On Fri, Jun 24, 2022 at 12:08 AM Eugenio Pérez <eperezma@xxxxxxxxxx> wrote:
>
> Implement suspend operation for vdpa_sim devices, so vhost-vdpa will
> offer that backend feature and userspace can effectively suspend the
> device.
>
> This is a must before get virtqueue indexes (base) for live migration,
> since the device could modify them after userland gets them. There are
> individual ways to perform that action for some devices
> (VHOST_NET_SET_BACKEND, VHOST_VSOCK_SET_RUNNING, ...) but there was no
> way to perform it for any vhost device (and, in particular, vhost-vdpa).
>
> Reviewed-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
> Signed-off-by: Eugenio Pérez <eperezma@xxxxxxxxxx>
> ---
> drivers/vdpa/vdpa_sim/vdpa_sim.c | 21 +++++++++++++++++++++
> drivers/vdpa/vdpa_sim/vdpa_sim.h | 1 +
> drivers/vdpa/vdpa_sim/vdpa_sim_blk.c | 3 +++
> drivers/vdpa/vdpa_sim/vdpa_sim_net.c | 3 +++
> 4 files changed, 28 insertions(+)
>
> diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> index 0f2865899647..213883487f9b 100644
> --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
> +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> @@ -107,6 +107,7 @@ static void vdpasim_do_reset(struct vdpasim *vdpasim)
> for (i = 0; i < vdpasim->dev_attr.nas; i++)
> vhost_iotlb_reset(&vdpasim->iommu[i]);
>
> + vdpasim->running = true;
> spin_unlock(&vdpasim->iommu_lock);
>
> vdpasim->features = 0;
> @@ -505,6 +506,24 @@ static int vdpasim_reset(struct vdpa_device *vdpa)
> return 0;
> }
>
> +static int vdpasim_suspend(struct vdpa_device *vdpa)
> +{
> + struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
> + int i;
> +
> + spin_lock(&vdpasim->lock);
> + vdpasim->running = false;
> + if (vdpasim->running) {
> + /* Check for missed buffers */
> + for (i = 0; i < vdpasim->dev_attr.nvqs; ++i)
> + vdpasim_kick_vq(vdpa, i);
This seems only valid if we allow resuming?
Thanks
> +
> + }
> + spin_unlock(&vdpasim->lock);
> +
> + return 0;
> +}
> +
> static size_t vdpasim_get_config_size(struct vdpa_device *vdpa)
> {
> struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
> @@ -694,6 +713,7 @@ static const struct vdpa_config_ops vdpasim_config_ops = {
> .get_status = vdpasim_get_status,
> .set_status = vdpasim_set_status,
> .reset = vdpasim_reset,
> + .suspend = vdpasim_suspend,
> .get_config_size = vdpasim_get_config_size,
> .get_config = vdpasim_get_config,
> .set_config = vdpasim_set_config,
> @@ -726,6 +746,7 @@ static const struct vdpa_config_ops vdpasim_batch_config_ops = {
> .get_status = vdpasim_get_status,
> .set_status = vdpasim_set_status,
> .reset = vdpasim_reset,
> + .suspend = vdpasim_suspend,
> .get_config_size = vdpasim_get_config_size,
> .get_config = vdpasim_get_config,
> .set_config = vdpasim_set_config,
> diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.h b/drivers/vdpa/vdpa_sim/vdpa_sim.h
> index 622782e92239..061986f30911 100644
> --- a/drivers/vdpa/vdpa_sim/vdpa_sim.h
> +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.h
> @@ -66,6 +66,7 @@ struct vdpasim {
> u32 generation;
> u64 features;
> u32 groups;
> + bool running;
> /* spinlock to synchronize iommu table */
> spinlock_t iommu_lock;
> };
> diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c b/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
> index 42d401d43911..bcdb1982c378 100644
> --- a/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
> +++ b/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
> @@ -204,6 +204,9 @@ static void vdpasim_blk_work(struct work_struct *work)
> if (!(vdpasim->status & VIRTIO_CONFIG_S_DRIVER_OK))
> goto out;
>
> + if (!vdpasim->running)
> + goto out;
> +
> for (i = 0; i < VDPASIM_BLK_VQ_NUM; i++) {
> struct vdpasim_virtqueue *vq = &vdpasim->vqs[i];
>
> diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim_net.c b/drivers/vdpa/vdpa_sim/vdpa_sim_net.c
> index 5125976a4df8..886449e88502 100644
> --- a/drivers/vdpa/vdpa_sim/vdpa_sim_net.c
> +++ b/drivers/vdpa/vdpa_sim/vdpa_sim_net.c
> @@ -154,6 +154,9 @@ static void vdpasim_net_work(struct work_struct *work)
>
> spin_lock(&vdpasim->lock);
>
> + if (!vdpasim->running)
> + goto out;
> +
> if (!(vdpasim->status & VIRTIO_CONFIG_S_DRIVER_OK))
> goto out;
>
> --
> 2.31.1
>
