On Fri, Jul 31, 2026 at 11:19:00AM +0800, Xixin Liu wrote:
> After ERS reports pci_channel_io_perm_failure, virtio-pci must ask the
> virtio driver to tear down the block device, not only mark virtqueues
> broken. Call the virtio driver shutdown hook from virtio-pci on
> perm_failure; virtio-blk implements shutdown with blk_mark_disk_dead().
>
> Fail new requests early in virtio_queue_rq when virtqueues were removed
> during frozen reset_prepare (vqs == NULL). A broken vq already fails in
> virtqueue_add; no separate disk_live() check is needed.
>
> Assisted-by: DeepSeek:deepseek-v3
> Signed-off-by: Xixin Liu <[email protected]>
> ---
> drivers/block/virtio_blk.c | 31 ++++++++++++++++++++++++++++++
> drivers/virtio/virtio_pci_common.c | 10 +++++++++-
> 2 files changed, 40 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
> index 32bf3ba07a9d..fda2d4f3c7c6 100644
> --- a/drivers/block/virtio_blk.c
> +++ b/drivers/block/virtio_blk.c
> @@ -435,6 +435,12 @@ static blk_status_t virtio_queue_rq(struct blk_mq_hw_ctx
> *hctx,
> blk_status_t status;
> int err;
>
> + /* VQs may be gone after frozen reset_prepare; avoid NULL deref. */
> + if (unlikely(!vblk->vqs || !vblk->vdev)) {
> + blk_mq_start_request(req);
> + return BLK_STS_IOERR;
> + }
> +
> status = virtblk_prep_rq(hctx, vblk, req, vbr);
> if (unlikely(status))
> return status;
> @@ -1561,6 +1567,30 @@ static int virtblk_probe(struct virtio_device *vdev)
> return err;
> }
>
> +
> +/* Stop I/O and mark the gendisk dead (ERS perm_failure or system shutdown).
> */
> +static void virtblk_shutdown(struct virtio_device *vdev)
> +{
> + struct virtio_blk *vblk = vdev->priv;
> + struct request_queue *q;
> + unsigned int memflags;
> +
> + if (!vblk || !vblk->disk)
> + return;
> +
> + virtio_break_device(vdev);
> + flush_work(&vblk->config_work);
> +
> + q = vblk->disk->queue;
> + memflags = blk_mq_freeze_queue(q);
> + blk_mq_quiesce_queue_nowait(q);
> +
> + blk_mark_disk_dead(vblk->disk);
> +
> + blk_mq_unquiesce_queue(q);
> + blk_mq_unfreeze_queue(q, memflags);
> +}
> +
> static void virtblk_remove(struct virtio_device *vdev)
> {
> struct virtio_blk *vblk = vdev->priv;
what happens with requests already outstanding in the queues?
e.g. does this leak memory?
> @@ -1684,6 +1714,7 @@ static struct virtio_driver virtio_blk = {
> .probe = virtblk_probe,
> .remove = virtblk_remove,
> .config_changed = virtblk_config_changed,
> + .shutdown = virtblk_shutdown,
> #ifdef CONFIG_PM_SLEEP
> .freeze = virtblk_freeze,
> .restore = virtblk_restore,
> diff --git a/drivers/virtio/virtio_pci_common.c
> b/drivers/virtio/virtio_pci_common.c
> index fff6b6e2d0c5..957b3282865c 100644
> --- a/drivers/virtio/virtio_pci_common.c
> +++ b/drivers/virtio/virtio_pci_common.c
> @@ -849,7 +849,15 @@ static pci_ers_result_t virtio_pci_error_detected(struct
> pci_dev *pci_dev,
> case pci_channel_io_perm_failure:
> dev_warn(&pci_dev->dev,
> "permanent failure, disconnecting device\n");
> - virtio_break_device(&vp_dev->vdev);
> + {
> + struct virtio_driver *drv =
> + drv_to_virtio(vp_dev->vdev.dev.driver);
> +
> + if (drv && drv->shutdown)
> + drv->shutdown(&vp_dev->vdev);
> + else
> + virtio_break_device(&vp_dev->vdev);
> + }
> return PCI_ERS_RESULT_DISCONNECT;
So this is blk specifically, I am somewhat lost as to why
is blk treated differently from other drivers here.
> default:
> break;
> --
> 2.43.0
