From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36046) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fa8YM-0008VG-M7 for qemu-devel@nongnu.org; Mon, 02 Jul 2018 19:48:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fa8YL-0007IK-Pn for qemu-devel@nongnu.org; Mon, 02 Jul 2018 19:48:18 -0400 Date: Tue, 3 Jul 2018 02:48:16 +0300 From: "Michael S. Tsirkin" Message-ID: <20180702234631.12268-4-mst@redhat.com> References: <20180702234631.12268-1-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180702234631.12268-1-mst@redhat.com> Subject: [Qemu-devel] [PULL 3/3] virtio-rng: process pending requests on DRIVER_OK List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Peter Maydell , Pankaj Gupta , qemu-stable@nongnu.org, Sergio lopez , Stefan Hajnoczi , Amit Shah From: Pankaj Gupta virtio-rng device causes old guest kernels(2.6.32) to hang on latest qemu. The driver attempts to read from the virtio-rng device too early in it's initialization. Qemu detects guest is not ready and returns, resulting in hang. To fix handle pending requests when guest is running and driver status is set to 'VIRTIO_CONFIG_S_DRIVER_OK'. CC: qemu-stable@nongnu.org Reported-by: Sergio lopez Signed-off-by: Stefan Hajnoczi Signed-off-by: Pankaj Gupta Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/virtio/virtio-rng.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/hw/virtio/virtio-rng.c b/hw/virtio/virtio-rng.c index 289bbcac03..855f1b41d1 100644 --- a/hw/virtio/virtio-rng.c +++ b/hw/virtio/virtio-rng.c @@ -156,6 +156,19 @@ static void check_rate_limit(void *opaque) vrng->activate_timer = true; } +static void virtio_rng_set_status(VirtIODevice *vdev, uint8_t status) +{ + VirtIORNG *vrng = VIRTIO_RNG(vdev); + + if (!vdev->vm_running) { + return; + } + vdev->status = status; + + /* Something changed, try to process buffers */ + virtio_rng_process(vrng); +} + static void virtio_rng_device_realize(DeviceState *dev, Error **errp) { VirtIODevice *vdev = VIRTIO_DEVICE(dev); @@ -261,6 +274,7 @@ static void virtio_rng_class_init(ObjectClass *klass, void *data) vdc->realize = virtio_rng_device_realize; vdc->unrealize = virtio_rng_device_unrealize; vdc->get_features = get_features; + vdc->set_status = virtio_rng_set_status; } static const TypeInfo virtio_rng_info = { -- MST