From 1a8c091c4ea5db3126514e3f7df678c9ee328802 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Thu, 20 Jun 2019 18:37:09 +0100 Subject: [PATCH] virtio-scsi: restart DMA after iothread When the 'cont' command resumes guest execution the vm change state handlers are invoked. Unfortunately there is no explicit ordering between classic qemu_add_vm_change_state_handler() callbacks. When two layers of code both use vm change state handlers, we don't control which handler runs first. virtio-scsi with iothreads hits a deadlock when a failed SCSI command is restarted and completes before the iothread is re-initialized. This patch uses the new qdev_add_vm_change_state_handler() API to guarantee that virtio-scsi's virtio change state handler executes before the SCSI bus children. This way DMA is restarted after the iothread has re-initialized. Signed-off-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- hw/scsi/scsi-bus.c | 4 ++-- hw/virtio/virtio.c | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/hw/scsi/scsi-bus.c b/hw/scsi/scsi-bus.c index 196136a307..fdc3a0e4e0 100644 --- a/hw/scsi/scsi-bus.c +++ b/hw/scsi/scsi-bus.c @@ -207,8 +207,8 @@ static void scsi_qdev_realize(DeviceState *qdev, Error **errp) error_propagate(errp, local_err); return; } - dev->vmsentry = qemu_add_vm_change_state_handler(scsi_dma_restart_cb, - dev); + dev->vmsentry = qdev_add_vm_change_state_handler(DEVICE(dev), + scsi_dma_restart_cb, dev); } static void scsi_qdev_unrealize(DeviceState *qdev, Error **errp) diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 18f9f4c372..a94ea18a9c 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -2362,8 +2362,8 @@ void virtio_init(VirtIODevice *vdev, const char *name, } else { vdev->config = NULL; } - vdev->vmstate = qemu_add_vm_change_state_handler(virtio_vmstate_change, - vdev); + vdev->vmstate = qdev_add_vm_change_state_handler(DEVICE(vdev), + virtio_vmstate_change, vdev); vdev->device_endian = virtio_default_endian(); vdev->use_guest_notifier_mask = true; } -- 2.39.2