVER_OK is set, after it sets DEVICE_NEEDS_RESET, the device MUST send a device configuration change notification to the driver." Commit "f5ed36635d8f virtio: stop virtqueue processing if device is broken" introduced a virtio_error() call that just does that: - internally mark the device as broken - set the DEVICE_NEEDS_RESET bit in the status - send a configuration change notification Unfortunately, virtio_notify_vector(), called by virtio_notify_config(), returns right away when the device is marked as broken and the notification isn't sent in this case. The spec doesn't say whether a broken device can send notifications in other situations or not. But since the driver isn't supposed to do anything but to reset the device, it makes sense to keep the check in virtio_notify_config(). Marking the device as broken AFTER the configuration change notification was sent is enough to fix the issue. Signed-off-by: Greg Kurz Reviewed-by: Cornelia Huck Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin Reviewed-by: Stefan Hajnoczi --- hw/virtio/virtio.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 03592c542a..890b4d7eb7 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -2451,12 +2451,12 @@ void GCC_FMT_ATTR(2, 3) virtio_error(VirtIODevice *vdev, const char *fmt, ...) error_vreport(fmt, ap); va_end(ap); - vdev->broken = true; - if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { virtio_set_status(vdev, vdev->status | VIRTIO_CONFIG_S_NEEDS_RESET); virtio_notify_config(vdev); } + + vdev->broken = true; } static void virtio_memory_listener_commit(MemoryListener *listener) -- cgit v1.2.3