From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48306) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dB6lC-00012Y-Qr for qemu-devel@nongnu.org; Wed, 17 May 2017 17:45:35 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dB6lB-0005S3-V8 for qemu-devel@nongnu.org; Wed, 17 May 2017 17:45:34 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56448) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dB6lB-0005Ro-PF for qemu-devel@nongnu.org; Wed, 17 May 2017 17:45:33 -0400 Date: Thu, 18 May 2017 00:45:29 +0300 From: "Michael S. Tsirkin" Message-ID: <1495057396-13387-12-git-send-email-mst@redhat.com> References: <1495057396-13387-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1495057396-13387-1-git-send-email-mst@redhat.com> Subject: [Qemu-devel] [PULL 11/13] virtio: allow broken device to notify guest List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Peter Maydell , Greg Kurz , Cornelia Huck , Stefan Hajnoczi From: Greg Kurz 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 03592c5..890b4d7 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) -- MST