On Tue, Aug 18, 2026 at 06:04:32AM +0200, Karl Mehltretter wrote:
> virtio_reset_device() promises that vq callbacks are not in progress
> once it returns, but vm_reset() only writes 0 to the status register.
> A callback that has already entered vring_interrupt() keeps running
> while the driver tears down the state it uses.
>
> Wait for a status read to return 0, so the device has stopped raising
> interrupts, then synchronize_irq() as vp_reset() does with
> vp_synchronize_vectors().
>
> Fixes: edfd52e63672 ("virtio: Add platform bus driver for memory mapped
> virtio device")
> Assisted-by: Claude:claude-fable-5
> Signed-off-by: Karl Mehltretter <[email protected]>
> ---
> drivers/virtio/virtio_mmio.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c
> index 510b7c4efdff8..a2ca03dbe803d 100644
> --- a/drivers/virtio/virtio_mmio.c
> +++ b/drivers/virtio/virtio_mmio.c
> @@ -55,6 +55,7 @@
> #define pr_fmt(fmt) "virtio-mmio: " fmt
>
> #include <linux/acpi.h>
> +#include <linux/delay.h>
> #include <linux/dma-mapping.h>
> #include <linux/highmem.h>
> #include <linux/interrupt.h>
> @@ -254,6 +255,11 @@ static void vm_reset(struct virtio_device *vdev)
>
> /* 0 status means a reset. */
> writel(0, vm_dev->base + VIRTIO_MMIO_STATUS);
> +
> + /* Wait for reset completion before flushing callbacks. */
> + while (vm_get_status(vdev))
> + fsleep(1000);
this is only required for transport version 3.
> + synchronize_irq(platform_get_irq(vm_dev->pdev, 0));
> }
>
>
> --
> 2.53.0
