On Thu, Apr 20, 2023 at 11:17 PM Cindy Lu <lulu@xxxxxxxxxx> wrote:
>
> While using the vdpa device with vIOMMU enabled
> in the guest VM, when the vdpa device bind to vfio-pci and run testpmd
> then system will fail to unmap.
> The test process is
> Load guest VM --> attach to virtio driver--> bind to vfio-pci driver
> So the mapping process is
> 1)batched mode map to normal MR
> 2)batched mode unmapped the normal MR
> 3)unmapped all the memory
> 4)mapped to iommu MR
>
> This error happened in step 3). The iotlb was freed in step 2)
> and the function vhost_vdpa_process_iotlb_msg will return fail
> Which causes failure.
>
> To fix this, we will not remove the AS while the iotlb->nmaps is 0.
> This will free in the vhost_vdpa_clean
>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: aaca8373c4b1 ("vhost-vdpa: support ASID based IOTLB API")
> Signed-off-by: Cindy Lu <lulu@xxxxxxxxxx>
Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
Thanks
> ---
> drivers/vhost/vdpa.c | 8 +-------
> 1 file changed, 1 insertion(+), 7 deletions(-)
>
> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> index 7be9d9d8f01c..74c7d1f978b7 100644
> --- a/drivers/vhost/vdpa.c
> +++ b/drivers/vhost/vdpa.c
> @@ -851,11 +851,7 @@ static void vhost_vdpa_unmap(struct vhost_vdpa *v,
> if (!v->in_batch)
> ops->set_map(vdpa, asid, iotlb);
> }
> - /* If we are in the middle of batch processing, delay the free
> - * of AS until BATCH_END.
> - */
> - if (!v->in_batch && !iotlb->nmaps)
> - vhost_vdpa_remove_as(v, asid);
> +
> }
>
> static int vhost_vdpa_va_map(struct vhost_vdpa *v,
> @@ -1112,8 +1108,6 @@ static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev, u32 asid,
> if (v->in_batch && ops->set_map)
> ops->set_map(vdpa, asid, iotlb);
> v->in_batch = false;
> - if (!iotlb->nmaps)
> - vhost_vdpa_remove_as(v, asid);
> break;
> default:
> r = -EINVAL;
> --
> 2.34.3
>
