Re: [RFC v2 PATCH] vdpa_sim: implement .reset_map support

[Stefano Garzarella]

On Tue, Oct 17, 2023 at 10:11:33PM -0700, Si-Wei Liu wrote:
> RFC only. Not tested on vdpa-sim-blk with user virtual address.
> Works fine with vdpa-sim-net which uses physical address to map.
>
> This patch is based on top of [1].
>
> [1] https://lore.kernel.org/virtualization/1696928580-7520-1-git-send-email-si-wei.liu@xxxxxxxxxx/
>
> Signed-off-by: Si-Wei Liu <si-wei.liu@xxxxxxxxxx>
>
> ---
> RFC v2:
>  - initialize iotlb to passthrough mode in device add

I tested this version and I didn't see any issue ;-)

Tested-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>

> ---
> drivers/vdpa/vdpa_sim/vdpa_sim.c | 34 ++++++++++++++++++++++++--------
> 1 file changed, 26 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> index 76d41058add9..2a0a6042d61d 100644
> --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
> +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> @@ -151,13 +151,6 @@ static void vdpasim_do_reset(struct vdpasim *vdpasim)
> 				 &vdpasim->iommu_lock);
> 	}
>
> -	for (i = 0; i < vdpasim->dev_attr.nas; i++) {
> -		vhost_iotlb_reset(&vdpasim->iommu[i]);
> -		vhost_iotlb_add_range(&vdpasim->iommu[i], 0, ULONG_MAX,
> -				      0, VHOST_MAP_RW);
> -		vdpasim->iommu_pt[i] = true;
> -	}
> -
> 	vdpasim->running = true;
> 	spin_unlock(&vdpasim->iommu_lock);
>
> @@ -259,8 +252,12 @@ struct vdpasim *vdpasim_create(struct vdpasim_dev_attr *dev_attr,
> 	if (!vdpasim->iommu_pt)
> 		goto err_iommu;
>
> -	for (i = 0; i < vdpasim->dev_attr.nas; i++)
> +	for (i = 0; i < vdpasim->dev_attr.nas; i++) {
> 		vhost_iotlb_init(&vdpasim->iommu[i], max_iotlb_entries, 0);
> +		vhost_iotlb_add_range(&vdpasim->iommu[i], 0, ULONG_MAX, 0,
> +				      VHOST_MAP_RW);
> +		vdpasim->iommu_pt[i] = true;
> +	}
>
> 	for (i = 0; i < dev_attr->nvqs; i++)
> 		vringh_set_iotlb(&vdpasim->vqs[i].vring, &vdpasim->iommu[0],
> @@ -637,6 +634,25 @@ static int vdpasim_set_map(struct vdpa_device *vdpa, unsigned int asid,
> 	return ret;
> }
>
> +static int vdpasim_reset_map(struct vdpa_device *vdpa, unsigned int asid)
> +{
> +	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
> +
> +	if (asid >= vdpasim->dev_attr.nas)
> +		return -EINVAL;
> +
> +	spin_lock(&vdpasim->iommu_lock);
> +	if (vdpasim->iommu_pt[asid])
> +		goto out;
> +	vhost_iotlb_reset(&vdpasim->iommu[asid]);
> +	vhost_iotlb_add_range(&vdpasim->iommu[asid], 0, ULONG_MAX,
> +			      0, VHOST_MAP_RW);
> +	vdpasim->iommu_pt[asid] = true;
> +out:
> +	spin_unlock(&vdpasim->iommu_lock);
> +	return 0;
> +}
> +
> static int vdpasim_bind_mm(struct vdpa_device *vdpa, struct mm_struct *mm)
> {
> 	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
> @@ -759,6 +775,7 @@ static const struct vdpa_config_ops vdpasim_config_ops = {
> 	.set_group_asid         = vdpasim_set_group_asid,
> 	.dma_map                = vdpasim_dma_map,
> 	.dma_unmap              = vdpasim_dma_unmap,
> +	.reset_map              = vdpasim_reset_map,
> 	.bind_mm		= vdpasim_bind_mm,
> 	.unbind_mm		= vdpasim_unbind_mm,
> 	.free                   = vdpasim_free,
> @@ -796,6 +813,7 @@ static const struct vdpa_config_ops vdpasim_batch_config_ops = {
> 	.get_iova_range         = vdpasim_get_iova_range,
> 	.set_group_asid         = vdpasim_set_group_asid,
> 	.set_map                = vdpasim_set_map,
> +	.reset_map              = vdpasim_reset_map,
> 	.bind_mm		= vdpasim_bind_mm,
> 	.unbind_mm		= vdpasim_unbind_mm,
> 	.free                   = vdpasim_free,
> --
> 2.39.3