On Mon, May 20, 2024 at 11:21 PM Steve Sistare
<steven.sistare@xxxxxxxxxx> wrote:
>
> Flush to guarantee no workers are running when suspend returns.
> Add a lock to enforce ordering between clearing running, flushing,
> and posting new work in vdpasim_kick_vq. It must be a spin lock
> because vdpasim_kick_vq may be reached va eventfd_write.
>
> Signed-off-by: Steve Sistare <steven.sistare@xxxxxxxxxx>
> ---
> drivers/vdpa/vdpa_sim/vdpa_sim.c | 16 ++++++++++++++--
> drivers/vdpa/vdpa_sim/vdpa_sim.h | 1 +
> 2 files changed, 15 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> index 8ffea8430f95..67ed49d95bf0 100644
> --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
> +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> @@ -322,7 +322,7 @@ static u16 vdpasim_get_vq_size(struct vdpa_device *vdpa, u16 idx)
> return VDPASIM_QUEUE_MAX;
> }
>
> -static void vdpasim_kick_vq(struct vdpa_device *vdpa, u16 idx)
> +static void vdpasim_do_kick_vq(struct vdpa_device *vdpa, u16 idx)
> {
> struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
> struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
> @@ -337,6 +337,15 @@ static void vdpasim_kick_vq(struct vdpa_device *vdpa, u16 idx)
> vdpasim_schedule_work(vdpasim);
> }
>
> +static void vdpasim_kick_vq(struct vdpa_device *vdpa, u16 idx)
> +{
> + struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
> +
> + spin_lock(&vdpasim->kick_lock);
> + vdpasim_do_kick_vq(vdpa, idx);
> + spin_unlock(&vdpasim->kick_lock);
> +}
> +
> static void vdpasim_set_vq_cb(struct vdpa_device *vdpa, u16 idx,
> struct vdpa_callback *cb)
> {
> @@ -520,8 +529,11 @@ static int vdpasim_suspend(struct vdpa_device *vdpa)
> struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
>
> mutex_lock(&vdpasim->mutex);
> + spin_lock(&vdpasim->kick_lock);
> vdpasim->running = false;
> + spin_unlock(&vdpasim->kick_lock);
> mutex_unlock(&vdpasim->mutex);
> + kthread_flush_work(&vdpasim->work);
>
> return 0;
> }
> @@ -537,7 +549,7 @@ static int vdpasim_resume(struct vdpa_device *vdpa)
> if (vdpasim->pending_kick) {
> /* Process pending descriptors */
> for (i = 0; i < vdpasim->dev_attr.nvqs; ++i)
> - vdpasim_kick_vq(vdpa, i);
> + vdpasim_do_kick_vq(vdpa, i);
>
> vdpasim->pending_kick = false;
> }
> diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.h b/drivers/vdpa/vdpa_sim/vdpa_sim.h
> index bb137e479763..5eb6ca9c5ec5 100644
> --- a/drivers/vdpa/vdpa_sim/vdpa_sim.h
> +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.h
> @@ -75,6 +75,7 @@ struct vdpasim {
> bool pending_kick;
> /* spinlock to synchronize iommu table */
> spinlock_t iommu_lock;
> + spinlock_t kick_lock;
It looks to me this is not initialized?
Thanks
> };
>
> struct vdpasim *vdpasim_create(struct vdpasim_dev_attr *attr,
> --
> 2.39.3
>
