Re: [PATCH V1] vdpa_sim: reset must not run

[Stefano Garzarella <sgarzare@xxxxxxxxxx>]

On Wed, Jan 17, 2024 at 11:23:23AM -0800, Steve Sistare wrote:
> vdpasim_do_reset sets running to true, which is wrong, as it allows
> vdpasim_kick_vq to post work requests before the device has been
> configured.  To fix, do not set running until VIRTIO_CONFIG_S_FEATURES_OK
> is set.
>
> Fixes: 0c89e2a3a9d0 ("vdpa_sim: Implement suspend vdpa op")
> Signed-off-by: Steve Sistare <steven.sistare@xxxxxxxxxx>
> Reviewed-by: Eugenio Pérez <eperezma@xxxxxxxxxx>
> ---
> drivers/vdpa/vdpa_sim/vdpa_sim.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> index be2925d0d283..6304cb0b4770 100644
> --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
> +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> @@ -160,7 +160,7 @@ static void vdpasim_do_reset(struct vdpasim *vdpasim, u32 flags)
> 		}
> 	}
>
> -	vdpasim->running = true;
> +	vdpasim->running = false;
> 	spin_unlock(&vdpasim->iommu_lock);
>
> 	vdpasim->features = 0;
> @@ -483,6 +483,7 @@ static void vdpasim_set_status(struct vdpa_device *vdpa, u8 status)
>
> 	mutex_lock(&vdpasim->mutex);
> 	vdpasim->status = status;
> +	vdpasim->running = (status & VIRTIO_CONFIG_S_FEATURES_OK) != 0;
> 	mutex_unlock(&vdpasim->mutex);

Should we do something similar also in vdpasim_resume() ?

I mean something like this:

diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
index be2925d0d283..55e4633d5442 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -520,7 +520,7 @@ static int vdpasim_resume(struct vdpa_device *vdpa)
        int i;

        mutex_lock(&vdpasim->mutex);
-       vdpasim->running = true;
+       vdpasim->running = (vdpasim->status & VIRTIO_CONFIG_S_FEATURES_OK) != 0;

        if (vdpasim->pending_kick) {
                /* Process pending descriptors */

Thanks,
Stefano